PCBs IN THE UNITED STATES INDUSTRIAL
USE AND ENVIRONMENTAL DISTRIBUTION
TASK I
FEBRUARY 25, 1976
FINAL REPORT
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF TOXIC SUBSTANCES
WASHINGTON, D.C. 20460
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EPA 560/6-76-005
PCBs IN THE UNITED STATES INDUSTRIAL
USE AND ENVIRONMENTAL DISTRIBUTION
Task I
EPA Contract No. 68-01-3259
EPA Project Officer: Thomas Kopp
For
Environmental Protection Agency
Office of Toxic Substances
4th and M Streets, S.W.
Washington, D. C. 20460
February 25, 1976
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REVIEW NOTICE
This report has been reviewed by the Office of Toxic Substances, EPA
and approved for publication. Approval does not signify that the contents
necessarily reflect the views and policies of the Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
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ABSTRACT
This document presents the current state of knowledge about the production,
usage, and distribution of polychlorinated biphenyls (PCBs) in the United States.
The information presented is derived from detailed studies on the production and
first tier user industries, the past and present generation and disposition of PCB-
containing wastes, environmental transport and cumulative loads, potential alterna-
tives to PCBs usage, inadvertent losses to and potential formation in the environ-
ment, and current regulatory authorities for PCBs control. These results indicated
that, although PCBs content of industrial wastes can be reduced through various
approaches (treatment, substitution, etc.), there exists a potentially severe future
hazard in the form of large amounts of PCBs currently contained in land disposal
sites. Further definition of this and other aspects of the PCBs problem, and
determination of ways to minimize the hazard, are recommended.
i.
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TABLE OF CONTENTS
SECTION I - INTRODUCTION 1
1.0 OVERVIEW OF THE PCBs PROBLEM I
2.0 OBJECTIVE AND SCOPE OF THE REPORT 2
SECTION II - SUMMARY 4
1.0 PRODUCTION, USAGE, AND DISTRIBUTION OF PCBs 4
1.1 Overview of PCBs Industrial Usage in the United
States 4
1.2 Cumulative PCBs Production and Usage in the United
States 5
1.3 Current Distribution of PCBs Usage and Associated
Wastes 8
1.4 Land Disposal and Environmental Load 8
1.5 Foreign Production of PCBs 10
2.0 OIARACTERIZATION OF INDUSTRY PRACTICE AND WASTE HANDLING
FOR THE PCBs PRODUCER AND MAJOR FIRST-TIER USERS 10
2.1 Manufacture of PCBs and PCB-Containing Capacitors and
Transformers 10
2.2 Treatment and Disposal of Industrial Wastes Containing
PCBs 12
2.2.1 Incineration 13
2.2.2 Treatment of PCB-Contaminated Wastewater ... 13
2.3 Characterization of the Investment Casting Industry . 15
2.4 Transformer Service Industry 16
3.0 SUBSTITUTES AND USE ALTERNATIVES FOR PCBs 16
3.1 Substitutes for PCBs in Capacitors 16
3.2 Substitutes for PCBs in Transformers 17
3.3 Alternatives to Other PCBs Applications 19
4.0 SOURCES OF INADVERTENT ENTRY OF PCBs INTO THE ENVIRONMENT. 19
4.1 Paper Recycling 19
4.2 Effluent Contamination by PCBs in Other Industries . 20
4.3 Inadvertent Production of PCBs in the Environment . . 20
11.
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TABLE OF CONTENTS (Con't)
SECTION II (Con't)
5.0 TRANSPORT AND DISTRIBUTION OF PCBs IN THE ENVIRONMENT ... 21
6.0 REGULATORY ACTIONS ON PCBs 23
SECTION III - CONCLUSIONS AND RECOMMENDATIONS 25
1.0 CONCLUSIONS 25
2.0 RECOMMENDATIONS 28
SECTION IV - CHEMICAL AND PHYSICAL PROPERTIES OF CHLORINATED BIPHENYLS 31
1.0 INTRODUCTION 31
1.1 The Chemistry of the Chlorinated Biphenyls 31
1.2 Conroercial Production and Chemical Makeup of the
Aroclors 34
1.3 Physical Properties of the PCB Aroclors 39
1.3.1 Physical Properties of Industrial and Technical
Interest 39
1.3.2 Physical Properties of Environmental Interest . 41
1.4 Chemical Properties of the Chlorobiphenyls 49
1.5 Photochemical Reactions Involving the PCBs 49
1.6 Metabolic Chemistry of the Chlorobiphenyls 51
SECTION V - INDUSTRIAL CHARACTERIZATIONS 54
1.0 INTRODUCTION 54
2.0 MANUFACTURING PROCESS - POLYCHLORINATED BIPHENYLS (PCBs) . 54
2.1 Process Description 54
2.2 Raw Wastes 57
2.3 Plant Water Usage 59
2.4 Wastewater Treatment and Housekeeping 60
2.4.1 Treatment Facility for the Effluent from Sauget
Complex 64
2.5 Plant Effluents 64
3.0 PCB USER INDUSTRIES 65
3.1 Askarel Capacitor Manufacturing Industry 65
111.
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TABLE OF CONTENTS (Con't)
3.1.1 Askarel Capacitor Manufacturing Plants 67
3.1.1.1 Askarel Handling 70
3.1.1.2 Process Description 71
3.1.1.3 Raw Wastes 76
3.1.1.4 Water Use 76
3.1.1.5 Wastewater Treatment 80
3.1.1.6 Effluent Composition 80
3.2 Askarel Transformer Manufacturing Industry 84
3.2.1 Transformer Manufacturing Plants 88
3.2.1.1 Askarel Handling 88
3.2.1.2 Process Description 91
3.2.1.2.1 Assembly and Askarel Filling
Procedure for the Distribution
and Power Transformer ... 92
3.2.1.3 Raw Wastes 98
3.2.1.4 Water Use 98
3.2.1.5 Wastewater Treatment 101
3.2.1.6 Effluent Composition 103
3.2.2 Askarel Transformer Repair Industry 103
3.2.2.1 Transformer Inspection and Maintenance. 103
3.2.2.2 Repair of Failed Transformers 108
3.2.2.3 PCS Usage in the Transformer Repair
Industry 114
3.2.2.4 Transformer Service Life 115
3.2.2.5 Usage Rate of PCBs in Transformer
Repair 115
3.3 Investment Casting 115
3.3.1 Background 116
3.3.2 Investment Casting Technologies 118
3.3.2.1 Principles of Investment Casting . . . 118
3.3.2.2 Foundry Process - Use of PCT and PCB
Filled Waxes 122
3.3.2.3 Waste Streams 125
3.3.3 Wax Manufacturing 127
3.3.4 Recommendations 128
3.4 Secondary Fiber Recovery (Paper Recycling) 128
IV.
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TABLE OF CONTENTS (Con't)
Page
3.4.1 Historical Use of PCBs in the Paper Industry. . 129
3.4.2 Fiber Recovery Mill Process 135
3.5 Industrial Use of PCBs as Hydraulic and Heat Transfer
Fluids 140
3.5.1 General 140
3.5.2 Use of Imported PCBs by Joy Manufacturing . . . 141
3.6 Recent Use of PCBs in Product Development Activities . 141
SECTION VT - WASTE TREATMENT TECHNOLOGIES 145
1.0 INTRODUCTION 145
1.1 Summary of Waste Management Problem Areas 145
1.1.1 Waste Liquid PCBs and Contaminated Scrap Oil . 145
1.1.2 PCBs in Wastewater 146
1.1.3 PCB-Contaminated Solid Wastes 146
1.1.3.1 Burnable Solid Waste Materials Con-
taining PCBs 146
1.1.3.2 Nonburnable Solid Waste Materials
Containing, or Contaminated with PCBs 147
1.1.4 Air Emissions of PCBs 147
1.2 Summary of Current PCBs Waste Control Practices ... 147
1.2.1 Control of Waste Liquid PCBs and Contaminated
Scrap Oils 147
1.2.2 Control of PCBs in Wastewaters 148
1.2.3 Control of Solid Wastes Contaminated with PCBs 149
1.2.4 Control of Air Emissions of PCBs 150
2.0 CANDIDATE PCBs WASTE TREATMENT TECHNOLOGIES CONSIDERED. . . 151
2.1 Treatment of Waste Liquid PCBs and Contaminated Scrap
Oils 152
2.1.1 Incineration 153
2.1.2 Sanitary or Scientific Landfill 154
2.2 Treatment of Wastewaters containing PCBs 154
2.2.1 Carbon Adsorption 154
2.2.1.1 PCBs Adsorption Testing by
Carborundum Company 156
v.
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TABLE OF CONTENTS (Con't)
SECTION VI (Con't)
2.2.1.2 PCBs Adsorption Testing by ICI-US ... 158
2.2.1.3 PCBs Adsorption Testing by Calgon Corp. 160
2.2.1.3.1 Adsorption Treatment of
Wastewater 164
2.2.1.3.2 Reactivation of the Granular
Carbon 165
2.2.1.3.3 Carbon Transport 166
2.2.1.3.4 Materials of Construction . 166
2.2.1.4 Carbon Regeneration Alternatives - Wet
Catalytic Oxidation 166
2.2.1.5 Further Applications Data 168
2.2.2 Ultraviolet-Assisted Ozonation 168
2.2.2.1 Molecular Responses to Ultraviolet
Energy 169
2.2.2.2 Photodegradation of PCBs 170
2.2.2.3 Experimental Factors in UV-Assisted
Ozone Oxidation of PCBs 172
2.2.2.4 Destruction of PCBs and Refractory
Organics at Houston Research, Inc. . . 173
2.2.2.4.1 PCB Destruction Data .... 173
2.2.2.4.2 Operating Data Obtained from
Refractory Organics Tests . 173
2.2.2.5 Destruction of PCBs and Refractory
Organics at Westgate Research Corp.. . 177
2.2.2.5.1 PCBs Destruction Data. . . . 177
2.2.2.5.2 Pilot-Scale Tests of Re-
fractory Organics Decomposi-
tion 181
2.2.2.6 Laboratory Test Results from AiResearch
Corp 185
2.2.2.7 Corments on UV/Ozone Tests 186
2.2.3 Non-Carbon Adsorbents for PCBs 186
2.2.3.1 The Atnberlite XAD Series of Macroretic-
ular Resins 187
VI.
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TABLE OF CONTENTS (Con't)
SECTION VI (Con't)
2.2.3.1.1 PCBs Adsorption Testing . . . 187
2.2.3.1.2 Process Concept for Resin
Adsorption of PCBs 187
2.3 Treatment of PCBs - Contaminated Solid Wastes 190
2.3.1 Incineration 190
2.3.2 Sanitary Landfill 190
2.4 Treatment of Air Emissions 190
2.4.1 Condensation Methods 190
2.4.2 Granular Adsorption Methods 190
2.4.3 Catalytic Oxidation of Organics in Evaporated
Effluents 191
2.5 The Potential for Zero Discharge 191
3.0 RATIONALE AND SELECTIONS OF CURRENTLY RECOMMENDED WASTE TREAT-
MENT METHODS 192
3.1 Incineration Recommended for Liquid PCBs and Scrap Oils. 192
3.2 Carbon Adsorption and UV-Assisted Ozonation Recommended
for PCBs in Wastewater 193
3.3 Incineration and Landfill Recoirtnended for Contaminated
Solids 194
3.4 Dry Carbon Filter Adsorption Reconmended for Control of
Air Emissions 195
SECTION VII - PRODUCTION AND DISTRIBUTION 198
1.0 PRODUCTION AND CURRENT USE 198
1.1 Domestic Production of PCBs and PCTs 198
1.2 Foreign Production and Distribution of PCBs 207
1.3 Summary of Recent PCBs and PCTs Imports 207
2.0 FIFTEEN YEAR EXTRAPOLATIONS FOR PCB PRODUCTION AND USE IN
ELECTRICAL EQUIPMENT 210
3.0 OVERALL MATERIAL BALANCE 215
SECTION VIII - SUBSTITUTES FOR PCBs 220
1.0 INTRODUCTION 220
vn.
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TABLE OF CONTENTS (Con't)
Page
SECTION VIII (Con't)
2.0 ELECTRICAL CAPACITORS 220
2.1 Function of the Dielectric Material 221
2.2 Practical Capacitors 224
2.3 Required Properties of Dielectric Liquid 225
2.4 The Use of PCBs in Capacitors 226
2.4.1 Properties of PCB Capacitor Dielectric Liquid . . 226
2.4.2 Advantages and Disadvantages of PCBs in
Capacitors 228
2.4.3 Usage of PCBs in Capacitors 228
2.5 Alternatives to the Use of PCBs in Capacitors 229
2.5.1 Substitutes for PCBs 229
2.5.1.1 Phthalate Esters 230
2.5.1.1.1 Dioctyl Phthalate:(DOP) . . . 230
2.5.1.1.2 Diisononyl Phthalate .... 230
2.5.1.2 Alkylated PCB 231
2.5.1.3 Alkylated Chlorodiphenyl Oxide 232
2.5.1.4 Silicones 233
2.5.1.5 Diaryl Sulfone 233
2.5.2 Elimination of Dielectric Liquids in Capacitors . 233
2.6 The Use of PCB Capacitors in Electrical Equipment. . . . 235
2.6.1 Power Factor Correction 235
2.6.1.1 High Voltage Power Factor Capacitors . . 239
2.6.1.2 Low Voltage Power Factor Capacitors . . 239
2.6.1.3 Lighting Ballast Capacitors 240
2.6.2 Motor Starting Circuits 242
2.6.3 Electronic Filter Capacitors 244
2.7 Institutional Barriers to Substitutes for PCBs in
Capacitors 244
2.7.1 Performance Acceptability 245
2.7.2 Fire Safety 246
2.7.2.1 Utility Use of Power Factor Correction
Capacitors 246
2.7.2.2 Industrial Use of Power Factor
Correction Capacitors 247
2.7.2.3 Lighting and Appliance Capacitors . . . 247
Vlll.
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TABLE OF CONTENTS (Con't)
SECTION VIII (Con't)
3.0 ELECTRICAL TRANSFORMERS 248
3.1 Heat Generation in Electrical Circuits 248
3.2 The Nature and Purpose of Transformers 250
3.3 Desired Properties for Transformer Heat Transfer Fluids. 251
3.4 Use of PCBs in Electrical Transformers 252
3.5 Present Alternates to the Use of PCBs in Transformers . 254
3.5.1 Mineral Oil-Filled Transformers 254
3.5.2 Open Air Cooled Transformers 255
3.5.3 Closed Gas Filled Transformers 257
3.6 Current Alternatives to the Use of PCB Cooled Trans-
formers 258
3.6.1 Vault Usage Requirements for Transformers . . . .258
3.6.2 Vault Construction Requirements for Transformers. 259
3.6.3 Transformer Vault Construction Costs 261
3.7 Substitutes for PCBs in Transformers 263
3.7.1 Fluorocarbons 264
3.7.2 Silicones 264
3.7.3 High Flash Point Mineral Oils 267
3.7.4 High Flash Point Synthetic Hydrocarbons 267
3.8 Institutional Barriers to the Use of Substitutes for
PCBs 268
3.9 Relative Merits of Alternatives to New Askarel
Transformers 271
3.9.1 Distribution Transformers 271
3.9.2 Power Transformers 271
3.9.3 Precipitator Transformers 273
3.9.4 Railroad Transformers 273
3.10 Replacement of Askarels in Existing Transformers .... 274
3.10.1 PCB Losses Due to Transformer Failures 274
3.10.2 Environmental Effects of an Askarel Replacement
Program 275
3.10.3 Effect of Leaving Askarel Transformers in Service 276
4.0 INVESTMENT CASTING
4.1 Function of the Filler Material 277
4.2 Use of PCBs in Investment Casting 278
4.3 Advantages and Disadvantages of the Use of Deka PCBs in
Investment Casting 278
IX.
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TABLE OF CONTENTS (Con't)
SECTION VIII (Con't)
4.4 Alternatives to the Use of Deka PCBs 279
4.4.1 Replacement Filler Materials 279
4.4.1.1 Isophthalic Acid 279
4.4.1.2 Polystyrene 280
4.4.2 Unfilled Waxes 280
4.5 Conclusions - Substitutes for PCB in Investment Casting. 280
SECTION IX - PCBs RELEASE AND CUMULATIVE ENVIRONMENTAL LOADS 286
1.0 ESTIMATES OF FREE PCBs IN THE ENVIRONMENT 286
1.1 PCBs Losses to the Environment Since 1930, by Use and by
Chlorine Content of Molecule 286
1.2 Total PCBs Accumulation and Current Rates 287
1.3 Current PCBs Disposal in Landfills and Dumps 291
1.4 Release of PCBs via Industrial Effluents (Waterborne). . 294
1.5 Spills of PCBs During Transport 294
SECTION X - INADVERTENT AMBIENT REACTIONS AS ROUTES OF ENTRY OF PCBs
INTO THE ENVIRONMENT 297
1.0 INTRODUCTION 297
2.0 COMMERCIAL BACKGROUND, PRODUCTION AND PROPERTIES OF BIPHENYL. 297
2.1 Origins and Commercial Usage Background 297
2.2 Production Methods and Rates for Biphenyl 298
2.3 Properties and Characteristics of Biphenyl 300
3.0 PROVEN BIPHENYL REACTIONS YIELDING PCBs 301
3.1 Chlorination of Biphenyl 301
3.2 Reactions Combining Phenyls to Produce Biphenyls .... 302
4.0 BIPHENYL USAGE IN HEAT TRANSFER FLUIDS, DYES AND PACKAGING. . 303
4.1 Heat Transfer Fluids 303
4.2 Dye Carriers for Polyesters and Polyolefins 303
4.3 Biphenyl as a Mold Preventive in Packaging 304
4.4 General Biphenyl Occurrence in the Environment 305
5.0 PCBs GENERATION AND WASTEWATER EXPERIMENTS IN A MAJOR U.S.
BIPHENYL USAGE LOCALITY 305
6.0 POTENTIAL DEGRADATION AND SUBSEQUENT REACTION OF DDT AND
RELATED COMPOUNDS IN THE ENVIRONMENT TO FORM PCBs 307
x.
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TABLE OF CONTENTS (Con't)
Page
SECTION X (Con't)
7.0 COMPARISON OF POTENTIAL 1ESIADVERTENT AMBIENT REACTIONS .... 308
8.0 PCBS FOUND IN THE EFFLUENTS OF THE MACHINERY AND MECHANICAL
PRODUCTS MANUFACTURING INDUSTRY 309
SECTION XI - MOVEMENT OF PCBs IN THE ENVIRONMENT - GENERAL DISTRIBU-
TION MODEL 314
1.0 INTRODUCTION 314
2.0 RATIONALE FOR MODEL DEVELOPMENT 315
2.1 Time Dependence of the PCB Input Rate [B(t)j 316
3.0 APPLICATION OF THE MODEL TO LAKE MICHIGAN 317
4.0 RESULTS AND CONCLUSIONS 319
4.1 Results 319
4.2 Conclusions 320
SECTION XII - REGULATORY ACTIONS ON PCBs 322
1.0 INTRODUCTION 322
1.1 Measures Taken by the Manufacturers 322
1.2 Measures Taken by the U.S. Government 323
1.2.1 Food, Drug and Cosmetic Act (21 U.S.C. 301 et
seg.) 323
1.2.2 The Egg, Meat and Poultry Acts 324
1.2.3 The Clean Air Act (42 U.S.C. 1857 et seg.). ... 324
1.2.4 Federal Water Pollution Control Act (33 U.S.C.
466 et seg.) 325
1.2.5 The Refuse Act of 1899 (33 U.S.C. 407) 326
1.2.6 The Occupational Safety and Health Act (29 U.S.C.
651-678) 326
1.2.7 Act to Regulate Transportation of Explosives
and Other Dangerous Articles (18 U.S.C. 831-835) 326
1.2.8 Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA) (7 U.S.C. 135-135K) 327
1.2.9 Needs for Federal Control 327
1.3 International Decisions and Agreement 328
1.4 Measures Taken by Foreign Governments 330
1.4.1 Measures Taken by Manufacturers - Limitations of
Sales 330
XI.
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TABLE OF CONTENTS (Con't)
SECTION XII (Con't)
1.4.2 Measures Taken by Seme Governments 331
1.4.2.1 PCB Producing Countries 331
1.4.2.2 Non-Producing Countries 332
1.5 U.S. Customs Regulations 333
APPENDIX A - PCB ADSORPTION TESTING BY XAD-4 FESIN A-l
APPENDIX B - MACRORETICUIAR RESINS FK)M ROHN AND HAAS CO B-l
APPENDIX C - NON-CARBON ADSORBTION AND OTHER RESEARCH STAGE PCB
TREATMENT TECHNOLOGIES C-l
APPENDIX D - MASS BALANCE MODEL FOR PCB DISTRIBUTION D-l
APPENDIX E - BACKGROUND DATA USED TO CONSTRUCT THE MODEL FOR PCBs IN
LAKE MICHIGAN E-l
APPENDIX F - TOXICOLOGICAL ASPECTS F-l
xn.
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LIST OF TABLES
Page
SECTION II
1.2-1
1.3-1
SECTION IV
1.1-1
1.2-1
1.2-2
1.3.1-1
1.3.1-2
1.3.2-1
1.3.2-2
1.3.2-3
1.3.2-4
1.3.2-5
SECTION V
3.1.1-1
3.1.1.3-1
3.1.1.3-2
3.1.1.6-1
3.1.1.6-2
3.1.1.6-3
3.2.1-1
3.2.1.3-1
Estimates of Cumulative PCBs Production, Usage, and
Gross Environmental Distribution in the United States
Over the Period 1930-1975 in Millions of Pounds . . .
Estimated Production, Usage, and Losses of PCBs in the
United States During 1974 in Millions of Pounds . . .
7
9
Empirical Formulation, Molecular Weights and Chlorine
Percentage in PCBs 35
Approximate Molecular Composition of Selected Aroclors 36
High Resolution Gas Chronatography of Aroclor 1248 . . 37
Chemical and Physical Properties of Representative
Aroclors
40
Electrical Properties of Some Aroclors 42
Solubility, Vapor Pressure and Halflife for Vaporization
from Water of Selected Aroclors at 25°C 43
Vaporization Rates of Aroclors 45
Percent Loss in Area of Seven Chromatogram Peaks of
Aroclor After Heating 46
Solubility of Chlorobiphenyls in Water 47
Relative Peak Heights (Peak 5 = 100) in Saturated
Aqueous Solutions of Aroclor 1254
U.S. Capacitor Manufacturing Industry Using PCBs . . .
Non-Product PCB Discharges
Quantity of Waste Loads
Range of Flow Rates & PCB Concentration in Effluents
from Capacitor Manufacturing Plants
Comparison of Discharges
Intake Water PCB Concentration
U.S. Transformer Manufacturing Industry Using PCBs . .
Non-Product PCB Discharges
48
69
77
78
81
82
83
89
99
xn i .
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LIST OF TABLES (Con't)
Page
SECTION V (Con't)
3.2.1.6-1 PCB Concentration in Effluents from Transformer
Manufacturing Plants 104
3.2.1.6-2 Influent and Effluent Compositions of Plant 103 ... 105
3.4-1 PCB Concentrations in Wisconsin Paper Plant Effluents. 130
3.4.1-1 History of Aroclor 1242 Consumption in the Manufacture
of NCR Carbonless Paper for the Years 1957 through
1971 131
3.4.1-2 History of NCR Carbonless Paper Production for the
Years 1957 through 1971 132
3.4.1-3 Ratio of Aroclor 1242 Consumption for Carbonless to
NCR Carbonless Estimated Production 133
3.4.2-1 Composition of Raw Water and Claifier Effluent .... 139
SECTION VI
2.2.1.1-1 Carborundum Co. Tests of PCBs (Aroclor 1254) Removal
from Water by an Experimental Activated Carbon . . . 157
2.2.1.2-1 ICI-US Tests of PCBs (Aroclor 1254) Removal from Water
by Two Types of Commercial Carbons 159
2.2.1.3-1 Results of Calgon Corp. Laboratory Isotherm Tests for
Carbon Removal of PCBs 162
2.2.2.5.1-1 UV Ozonolysis Destruction of Typical Capacitor and
Transformer PCBs at Westgate Research 180
2.2.2.5.2-1 Simulated Two-Stage, Continuous UV-Ozonation of a 5
Component Mix at Westgate Research Corp 184
SECTION VTI
1.1-1 PCB & PCT Manufacture and PCB Sales Monsanto Industrial
Chemicals Company (1957 thru 1964) 199
1.1-2 PCB & PCT Manufacture and PCB Sales Monsanto Industrial
Chemicals Company (1965 thru 1974)
1.1-3 PCB Manufacture and Sales Monsanto Industrial Chemicals
Company (First Quarter - 1975) 205
1.1-4 End-Uses of PCTs and PCBs by Type 206
xi v.
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LIST OF TABLES (Con't)
Page
SECTION VII (Con't)
1.2-1 Production, Trade and Use of PCBs OECD Member
Countries (1973) 208
1.3-1 Preliminary Summary of PCBs Import Data for 1971-75
Versus Monsanto Production and Sales Data 209
2-1 Total PCB Breakdown by Use (1966-1975) 212
SECTION VIII
3.8-1 Properties of Transformer Liquids Tested by RTE
Corporation 270
3.9-1 Relative Merits of Alternatives to the Use of Askarel
Transformers in New Applications 272
SECTION IX
1.1-1 PCB Environmental Load by Aroclor Type 288
1.1-2 Cumulative Environmental PCB Load by Chlorine Content. 289
1.1-3 Computed Spectrum of Chlorine Content for Wild PCBs. . 290
SECTION X
2.3-1 Physical Constants of Biphenyl 300
8-1 PCBs Concentration in the Effluents of the Machinery
& Mechanical Products Manufacturing 311
SECTION XI
2.1-1 Summary of PCB Input Sources (1973-1974) to Lake
Michigan 317
3.0-1 Overall PCBs Balance for Lake Michigan Area During the
Period 1930-1975 318
3.0-2 Derived PCB Concentrations in Lake Michigan Water and
Biota Over the Period 1930-1975 318
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LIST OF FIGURES
SECTION II Page
1.0-1 U.S. Production and Usage of PCBs Summary
Over 1972-75 6
SECTION IV
1.2-1 Moieties front Which Principal Chlorobiphenyl
Isoners are Formed 38
SECTION V
2.1-1A Preparation of Crude Chlorinated Biphenyls-
Monsanto Krunmrich Plant 55
2.1-IB Distillation of Crude Products-
Monsanto Krunmrich Plant 55
2.2-1 Non-Product PCB Discharges at Monsanto's
Krummrich Plant 58
2.4-1 Process Flow Diagram of the John Zink Incinerator
at Monsanto's Krummrich Plant 61
3.1.1-1 Medium Size Industrial Capacitor 68
3.1.1.2-1 Generalized Flow Diagram for the Manufacturing of
Large Capacitors 72
3.1.1.2-2 Generalized Flow Diagram for the Manufacturing of
Small Capacitors 73
3.2.1-1 Substation Transformer 90
3.2.1.2.1-1 Transformer Filling With Vapor Phase Predrying
of Interiors 93
3.2.1.2.1-2 Transformer Filling With Oven or Vacuum Chamber
Predrying of Transformer Internals 96
3.2.1.2.1-3 Transformer Filling Operation With Oven Predrying
of Assembled Hardware 97
3.2.1.3-1 Non-Product PCB Discharges 99
3.2.1.5-1 Process Flow Diagram for Thermal Oxidizer
Incinerator at Plant 103 102
xvi .
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LIST OF FIGURES (Continued)
SECTION V (Continued) Page
3.2.2.2-1 Transformer Maintenance & Servicing 110
3.2.2.2-2 Transformer Repair Ill
3.3.2.1-1 Investment Shell Process 119
3.3.2.2-1 Flew Chart of PCBs Usage in Investment Casting . . 123
3.3.2.3-1 Idealized Flow Chart for an Investment Casting
Foundry, Showing Waste Streams 126
3.4.2-1 Mill Fiber Recovery Process and Water Effluents . . 136
SECTION VI
2.2.1.3-1 Equilibrium Carbon Msorption of PCBs From Water
at Low Concentrations (Calgon Data) 163
2.2.2.4.1-1 Lab Scale Apparatus for Reaction and Mass Transfer
Studies at Houston Research, Inc 174
2.2.2.4.1-2 Aroclor 1254 Destruction by UV-Assisted
Ozonation 175
2.2.2.4.2-1 Ozone Oxidation of Acetic Acid, Effect of UV and
Temperature (Initial CH-.COOH-105 rog/1, (Ml) =
3.5 mg/1) 176
2.2.2.4.2-2 Ozone/UV Oxidation of Acetic Acid; Effect of
Increased Radiation Input 178
2.2.2.5.2-1 The Effect of UV Path Length on TOC Destruction . . 182
2.2.2.5.2-2 Schematic of Bench Reaction System at Westgate
Research Corp 183
2.2.3.1.2-1 PCBs Removal Process Concept Flew Sheet by Rohm
and Haas Company 189
SECTION VII
1.1-1 U.S. Production of PCBs and PCTs and Domestic Sales
and Exports of PCBs 201
1.1-2 U.S. Domestic Sales of PCBs by End Use Applications 202
xvii.
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IJST OF FIGURES (Continued)
SECTION VII (Continued Page
1.1-3 U.S. Dctuestic Sales of PCBs by Type 203
2-1 Unbiased Extrapolations of Least-Square Linear
Curves for PCB Production and Use in Electrical
Equipment 214
xvi11 .
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ACKNOWLEDGEMENTS
The preparation of this report was accomplished through the efforts of
the staff of Versar Inc., Springfield, Virginia, under the overall direction
of Dr. Robert L. Durfee, Vice President.
The considerable aid furnished by personnel of the Environmental Protection
Agency, Office of the Toxic Substances, is acknowledged. Mr. Tom Kopp served
as Project Officer and provided guidance for the project effort.
Appreciation is extended to The Electric Industries Association, The
National Electrical Manufacturers Association, The Investment Casting Institute,
The Wisconsin Paper Council, and the many individual companies who gave us
invaluable assistance and cooperation in this program.
Appreciation is also extended to the individuals of the Staff of Versar
Inc., for their contributions and assistance during this program. Specifically,
our thanks to:
Mr. James D. Barden, Environmental Engineer
Mrs. Gayaneh Y. Centos, Senior Chemical Engineer
Dr. E. Ellsworth Hackman III, Senior Scientist
Dr. Mohammad N. Khattak, Analytical and Environmental Chemist
Miss Susan A. Perlin, Environmental Engineer
Mr. Bennett Y. Ryan, Ecologist
Mr. Robert A. Westin, Senior Chemical Engineer
Dr. Frank C. Whitmore, Senior Scientist
Also our acknowledgement and appreciation is given to the secretarial
staff of Versar Inc., for their efforts in the typing of drafts, necessary
revisions and final preparation of this document. Our special thanks to:
Mrs. Nancy C. Downie
Mrs. B. Lynn Waller
Mrs. Lillette A. Steeves
xix.
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SECTION I
INTRDDUCTION
1.0 OVERVIEW OF THE PCBs PROBLEM
The term polychlorinated biphenyls (PCBs) refers to a family of organic
chemicals which have been produced and marketed in this country for 45 years
as a series of relatively complex mixtures under the trade name Aroclor. Each
of these mixtures contains a number of chlorinated biphenyl isomers out of an
overall range of chlorine content from one chlorine to ten chlorines per molecule.
In general, higher chlorine content corresponds to greater resistance to chemical
(and biochemical) degradation.
PCBs are among the stable organic compounds known, and, in addition, they
exhibit other properties which render them extremely advantageous for use as
dielectric and heat transfer fluids. These properties include low solubility in
water, low vapor pressure, low flairmability, high heat capacity, low electrical
conductivity, favorable dielectric constant, and suitable viscosity-temperature
relationships. Because of these properties, and also because PCBs exhibit little
acute toxicity (toxic effects from high level, short term exposure), this family
of materials has been extensively used in many industrial applications, primarily
in "closed" or "semi-closed" systems such as electrical transformers and capacitors,
heat transfer systems, and hydraulic systems. Most of the PCBs marketed to U.S.
industry are still in service, primarily in electrical equipment. The remainder
has entered the general environment; a significant fraction of this amount is
present in air, water, soil, and sediment, but most of the PCBs in the environment
are believed to be in landfills and dumps across the country.
In the late 1960's it became apparent that, although PCBs exhibit little
acute toxicity, they are accumulated in the tissues of many biological species
and do exhibit chronic (long-term) toxicity to many species even when the exposure
is to very low concentrations. The effects of chronic PCB exposure may be con-
sidered as roughly comparable to those of DDT.
-------
The recognition of this problem resulted in a major program designed to
lessen the envirormental stress arising from widespread use and dissemination
of PCBs; by mid-1971, the Monsanto Industrial Chemicals Co., the sole U.S. pro-
ducer, had voluntarily terminated sales of Aroclors (PCBs and polychlorinated
triphenyls, or PCTs) for all but closed electrical systems uses. Monsanto also,
in the same time frame, offered incineration services for waste liquid PCBs and
terminated production of the most highly chlorinated Aroclors.
During 1972 and 1973, the Pood and Drug Administration developed limita-
tions on PCBs concentrations, designed to eliminate interstate transport of PCB
contaminated foodstuffs, for a number of important dietary items and packaging
materials used for foods. These limitations also reinforced the elimination of
PCBs usage in the U.S. except for closed electrical systems.
After approximately five years of the voluntary industrial restrictions,
and about three years following the FDA limitations, a National Conference on
PCBs was held in Chicago during November, 1975, under the joint sponsorship of
EPA and other Government agencies. By that time it had become apparent that,
although dietary intake of PCBs had declined (apparently as a result of the FDA
actions plus cooperation of the food and food packaging industries), improved
analytical techniques plus more extensive monitoring efforts had revealed PCBs
contamination at envirormentally significant levels to be more widespread than
originally thought.
Results presented at the Chicago meeting indicated PCB levels in the
environment, on an overall basis, to have been more or less constant since 1971,
although there were local instances of both increases and decreases in PCB
levels. It thus appears that, unlike DDT, elimination of PCBs from dissipative
uses has not resulted in a significant reduction in environmental load.
2.0 OBJECTIVE AND SCOPE OF THE EEPORT
It was against the above background that the work upon which this report
is based was performed. The objective of this report is to present the current
state of knowledge about PCBs production, distribution, usage, and losses to
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the environment in the United States. Many, but not all, of the facets of the
PCBs problem are addressed; many of the estimates presented are based on
engineering and scientific judgement instead of hard data, simply because hard
data in these areas are not available. We hope that all assumptions and
judgements in the report are clearly identified as such, and that sufficient
supporting information, where available, is presented to justify the choices
made.
While this report attempts to shed seme light on the possible reasons why
PCB levels in the environment are not decreasing as rapidly as had been hoped,
its scope also includes a detailed presentation of past and present production
and usage of PCBs in the United States, an analysis of PCB distribution and
environmental ransport as applied to Lake Michigan, a treatment in detail of
potential substitutes and use alternatives, a discussion of the technical
aspects of substitution, and discussions of various other aspects of the over-
all problem. Toxicological and human health aspects are not addressed; nor
are the various current activities of EPA, other Government agencies, and
individual states toward reducing entry of PCBs into the environment.
The information and data contained in the report were collected from
personal interviews and telephone conversations with representatives of many
of the firms handling or using PCBs, from trade associations, from the open
literature, and from local, state, and Federal Government personnel,
researchers, and other parties having interest in and information concerning
the PCBs problem. Ten visits to plants were made; these covered the
categories of PCBs production, small and large capacitor manufacturing, trans-
former manufacturing, investment casting, and waste disposal contracting
(waste PCBs). The degree of cooperation, and therefore the accuracy of the
data obtained, varied widely from industry to industry. Electric utilities
provided key information, as did also other users or distributors of products
containing PCBs.
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SECTION II
SUMMARY
1.0 PRODUCTION, USAGE, AND DISTRIBUTION OF PCBs
1.1 Overview of PCBs Industrial Usage in the United States
Over the past four years the domestic production and use of polychlo-
rinated biphenyls (PCBs) have been approximately constant with averages of 40
million pounds per year for production and 33 million pounds per year for domestic
sales. During this period Monsanto Industrial Chemicals Corp., the sole domestic
producer, has supplied approximately 99 per cent of the domestic market. Monsanto
sells several PCB mixtures under the generic trade name Aroclor, and purchase has
been limited to intended use in nominally closed electrical systems (transformers
and capacitors) since 1971 under voluntary restrictions imposed by Monsanto.
The remainder of the domestic usage depends on imported PCBs, most of
which originate in Italy and the remainder in France. Decachlorobiphenyl is
imported from Italy for use in investment casting wax, and the material imported
from France is used in cooling systems of mining machinery.
Of the domestic sales of PCBs, 65 to 70 per cent are to manufacturers of
capacitors, and the remainder to manufacturers of transformers. Transformers,
which contain 2,000 to 2,500 pounds of PCBs on the average (present as a 60 to 70
per cent component of mixtures with trichlorobenzene called Askarels) are used
primarily to change voltages during the transmission and distribution of electrical
power. Approximately five per cent of the transformers in service in this country
contain PCBs; most transformers contain mineral oil instead of PCBs. Capacitors
containing PCBs are of two general types; small capacitors which are built into
electrical appliances such as fluorescent lights, TV sets and small motors, and
large capacitors which are used as separate units in electrical power distribution
systems and with large industrial machinery such as electric motors and welding
machines. PCBs are used in about 95 per cent of U.S.-produced liquid impregnated
capacitors (most small capacitors in radios and other electronic equipment are
solid-state units).
-4-
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PCBs are typically used in transformers where protection against fire
is of paramount importance. Use of PCBs in capacitors is based on a number of
factors, but fire protection and service life appear to be the most important.
Industry codes, such as the National Electrical Code, specify the use of PCB-
filled transformers and capacitors under a number of conditions. These codes
will serve as institutional barriers to rapid reductions in PCBs usage, but at
present there are also technical barriers to substitution of other materials for
PCBs in electrical equipment.
The above overview of current PCBs usage in the U.S. is summarized by
Figure 1.0-1, which traces domestic PCBs production and importation through first
tier usage and distribution of PCBs - containing products.
1.2 Cumulative PCBs Production and Usage in the United States
Estimates developed for total PCBs production and utilization in the
U.S. since their introduction to industry in 1929-30 are presented in Table 1.2-1.
These data define the estimated proportions of PCBs used in various applications,
and an accounting, based on available data plus estimates, of the current distri-
bution of this material. Of the roughly 1.25 billion pounds purchased by U.S.
industry, it is estimated that only 55 million pounds, or 4.4 per cent, have been
destroyed by incineration or by degradation in the environment. About 60 per cent
of the total domestic sales is still in service, almost all in capacitors and
transformers. The remainder, about 44 million pounds, are in the environment; it
is estimated that 290 million pounds are in landfills or dumps and 150 million
pounds are "free" in the general environment (air, water, soil, sediments) and
presumably available to the biota.
Some of the values in Table 1.2-1 are relatively well-established, while
others are gross estimates resulting from a lack of data in the area. The esti-
mated reliability for each value presented is shown on the table. For instance,
the PCBs usage in carbonless copy paper is a firm value obtained from the only
producer (NCR), where as the amount of PCBs environmentally degraded could con-
ceivably range from a low value to the total of mono-, di-, and trichlorobiphenyl
utilized but not still in service. The value for U.S. production could not be
-5-
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IMPORTS
"0.5XI06 LB/YR
'15%
HEAT TRANSFER
FLUID
/ FROM FRANCE-\
SIMILAR TO
\AROCLOR" 1242!
DOMESTIC PRODUCTION-MONSANTO
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Table 1.2-1
Estimates of Cumulative PCBs Production, Usage, and Gross Environmental
Distribution in the United States Over the Period 1930-1975 in Millions of Pounds
LF.S. PCS Production
Total U.S. PCB Imports
U.S. PCB Dotestic Usage
Total U.S. PCB Exports
PCB by Use Category:
Petroleum Additives
Heat Transfer
Misc. Industrial
Carbonless Copy Paper
Hydraulics and Lubricants
Other Plasticizer Uses
Capacitors
Transformers
Uses other than Electrical
PCB Degraded or Incinerated:
Environmentally Degraded
Incinerated
landfills and PCBs in Dumps:
Cap. and Trans. Production
Wastes
Obsolete Fie. Equipment
Other (paper, plastic, etc.)
Free PCBs in the Environment
(soil, water, air, sediment)
'Total
Commercial
Production
1,400
3
1,403
Commercial
Sales
1,253
150
1,403
Industrial
Purchases of PCB
1
20
21
45
80
115
630
335
1,253
PCBs Currently
in Service
450
300
8
-
758
PCBs Currently
in Envirorraent
110
80
100
150
440
PCBs
Destroyed
30
25
55
Estimated
Reliability
of Values
+ 5%
- 20%
± 30%
+ 5%
- 20%
i 20%
t 50%
± 10%
15%
5%
10%
15%
20%
t 20%
± 60%
± 70%
± 10?
± 20%
t 40%
± 40%
± 30%
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much over 1.45 billion pounds nor less than 1.1 billion pounds, based on analysis
of other available or estimated data; hence, the estimated confidence interval
for this value on Table 1.2-1 of +5 per cent and -20 per cent.
One of the more important conclusions from this work is the estimation
of about two times the amount of PCBs in landfills and dumps as compared to the
amount of PCBs already free in the environment. The material in land disposal
sites may be considered a threat to become widely dispersed over a long period of
time. The length of time required can only be guessed at, but is probably short
in comparison to the time required for degradation of the PCBs by natural pro-
cesses. Thus, release of the land disposal material through slow vaporization and
leaching could very well worsen an already severe environmental problem.
1.3 Current Distribution of PCBs Usage and Associated Wastes
A material balance for PCBs production, sales, distribution, and wastes
in 1974 is presented in Table 1.3-1. Reliability of the values were estimated as
for the previous table. The amounts estimated to be land disposed, totaling 1.18
million pounds, do not include land disposal of previously used PCBs. However, the
amounts listed under scrap PCBs incinerated account for all PCBs incineration in
the U.S. during 1974 at the reconmended temperature-time conditions (> 2000°F;
> 1.5 seconds residence time). Of the total of 2.61 million pounds incinerated,
the Monsanto facility accounted for over half. Other companies currently providing
incineration services include General Electric, Rollins Environmental Services,
and Chem-Trol Pollution Services, but the total number of such facilities known to
be available in the U.S. is six.
1.4 Land Disposal and Environmental Load
The 1.18 million pounds per year of land-destined wastes estimated above
is only a small portion of the total PCBs entering landfills and dumps yearly; the
current estimated yearly rate of PCBs entering land disposal sites is about 12
million pounds. The largest source of this material is capacitors which have failed
or become obsolete, or which are contained in obsolete equipment. Other important
sources are industrial solid wastes from PCBs production and first-tier usage, and
the total of otiicr (non-electrical) municipal and industrial solid wastes.
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Table 1.3-1
Estimated Production, Usage, and Losses of PCBs in the United States
during 1974 in Millions of Pounds
Domestic Production
Total Imports
Monsanto Domestic Sales
Exports
Import Sales
From Mfg. Inventory, etc.
PCBs Usage by Product
Category
Capacitors
Transformers
Investment Casting Wax
Other
PCBs Disposal to Land
(assume PCBs to be 30% of
total solid wastes)
From PCBs manufacture
From capacitor industry
From transformer industry
From investment casting
Incineration of Scrap PCBs
From PCBs manufacture
From capacitor industry
From transformer industry
Industrial Discharges to
Water and Sewers (as PCBs)
From PCBs manufacture
From capacitor industry
From transformer industry
Spills during Transport
Totals
Production
or Imports
40.466*
0.45
40.916
Ccmnercial
Sales
34.406*
5.395*
0.45
0.665*
40.916
Industrial
Purchases
by Category
22.0
12.0
0.4
0.05
35.45
Amount Disposed
or Lost
0.03
0.48
0.27
0.4
0.52
1.45
0.64
0.0011**
0.0021**
0.0001**
0.01
3.80
Estimated
Reliability
of Values
± 10%
± 50%
± 10%
± 10%
± 50%
± 10%
± 20*
± 20%
± 20%
i 70%
± 50%
± 50%
+ 50%
± 30%
± 15%
± 20%
1 20%
± 40%
t 60%
± 60%
± 50%
* From Mansanto data
** Developed from data supplied by industry. Most analyses for PCBs concentrations in industrial
wastewaters are probably not more accurate than ± 50 per cent.
-9-
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The total current environmental load of "Free" PCBs was estimated to
be about 150 million pounds. An analysis of environment load (Free PCBs) average
chlorine content per molecule indicated that, if mono-, di-, and trichloro isomers
were disregarded, the average chlorine content of Free PCBs would be within seven
per cent of the value for Aroclor 1254.
1.5 Foreign Production of PCBs
Known current producers of PCBs besides the United States include the
United Kingdom, Czechoslovakia, France, Germany, Spain, and the U.S.S.R. Japan
was a producer until 1972. In 1973, total foreign production of PCBs is estimated
at 43 million pounds, corresponding to a 50 per cent reduction since 1971. On
this basis, the U.S. production appears to be about half of the world total.
Usage of PCBs in all countries is expected to decrease further as a result of re-
cent findings on adverse environmental effects and potential human health hazards
from PCBs, and this usage is expected to be essentially confined to use in capac-
itors and transformers.
2-0 CHARACTERIZATION OF INDUSTRY PRACTICE AND WASTE HANDLING FOR THE PCBs
PRODUCER AND MAJOR FIRST-TIER USERS
2.1 Manufacture of PCBs and PCB-Containing Capacitors and Transformers
PCBs are produced domestically only by Monsanto at Sauget, Illinois.
The process involves the batch chlorination of biphenyl and subsequent separation
and purification of the desired chlorinated biphenyl fractions. The degree of
chlorination is determined by the contact time in the reactor. Depending on the
distance and size of shipment, transport is via tank car, tank truck, or common
carrier (drums).
There are 17 capacitor plants and 18 transformer plants utilizing PCBs
in the United States. Manufacture of both types of units involves initial pre-
paration of internal and external cases, filling with PCBs under vacuum, cleaning
and degreasing, and performance testing. The greatest PCB wastes occur in the
filling operations. Filling of small capacitors (less than 2 pounds of PCBs) and
most large capacitors is performed in chambers holding many small capacitors or
fewer large ones. The chamber and the capacitors are evacuated and then flood-
filled with the PCB liquid. Excess liquid is removed from the chamber, the filled
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units are cleaned and sealed, and then the sealed units are degreased, painted,
and tested. Transformers and the largest types of capacitors are filled individ-
ually after evacuation; this produces relatively less chance of PCBs loss than
the flood-filling process.
Of the 38 plants in the above categories, 10 discharge their effluents
into the water ways while the remainder discharge into the sewage treatment plants.
All plants in these categories have discharges under heavy rainfall conditions.
There are three types of waste materials generated at these plants that require
treatment and proper handling in order to minimize the PCB into the environment.
These are:
(a) Waste waters containing trace quantities of PCBs
(10 to 500 ppb PCBs);
(b) Waste PCBs, scrap oils and small quantities of process
water highly contaminated with PCBs; and
(c) Burnable and non-burnable solid materials contaminated
with PCBs.
Quantitative estimates of these wastes are given below:
Waste Loads, Daily Average
PCB Discharge
in Waterways
or Sewers
3.06 Ibs
5.86 Ibs
0.17 Ibs
Land-Destined
PCB
Wastes
301 Ibs
4440 Ibs
Unknown
Scrap Oils
to
Incineration
1425 Ibs
3968 Ibs
1750 Ibs
PCB Manufacturer
Capacitor Industries
Transformer Industries
The above waste loads represent current industrial practice. It may be
assumed that, prior to knowledge of the adverse environmental effects of PCBs,
much of the types of material currently landfilled or incinerated was not disposed
of properly and thus entered the environment directly.
As yet, very little is being done at these plants to control air emissions.
The general industry assumption is that the vapor pressure of PCBs is so low that
there will be essentially no air contamination. A few facilities, however, were
reported to be filtering and chilling exhaust air from PCBs impregnation areas,
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and plant personnel are beginning to realize that evaporation of PCBs nay make
a significant contribution to general contamination of the plant area.
Since most water used at these facilities is for non-contact'cooling
purposes, at most plants it is possible to significantly reduce the effluent
volume by segregation of wastewaters, recycling and proper housekeeping measures.
Most user plants and the PCS producing plants have already undertaken PCBs contain-
ment programs in order to minimize the entry of PCBs into the environment. While
the emissions of PCBs to water are expected to decrease due to improved pollution
abatement of waterborne wastes, the release of PCBs to air and land may increase.
One potential source of increasing air emissions is the increase in incineration
due to proper handling of wastes which were previously discharged into the water-
ways or sewers. The quantities of land-destined wastes are expected to increase
due to improved housekeeping measures.
Rivers receiving PCBs discharges for a number of years vary greatly in
PCBs content with time, apparently depending upon PCB content in storm water run-
off and the degree to which contaminated bottom sediments are agitated and sus-
pended. Whereever there have been PCB operations in the past, there are probably
high concentrations in local waterways bottom sediments.
Over the past 45 years, waste PCBs from transformer and capacitor opera-
tions have been used as local road oiling compounds. Sometimes they were discarded
in dumps adjacent to manufacturing facilities. These are sources of long term
leaching of PCBs into waterways, particularly with storm water runoff.
2.2 Treatment and Disposal of Industrial Wastes Containing PCBs
A study was performed to determine and compare the methods available for
the treatment of PCB-containing wastes from the PCBs production, capacitor manu-
facturing, and transformer manufacturing industry categories. A full treatment
of this technology, including cost estimates for treatment, may be found in the
Task II Report under Contract 68-01-3259. Much of the technical portion of this
work is reproduced herein and summarized below.
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2.2.1 Incineration
The most advanced treatment technology in use is incineration.
The PCBs manufacturer and one user have plant scale facilities capable of destroy-
ing PCBs with very high efficiency. There are at least two commercial services
available, with four incinerator locations in the Eastern and Southern U.S., for
PCBs incineration.
Incineration is primarily applicable to waste PCBs and scrap
oils contaminated with PCBs. Incinerators for PCBs destruction have the capacity
of "burning" some contaminated wastewater but, of course, the proportion of that
water to the exothermic oil burning must be kept low. Only one coimiercial incin-
eration service (Rollins) can routinely handle all kinds of PCBs contaminated
transformer and capacitor components, sludges, fuller's earth and other solids,
as long as they can be contained in a 47 gallon fiber drum. One PCB user company
incinerates transformer internals for purposes of metal recovery.
Waste liquid PCBs and scrap oils (contaminated PCBs) are best
handled, as a guideline, by high temperature (2000-2400°F) and long residence time
(2-3 seconds) incineration. However, because of incinerator design variables,
the conditions should be chosen in each case to lead to 99.999% destruction. The
best incinerator combination for handling wastes from these industries is a rotary
burner fired by a liquid burner, and followed by an afterburner and scrubber system
for HC1 and particulate control. The rotary burner can be designed to handle a
variety of solid materials, and the liquid burner can handle both the oily and
water type wastes.
2.2.2 Treatment of PCB-Contaminated Wastewater
There is no commercial scale wastewater treatment for PCBs removal
being practiced beyond those of gravity settling of the heavy PCBs layers as a
sludge from the bottom of sumps or tanks, and skimming of a contaminated oil-layer
from the water surfaces.
Adequate methodology is available for those plants wishing to con-
trol the release of PCBs to the environment. Currently available technologies can
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be applied to the efficient removal of PCBs from wastes, or their destruction
with the other wastes. The PCBs content of wastewaters can be lowered to the 1
ppb level or below by removal of solids (and oil layers, where applicable),
followed by adsorption of PCBs onto carbon, macroreticular polymer resins or
possibly other adsorbents.
Carbon adsorption is currently the best available technology for
plant scale treatment of PCBs wastewaters. This conclusion is based on laboratory
tests with PCBs in water, and on the long background of plant scale use of carbon
adsorption for removal of organics from water.
Polymeric resins (AMBEKLITES) were found in laboratory tests to be
approximately as effective as carbon in removing PCBs from water. Further pilot
scale testing is needed with this newer (than carbon) technology to accurately
assess its potential.
Ultraviolet catalyzed ozonation was determined to be the best
method, demonstrated on a laboratory scale, for destruction of PCBs in wastewaters
when the streams occur in large volume, on a relatively continuous flow basis and
with PCBs at the ppb concentration levels. This technology has the potential for
conversion of PCBs to CO_, HO and HC1. However, significant development and
optimization work would be required before application of the process becomes
practical. In addition, the potential exists for production of toxic degradation
products by UV-ozonation.
Although still in the laboratory stage, catalytic reduction of
PCBs offers the possibility of reduction to biphenyl and HCl; and catalytic
oxidation is another process which offers a potential for destruction of PCBs to
CO2, H2O and HCl.
It is believed that wastewater treatment systems employing acti-
vated carbon and possibly UV-ozonation could produce effluents which would be at
or below the limits of detectability for PCBs with current analytical techniques.
However, since no full scale systems for the treatment of PCBs are in operation at
this time, this possibility cannot be confirmed.
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Unfortunately, no methodology is presently available which can
guarantee "zero discharge" of PCBs to the environment. "Zero discharge" objec-
tives can be best net now by eliminating discharge streams and developing recycle
systems. All streams that are high in pollutants and cannot be treated for reuse,
including rainwater runoffs, could be collected and incinerated under a "zero
discharge" objective.
2.3 Characterization of the Investment Casting Industry
Investment casting is a lost-wax process by which metal castings which
are of intricate shapes or which require close dimensional tolerances are mass-
produced. The pattern wax, some of which contains PCB filler, is molded and then
used to make a ceramic shell (investment) whose internal dimensions are those of
the desired product. The wax is typically melted from the shell, and the shell is
fired (sintered), which removes the last traces of the wax. Then molten metal
is poured into the mold (shell) and cooled to form the castings.
There are currently 135 investment casting foundries and four major
investment casting wax manufacturing plants in the United States. The Yates
Manufacturing Company, Chicago, 111., is the sole known U.S. supplier of decachloro-
biphenyl (deka) waxes. The deka content is 30 per cent of the total wax by weight.
Yates currently imports deka from Italy and manufactures between 1 and 1.5 million
pounds of deka wax annually. Very little is known about the wax manufacturing
process. Wax manufacturers are also believed to use polychlorinated terphenyls
(PCTs) imported from France.
The major losses of the virgin and used waxes appear to occur during the
dewaxing of the ceramic mold. The mold is fired in a furnace to set the mold and
remove the wax. Depending on furnace conditions, the deka or PCT in the wax is
either burned or released to the atmosphere. The magnitude of these emissions is
not known.
Most foundries recover the drained pattern wax and reuse it several
times. It is estimated that the purchased wax is used an average of 2.5 times.
Little of the wax is destroyed in the process; therefore, it is considered probable
that the investment casting foundries store or dispose of relatively large amounts
of used PCB- or PCT~containing wax.
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2.4 Transformer Service Industry
Most servicing of transformers is performed by electrical repair shops
rather than by the utility or the owner of the transformer. Thirteen companies
were identified as offering transformer service at a total of 131 locations.
Servicing of askarel-filled transformers may include the filtering of the askarel
to remove degradation products and moisture or the replacement of the askarel with
new liquid. PCB wastes include filter media, scrapped askarel, and miscellaneous
solvents, rags, etc. The proper disposal of these wastes is specified by a volun-
tary NEMA standard. Liquid PCBs are incinerated in most, but not all, cases. The
total usage of PCBs by the transformer repair industry is about 800,000 Ib/year,
or about seven per cent of the amount used to manufacture new transformers.
3.0 SUBSTITUTES AND USE ALTERNATIVES FOR PCBs
Potential substitute materials and use or process alternatives which would
eliminate or reduce the current requirements for PCBs were investigated. Important
points from this study are summarized below.
3.1 Substitutes for PCBs in Capacitors
PCBs (primarily Aroclor 1016) are currently used in almost all U.S.-made
capacitors for AC service (liquid-filled capacitors) and are uniquely suited for
this application because of their high dielectric constant, high resistance to
current flow and electrical breakdown, chemical stability, and non-flammability.
A number of different liquid materials now under development or testing have been
proposed as substitutes for PCBs in capacitors, including phthalate esters,
synthetic hydrocarbons, alkylated chlorodiphenyl oxide, alkylated PCBs, diaryl
sulfones, and silicones.
Since each of these materials is relatively more flammable than Aroclor
1016, it appears that use of any liquid substitute will probably pose more of a
fire hazard than use of PCBs. Vulnerability of capacitor manufacturers to lia-
bility for damages from capacitor failure is a major factor in industry acceptance
of a substitute capacitor fluid. The conservative code structure now in force
could also pose significant barriers to reduction or elimination of PCBs usage in
-16-
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capacitors. In addition, data on electrical performance, toxicity to humans, and
environmental effects of the potential substitutes are not presently sufficient
to allow meaningful comparisons with PCBs.
Dry AC capacitors (film-type) are in the development stage. These
capacitors are significantly larger than liquid-filled capacitors and are limited
to a maximum of 280 volts. Satisfactory dry film capacitors will not be available
until there are two separate technological breakthroughs: 1) the development of
a plastic film that combines a high dielectric constant with a low loss-tangent;
and 2) the development of winding techniques that exclude all air from the winding
of the capacitor.
Although it is considered probable that satisfactory substitutes for PCBs
will be developed within the next 5 years, no such material is presently available
and much additional research remains to be done. On the other hand, a significant
portion of the large capacitors used by utilities, and some in industry, are situ-
ated out-of-doors. These could be replaced by capacitors containing a more flam-
mable fluid without significantly increasing the risk of fire.
Although direct replacement of existing PCB-filled capacitors with units
containing substitutes appears possible for many large capacitors, anticipated
size differences will present severe problems in retrofitting. The new fluids
also cannot be directly substituted for PCBs in existing capacitors. In addition,
disposal of obsolete or replaced units will probably be in landfills for many years
to come. It is probable that the best replacement scheme for capacitors, assuming
cessation of PCBs production and use, would be use of non-PCB replacements as units
become obsolete or fail.
3.2 Substitutes for PCBs in Transformers
Aroclors 1242 and 1254 are currently used in about five per cent of U.S.-
built transformers; most transformers are cooled with mineral oil. Transformers
filled with askarel (60-70 per cent PCBs) are often specified for use in buildings
and in hazardous locations where minimization of the fire hazard is of paramount
importance. The National Fire Code requires that oil-filled units, and askarel-
filled units rated for service over 35 kV, be enclosed in fireproof vaults when
-17-
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used in buildings. For units below 35 kV, the higher cost (by 20 to 30 per cent)
of an askarel unit is more than offset by the savings on vault construction.
Open, air-cooled transformers are limited to a clean, dry environments,
but are being increasingly used in commercial buildings. Closed, gas-cooled
transformers are more expensive than askarel units. Both of the above types have
voltage limitations and much less overload capacity than the askarel-filled type.
Several substitute liquids have been suggested for use in transformers
which are less flammable than the currently used mineral oil, but which are more
flammable than askarel. The most promising are a silicone oil and a synthetic
paraffinic hydrocarbon. These liquids are characterized as being self extin-
guishing - i.e., they do not continue to burn after being ignited by a momentary
electrical arc. Proposals have been submitted to the National Electrical Code to
allow the use of these self extinguishing materials under those conditions where
askarels are presently specified. Because of the relative lack of service experi-
ence with these liquids, it is unlikely that these proposals will be accepted.
The next Code revision (1978) will probably continue to recognize only askarel
and "oil filled" transformers.
It is likely that the "self extinguishing" liquids will prove to be satis-
factory alternatives to PCBs. Substantial experience on the performance of the
liquids will be required before the code requirements will be changed to allow
their use. The restrictive Electrical Code, which has been incorporated into the
OSHA Standards, may act to inhibit the accumulation of this data and thereby act
to postpone the general acceptance of these substitutes for PCBs.
The major conclusion from this portion of the study was that technically
acceptable alternatives to the use of PCBs in transformers exist and that their
use should not result in a significant increase in fire hazards from transformer
failure. At present the selection of PCB (askarel) transformers appears to be
based primarily on cost rather than technical considerations.
As with capacitors, direct replacement of PCBs in existing transformers
would present potentially severe problems. These include the extreme difficulty
of removing more than 90-95 per cent of the PCBs, even by repeated flushing with
-18-
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a compatible solvent (trichlorobenzene), and the requirements of incinerating
such large quantities of PCBs and contaminated solvent.
3.3 Alternatives to Other PCBs Applications
On a preliminary basis, there appear to be no overriding technical (or
institutional) barriers to the use of alternatives to decachlorobiphenyl filler
in investment casting waxes. (This also appears to be the case for the poly-
chlorinated terphenyls.) Potential alternatives include use of materials such as
isophthalic acid as the filler and use of the new low-shrinkage unfilled waxes.
A cost increase of about ten per cent is projected for each of the above altern-
atives .
Since the voluntary restriction by Monsanto in 1971 of PCBs sales for
use in closed electrical systems only, PCBs have largely been eliminated from
usage in hydraulic and heat transfer systems. Adequate substitutes were generally
available at the time of the Monsanto restriction, and the present usage of PCBs
(believed to be minor) should be replaceable by alternatives with minimal dis-
advantage.
4.0 SOURCES OF INADVERTENT ENTRY OF PCBs INTO THE ENVIRONMENT
4.1 Paper Recycling
Over the period 1957 to 1971, approximately 45 million pounds of Aroclor
1242 was used by a single producer (NCR) in the production of carbonless copy
paper. Some fraction of this material has entered the paper recycling stream and
is apparently a major source of observed PCBs contamination of effluents from the
secondary fiber recovery industry. PCBs were also added to paper in inks and
possibly in other additives; this material was probably Aroclor 1254.
Thus, in its effort to conserve resources profitably, the secondary fiber
recovery (paper recycling) industry is inadvertently releasing previously used and
"stored" PCBs into the general environment, primarily to water. Reliable estimates
of the amounts of PCBs so released are not available, and, although the significance
of this release should diminish as office files are emptied, the amounts remaining
to be released are not known.
-19-
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Results from an analysis of PCBs entering Lake Michigan, discussed later
in Section 5.0, indicate that, although there is a significant concentration of
paper recycling activities in the area of this lake, the contribution of paper
mills to the total PCBs input to Lake Michigan is small in comparison to atmos-
pheric fallout. However, effluents containing amounts of PCBs which are very
small compared to the total environmental load can be extremely important on a
local basis, and further investigation of this problem is urged.
It should be noted that water usage in the paper recycling industry is
high and effluent PCB concentrations are typically 5 to 10 ppb. The cost of PCBs
removal would therefore probably be higher per unit of profit than for the other
industry categories described herein.
4.2 Effluent Contamination by PCBs in Other Industries
High concentrations of PCBs were recently reported in effluents from a
number of plants engaged in the manufacture of machinery and mechanical products.
These measurements have not been verified to data. PCBs were, in the past, used
extensively in hydraulic and heat transfer systems, in lubricants, and in paints
and plastics, so that it is not inconsistent that effluents from the machinery
manufacturing industry contain PCBs. PCB contamination of effluents is known to
have occurred via slow release of old deposits in sewers and elsewhere, although
industrial usage in semi-open applications is believed to be continuing at a low
level.
4.3 Inadvertent Production of PCBs in the Environment
Three general types of reactions were considered as potential sources of
inadvertent production of PCBs. Of the three, the one considered most likely to
occur is chlorination of biphenyl in wastewater during treatment. This refers
specifically to the discharge of wastewater containing biphenyl to a municipal
sewer and the subsequent chlorination of the material in the treatment plant.
Biphenyl is used extensively as a dye carrier for the dyeing of synthetic
fibers; in this application, much of the biphenyl leaves the process as waste.
The estimated U.S. industrial usage of biphenyl is about 50 million pounds per year,
of which at least half is used in dyeing operations. Although chlorination of
-20-
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biphenyl in sewage treatment appears likely, the extent of neither the initial
chlorination nor further chlorination is known. Further investigation of biphenyl
chlorination as a possible source of PCBs is recommended.
Chlorinated biphenyls have been produced by the decomposition of DDT,
although this requires recombination of phenyl radicals from cleavage of two
DDT molecules. Significant production of PCBs in the environment by this mecha-
nism is considered unlikely. Formation of PCBs via chlorination of the product
formed from the combination of two substituted benzenes is also considered of less
potential significance than direct chlorination of biphenyl in wastewater.
5.0 TRANSPORT AND DISTRIBUTION OF PCBs IN THE ENVIRONMENT
A first order mass balance model was developed and used to study the trans-
port and distribution of PCBs in the environment. The total environmental load
of "free" PCBs was regarded as a "pool" of mixed PCBs. In applying the model,
the pool was assumed to exhibit properties roughly similar to those of Aroclor
1254. The model was applied to Lake Michigan; the boundaries of the region studied
were taken to be the drainage basin of the lake. Lake Michigan is a nearly closed
body of water of sufficient size to allow averaging of properties and of sufficient
interest that some pertinent data were available.
The estimated total input of PCBs to Lake Michigan (1973-1974) was 13,400
Ib/yr, of which 1,600 Ib/yr came from point sources (summation of industrial and
municipal discharges reaching the lake), 6,400 Ib/yr represented fallout directly
onto the lake, and 5,400 Ib/yr was derived from fallout on the drainage basin
(assumed to be 50 per cent of total fallout on the basin) . Thus, it is estimated
that about 88 per cent of the PCBs currently entering Lake Michigan arise from
fallout.
Application of the model produced the following cumulative values for the
period 1930 to 1975 (input function assumed proportional to domestic sales):
Total input 1.49 x 105lb
Total in solution 1.0 x 10 Ib
Total in biota 3.64 x 10 Ib
Total in sediments 1.7 x 10 Ib
-21-
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Total in outflow 9.07 x 1Q3 Ib
Total evaporated 1.93 x 104 Ib
Since degradation of PCBs in the lake was assumed to be zero, the closing
of the material balance depended upon total evaporation from the lake being
4
1.93 x 10 pounds, or about 13 per cent of the total input. This value is in
excellent agreement with values derived both from kinetic theory and from co-
distillation theory; this result substantiates both the model form and the material
balance above.
Average water and biota concentrations derived from the analysis (using a
4
bioconcentration factor over water of 4 x 10 ) are, for recent years:
Water Cone, (ppt) Biota Cone, (ppb)
1960 1.60 64
1965 2.92 117
1970 5.35 214
1975 9.10 364
The above agrees well with available data on lake and biotic concentrations since
1970.
Mean residence times of PCBs in air and water, and the transport mechanisms
which operate at the various phase interfaces, are very important to the under-
standing of environmental transport and distribution. Lifetime values are extremely
sensitive to the assumptions required for their calculation (required because of
the lack of adequate experimental data). Estimates derived from work by others
range from 20 days to eight years for the average lifetime to fallout of airborne
PCBs. Residence times to evaporation in Lake Michigan appear to be on the order of
ten hours, based on theoretical calculations, whereas residence times to evapora-
tion from sea water may be one to two orders of magnitude lower.
The picture of gross PCBs transport consistent with all of the above findings
is the one dominated by air transport. Terrestial components, including fresh water,
are partial sinks responding primarily to input from fallout. Losses are to
evaporation and to rivers, which enter the oceans where further (possibly rapid)
-22-
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evaporation occurs. Degradation of PCBs, which was assumed to be zero in the
Lake Michigan analysis, appears too slow to have a significant effect. Industrial
and municipal effluents and air emissions are sources of both old and new PCBs;
large amounts enter landfills and a small fraction enters the cycle through leach-
ing and evaporation.
If the above is even partially correct, then one possible answer to the
question of why the restriction on uses beginning in 1971 has not caused the
hoped for diminution in PCBs distribution is as follows:
(1) The systems which cause concern with regard to PCBs (fresh-
water systems and associated biota) serve as sinks for PCBs;
(2) Other possible sinks are not available or are ineffective
in retaining PCBs; and
(3) The environmental degradation of PCBs is too slow to be
significant over a five year period.
Further work in many aspects of PCBs transport and distribution are needed in
order to estimate the real magnitude of the future environmental problem from these
materials. Such work should also assist in identifying potential methods for re-
ducing the environmental load of PCBs.
6.0 REGULATORY ACTIONS ON PCBS
Four government agencies, the Monsanto Company and NEMA comprise the regulatory
forces currently restricting the use and distribution of PCBs. EPA, OSHA, FDA and
USDA have, between them, authority to regulate and monitor food levels, disposal
into waterways, industrial housekeeping, and safety practices in the work place.
Each of these available authorities has a limited focus and is inadequate to pre-
vent more PCBs from entering the environment.
There are currently no regulations to restrict the importation of PCBs as a
chemical for use in applications banned by the Monsanto Company. As a result,
PCB is being imported by a few companies for use in several "open-end" or ''nominally-
closed" applications.
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Several producing nations have voluntarily limited sales of PCBs. Since
1972, Japan has banned production and importation of PCBs. The United Kingdom
has barred sales of PCBs to all applications except usage as dielectric fluids,
while Germany has lessened this restrictive measure to include use in heat
transfer and hydraulic systems. Among non-producing countries, Sweden and
Norway have stringent regulations. In Sweden, only the Environmental Protection
Board can authorize the use of PCBs or conpounds containing PCBs, while in Norway
only the Ministry of Social Affairs can authorize the use of PCBs.
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SECTION III
CONCLUSIONS AND RECOMMENDATIONS
1.0 Conclusions
Conclusions which have resulted directly from the work reported herein are
presented below. Some of these have been discussed briefly in the preceding
section, but each is believed to be justified by information contained in the text
of the report and the appendices.
(1) It is estimated that approximately 1.25 billion pounds of PCBs
have been sold for industrial use in the U.S. since initiation
of production around 1930.
(2) Of this amount, at least 95 per cent are still in existence;
most is in service in capacitors and transformers, but about
290 million pounds are believed to reside in landfills and dumps
and about 150 million are believed to be "free" in the environment.
The magnitude of these values indicates that there is a strong
future threat from PCBs present in land disposal sites.
(3) In 1974, U.S. usage of PCBs sold by Monsanto, the sole domestic
producer, was distributed between capacitor manufacture (22
million pounds) and transformer manufacture (12 million pounds).
Imported materials amounted to about one per cent of U.S.
industrial purchases of PCBs in 1974; about 400,000 pounds
(of decachlorobiphenyl) were used in investment casting and
and an estimated 50,000 pounds of new material were used in
specialized heat transfer systems.
(4) Waterborne effluents from PCBs production and first-tier use
currently release amounts to the environment which are very
small in comparison to the amounts entering land disposal sites
from these industries. However, these effluents can have
severe local impacts, as evidenced by the current PCBs pro-
blem in the Hudson River.
-25-
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(5) Monsanto and portions of the electrical equipment industry
utilizing PCBs have greatly reduced PCB releases to water
and land over the past few years, primarily through improve-
ment of plant housekeeping, improved waste collection and
handling, and disposal of liquid wastes through incineration.
(6) There is no plant-scale process used at present for the specific
purpose of removing PCBs from industrial wastewater.
(7) The best available treatment technology for removal of PCBs
from wastewater is carbon adsorption coupled with solids and
oil/grease removal. Carbon treatment can produce end-of-pipe
PCBs concentrations of one ppb or less. Other adsorbents, such
as resins, also appear effective to this extent.
(8) The most promising method, of those water treatment technologies
under development, for PCBs destruction is ultraviolet-catalyzed
ozonation.
(9) Incineration is an effective method of disposal for liquid
PCBs. Landfilling is the only generally available disposal
method for PCBs-contaminated solid wastes, but incineration of
these wastes is technically feasible.
(10) "Zero discharge" to water of PCBs from production and first-
tier use is available only through extensive water reuse
plus extensive incineration of lightly contaminated wastewaters.
(11) Significant amounts of solid PCB (decachlorobiphenyl, or deka)
wastes are stored or disposed of on land by the investment
casting industry. Air emissions of deka may also be significant
in amount, but no evidence of potential health hazards from this
material has been reported.
(12) The total present usage of PCBs for open and semi-closed applic-
ations is not known but is believed to be small in comparison
to closed electrical system usage. A few capacitor manufacturing
-26-
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plants report recent use of PCBs in vacuum pumps, and a
significant amount of carbonless copy paper containing PCBs
must still be in inventory and in files.
(13) Chlorination of waste biphenyl in industrial wastewaters
discharged into municipal sewers is a potential mechanism
for inadvertent production of PCBs.
(14) PCBs are uniquely suited to the requirements of capacitors
for AC service. Although a number of potential substitutes
for this application are under development and test, they
are all more flammable than Aroclor 1016 and neither their
performance in service nor their potential toxicity to man
and other species have been evaluated sufficiently to allow
a definitive comparison with 1016.
(15) Alternatives to PCBs usage in new transformers are available.
In addition, testing of promising substitute fluids (termed
"self-extinguishing") is underway; these fluids may gain
industry-wide acceptance within three years as substitutes for
PCS fluids. At present, specification of PCB-filled trans-
formers appears to be based primarily on cost considerations.
(16) No technical barriers to substitution for PCBs (deka) in
investment casting waxes are apparent. Several potential
alternatives have been previously used by this industry.
(17) Atmospheric fallout is a major source of PCBs input to fresh
water systems. In Lake Michigan, the PCBs contribution at
present appears to be much larger than the total of PCBs inputs
from point sources such as municipal sewage treatment and paper
recycling.
(18) The importance of atmospheric transport of PCBs relative to
other potential inputs to water indicates that the availability
of environmental sinks from PCBs is limited, possibly due to
short residence times to evaporation in sea water.
-27-
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(19) At present, regulatory authority over PCBs in the United
States is insufficient to significantly reduce future PCBs
inputs to the environment, although inputs directly to the
waterways from industrial sources can be reduced from their
present level. Current disposal practices, except for in-
cineration, tend to delay instead of prevent the PCBs entry
into the "free" (available to the biota) state, and these
practices are regulated only minimally.
2.0 RECOMMENDATIONS
During December, 1975 and January, 1976, EPA Administrator Russell Train
called for a cooperative effort between Government and industry to eventually
eliminate PCBs from production and usage in the United States. The recommendations
listed below were developed with this objective in mind, although each recommenda-
tion also reflects the still existing needs for further definition of the current
and future PCBs problem and for the development of methods for reducing the
potential damage to human health and the environment.
(1) The current distribution and losses to the environment of PCBs
should be defined more accurately. Study is needed for the
following aspects of past and present usage:
(a) Present extent and distribution of usage in semi-
closed systems such as heat transfer and hydraulic
systems (dissemination of information concerning PCBs
effects and available substitutes will result in
voluntary reduction of PCBs usage);
(b) Definition of past and present usage in investment
casting, including quantification of air emissions,
disposal on land, and waterborne contamination;
(c) Present distribution and projected future trends for
PCBs in the pulp and paper industry, especially the
secondary fiber recovery portion; and
-28-
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(d) Extent of inadvertent PCBs contamination in
effluents from other industries which are currently
not purchasers of PCBs.
(2) The basic transport properties of PCBs, particularly those re-
lating to evaporation and atmospheric fallout, should be studied
in depth. This and other information should be used to investi-
gate global transport characteristics of PCBs and to predict the
potential magnitude of the global PCBs problem. Potential sinks
and destruction methods for PCBs should be investigated.
(3) The type of analysis presented herein for Lake Michigan should
be further expanded and refined for application to other
important fresh water systems. The model should be extended
to a prediction of future effects and the influence of possible
reductions in PCBs usage.
(4) Transport of PCBs from landfills should be investigated; in
particular, potential methods for delaying or reducing PCBs
release from landfills should be studied.
(5) Development and testing of potential substitutes for PCBs
in capacitors, transformers, and investment casting waxes
should be encouraged strongly. Technical and institutional
barriers to the use of alternatives should be attacked on all
possible fronts as soon as possible. Extensive toxicological
testing of proposed substitute materials should be performed
prior to acceptance.
(6) Methods for treatment of PCBs-contaminated water effluent should
be developed and applied. Research and development activities
on directly destructive treatment methods, such as UV-assisted
ozonation and catalytic oxidation or reduction should be encouraged,
but further work on adsorptive techniques is also needed.
-29-
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(7) Alternative approaches and schedules for PCBs elimination
from U.S. comnerce should be evaluated with regard to technical
feasibility, institutional acceptability, and economic and
environmental impact. Based on these considerations, an optimized
path to PCBs elimination should be developed.
(8) Possible inadvertent formation of PCBs in the environment should
be studied; in particular, it is recommended that the chlorina-
tion of biphenyl in wastewaters be evaluated as a potential source
of PCBs.
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SECTION IV
CHEMICAL AND PHYSICAL PROPERTIES OF CHLORINATED BIPHENYLS
1.0 INTRODUCTION
The purpose of this section is to present a precis of the salient charac-
teristics of the commercial preparations of the polychlorinated biphenyls which
have generated concern as environmental pollutants. The emphasis is directed
to those properties that have led to the relatively widespread use of these
materials. In addition, attention will also be directed to those physical and
chemical properties that contribute to the environmental effects arising from
the general distribution of these materials. The discussion is not meant to be
exhaustive, but rather'to offer the basic technical information that is used to
support the other sections of the total report. The most complete compilation of
the relevant information that has been published to date is that by Hutzinger
et al (0. Hutzinger, S. Safe, and V. Zitko, "The Chemistry of PCBs", CRC Press,
1974) and the authors express their debt to this publication.
1.1 The Chemistry of the Chlorinated Biphenyls
The polychlorinated biphenyls (PCBs) constitute a large class of
compounds produced by the partial (or complete) chlorination of the biphenyl mole-
cule. Since their introduction in 1929 in commercial quantities, these compounds,
or rather commercial mixtures of various members of the class, have been applied
in a considerable variety of industrial applications. The unique physical and
chemical properties of these compounds, including low vapor pressure at ambient
temperatures; resistance to combustion; remarkable chemical stability; high
dielectric constant and high specific electrical resistivity have been utilized
in such applications as electrical insulating fluids; fire resistant heat trans-
fer and hydraulic fluids; lubricants for use at high temperatures and pressures
in critical applications and as a constituent in a variety of elastomers, adhesives,
paints, lacquers, varnishes, pigments and waxes.
-31-
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PCBs and mixtures of chlorobiphenyls have been produced in a number
of countries and marketed under several trade names including Aroclor, Clophen,
Phenoclor, Kanechlor and Fenclor. The essential characteristics of all these
mixtures, which depend in detail on the specific mixtures of chlorobiphenyls that
make up the specific preparation, are sufficiently alike that it will suffice to
discuss all in terms of the Aroclors, which is the trade name of the preparations
of Monsanto Chemical Company. In those special cases wherein there is some
particular property peculiar to one of the foreign PCS mixtures, a note will be
made.
A great deal of confusion has appeared in the literature because of
the nomenclature that is used to describe the commercial preparations and the
individual authenticated chlorobiphenyls. In order to clarify the nomenclature
to be used herein, it is appropriate to digress briefly as follows. The biphenyl
molecule has a total of ten (10) carbon-hydrogen bonds at which chlorine sub-
stitution can be accommodated. A schematic representation of the biphenyl mole-
cule with the various positions at which substitution can be accomplished numbered
in the American Chemical Society standard notation is presented below:
ACS Convention for Numerical Assignments
of Biphenyl Substitution
In the interest of a common usage, the following rules will be
followed in this report:
a. When referring to a mixture of different species, as
occurs in the commercial products, we will use the term
polychlorinated biphenyls or the acronym PCB.
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b. Those species of chlorinated compounds that arise from a
specified number of chlorine substituents on the biphenyl
molecule will be referred to as chlorobiphenyls with a
suitable numerical prefix to define the number of sub-
stituted chlorines; i.e., dichlorobiphenyl. Thus, there
are a total of ten (10) chlorobiphenyls that might appear
in the commerical mixtures.
c. Those specific compounds that represent the class of
compounds formed by a specific number of substituent
chlorine atoms but differ in the locations at which
substitution has taken place are referred to as isomers.
Thus, in terms of the above, the proper manner of referring to a commercial PCS
mixture is as a "mixture of chlorobiphenyls containing various proportions of
the iosmers of each".
To illustrate the utility of the numbering system indicated pre-
viously, the correct names of the compounds shown below are:
Cl Cl
Cl Cl
2,3',5,5'-tetrachlorobiphenyl
Cl
Cl Cl
3',4,4',5-tetrachloro-2-biphenylamine
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The ten chlorobiphenyls and some of the salient chemical data are
listed in Table 1.1-1; note that the total of all the isomers of the chloro-
biphenyls are 209 separate compounds.
1.2 Commercial Production and Chemical Makeup of the Aroclors
i The commercial process by which the PCBs are made involves the
chlorination of biphenyl with anhydrous chlorine in the presence of a catalyst
which may be either iron filings or ferric chloride. The crude product is generally
purified to remove color, traces of hydrogen chloride, and the catalyst by
treatment with alkali and subsequent distillation. The resulting product is then
a more or less complex mixture of the chlorobiphenyls, the precise composition
depending on the conditions under which chlorination was carried out. The approxi-
mate composition of selected Aroclors is given in Table 1.2-1.
By way of explanation, the products made by Monsanto under the trade-
name Aroclor are designated as to the starting material, with biphenyl represented
by the 12 prefix, and with the approximate chlorine percentage by the second set
of digits; i.e., Aroclor 1248 is a chlorinated biphenyl containing approximately
48 percent chlorine.
From the data presented in Table 1.1-1 and 1.2-1, it might be inferred
that all of the isomers of the individual chlorobiphenyls are to be found in each
of the commercial mixtures. To illustrate the actual situation, Aroclor 1248,
which is made up primarily of the di-, tri-, tetra-, penta- and hexa- chlorobiphenyls,
could be expected to contain something of the order of 140-150 separate isomers.
In point of fact, there are less than 50 identifiable peaks observed in the high
resolution gas chromatogram of typical specimens of Aroclor 1248 as is illustrated
in Table 1.2-2.
The observations relative to the high resolution studies of the
commercial Aroclor mixtures have been summarized by Hutzinger, et al (ibid), in
the form of Figure 1.2-1 which indicates the structural units of which the signi-
ficant isomers are constructed.
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Table 1.1-1
Empirical Formulation, Molecular Weights
and Chlorine Percentage in PCBs
Empirical formula
chlorobiphenyls
C12H10
C12H9C1
C12H8C12
C12H7C13
C12H6C14
C12H5C15
C12H4C16
C12H3C17
C12H2C18
C12HC19
c n
12 10
Molecular weight*
154
188
222
256
290
324
358
392
426
460
494
Percent chlorine*
0
18.6
31.5
41.0
48.3
54.0
58.7
62.5
65.7
68.5
79.9
No. of isomers
1
3
12
24
42
46
42
24
12
3
1
*Based on Cl
35
-35-
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Table 1.2-1
Approximate Molecular Composition
of Selected Aroclors
Aroclor Type or Grade
Chlorobiphenyl
C12H10
C12H9C1
C12H8C12
C12HyCl3
C12H6C14
C12H5C15
C12H4C16
C12H3C17
C12H2C18
C12H1C19
C12C110
1221
11
51
32
4
2
0.5
ND
ND
ND
ND
ND
1242
(pa
<0.1
1
16
49
25
8
1
<0.1
ND
ND
ND
1248
rcent cc
2
18
40
36
4
1254
mpositi
<0.1
<0.1
0.5
1
21
48
23
6
ND
ND
ND
1260
on)
12
38
41
8
1
1016
<0.1
1
20
57
21
1
<0.1
ND
ND
ND
ND
-36-
-------
Table 1.2-2
High Resolution Gas Chromatography of Aroclor 1248
Peak number*
1
2
3
4
5
6
7
8
9
10
11/12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41/42
43
44
45
46
No. of Cl
2
3
2
3
3
3
3
3,4
3,4
3,4
3
3
3
3,4
3,4
3,4
3,4
4
4
3,4,5
4,5
4,5
4
4
4
4
4
4,5
4,5
4,5
4,5
5
5
6
4
6
5
5,6
6
6
6,7
% In Aroclor 1248
0.4
1.0
3.2
11.2
3.2
3.1
2.0
1.4
1.4
0.8
8.5
9.7
2.1
7.4
7.4
6.0
4.5
3.1
2.6
0.8
1.2
1.0
0.2
5.0
3.3
2.0
2.1
1.0
0.5
0.5
0.8
1.0
0.4
<0.1
<0.1
0.2
0.3
0.2
<0.1
0.2
(0.7)
% In fatty tissue
0.9
1.4
0.9
2.4
0.5
0.2
4.8
0.8
0
1.6
1.6
0.8
0.5
-
7.0
4.1
0.3
0.4
-
1.0
-
—
5.3
2.0
0.4
0.5
2.9
29.0
1.4
-
1.7
1.4
0.1
0.1
11.0
1.1
8.0
5.3
0.9
(1.1)
-37-
-------
Figure 1.2-1
mieties from Which Principal
Chlorobiphenyl Isomers are Formed
Cl per
benzene ring
most likely substitution pattern
Cl
Cl Cl Cl
Cl Cl
3
4
The most common substitution patterns for the chlorobiphenyls
found in PCB preparations. Only one phenyl-ring is shown. The
most abundant tetrachlorobiphenyls, for example, are those from
the dichlorophenyl-moieties shown. One di- and one trichlorophenyl-
would give most abundant penta-chlorobiphenyls, etc.
-38-
-------
Several Garments are necessary at this point: The importance of
such detailed determination and identification of the isomers characteristic of
the conmercial PCBs lies in the observations, to be discussed below, that bio-
accumulated chlorobiphenyls show what appear to be significant differences in the
distributions of the individual isomers from the source materials. The most pro-
bable explanation for these observations seem to be that at least some of the
chlorobiphenyls are metabolized principally to hydro-chlorobiphenyls. Only
after very complete isomeric spectra are available can such effects be properly
studied.
Secondly, the detailed study of the PCBs has shown that there are
no major compounds in these mixtures aside from the chlorobiphenyls. On the
other hand, products formed by the addition (rather than by substitution) of
chlorine to the biphenyl molecule in laboratory studies, yield significant con-
centrations of partially saturated structures. These structures are apparently
either not formed under the conditions of chlorination that prevail during the
industrial processing or alternatively are destroyed during the purification
steps of the process. In contrast to the Aroclors, some of the foreign products
have shown traces of polychlorinated naphthalenes and polychlorodibenzofurans;
a fact that may have considerable toxicological significance in view of the rather
more toxic nature of these latter products. However, recent information published
by FDA indicates that impurities of chlorodibenzofurans have been also detected
in Aroclors.
1.3 Physical Properties of the PCS Aroclors
The relevant physical properties of the Aroclor mixtures naturally
separate into two groups; those properties that have led to the widespread in-
dustrial use of these materials, and those properties that result in the intro-
duction of these materials into the environment with what appears to be con-
siderable potential danger.
1.3.1 Physical Properties of Industrial and Technical Interest
The most useful compilation of the physical properties of
the various Aroclors that has so far appeared in the literature is that given
by Hutzinger, et al (ibid), a portion of which is herein reproduced (with minor
changes) as Table 1.3.1-1.
-39-
-------
I
£>.
O
Table 1.3.1-1
Chemical and Physical Properties of
Representative Arcclors
H» - hut .
• - saro chlorine content as dac» ohlorofci
1.182-1.192
(25V15.5-C)
9.85
275-320
1.0-1.5
141-150
286-302
176
349
1 (crystals)
34 (crystals)
_
1.617-1.618
39-41
35-37
30-31
1.15
Aroclor
1232
Clear,
mobile oil
100 APM
31.4-32.5
0.014
-
0.00073
(25--100-C)
1.270-1.280
10.55
290-325
1.0-1.5
152-154
305-310
238
460
-35.5
-32
_
1.620-1.622
4J-51
39-41
31-32
.04
Aroclor
1016
Clear,
srrdla oil
-41
<25V15^S-C)
11.40
32J-356
170
none to
toiling
point
1. 622-1. 624
(t 25-O
71-81
MR
NR
SH
Krodoc
1242
Clear,
•obOeoil
100 APHA
42
0.015
50
0.00068
(25--65-C)
1.381-1.392
(25V15..5-C1
11.50
325-366
0-0.4
3.0-3.6
176-180
348-356
r»na to
tx>ilirq
point
-19
2
-
i. u7-i.cn
82-92
49-56
34-35
3.10
Aroclor
1248
near.
nobxle oil
100 APlft
48
0.010
50
0.00070
I25'-65"C>
1.405-1.415
12.04
340-375
0-0.3
3.0-4.0
193-1%
379-384
none to
boiling
point
-7
19.4
-
1.630-1.631
185-240
73-60
36-37
3.30
Aroclor
1254
Light-yellow
viscous
liquid
100 APHA
54
0.010
50
0.00066
(25--65'C}
1.495-1.505
(65V15.5»C)
12.82
365-390
0-0.2
1.1-1.3
none to
roiling
point
none to
tolling
point
10
50
-
1.629-1.641
1800-2500
260-340
44-48
4.96
Aroclor
1260
Light-yellow
soft.
sticky resin
150 APHA
60
0.014
50
0.00067
(20'-100'C)
1 555-1.566
(90Y15,5*C)
13.50
185-420
0-0.1
0.5-0.8
none to
boiling
point
none to
boiling
point
31
88
-
1.647-1.649
J200-4500
72-78
6.30
Aroclor
1262
Light-yellow
sticky
viscous resin
150 APHA
61.5-62.5
0.014
-
0.00064
(25"-65'C)
1.572-1.583
(9oyi5.5'C)
13.72
390-425
0-0.1
0.5-0.6
rune to
lolling
point
rone to
boiling
point
35-38
99
-
1.6501-1.6517
600-850
(160'Fi
71 'CI
Bb-100
6.80
Aroclor
1268
Mute to off-
white pcwfer
1.5 NPA
(molten)
68
0.05
-
0.00067
(20--100-C)
1.804-1.811
(25V25"CI
15.09
435-450
0-0.06
0.1-0.2
none to
toiling
pojjit
none to
toiling
(joint
-
150-170
302-338
(lold point)
-
f
8.70
Aroclor
1270'
Hhibe crystal
line powder
71
1.9J1-1.960
(25'/25'C)
16.30
450-460
none
none
249-300
NR
Aroclor
54<2
Yellow, trans-
parent
sticky resin
42
1.470
(25V25')
12.25
215-300
247
>350
46
46-52
HR
Aroclor
5460"
Clear yellow-
tD-arber
brittle resin
60
1.670
(25V25-)
13.90
280-335
none
none
—
S8-105.5
1.660-1.665
13)
-------
In addition to the chemical stability and resistance to
coirbustion illustrated in Table 1.3.1-1, the electrical properties of the PCS
Aroclors are of extreme significance in the utilization of these materials. A
compilation of the relevant data is presented as Table 1.3.1-2, which illustrates
the nature of the problem that is encountered when one undertakes a search for
a suitable substitute for these compounds in such segments of the electrical in-
dustry as the manufacture of capacitors. Specifically, the dielectric constants
for most dielectric liquids lie in the range up to perhaps half of that of the
polychlorinated biphenyls.
1.3.2 Physical Properties of Environmental Interest
The essentially world-wide distribution of the chlorinated
'hydrocarbons such as the PCBs suggest that a major route by which such compounds
are transported is through the atmosphere either in the form of vapor or perhaps
sorbed onto dust particles. In addition, it is observed that there is a wide-
spread accumulation of these compounds within the biota ranging from the smallest
on up the food chain until truly enormous loads are found in the highest members
of the chain. Since this bioaccumulation also includes the aquatic biota, the
possibility of considerable transport via the solubility of these compounds in
water must also be taken into account. Table 1.3.2-1 lists some of the vapor
pressure and solubility data for several of the Aroclors (D. MacKay and A. W.
Wolkoff, Env. Sci. and Tech., !_• 611 ff (1973)).
The analysis of co-evaporation (MacKay, ibid) of dilute solu-
tions of the Aroclors by equilibrium thermodynamics suggests that, because of the
very high activity coefficients of the chlorobiphenyls in water, the potential
for evaporation is quite high enough that this mechanism is a major portal by which
such compounds enter the atmosphere. The fourth column of Table 1.3.2-1 indicates
the theoretical time for a fifty percent reduction in the concentration of the
Aroclor from a saturated water solution (pure water plus PCBs), assuming the water
depth to be 1 meter thick. Clearly, the results of this analysis need to be ex-
perimentally verified.
-41-
-------
Table 1-3.1-2
Electrical Properties of Some Aroclors
Dielectric constant
at 1000 cycles5
Volume
. . . b
resistivity,
8 cm at 100°C
Dielectric
Power factor/
100°C, 1000
Aroclor
1232
1242
1248
1254
1260
1268
5442*
5460*
25
5
5
5
5
4
2
3
2
°C
.7
.8
.6
.0
.3
.5
.0
.5
100
4.
4.
4.
4.
3.
4.
3.
°C
6
9
6
3
7
9
7
500 V
above
above
above
above
above
, de
500
500
500
500
500
x 10
x 10
x 10
x 10
9
9
9
9
strength, kV cycles, %
>35 <0.1
>35 <0.1
>35 <0.1
>35 <0.1
x 109
— —
ASTM D-150-47T
ASTM D-257-46
"ASTM D-149-44
*Polychlorinated terphenyls
-42-
-------
Table 1.3.2-1
Solubility, Vapor Presure and Halflife for
Vaporization from Water of Selected Aroclors at 25°C
PCB Type
Solubility
(mg/1)
Vapor Pressure
(mm Hg)
Theoretical halflife
for vaporization
from 1 m. water column
Aroclor 1242
Aroclor 1248
Aroclor 1254
Aroclor 1260
0.24
5.4 x 10
1.2 x 10
2.7 x 10
-2
-2
-3
4.06 x 10
4.94 x 10
7.71 x 10
4.05 x 10
-4
r4
-5
-5
5.96 hr.
58.3 min.
1.2 min.
28.8 min.
-43-
-------
As pointed out above, not only is each of the Aroclors a
mixture of several chlorobiphenyls, but there are a number of isomers present for
each of the chlorobiphenyls. Thus, the solubility of an Aroclor, or the vapor
pressure of an Aroclor, represents an average over the various species that make
up the mixture. To illustrate the effect of the structural complexity, Table
1.3.2-2 (Hutzinger, ibid) details the measured vaporization rates of the several
Aroclors. On the other hand, the changes in the mixture corresponding to Aroclor
1254 on extended heating are displayed in Table 1.3.2-3 (Hutzinger, ibid) .
The possible implications of these data lie in the fact that
much of the Aroclor that is found in typical environmental samples seems to
demonstrate lesser amounts of the lower chlorine number chlorobiphenyls than is
characteristic of freshly manufactured samples. This observation has frequently
been attributed to possible metabolism of the more lightly chlorinated species
coupled with enhanced fixation of the higher chlorinated species.
A partial listing of the measured solubility in water of
identified authentic chlorobiphenyls is shown in Table 1.3.2-4 (Hutzinger, ibid)
and the effect of the solubility differences of the individual chlorobiphenyls
on the constitution of Aroclor 1254 solutions is illustrated in Table 1.3.2-5
(Hutzinger, ibid).
A factor that is most probably of considerable importance in
the admission of such compounds as the PCBs into the environment is a measure of
the partition coefficients between such interface systems as soil-air; soil-water;
lipids-water; and, more generally, water-solid particles. At the present time
there seems to be very little actual data available in direct form, although much
should be possible to infer from the effects of various combinations of stationary
phase and support in gas cnromatography on the retention index. An interesting
and probably significant point of datum has been presented by D. R. Branson of
the Dow Chemical Co., who reports that the distribution of 2,2',5 trichlorobiphenyl
between sludge-water-air was 92%-3%-5%, respectively.
-44-
-------
Table 1.3.2-2
Vaporization Rates of Aroclors
Aroclor
(Surface area: 12.28 cm )
Wt. loss
(g)
Exposure
at 100°C
(hr)
Vaporization
rate
2
(g/cm /hr)
1221
1232
1242
1248
1254
1262
1260
1270 (Deca)
0.5125
0.2572
0.0995
0.0448
0.0156
0.0039
0.0026
0.0015
24
24
24
24
24
24
24
24
0.00174
0.000874
0.000338
0.000152
0.000053
0.000013
0.000009
0.000005
-45-
-------
Table 1.3.2-3
Percent Loss in Area of Seven Chromatogram
Peaks of Aroclor After Heating
% Peak Remaining After Heating
with water without water
Aroclor 1254 peak 25 min 60 min 10 mm
1 34 17 13
2 59 26 15
3 78 27 20
4 60 46 20
5 86 49 27
6 100 85 28
7 100 67 16
-46-
-------
Table 1.3.2-4
Solubility of Chlorobiphenyls in Water
Compound Solubility rog/1 (ppm)
Monochlorobiphenyls
2- 5.9
3- 3.5
4- 1.19
Dichlorobiphenyls
2,4- 1.40
2,2'- 1.50
2,4'- 1.88
4,4'- 0.08
Trichlorobiphenyls
2,4,4'- 0.085
2',3,4- 0.078
Tetrachlorobiphenyls
2,2',5,5'- 0.046
2,2',3,3'- 0.034
2,2',3,5'- 0.170
2,2',4,4'- 0.068
2,3',4,4'- 0.058
2,3',4',5- 0.041
3,3',4,4'- 0.175
Pentachlorobiphenyls
2,2',3,4,5'- 0.022
2,2',4,5,5'- 0.031
Hexachlorobiphenyl
2,2',4,4',5,5'- 0.0088
Octachlorobiphenyl
2,2',3,3',4,4',5,5'- 0.0070
Decachlorobiphenyl 0.015
4,4'-Dichlorobiphenyl
4Tween 80 0.1% 5.9
-HTween 80 1% >10.0
+Humic acid extract 0.07
-47-
-------
Table 1.3.2-5
Relative Peak Heights (Peak 5 = 100) in Saturated
Aqueous Solutions of Aroclor 1254
Peak No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Saturated aqueous
solution (26°C)
172
91
47
14
100
33
57
5
21
8
4
11
6
Saturated aqueous
solution (4°C)
144
72
41
9
100
28
59
5
24
13
4
24
10
Aroclor 1254 standard
35
16
30
1
100
23
55
10
25
31
6
50
11
-48-
-------
1.4 Chemical Properties of the Chlorobiphenyls
Considerable detail on the most important chemical reactions that are
known to occur with the chlorobiphenyls is presented in Chapter 5 of the treatise
on "The Chemistry of the PCB" by Hutzinger, et al. Suffice it to say here that
oxidation and hydrolysis can be carried out, but only under conditions which are
considerably more rigorous than would be obtained in industrial applications. This
relative stability is, of course, one of the most attractive features of these
compounds in technological practice.
The class of reactions to which the chlorobiphenyls are susceptible
and which is of most interest in terms of their possible toxicological significance
are those which result in cyclization. Of particular interest in this context is
2,2' dichlorobiphenyl, which on cyclization yields the compound dichlorodibenzofuran.
The toxicological data on these two compounds indicates the nature of this change:
the LD for oral doses to rats is of the order of 250 mg/kg for the dibenzofuran
whereas the corresponding toxicity for the chlorobiphenyl is in excess of 4000
mgAg- (Data from the "Toxic Substances List", HEW, 1973).
The close proximity of the 2 and 21 substituents on the biphenyl
molecule facilitates intermolecular cyclization reactions under a variety of con-
ditions. Of special interest is the observation that alkali fusion of 2-chloro-
2'-hydroxybiphenyl and the dehydration of 2,2'-dihydroxychlorobiphenyl yield the
corresponding chlorodibenzofurans; hydroxylation of the chlorobiphenyls is the
common initial step in the metabolism of these compounds. The immediate biological
significance of this is unknown at this time since the chlorodibenzofurans have
not been isolated from animal experiments.
1.5 Photochemical Reactions Involving the PCBs
A great deal of effort has been directed to the study of the effects
of ultraviolet (UV) radiation on the chlorobiphenyls since photodestruction is
believed to be a possible major mechanism for the environmental decay of chloro-
hydrocarbon pesticides such as DDT. There has been much speculation as to the role
that UV photodisintegration might play in terms of the chlorinated biphenyls.
The earlier work was carried out using mercury vapor UV sources with the result
-49-
-------
that, because of the significantly harder radiation (mercury source 250 ran, solar
radiation at surface of the earth with an effective cutoff at 290 nm), cross
section and reaction paths are difficult "to extrapolate to environmental situations.
In more recent times, such irradiation studies have been carried out using General
Electric "Black Light" sources which much more nearly approximate the spectral
distribution of solar radiation.
A number of types of effects have been observed including partial
dechlorination and even, in some cases, the formation of very viscous semi-solids
that apparently arise from complex polymerizations. Again, the extension of the
experimental results to environmental conditions is somewhat limited in value
since the majority of the irradiation studies have been carried out in solvents
other than water. The very low solubility of even the least chlorinated chloro-
biphenyls in water makes the experimental study of aqueous solutions especially
difficult, particularly when the information of concern is the quantitative
evaluation of the reaction products that are formed. It must be said, at this time,
that the probability of UV disassociation being a major source for the environ-
mental decay of the chlorobiphenyls seems to be significantly less than that for
the chlorinated hydrocarbon pesticides.
Since it is assumed that a major portion of the chlorinated biphenyls
are transported and distributed throughout the world through the medium of ad-
sorption on dust particles or as a vapor, it follows that studies of the stability
of thin sorbed films or of vapors of the chlorinated biphenyls against long term
UV irradiation are of importance. The earlier attempts to discover the presence
of reaction products resulting from long term exposure of selected chlorobiphenyls
to solar radiation were subject to the differential evaporation of the less chlor-
inated species; this result seriously biased the observations. The recent experi-
ments that have been conducted within quartz containers seem to obviate evaporation
problems and, further, seem to indicate that the mono- and dichlorobiphenyls are
essentially completely destroyed when exposed to hard UV for times of the order of
weeks or months. Problems of detection sensitivity continue to plague attempts to
elucidate the detailed mechanisms and pathways.
-50-
-------
Studies of thin films of chlorobiphenyls sorbed onto appropriate
surfaces have also been carried out within a quartz enclosure. To date, the
major objection to such experiments, in terms of extrapolation to environmental
conditions, seems to be that the concentration, or rather the absolute density
of the surface layer, is sufficiently high that the activated species remain in
contact for sufficiently long times as to allow the formation of products that
might well be very rare events in corresponding environmental concentrations.
At this time there appears to be significant research being directed
to the determination of the stability of chlorobiphenyls against ultraviolet
radiation and that it is to be expected that the situation which obtains in
typical environmental conditions will be greatly illuminated in the near future.
1.6 Metabolic Chemistry of the Chlorobiphenyls
The very combination of physical and chemical properties that have
made the chlorobiphenyls and their technical mixtures of such wide technical
interest also result in these compounds being of significance as environmental
pollutants, especially in terms of their impact on the biota. The very low
chemical activity, coupled with high lipid-water partition coefficients, ap-
parently contribute to the bioaccumulation whereby the chlorobiphenyls,
pecially the more highly chlorinated species, tend to become fixed within the
body fats and particularly in higher members of the food chain. There is evidence
that this fixed load of refractory chlorinated organic materials, or the circulating
levels of the same compounds that must accompany such fixed loads, represents a
serious hazard to the bearer or progeny. The toxic consequences of body burdens
of chlorobiphenyls is more fully discussed in the section of this report concerned
with toxicology of the chlorobiphenyls.
The mechanisms by which an organism can deal with ingested refractory
compounds are naturally separated into physical and chemical processes. The
physical processes are primarily associated with the requirements of free energy
across the boundary between differing phases such as a water-lipid boundary, or
a cell wall, etc. Since there does not exist a significant body of partition
coefficient data for various combinations of interfaces, little of a quantita-
tive nature can be stated as to the biological significance of such physical
processes.
-51-
-------
On the other hand, as is pointed out in Section 2.4, hydroxylation
is a rather easily accomplished process for at least the less chlorinated chloro-
biphenyls. Thus, it might be assumed that one should observe the hydroxylated
chlorobiphenyls as intermediate metabolic products in a variety of organisms.
Experimental data is available to indicate that such hydroxylation processes are
indeed exhibited by a wide variety of organisms. The principle species re-
lated differences seem to be in the rate at which such processes are found to
occur — very rapidly in rodents and very slowly in fish. In addition, once
the target chlorobiphenyl has been hydroxylated to a more or less degree, there
appear to be available a wide variety of species-specific addition processes
which could make use of the hydroxylated molecule. Interestingly, there is to
date no evidence of biologically or metabolically induced cyclization; it thus
appears likely that the chlorodibenzofurans are not biologically formed.
The salient observations to date on the metabolism of chlorobiphenyls
might best be summarized as follows:
a. When the challenge to the animal is a technical
mixture of chlorobiphenyls, there is a preferential
storage of the more highly chlorinated species, with
the result that the homologue spectrum of stored
PCBs often represents a more heavily chlorinated
mixture than the original test mixture.
b. There is conflicting and often species-dependent
data as to the mechanism by which the less chlori-
nated species are differentiated; whether the pro-
cesses involve metabolism, physical partitioning,
or some combination of such processes has not been
settled.
-52-
-------
c. Conflicting and confusing evidence exists indicating
marked differences in accumulation and differentiation
between specific isomers especially at the middle levels
of chlorination. These differences also seem to be
species-dependent in a number of cases.
d. There is significant evidence that PCB metabolism
proceeds through an intermediate step of hydroxylation
(often this appears to be the terminal step whereby
the increased aqueous solubility of the hydroxylated
species accomplishes the end of its removal).
e. There are several observations indicating that iso-
merization can be accomplished during metabolic
reactions. In this context, the results of Bagley
and Cromartie (Bagley, G.E. and E. Cromartie,
J. Chrom. 75, 219-226, (1973)), with the elinunation
of Aroclor 1254 in the Bobwhite, are most pertinent.
In conclusion, there has been much work directed to the study of the
mechanisms whereby living organisms are able to eliminate chlorinated biphenyls
from their system. In spite of this effort and because of the inherent com-
plexity of this subject, the nature of these mechanisms remains a mystery.
-53-
-------
SECTION V
INDUSTRIAL CHARACTERIZATIONS
1.0 INTRODUCTION
This section discusses polychlorinated biphenyls (PCBs) production and
each PCBs user (capacitor, transformer, investment casting, paper recycling
and miscellaneous) manufacturing process. When known, for each operation
the following information is given:
Name and the location of companies in each category;
. A description of the processes at the facilities studied
and pertinent flow diagrams, where appropriate;
. Raw waste load data per ton of PCB used and sources of
these wastes;
. Water usage data in terms of gallons per day;
Treatment and housekeeping measures practiced at the
facilities and on-going PCB containment programs;
. Plant waste effluents found and their composition.
2.0 MANUFACTURING PROCESS - PQLYCHDORINATED BIPHENYLS {PCBs)
2.1 Process Description
Monsanto, the sole domestic manufacturer of PCBs, manufactures
this chemical in their Sauget, Illinois plant. The basic raw material is
biphenyl which is manufactured from pure benzene in another Monsanto plant.
The PCB manufacturing operation is conducted in two steps. First, biphenyl
is chlorinated with anhydrous chlorine in the presence of ferric chloride to
produce crude PCBs and then the crude PCBs are distilled to obtain the finished
product. A schematic flow diagram of this process is given in Figure 2.1-1A
and B.
-54-
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I
en
Ln
FIGURE 2.1-1A. PREPARATION OF CRUDE CHLORINATED BIPHENYLS-MONSANTO KRUMMRICH PLANT
I VENT
BIPHENYL
F«CI3
jAIR
1 AIR
COOLER
hp
BATCH ARC*
CHLORINATOR a f
G/
I 'PIMP *
PCB HCI TO „
1 1 PURIFICATION IAIR ^
0 .. DEMISTER |
___I*'R
RUBBER ALKALI
1 1 1 IAIR L— Hz° i
CRUDE
CLOR or BURR™ AROCLOR BLOWER
-------
The reaction section consists of 6 reactors (3 batch and 3 cascade).
Currently, Monsanto manufactures four different types of Aroclors (1242, 1016,
1254 and 1221). For the manufacture of any given product, the chlorinator is
charged with proper quantities of biphenyl and catalyst and heated above the
melting point of biphenyl. The flow of vaporized chlorine is then started and
the charge is circulated with a pump. Throughout the chlorination, the tempera-
ture is kept above the melting point of the mixture, but below 150°C to avoid
excessive sublimation and plugging of the line discharging the hydrogen chlorine
produced by the chlorination. The reaction pressure is maintained near atmos-
pheric. The degree of chlorination is principally determined by the time of
contact with anhydrous chlorine. The contact time varies from 12 to 36 hours
for the manufacture of different Aroclor types. The degree of chlorination
is measured by the specific gravity of the mixture or the ball and ring soften-
ing point when the product is viscous.
The vapors from the chlorinator (HC1 containing PCBs) are scrubbed
with liquid Aroclor and the gaseous HC1 is sent to another plant at the Sauget
complex for purification. The crude product is held at an elevated temperature
and blown with dry air for several hours, after which it is sent to the raw
Aroclor storage tank where a few tenths of 1 percent of alkali are stirred with
the material to react with any remaining hydrogen chloride or ferric chloride.
The air from the blower tank is scrubbed with water and vented to the atmosphere
through a demister.
The raw Aroclor is subsequently batch distilled under reduced pres-
sure to remove the color, and the traces of hydrogen chloride and ferric chloride.
The methods of purification are different for the different types of end pro-
ducts. Raw Aroclor 1254, 1242 and 1221, each are distilled in stills under re-
duced pressure, achieved via steam jet ejectors; the condensate from the still
is the finished product while the bottoms are the Montars which are drummed and
sent to incineration.
The distillation section for the 1016 product consists of a gas fired
retort and a vacuum distillation tower. The latter is used to allow the separa-
tion of the higher chlorinated, less biodegradable compounds from the relatively
-56-
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lower chlorinated and more biodegradable ones. The raw Aroclor (42% chlori-
nated material) is fed into the reboiler. The vacuum in the tower is maintained
at about 100 mm Hg by steam jet ejectors. The steam is partially condensed and
the condensate is discharged into the plant discharge sump. The first cut from
this tower is recycled back to the retort. At a preset overhead temperature
the 1016 product is collected and sent to the product storage. The high boiling
residue from the tower is sent to a subsequent chlorination cycle and the re-
sulting raw Aroclor is distilled in a still. The overhead from this still is
the finished product. The bottoms from this tower are the Montars. The spent
ferric chloride catalyst, used in PCB manufacturing, is sent to incineration
with IVbntar residues.
For special orders, in order to increase electrical resistivity,
the Aroclors are stirred at an elevated temperature with a few tenths of 1%
of well-dried fuller's earth and then filtered through paper.
All Aroclors are stored at 150°F. Steam coils are used on the
storage tanks for heating these tanks.
2.2 Raw Wastes
The raw wastes from the manufacturing area consist of the liquor
from the scrubber, the condensate from the steam jet ejectors, water used for
showers and eye baths, miscellaneous floor wash downs, waste oil collected in
drip pans and drums, and montars which are the bottom cut from their stills.
The composition and the quantities of the individual waste stream are not moni-
tored. All effluent streams generated in the manufacturing area are directed
into the sumps in this area. The waste oil collected in the drip pans and the
Montars are emptied into 55 gallon drums and sent to incineration.
The raw wastes generated in the incinerator consist of the venturi
scrubber liquor and the water phase from the separator sump in the incinerator
area. The composition of the combined stream is monitored. However, the com-
position of the individual streams is not known. Non-product PCB discharges
are shown in Figure 2.2-1. It has been estimated that this plant generates
-57-
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FIGURE 2.2-1. NON-PRODUCT PCS DISCHARGES AT MONSANTO'S KRUMMRICH PLANT
VAPOR FROM JET EJECTORS
EXHAUSTS FROM THE SCRUBBER
SURFACE AREA EVAPORATION (IN GENERAL)
AIR
CONDENSATE FROM STEAM EJECTORS
NON-CONTACT COOLING WATER
SCRUBBER LIQUOR
TO
SEWERS
MONTARS
BOTTOMS FROM SEPARATOR SUMP
COLLECTION FROM ALL DRIP PANS
INCINERATION
RAGS FOR CLEANING
FLOOR DRY
SPENT FILTER PAPERS
FULLERS EARTH
a
LANDFILL
-58-
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about 25 Ibs of scrap oil and Nontax per ton of PCB produced. Additionally,
the quantities of material sent to landfill approximates to 5.4 Ibs per ton of
PCB produced. Further, Monsanto reports that the plant's PCB contribution to
the air is under 1 Ib/day.
2.3 Plant Water Usage
On the average, the PCB plant uses a maximum of 388,800 gallons
of water and a maximum of 360,000 Ibs of steam daily. Water is used for non-
contact cooling purposes in shell and tube condensers, in a water scrubber, for
floor washings, for showers and in eye baths. Steam is used in the steam jet
ejectors and for steam tracing purposes. The plant uses municipal water and
purchased steam.
The process water from this facility consists of the liquor from
their scrubber and the steam condensates which are discharged in one of the
two sumps in the manufacturing area.
Additionally, 273,600 gallons of water are used in the incinerator
daily for quenching the hot gases from the fire box. The resulting weak muria-
tic acid in the quench pot is used in the venturi scrubber and in the packed
tower.
The type and quantities of water used and discharged at this plant
are summarized below:
Water Balance
Manufacturing Plant
Process Water
in water scrubber
misc. floor wash downs
condensate from steam jet ejectors
Quantities, GPD
Used
14,400
7,200
—
Discharged
14,400
7,200
14,400
-59-
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Water Balance (Can't)
. Manufacturing Plant
Quantities, GPD
Used Discharged
Non contact cooling water 360,000 360,000
showers, eye bath 7,200 7,200
condensate from steam tracers — 28,800
Total 388,800 432,000
. Incinerator
water used for hot gas quenching 273,600 273,600
water phase from the sump ___!!_ 14,400
Total 273,600 288,000
2.4 Wastewater Treatment and Housekeeping
Monsanto reports significant environmental controls at their
Krummrich, Sauget plant. Since 1969, they have invested more than 22 man-years
of work and millions of dollars in this program. The in-house goals have re-
duced the PCB discharges into water to about three pounds per day.
A John Zink designed incinerator was erected at Sauget in 1970 to
safely dispose of PCBs. A schematic flow diagram of this operation is given
in Figure 2.4-1. Aroclor is steam atomized and fed into the fire box. Natural
gas is used for combustion and the feed is incinerated at temperature above
2200°F at 5 percent excess oxygen with a retention time of 2-3 seconds. The
gases are quenched with water and the exhausts from the quench pot are passed
through a high-energy venturi scrubber, then through a packed column which is
irrigated by the weak muriatic acid originating from the quench pot. Exhausts
are then vented to atmosphere through a demister. These exhausts as well as
the effluent from the incinerator section are monitored.
In the incineration area, drainage is directed to trenches and
piping which flow into a 10,000 gallon underground concrete basin. The water
-60-
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FIGURE 2.4-1. PROCESS FLOW DIAGRAM OF THE JOHN 2JNK INCINERATOR
AT MONSANTO'S KRUMMRICH PLANT
rLIQUID WASTE STREAM
NATURAL
GAS —
AIR
STEAM
VENT
HgO PHASE
FROM THE
SUMPn
TO THE SAUGET
SEWER SYSTEM
-------
layer from, this basin is pumped continuously, combined with the scrubber liquor,
metered, monitored and discharged into the sanitary sewers of the Sauget com-
plex and from there it is sent to the East St. Louis municipal sewers. The
organic phase from the sump is periodically pumped into waste storage tanks for
incineration.
The incineration unit has a rated design capacity of 10 million
pounds per year. However, since the start of its operation this unit has
achieved a service factor of about 0.60. Monsanto reports that this incinerator
can achieve a maximum of 6 million pounds of capacity annually; the unit is
plagued with various mechanical problems.
Monsanto uses their incinerator to process both their own wastes
and as a service to other industries. The service charge for incineration is
an average of 5C per Ib of material, but the cost appears to be increasing.
The incinerator feed is brought into the plant either by truck in
55 gallon sealed drums, by tank trucks or by rail. The drums are opened,
picked up by a fork lift and emptied into a concrete pit. The tank truck
carrying the waste liquids enters the incinerator area and the liquid waste is
then pumped from the truck into the pit. The material in this pit is periodi-
cally pumped via a vertical certrifugal pump into one of the four 20,000 gallon
incinerator waste feed tanks.
The rail car is brought into a designated area close to the incinera-
tor site. The material from the rail car is normally pumped into a long term,
500,000 gallon storage tank. The material from this tank is pumped into the
incinerator feed tanks located on the incinerator pad when required.
Drainage is provided along the rail tracks. These drains empty
into the 10,000 gallon sump located under the incinerator pad.
In the manufacturing area, Monsanto has taken a number of significant
steps to prevent loss of PCBs to the environment. Drainage is directed to
trenches and piping, and then to one of two concrete 3,000-gallon underground
settling basins. This insures PCB containment in case of accidental spill or
-62-
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equipment failure. Relief valve lines and atmospheric vents are routed through
catch tanks, or are redirected to settling basins.
When small quantities of PCBs are collected in the settling basins
of the manufacturing area they are later pumped into 55 gallon drums, and
eventually incinerated. The overflow from these sumps is combined with the non-
contact cooling water used at the plant, monitored and then discharged into the
Sauget complex's sanitary sewer and from there to the East St. Louis municipal
system.
PCBs are packed and shipped in galvanized-steel 55 gallon drums,
or in railroad tank cars. All tank cars are top loaded. In the drum filling
area spills are cleaned via rags or floor dry and these materials are drummed
and sent to landfill located in the town of Sauget.
In the PCB truck or rail car loading area, drainage is directed
into a small concrete pit. The material accumulated in this pit is periodically
pumped into the basins located in the manufacturing area.
Nitrogen blanketing is provided on storage tanks to eliminate any
"breathing" of the tanks and resultant PCB escape.
Mist eliminators have been installed in vapor lines to eliminate
the possibility of PCBs leaving the manufacturing area through these lines.
Finally, underground sewers have been replaced with above-ground
sewers, and repaired or combined with others, so that the effluent from the
department can be monitored. In addition, this step will prevent any unknown
buildup of PCBs in the sewer systems or any contamination of PCBs into other
sewers.
A high housekeeping level is maintained in the plant itself.
Housekeeping responsibilities which the operators have assumed are as follows:
pumps are checked for leakage on every shift.
Drip pans that collect leaks are emptied into
scrap PCB drums.
-63-
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. All leaks are reported and documented so that
corrections can be made and settling basins
observed.
. "Floor Dry" is used to absorb any PCBs that
have spilled or leaked. If it becomes necessary
to flush PCBs to the settling basin, a minimum
amount of water is used.
. Sampling drums and scrap PCB drums are quickly
palletized, labelled and transferred to the in-
cineration area.
2.4.1 Treatment Facility for the Effluent from Sauget Complex
The processing and incineration departments' aqueous effluent
enters the plant sewer system, and this system discharges into the Sauget Village
waste sewer system. The combined streams then flow to the village primary treat-
ment plant. The village treatment plant is under expansion to a secondary
chemical treatment plant, scheduled for 1976 completion.
Additionally, evaluations are being conducted to include the
village plant discharge in a projected regional biological treatment plant.
2.5 Plant Effluents
This plant has no point source discharge from their operation.
There is a single discharge from the manufacturing operation (the combined
stream of process and non-contact cooling water) to the main sewer system of the
Sauget complex and there is a second discharge from the incinerator area to the
same sewer system. The composition of these streams as reported by Monsanto are
as follows:
Effluent from the Effluent from the
Manufacturing Incineration
Operation area
flow rate, gpd 432,000 288,000
PCBs, ppm 0.75 0.15
PCBs, Ibs/day 2.70 0.36
-64-
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It has been reported that these effluents are clear liquids with
essentially no suspended solids. The incinerator effluent may contain sate
amounts of chloride. However, no information is available on the chloride
content.
3.0 PCB USER INDUSTRIES
3.1 Askarel Capacitor Manufacturing Industry
Presently 90-95 percent of all impregnated capacitors manufactured
in the U.S. are of the PCB type. Two important types of capacitors are phase
correctors on power lines and ballast capacitors for fluorescent lighting.
Aroclor 1016 is the principal PCB used in this application; at some plants
Aroclor 1242 and 1221 are also being used in limited quantities. The principal
types of Aroclor impregnated capacitors and their applications are given below.
A. High Voltage Power
Generally AC capacitors are used to improve the power factor of a circuit.
Power factor is the ratio of true power in watts to the apparent power as ob-
tained by multiplying the current flowing to the load by the circuit voltage.
The power factor correction can be made directly at the load or at utility sub-
stations. In the latter case high voltage units will be designed for 4,800 to
13,800 volt service. To the utility engineer the use of capacitors is purely a
matter of economics. The main benefits that result from the use of capacitors are:
1. Reduction of losses associated with the delivery of electrical
power to the point of use.
2. Reduction of the investment required in equipment for delivering
electrical power to the point of use, which may be broken down
into:
a. Reduction of line current for the same kilowatt load.
b. Reduction of the kva rating of equipment required to
handle the same kilowatt load.
-65-
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c. Induction of the transmission line voltage drop for
a given kilowatt load.
d. Control of delivered voltage if the capacitor kva is varied.
Electric utilities also use capacitor banks in series with distribution
circuits to improve voltage regulation.
B. Low Voltage Power
Capacitors installed in industrial plants at the demand site (typically
large motors and welders) are designed for 230 to 575-volt service. Capacitors
installed near the loads are the most efficient way to supply the magnetizing
current to produce the flux necessary for the operation of inductive devices.
Rates for the sale of power are generally structured to encourage power factor
correction at the site, eliminating the need for the electric utility to trans-
mit both power-producing current and magnetizing current all the way from the
generator to the plant site.
The same considerations apply to induction heating applications, the
principal difference being that capacitors for this application are designed for
operation at 960 to 9600 Hz'.
C. Lighting
Capacitors improve the efficiency of lighting systems. A fluorescent or
mercury vapor lamp can be ballasted without the use of a capacitor, but the power
factor of the lighting system would then be in the range of 50 to 60%. For commer-
cial or industrial lighting with either fluorescent or high intensity discharge
lamps, the use of a capacitor in the circuit provides part of the lamp ballasting
and brings system power factor into the range of 90 to 95%.
D. Air Conditioning
As in the lighting applications, the capacitor improves system efficiency.
Air conditioners could be made to operate without capacitors, as do home re-
frigerators, but because of the higher capacity required for air conditioners,
-66-
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the resultant line current would virtually eliminate home "plug-ins" and would
still further overburden a seriously threatened national power network. Almost
all air conditioner pump motors are of the split-winding type on which the
capacitor provides phase differential for the so-called start winding, thus
delivering good starting torque. The proper size capacitor permits high (90%)
power factor after start-up.
E. Industrial Electronics
This market category is a catchall covering many varied applications, two
important ones being motor run and power supply applications. Motor run appli-
cations are for pumps, fans, and farm feed equipment, and do not differ signifi-
cantly from air conditioning applications. The power supply market uses capacitors
principally to provide high power factor, but through careful design the capacitor
can also provide wave shaping where desired.
3.1.1 Askarel Capacitor Manufacturing Plants
There are seventeen companies in the U.S. which manufacture
askarel capacitors at nineteen plants. The name and the location of these plants
are given in Table 3.1.1-1. Some plants manufacture industrial capacitors only
and others manufacture power capacitors.
Ten major companies were contacted. Detailed information was
obtained on six plants. Four plants were visited. The data herein represents
approximately 50 percent of 1974 PCB usage in capacitor application. The PCB
usage in this category was approximately 22,000,000 Ibs. in 1974. The PCB usage
in individual plants is considered by these companies to be confidential infor-
mation. The range of PCB usage at these plants was 64,000 fold in 1974. Plant
ages range from five to thirty-seven years.
Capacitors used in lighting and air conditioning applications
contain 0.05 to 1.0 Ibs. of Aroclor. The largest power capacitors contain about
77 Ibs. of Aroclor. The most popular size contains 36 Ibs. A sketch of a
medium size industrial capacitor is shnwn in Piour^ 3.1.1—1. Capacitors are not
rebuilt and returned to service after failure. They are disposed of and replaced
by new units. G.E. reports that high voltage utility capacitors, low voltage
-67-
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FIGURE 3.1.1-1. MEDIUM SIZE
INDUSTRIAL CAPACITOR
-68-
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Table 3.1.1-1
U.S. Capacitor Manufacturing Industry Using PCBs
Company Nane
(In order of PCBs Usage)
General Electric Company
Westinghouse Electric Corp.
Aerovox
Universal Manufacturing Corp.
Cornell Dubilier
P.R. Mallory & Co., Inc.
Sangamo Electric Co.
Sprague Electric Co.
Electric Utility Co.
Capacitor Specialists Inc.
JARD Corp.
York Electronics
McGraw-Edison
RF Interonics
Axel Electronic, Inc.
Tobe Deutschrnann Labs.
Cine-Chrome Lab, Inc.
Location of the Plant
Hvdson Falls, N.Y.
Ft. Edward, N.Y.
Blocmington, Ind.
New Bedford, Mass.
Bridgeport, Conn.
Totowa, N.J.
New Bedford, Mass.
Waynesboro, Term.
Pickens, S.Carolina
North Adams, Mass.
LaSalle, 111.
Escondido, Calif.
Bennington, Vt.
Brooklyn, N.Y.
Greenwood, S. Carolina
Bayshore, L.I., N.Y.
Jamaica, N.Y.
Canton, Mass.
Palo Alto, Calif.
-69-
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power capacitors, and induction heating capacitors are manufactured at a rate of
200,000 per year, about 2 to 3% of which are replacements; the balance are for
new installations. The current market for capacitors used in lighting appli-
cations is about 44,000,000 units annually of which 10% are estimated to be
replacement ballasts. The current market for capacitors in air conditioning
application is above 12,000,000 units annually, with 5% of these estimated to
be for replacement usage. The market for capacitors in industrial electronics
applications is estimated at 23,000,000 units per year with no estimate as to
the relative size of the replacement market.
3.1.1.1 Askarel Handling
In most plants PCBs are shipped via tank car to a
rail siding several miles from the plant. Individual plants provide a de-
signated tank truck for the transfer of the PCBs from the rail yard to the manu-
facturing plant. To large plants, PCBs are brought via rail cars into the plant
site.
In most plants PCBs are unloaded and transferred to
the PCB storage tank without the benefits of any curbs or dikes. At a very few
plants, the unloading operation of the PCBs from the tank car to the storage
facility is confined and the receiving area is roofed and diked.
PCBs from the raw storage PCB tanks are filtered
through fuller's earth and stored in finished product storage tanks. PCBs are
next pumped from the storage tanks to the impregantion areas for use. Excess
PCBs from these areas are recycled back to a designated tank and from there either
filtered and reused or, if defective, are pumped into the scrap storage tank.
Spent fuller's earth employed at these plants is
either drummed and stored at the plant site or is sent to a landfill.
-70-
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3.1.1.2 Process Description
Most plants in this category manufacture either large
power capacitors or small (including less than 2 Ibs. of PCBs) industrial type
units. The large capacitors are either flood filled or manifold filled. All
small capacitors are flood filled either in a vacuum tank or in an automatic
"carousel" arrangement where loading and unloading occurs at one station, and
the capacitors in each cell are progressively dried, evacuated and filled.
A generalized schematic flow diagram for the manu-
facture of large capacitors and small industrial capacitors are given in Figures
3,1.1.2-1 and 3.1.1.2-2, respectively. The basic manufacturing operation at these
plants can be divided into two major operations.
a) Non PCB related operations consist of the following steps:
. Fabrication of capacitor cans, covers and brackets from
sheet aluminum or steel. Smaller plants, however, purchase
capacitor casings, capacitor terminals, connectors and foil.
. Vapor degreasing or detergent washing of metal components.
At some plants, ultrasonic cleaning is used to clean smaller
components.
. Roll winding the capacitor paper or polypropylene film with
aluminum foil.
. Complete assembly of capacitor components and sealing the
covers. In some units fill holes are provided for PCB intro-
duction; in others PCBs are introduced through bushings or
a valve.
. Leak testing via mass spectrometer and pressure testing prior to
vacuum drying.
b) PCB related operations
Three completely different impregnating techniques are employed
by this industry.
-71-
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TRICHLORO.
RECOVERING
SLUDGE WASTE
IHjO
V
SHEET ALUMINUM —
PAPER a FOIL
DIELECTRIC
PCB FROM ,
RAIL CAR
MANIFC
FILLED
:B SPILLS
OF
CAN, COVERS
8 BRACKETS
WINDING OR
"~ ROLLING
1 u _
\H& -
— •- DETERGENT WASHING OR ' i »
ULTRASONIC CLEANING
KO
RECYCLED PCBt TO FILTRATION
1
FILTERED PCBt
{SCRAP
1 PCB»
TRICHLORO.
RECOVERING
FLOOD I
FILLED HEAT SOAKING J
JNITS VAPOR DEGREASI
1 P , < _.. .
{SPENT
1 FULLER'S EARTH
TRICHLORO.
)| RECOVERING
INCH ERATION 1 , 1
HHEAT SOAKING 8 ^ 1 VAPOR
ELECTRIC TESTING )i 1 DECREASING
CAPACITOR
ASSEMBLY,
WELDING,
8 TESTING
IHjO DISCHARGE FROM
WELDING
ASSEMBLED
CAPACITORS
VACUUM
IMPREGNATION,
FLOOD FILLING,
OR
MANIFOLD
FILLING
HzC
PCB SPILLS a
CONTAMINATED
PUMP OIL TO
SUMPS OR PANS
CAUSTIC
1
H PAINTING
DRYINC
^CAPACITORS
WASTE
RFJFCTPD ^.n. «.^ — ~
a
>
I
H,0 SPENT
BATH
UNITS SPOT CLEANING 1 CAPACITORS ~*' ^J.',01*
r WITH TRICHLORO. | " OPERATION -,
1 1
CAPACITOR TO
PACKAGING a
SHIPPING
CAUSTIC
1
SCRAP PCB
DRIPS INTO
PANS
CAPACITOR INTERIORS TO SOLID WASTE
CASINGS TO VAPOR DECREASING
Figure 3.1.1.2-1
GENERALIZED FLOW DIAGRAM FOR THE MANUFACTURING OF LARGE CAPACITORS
-------
CANS
CAUSTIC
RINSE
H20
ALUMINUM_ _ ! FABRICATION OF 1 COVERS a
INGOTS — : TAMt! A m\/FB<5 !<:Tlin<:
TRICHLORO.
RECOVERING
VAPOR DECREASING
CANS 6 COVERS [STUDS
I -i r- [_ I'*"
I SANS I L__"^|DETERGENT WASHING)
" I UJACTT U.rt f
CAUSTIC, *
BATCH DISCHARGED
WASTE H20
I WASTE
HjO
POLYPROPYLENE FILM
PAPER B FOIL DIELECTRIC
i"
i
i
RECYCLED PCB TO FILTRATION
ASSEMBLED UNlfsl
I
OVEN
PCB FROM RAIL CAR
I
--J
CO
-\ PCB STORAGE 8 FILTRATION SECTION t
I •• • f .-.-.!..— . .11 .—.I - -I .1 I lei
T
SPENT
FULLER'S
EARTH
T
r
I |HjO USED IN
I (NASH PUMP
I i j STEAM USED IN
L _I_ J_ -.JET EJECTORS
VACUUM
IMPREGNATION,!
CAROUSEL I
FLOOD FILL
'1
SCRAP
PCBs
PCB SPILLS a
CONTAMINATED PUMP
OIL TO SUMP OR PANS
I FLOOD FILL
1"TT
PCB SPILLS j
TO SUMP •
WASTE
OR FLOOR 1
H20
t
CRIMPING DETERGENT
SEALING j DRYING
! WASTE H,0
J BATCH DISCHARGE
l-*-| VAPOR DEGREASIN
i i
1
1
1
1
1 DC
— RE
QJ
HEAT S
ELECTRIC
TESTING
SOLID WASTE,
JECTED CAPACITORS
FLU
L,
_
H20
}
PHOSPHATE OR
FLUORIDE TREAT
1 1
SPENT WASTE
DRIDE BATH H20
OPEN TOP
VAPOR DECREASING
~f
1
1
1
HZO
J
WASTE
HaO
CAPACITORS TO
PACKAGING 8
SHIPPING
TRICHLDRO.
RECOVERING
SLUDGE WASTE
NOTE- (I) DOTTED LINES DENOTE ALTERNATIVE OPERATIONS
Figure 3.1.1.2-2
GENERALIZED FLOW DIAGRAM FOR THE MANUFACTURING OF SMALL CAPACITORS
-------
(1) Conventional flood filling of capacitors
This type of filling operation is used for impregnating large
power and small industrial capacitors. Here the capacitors are
?
arranged in baskets or in large tanks which are subsequently
transferred into vacuum chambers. Vacuum is then drawn and the
capacitors are kept under vacuum at an elevated temperature for
a specific period of time in order to evaporate the moisture from
the capacitor interiors. The temperature of the tank is next
lowered and PCBs are introduced under vacuum. The capacitors are
allowed to soak for some time after which they are transferred to
the sealing or crimping station via mobile car, sealed, and excess
PCBs are then drained. The sealed capacitors are next sent to
vapor degreasing or detergent washing for cleaning the exterior
of these units. The clean units are heat soaked and heat tested
in an oven and then sent to 100% electrical testing.
Subsequent to electric testing, the capacitors with steel casings
are pretreated prior to painting. The pretreatment is either vapor
degreasing for painting in an electro-static field or it is
several stages of phosphatizing and rinsing operations, prior to
automatic spray painting, where water is used to scrub the vapors
generated during painting. Most capacitors with aluminum casings
are marketed unpainted. However, at some plants a portion of capac-
itors with aluminum casings are fluoride treated and then spray
painted. The capacitors are next either air dried or dried in an
infrared oven prior to packaging and shipping.
(2) Automatic Flood Filling Operation (Carousel)
In this method of capacitor impregnation, the assembled units are
placed in ovens for the removal of moisture from the capacitor
interiors. The baskets containing these capacitors are next trans-
ferred to the carousel chamber which is at the loading position.
The carousel passes through 13 subsequent cycles consisting of
-74-
-------
various degrees of vacuum applications and then subsequent PCB
filling and soaking positions. The PCBs are next drained out
of the chamber, and the capacitor baskets are removed from the
vacuum chamber and tilted to drain excess PCBs into a sump located
adjacent to the carousel loading and unloading station. The capac-
itors are next transferred to the crimping or sealing stations.
From this point on the remainder of the manufacturing steps are
identical to those employed in conventional flood filling operation.
In general, vacuum in conventional flood filling operations is
achieved via mechanical pumps, whereas vacuum in each automatic
flood filling station is achieved via a vacuum pump and several
stages of steam jet ejectors.
Rejected industrial capacitors are disposed of in 55 gallon drums
either directly or after disecting. Rejected power capacitors
which are flood filled are returned to the salvaging operation.
Here the capacitor covers are cut on an end mill, the PCBs drained
and the interiors examined to find the cause of the electrical
failure. Where possible the rejected units are then repaired and
reprocessed. Otherwise, the capacitor interior is discarded in a
designated solid waste drum. The capacitor casing is sent to vapor
degreasing and it is subsequently sold to a scrap dealer.
(3) Manifold Filling Operation
At some plants, large capacitors are filled by this method. Here,
the capacitors are completely assembled, sealed and vacuum tested;
then each unit is filled individually under vacuum through a mani-
fold. The capacitor valve is next sealed, the exteriors spot cleaned
with trichloroethylene and then these units are transferred into an
oven where they are heat soaked for a given period of time prior
to electrical testing. Those capacitors which pass the electrical
tests successfully are vapor degreased, painted, dried, packaged and
shipped. The rejects are returned to the filling station where
-75-
-------
the majority of the PCBs are retrieved through the fill valve
under vacuum. The rejects are next transferred to the salvage
operation.
Mechanical pumps are used throughout the system to achieve
vacuum.
3.1.1.3 Raw Wastes
The raw wastes originating from these plants consist
of scrap PCBs collected in sumps, drums and drip pans, contaminated vacuum pump
oils, the fractionator bottoms from the trichloroethylene recovery, the caustic
bath used, at some plants, for purposes of paint stripping, spent detergent wash
and rinse water from capacitor or component cleaning operations, rinse water used
in the welding and plating operations, steam condensate from jet ejectors, the
seal water used in vacuum pumps, water used in phosphatizing and fluoride baths,
water spray used in the paint booths, boiler blow downs and cooling tower blow downs.
Furthermore, in at least one plant in this category,
water infiltrating at a subgrade elevator shaft creates an additional waste stream.
Solid wastes from these plants consists of scrap capac-
itors or capacitor interiors, floor dry and rags and newspapers used for cleaning
spills, spent fuller's earth and other filtering media used for PCBs filtration
and waterless cleaners used at some plants for hand cleaning purposes.
Non-product PCB discharges, their source and disposition
are given in Table 3.1.1.3-1. Adequate data to quantify the various wastes generated
at these plants is not available. Information on waste loads reported by some
plants are given in Table 3.1.1.3-2.
3.1.1.4 Water Use
The water used at these plants is in the range of
12,500 to 1,260,000 gallons per day. In most plants, water is used primarily for
once-through non-contact cooling in vapor degreasers, in pumps and in vacuum tanks.
Plant 101 recycles their non-contact cooling water through a cooling tower.
-76-
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TABLE 3.1.1.3-1. NON-PHDDUCT PCB DISCHAKES
i
•vj
Source
Vacuum pump exhaust
Evaporation 4 ventilation
Vapors from last stage of jet ejectors
Personal hygiene
Laundry water
Water phase from punp oil/vater separator
Sanitary & dorestic water
PCB contaminated vater
Non-contact cooling water
Rainfall & surface runoff
Rinse water from component detergent
washing
Water used in non-PCB electrolytic
capacitor operations
Ground water infiltration
Controlled sink drains'
Rinse water used in the caustic bath
& welding
Water used in paint scrubbing
Phosphatizing bath & rinse
Scrap oil in drip pans, drums & sumps
Spent fuller's earth, clay & filter cart-
ridge
Rinse water from dry-well
Fractionator bottoms (sludge) frcn
trichloro recovery
Spent detergent wash of capacitor
exteriors
Spent fluoride wash
Reject capacitors or capacitor internals
Newspaper, floor dry S rags
Caustic bath
100 101
Air Air
Air Air
None None
Sewer Sewer
None None
Sewer None
Sewer Sewer
River
River Recycled
River Storm sewer
None Dry well
None None
None None
None Sewer
None None
None None
None None
Incineration Incineration
Incineration None
None Incineration
Incineration None
None Landfill
None None
Landfill Landfill
landfill Landfill
tfene None
Plants
102
Air
Air
None
Septic tank
Septic tank
Hone
Septic tank
Treatment plant
then river
Treatment plant
then river
Treatment plant
then river
None
Treatment plant
then river
None
None
None
None
None
Incineration
Incineration
None
Incineration*
None
None
Landfill
Landfill
None
104
Air
Air
None
Incineration*
None
None
Sewer
River
River
River
River2
None
Decant then to
river
River
River
Decant then to
river
None
Incineration
Stored on site
None
Incineration
None
None
Stored on site
Stored on site
Stored on site
105
Air
Air
Air
Incineration1
None
None
Septic tank
leach field
system
River
River
River
None
None
None
River
None
River
River
Incineration
Stored on site
None
Incineration
Incineration
Incineration
Stored on site
Stored on site
None
106
Air
Air
None
Sewer
None
None
Sewer
Sewer
Sewer
Storm Sewer
None
None
None
None
None
None
None
Incineration
Landfill
None
Incineration
None
None
Landfill
Landfill
None
Notes: 'sinks at the impregnation areas are contained; water from the sumps are sent to incineration.
2Rinse water from non-PCB, conponent washing operation.
'anployees are advised to use waterless hand cleaning material prior to washing their hands.
"Only liquids from this operation are sent to incineration. The sludge from this operation is sent
to a municipal landfill.
-------
TABLE 3.1.1.3-2
QUANTITY OF WASTE LOADS
(Ibs/ton of PCB used)
Land Destined Waste
Wastes to Incineration
Spent Fuller's Earth to
Incineration
Notes:
(1)
(2)
(3)
(4)
(5)
100
73
100
4.1
(1)
101
129
56
None
Plants
102
104
105
65
98
(2) (3)
(4)
(4)
109
127
106
_(5)
300
Unknown
Reported as PCBs. We estimate an additional 175 Ibs/ton of PCB con-
taminated solid material which is being landfilled locally.
PCBs are filtered through packed Porocell cylindrical filters. The
filter media has an estimated life cycle of 20 years.
This plant uses clay for PCB filtration. The quantity of spent clay
sent to incineration is not known.
These plants store their solid wastes consisting of spent fuller's
earth, rejected capacitors, rags and floor dry, on site. Plant 104
generates ten 55-gallon drums of waste and plant 105 forty 55-gallon
drums of waste each week.
The weight of materials sent to landfill is not known. However, this
company reports that during 1974 approximately 650 capacitors were
rejected. The rejected units were drained and then sent to a landfill.
-78-
-------
Process water used at various plants consists of water
used in detergent washing, in ultrasonic washing, condensate from the steam jet
ejectors, seal water from the vacuum pumps, water used in phosphatizing and in
fluoride baths and rinses, and water used in caustic treatment and painting opera-
tions. Additionally, water is used for sanitary purposes and in some plants it
is also used as boiler feed.
are given below:
The quantities and types of water used at these plants
Plants
Intake gallons/day
Water Usage in gallons/day
Non-contact cooling
Process water
Rinse water from hot
solder dip
Detergent washing &
rinsing
Phosphatizing baths
Water used in tin plating
Fluoride bath & rinse
Water used in painting
Pump seal water & steam
condensate
Sanitary
Boiler feed make-uo
100
740^000
200
44,9O
40,000
101
12,500
655,000 3,000
8,000
1,500
102 104 105 106
,000,OOO1 1,260,000 480,000 336,500
388,OOO3 1,195,000 387,000 326,500
52,000
25,000^
-
-
-
10,000
30,000
200
400
12,000
50
50
44,000
65,000
15,000
(1) 560,000 gallons/day of this water is used as process rinse water
in non PCB associated, electrolytic capacitor operation
(2) Make-up water
(3) It has been estimated that only 150,000 gallons of this water is
associated with the plants PCE operation. The balance is used in
the manufacture of Mica capacitors
(4) It includes wator used in paint stripping and welding operations.
5,000
5,000
-79-
-------
3.1.1.5 Wastewater Treatment
The major in-plant PCB wastes which reach water
streams originate in the impregnation areas. Due to the nature of water
requirements in this industry, at some plants it is possible to significantly
reduce the quantities of wastes entering the water systems by adoption of
proper housekeeping measures. Since there is no demonstrated technology
available for the terminal treatment of PCBs in wastewaters, there are no PCB
wastewater treatment techniques currently in use at any facility. Details on
wastewater treatment techniques used at various facilities for purposes of oil
recovery or neutralization and on-going containment programs undertaken by
some plants to prevent the entry of PCBs into the environment are given in
Task II report, "Assessment of Wastewater Management, Treatment Technology, and
Associated Cost for Abatement of PCBs Concentrations in Industrial Effluent",
February 3, 1976, pages 46 through 52.
3.1.1.6 Effluent Composition
Effluent from plants in this category range from
2500 to 1,260,000 gallons per day. As indicated in the waste treatment section,
these effluents are sent either into receiving waterways or into municipal sewers
without any PCB treatment. Available information on effluent flow rates and their
PCB contents, for most plants in this category, are given in Table 3.1.1.6-1. More
detailed effluent information were obtained on four plants and Table 3.1.1.6-2
compares the discharges from these plants. Table 3.1.1.6-3 lists PCB concentra-
tion of the plant intake water from various sources.
It is of interest to note that one plant (plant 100)
reported large variations in the PCB content of the receiving waters even at the
time when the plant was not in operation. They attributed the variations to
storm conditions, stirring-up the sediments from the bottom of the river and
greatly increasing the PCB concentration in the water phase.
-80-
-------
TABLE 3.1.1.6-1
RANGE OF FLOW RATES & PCB
CONCENTRATION IN EFFLUENTS
FROM CAPACITOR MAMJFACTURXNG
PLANTS
Effluent
Flow Rate
Plant No. Outfalls g
100
101
102
104
10f>
106
107
108'
109
110
1113
112 3
113
126
Notes:
001
None
001
002
003
Major outfall 1
Cooliny water
& roof drains
Lab & roof
drains
Compressor cooling
water
Paint strip rinse
Major outfall
From spray paint
booths
None
None
Cooling water
& boiler blowdown
Cooling water
Roof runoff
Storm runoff
001
None
None
None
001
None
al/uay
800,000
9,000
807,000
165,000
36,000
,060,000
100,000
32,000
72,000
50
650,000
1,500'
336,500
150,000
48,000
129,000?
2,900
unknown
100,000
2,570
18,000
10,224
12,000
580
Effluent
ppb
avg/max
17/55
161/161
9
3.2
3.4
21
7.8
4.4
3.7
4800
370
13,300
26.6
1900/4000
45/108
338/705
1360/2370
3/]l
57/83
821
8.7
130
14.3
C2003
PCB Content
IDS /day
avg/max
0.1134/0.3670
0.0121/0.0121
0.0605
0.0044
0.0010
0.1856
0.0065
0.0011
0.0022
0.0002
2.0058
0.1064
0.075
2.3769/5.7546
0.0180/0.0432
0.3636/0.7585
0.3290/0.0573
-
0.0475/0.0692
0.0176
0.0013
0.0110
0.0014
0.03
Disposition
of effluent
River
Sewer
River
River
River
River
River
River
River
River
River
River
Sewer
Sewers
River
Sewer
River
River
River
S&rfer
Sewer
Sewer
River
Sewer
(1) Discharged once every 4-5 weeks.
(2) Contains 10,000 gpd
sam tary
sewage and
8000 gpd of surface water infiltration
(3) These facilities recycle most of the non-contact cooling
water used at the plant. These effluents consist of a small
fraction of the cooling water plus thtar Sana tary discharge.
-81-
-------
TABIE 3.1.1.6-2
Conparison of Discharges
Plant
Outfall
PH
TSS, mg/1
PCB, ppb
Oil & Grease, mg/1
Aluminum, mg/1
Lead, mg/1
Copper, mg/1
oo Chromium, mg/1
V
1 Phenols, mg/1
Iron, mg/1
30D, mg/1
ND - Non detectable
UK - Unknown
100
001
7.3
3
17
UK
UK
<.05
<.003
<.005
<.001
<.19
001
7.4
16.6
9
3.10
ND
UK
UK
UK
UK
UK
4.37
102
002
7.3
1.54
3.2
3.38
ND
UK
UK
UK
UK
UK
2.45
104
003
7.2
2.8
3.4
2.18
ND
UK
UK
UK
UK
UK
1.7
002
6.5-12.0
5.2
21
7.20
0.15
UK
0.03
0.003
UK
0.29
UK
003A
5.5-9.8
4.7
7.8
14.40
0.06
UK
0.02
ND
UK
0.30
UK
003B
4.0-9.1
4.0
4.4
30.70
0.11
UK
0.04
ND
UK
0.34
UK
006
6.8-11.6
3.1
3.7
2.66
2.0
UK
0.03
ND
UK
1.66
UK
105
004
5.5-8.6
9.5
370
12.8
UK
UK
0.03
UK
0.52
UK
-------
Table 3. LI.6-3
Plant
Source
100
Municipal
Intake
101
Municipal
Water PCB Concentration
104
River
105
Well
Water
106
Municipal
111
Municipal
112
Municipal
PCB, ppb 0.09-2.5 4-7 57.0 40.0 0.25 1.0 1.0
i
oo
-------
3. 2 Askarel Transformer Manufacturing Industry
All plants in this category manufacture transformers using mineral oil
as the dielectric fluid. This dielectric fluid is the principal impregnant used
at these facilities. PCB transformer oils (blends of 60 to 70 percent Aroclor
1254 or 1242 and 40 to 30 percent trichlorobenzene) are used in only 5-10 percent
of these plants' manufacturing volume.
In general, a transformer consists of a core and coil irrmersed in a
dielectric fluid. There are two broad classifications of transformers: distri-
bution transformers, which are used to step down voltages, and power transformers,
which are used primarily to step up voltages. The precipitation power supply units
can be actually classified as a third class of askarel transformer. However, the
larger plants in this category have only two manufacturing departments — distri-
bution and power; and they manufacture the precipitator transformers in their
distribution transformer department. The following types of askarel transformers
are manufactured at these plants:
A. Askarel Distribution Transformers
1. Network (Receive up to 14,400 volts and deliver 120,
240 and 480 volts)
2. Pad - mounted (Receive up to 14,400 volts and deliver
120, 240 and 480 volts)
3. Pole - mounted (Receive up to 14,400 volts and deliver
120, 240 and 480 volts) The application of these trans-
formers in power distribution systems places a great
premium upon their reliability and high overload
capability.
4. Precipitator power supply (Receive 480 AC volts and
deliver 50-60 kilovolts low amperage DC) These units
are generally installed close to hot gas stacks in
an atmosphere that would be a fire hazard to oil-insulated
transformers and a corrosive hazard to open dry-type
transformers. Sealed dry-type transformers are impractical
for high-voltage DC.
-84-
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Voltages listed cover the majority of askarel distribution trans-
formers. Product scope includes up to 34,500 primary volts and virtually any
secondary voltage, 34,500 and below.
Quantities of askarel used in this class of transformers are in
the range of 500 to 5,000 Ibs. in each unit depending on the rating and the size
of the transformer.
A great majority of distribution type transformers have pro-
vision for venting. Many of these units are equipped with spring loaded venting
devices which vent upon a pressure excursion, and diaphragm rupture discs are
offered as a customer option.
B. Askarel Power Transformers
1. Secondary substation
(a) Load center units
(b) Secondary substation generation units
(c) Switchboard units
(d) Internal units
(e) Motor control units
•These 5 comprise the largest group of askarel-
insulated transformers and they find widespread
application in the automobile, paper, chemical,
textile, steel, nonferrous metal, cement, mining
and petroleum industries. They are used in com-
mercial and public buildings, such as schools
and hospitals; in defense and nuclear energy
installations; and by private and public utilities.
2. Master unit substation
3. Primary unit substation
4. Limited ampere substation
5. Industrial furnace
-85-
-------
Furnace transformers used in the hot, dirty atmosphere
in proximity to glass melting and induction furnaces, which require high current,
low voltage power supplies (receive up to 15,000 volts and contain 2000 to 4000
Ibs. of askarel each). Existing technology does not permit construction of
sealed dry-type transformers for these power ratings.
6. Rectifier
Rectifier transformers used for large rolling mills and EC
industrial power supplies (receive up to 15,000 volts AC and deliver low voltage
high amperage DC. Each unit contains about 19,000 Ibs. of askarel). These units
are covered by the same comments given for industrial furnace transformers.
7. Transportation
Railroad transformers used on-board in electric locomotives
or multiple unit electric railroad cars (receive up to 25,000 volts and contain
700 to 2400 Ibs. of askarel in each unit depending on the rating and size of the
transformers).
(a) Third rail
These transformers are used for rapid transit
systems, and are basically serving a rectifier
function
(b) Locomotive
Prior to 1932, all on-board transformers were open
dry type. Because of problems with them, railroads
went to askarel-insulated transformers. The changes
in locomotive design since the 1930's would not now
accomodate open dry-type transformers as replacements
for askarel units. A recent trend has been to replace
askarel by oil units, and this will continue unless
new Department of Transportation regulations require
nonflammability.
-86-
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However, since a tunnel fire in 1940 caused by an oil
filled locomotive transformer, Perm Central
will not allow any oil containing transformer
equipped locomotive into New York City.
(c) Multiple-unit car (MJ)
These transformers are mounted under the flat-bed
of passenger cars. They ride along in this location,
about 8 inches above the rail, at speeds up to 150
mph. The transformer must be ruggedly built to with-
stand the impact of flying debris and constant vibra-
tion. Power to the cars is brought in through an
overhead catenary and is fed to the underside of the
car where the transformer, controls, and propulsion
equipment are located.
Space and weight are critical in this application.
There are only about 33 inches above the rail. The
width of the transformer is limited by the width of
the car.
Only oil- or askarel-insulated units would provide
the required performance levels in the space avail-
able. As with locomotive applications, present
Department of Transportation regulations do not
restrict the use of flammable liquids, and the use
of askarel units has been dictated largely by the
economic considerations of fire insurance rates,
and by Penn-Central safety regulations.
8. Reactors
These units provide reactance (receive up to 15,000 volts
under normal operating conditions. During normal operating conditions, they
deliver volts and current as received. During power surges they choke the voltage
and deliver the normal output).
9. Grounding,transformers (receive up to 15,000 volts).
-87-
-------
3.2.1 Transformer Manufacturing Plants
There are thirteen companies in the U.S. which manufacture askarel
transformers at eighteen plants. The name and location of these plants are given in
Table 3.2.1-1. Some plants manufacture various types of transformers described
above and others manufacture only one specific line of transformers.
All plants in this category were contacted to obtain informa-
tion on their waste water. Detailed information was obtained on two plants
which were visited. The largest U.S. transformer plant (based on quantity of PCB
use) was not visited because of lack of cooperation. The data base represents
approximately 20 percent of the 1974 PCB usage for transformer application. The
PCB usage in this category was 12,000,000 Ibs. in 1974 (equivalent to 15.0 to 17.0
million Ibs. PCB transformer oil). The PCB usage in individual plants is considered
by these companies to be confidential information. The range of plant PCB usage was
975 fold in 1974. Plant ages range from three to eighty-five years.
The amount of askarel used in individual transformers ranges
from 40 to 1500 gals. (516 to 19,350 Ibs.) with an average of about 232 gals.
(3,000 Ibs.). A sketch of a large substation transformer is shewn in Figure
3.2.1-1. G.E. estimates that the total askarel-insulated units that have
been put into service in the United States since 1932 is 135,000, and virtually
all of these units are still in service. The lifetime-before-failure is often
longer than 30 years, and almost all units that do fail are rebuilt and returned
to service. The current production rate of askarel transformers is about 5,000
units per year.
3.2.1.1 Askarel Handling
Few plants in this category purchase PCBs and tri-
chlorobenzene and do their own compounding. Most plants purchase pre-compounded
askarel from Monsanto. Smaller plants purchase their askarel in 55 gallon drums,
filter the askarel and pump directly into the transformer tanks. To large plants
askarel is shipped via rail cars. Rail cars enter in a designated area at the
plant site. Askarel is then pumped from the rail cars into the raw askarel storage
tank. Any spillage in this area is cleaned by rags or floor dry. The raw askarel
-88-
-------
Table 3.2.1-1
U.S. Transformer Manufacturing Industry Using PCBs
Company Name
Westinghouse Electric Corp.
General Electric Company
Research-Cottrell
Niagara Transformer Corp.
Standard Transformer Co.
Helena Corp.
Hevi-Duty Electric
Kuhlman Electric Co.
Electro Engineering Works
Envirotech Buell
R.E. Uptegraff Mfg. Co.
H.K. Porter
Van Tran Electric Co.
Location of the Plant
South Boston, Va.
Sharon, Pa.
Rome, Ga.
Pittsfield, Mass.
Finderne, N.J.
Buffalo, N.Y.
Warren, Ohio
Medford, Oregon
Helena, Alabama
Goldsboro, N.C.
Crystal Springs, Miss.
San Leandro, Calif.
Lebanon, Pa.
Scottsdale, Pa.
Belmont, Calif.
Lynchburg, Va.
Vandalia, 111.
Waco, Texas
-89-
-------
O
FIGURE 3.2.1-1. SUBSTATION TRANSFORMER
-------
is next filtered through attapulgite clay or fuller's earth and is often passed
through a plate and frame type filter for final cleaning and then stored in the
finished product storage tanks. Spent clay or fuller's earth from this opera-
tion is drurmied and stored on site or sent to a landfill.
In some plants, the entire storage area is located
within dikes and curbs designed to contain at least the contents of the largest
single tank plus sufficient free board to allow for precipitation.
At most plants the askarel is distributed frcm the
tank farm area to the filling station, but at one plant (Plant 103) the finished
askarel is next trucked from a covered/curbed storage area to an uncovered/
bermed tank farm area. Here the truck enters a shelter area, and the askarel is
then pumped from the truck into distribution storage tank.
Recycled askarel from the manufacturing operations is
generally returned through pumps into a storage tank or into 55 gallon drums and
from there it is either filtered for reuse or is sent to incineration if it is
proved to be defective.
3.2.1.2 Process Description
Most plants manufacture all the hardware and compo-
nents necessary for the transformer assembly. The transformer interiors and the
containers are brought to the askarel filling stations where transformers are
assembled, filled and sealed.
The filling operation is done in a designated station.
At plants where small quantities of askarel are handled, spills and drips are
cleaned via floor dry or rags. At plants where large quantities of askarel are
handled, filling operation is conducted on gratings located on sumps. All
drainage is directed into these sumps. The sumps are inspected and cleaned
periodically. All scrap askarel from sumps is pumped into drums and sent to
incineration.
Various transformer assembling and filling procedures
are being practiced throughout this industry. In general, all transformer assem-
bling and filling operations consist of a predrying step for removing moisture
-91-
-------
frcm the transformer interiors, several stages of askarel filling and askarel
topping, addition of electrical connections and bushings, electrical testing and
sealing.
At plants where relatively small quantities of askarel
are used, the assembly and filling procedure for distribution and power trans-
formers are alike. Some plants manufacture only a given size of transformers
(single tank size operations). At larger plants different assembling and askarel
filling procedures are employed for various transformer subcategories. Some of
the askarel transformer assembling and filling procedures practiced within this
industry are described below.
3.2.1.2.1 Assembly and Askarel Filling Procedure for
the Distribution and Power Transformers
A. Vapor Phase Drying Prior to Filling
This procedure is primarily used in
the filling of network and pad-mounted transformers. The drying of the trans-
former internals is a vapor phase treatment with a kerosene-like petroleum distill-
ate. A schematic flow diagram depicting this system is given in Figure 3.2.1.2.1-1.
The assembling steps for these transformers include the following:
. First the transformer interiors are placed in large vacuum chambers
heated with steam coils. The petroleum liquid is admitted, vacuum
and heat are applied. The petroleum vapors rise to be condensed
on the interiors, exchanging latent heat for sensible heat and
raising the temperature of the interiors. After a specific time
the liquid is pumped out; vacuum and heat are continued to dry the
internals.
. The internals are next removed and placed in their own containers
and flushed with askarel at atmospheric pressure. The askarel
is kept in the tank until the liquid temperature is lowered to
a preset level at which time it is pumped out of the tank. The
purpose of askarel flushing is to chill the transformer interiors
prior to final filling.
-92-
-------
I
vo
PCB8 _
TRICHLORO-^
BENZENE
ASKAREL
BLENDING ASKAR
FILTERING
a STORING
t I
SCRAP SPENT
ASKAAEL FULLER'S
EARTH
DISTILLATE
TRANSFORMER
IN TERNAL8
VAPOR PHASE TCANSR
DRYING IN .1
VACUUM NTERN
i
DISTILLATE
COMPONENT
FABRICATION
(TANKS 8 INTERIORS)
VACUUM
EL rHAUHFR ^
TRANSFORMER
FILLING
H
AS8EM
TRAKSFOR
f i
BLED SCRAP
MERS OILS
JRUER TRANSFORMER
M-S ASSEMBLY
FINISH ELECTRICAL
ASSEMBLING, _ ™
ELECTRICAL "^TO
8 PRESSURE
TESTING
ASKAREL
irr
1 SCP
ASKAREL
FLUSHING RECYCt£0
TRANSFORMER
INTERIORS
TRANSFORM ER
TANKS
TRANSFORMERS
SHIPPING
Figure 3.2.1.2.1-1
TRANSFORMER FILLING WITH VAPOR PHASE PREORYING OF INTERIORS
-------
The tank is next placed in a designated vacuum chamber. Vacuum
is drawn and then fresh askarel is metered in slowly to avoid
foaming or flooding.
The vacuum chamber is next opened, the electrical connections
are made and the liquid level in the tank is then brought to
the operating level at atmospheric pressure. The transformer
tank is then crane lifted and lowered onto conveyors and sent to
specified test stations for a series of electrical tests before
the transformer is completely sealed.
If a transformer fails the electrical tests, it is returned; the
askarel is drained and reprocessed. Otherwise, the transformer is
sent to cover welding operations.
The tank is next lifted and sent back via conveyor belts to the
filling station where it is topped with askarel through an access
overhead pipe. The transformer is next pressure tested for leaks.
The bottom drain valve is then sealed and the top opening is pipe
fitted and sealed. Sealing is accomplished primarily by teflon
tape. However, for some transformers, the sealing is done by an
air cured sealant at customer's request.
B. Oven Drying of Transformer Internals
Prior to Filling
This procedure is used primarily in
the assembly of pole type or precipitator transformers. The drying of internals
for this category of transformers is accomplished in a convection oven. The
internals are then placed in their own casings and the bushings and electrical
connections are next made. Vacuum is then applied via a mechanical pump and the
tank is filled with askarel while the transformer internals are still at a pre-
determined elevated temperature. Exhausts from this operation are pulled through
a venting system.
-94-
-------
Most transformers in this subcategory
have gasketed covers with barrel band type connections. Subsequent to the fil-
ling operation, the transformers are sealed and pressure tested for leaks. The
large units are liquid pressure tested while the smaller ones are air pressure
tested. A schematic flow diagram depicting this system is shown in Figure
T O I 9 I-''
-J«Z-»J-*
-------
PCBS
TRICHLORO.
BENZENE
SPENT
FULLER'S
EARTH
T
TRANSFORMER
INTERNALS T
TRANSFORMER
ASSEMBLING
| VACUUM I
DRYING I
I 1
TANKS
,J
FILLING OF
TRANSFORMERS
UNDER
VACUUM
TRANSFORMER
SEALING
AND
TESTING
TRANSFORMERS
TO SHIPPIN8
SCRAP
OILS
NOTE
VACUUM PREPRYINO OPERATION, SHOWN IN DOTTED
LINES, IS USED PRIMARILY IN THE ASSEMBLING OF
POWER TRANSFORMERS.
Figure 3.2.1.2.1-2
TRANSFORMER FILLING WITH OVEN OR VACUUM CHAMBER PREDRYING OF TRANSFORMER INTERNALS
-------
TRANSFORMER
COMPONENT
FABRICATION
8 ASSEMBLY
ASSEMBLED
UNITS
OVEN
DRYING
PCBS
TRICHLORO-
BENZENE
ASKAREL
BLENDING
FILTERING
a STORING
ASKAREL
FILLING OF
TRANSFORMERS
UNDER
VACUUM
TRANS-
FORMERS
PRESSURE
TESTED
TRANSFORMERS
TO SHIPPING
SCRAP
ASKAREL
SPENT
FULLER'S
EARTH
SCRAP
OILS
TRANSFORMER
Figure 3.2.1.2.1-3
FILLING OPERATION WITH OVEN PREDRYING OF ASSEMBLED HARDWARE
-------
All power transformers have air space
on the top and are equipped with an air cooled circulation system. Additionally,
each unit has a spring loaded relief valve as standard equipment. These trans-
formers have a greater potential for environmental contamination through the
vent system, via leaks on the pump and the valves.
3.2.1.3^ Raw Wastes
In general, the process raw wastes from these plants
consist of waste askarel collected in sumps or pans at the filling stations, con-
taminated vacuum pump seal oil, contaminated kerosene-like petroleum distillate
(used in at least one plant in the vapor phase drying operation), contaminated
askarel used for transformer interior flushing and contaminants in the plant
effluent.
Additionally, plant 103 has a unique waste stream con-
sisting of contaminated ground water which is being pumped from three caissons at
the plant site. Plant 103 also has a bleedwater discharge from their incineration
system.
Solid wastes fron these plants consist of rags and
floor dry used for miscellaneous cleaning purposes and spent clay used for
Aroclor filtration. Additionally, at plant 103 it includes the sludge from oil/
water separators.
Non-product PCB discharges are shown in Table
3.2.1.3-1. Estimates on the quantities of raw waste generated in two plants
which were visited are given below.
Plants
Quantities of Waste Loads 103- 114
Wastes to incineration, Ibs/ton of PCB used 115 98.0
Solid waste material stored on site in
55 gallon drums 135 units Unknown
3.2.1.4 Water Use
Water is not an essential component of the transformer
manufacturing process. PCB wastes which reach water streams at these plants are
due to inadvertent occasional loss during handling and residuals accumulated
-98-
-------
TABIE 3.2.1.3-1
NCN-PJODUCT PCB DISCHARGES
Source
Plant exhaust
Incinerator exhaust
Personal hygiene and sanitary water
Ground water punped through caissons
Water used at plant
Contaminated oils and waste PCBs
Floor sweepings and rags used for cleaning
Rejected transformar interiors for copper
recovery
Contaminated and defective empty drums
Sludge from the oil separator
Clay used for askarel filtration
103
Air
Air
Sewer
To oil separators
then river
To oil separators
then river
incineration
decapsulator
decapsulator
To steel furnace
in steel mill
Stored on site
Stored on site
114
Air
None
Sewer
None
Sewer/river
Incineration
Incineration
Stored on site
Shipped to the
cotpany which
handles their
contaminated oils
None
None
-99-
-------
around the drainage systems from past operations when no precautions were taken
in handling and disposal of PCBs.
This category uses water primarily for non-contact
cooling purposes in vacuum pumps, compressors and at some plants as contact cooling
in their welding and plating operations and in phosphatizing of the steel surfaces
prior to painting. All contact cooling operations listed above are primarily non-
PCB related operations. Only plant 103 has a PCB related process water which con-
sists of the water used in their waste incineration system for quenching the hot
gases from the reaction section. Plant 103 is also the major water user in this
category.
In most smaller plants all cooling is accomplished by
air. At these plants water is primarily used for hygiene and sanitary purposes and
for occasional compressor or pump cooling purposes. The only water that comes into
contact with PCBs at these latter plants is that used for personal hygiene. The
types and quantities of water used at two plants visited are given below.
Plant No.
Water Usage in Gallons/day 103 114*
Non-contact cooling 1,646,000 38,000
Process water
. Contact cooling 183,000 None
. Detergent washing 2,000 None
Incineration quench 122,000 None
Hygiene Unknown 300
Boiler make-up Unknown 200
Sanitary Unknown 9,000
Non PCB related
. Water used in a lab Unknown 500
Water used for external cleanups None 4,000
*Breakdown of the water usage was estimated.
-100-
-------
3.2.1.5 Wastewater Treatment
There are no effluent treatment techniques in practice
at any plant in this category for the removal of PCBs. However, in 1972, a John
Zink designed thermal oxidation incinerator was erected at plant 103 to safely
dispose of PCBs. A schematic flow diagram of this unit is given in Figure
3.2.1.5-1. This unit consists of two steam atomized burners and a long
cylindrical chamber to provide residence time for thermal degradation. Follow-
ing the chamber is a water spray quench pot and a counter current packed
scrubber column located at the base of the stack.
The waste oils are brought into the incinerator site
in 55 gallon drums or by truck trailers. These waste oils are next pumped from
the drums or from the trailers into the incinerator feed tanks. The steam
atomizing burners inject the combustible liquid wastes into the combustion
section with air, in such a manner to create a vortex type turbulence. This
produces high heat release and effective combustion promoting the thermal degra-
dation process. After combustion, the waste gases proceed through the oxidation
chamber which provides 3 to 12 seconds of residence time at temperatures 1600
to 1800°F for the degradation reactions to go to completion. The flue gases
from the chamber pass through a quench pot which contains a series of water
sprays to cool the gases. An induced draft fan then forces the cooled gases
through the packed bed scrubber column. Here, acidic ions produced during the
combustion process are absorbed in the scrubber liquor. The scrubber liquor is
then neutralized and disposed into the sewer.
A high temperature decapsulator has been incorporated
in the thermal oxidizer unit for solid incineration and copper recovery. The
exhaust of this unit is routed to the upper end of the oxidizer chamber.
Details on wastewater treatment techniques utilized
at one facility (plant 103) for purposes of oil recovery and on-going contain-
ment programs undertaken by two plants (plants 103 and 114) in order to prevent
the entry of PCBs into the environment are covered in the Task II report,
"Assessment of Wastewater Management Treatment Technology, and Associated Costs
-101-
-------
SOLID WASTE
DECAPSULATOR
AIR
WASTE OIL
WASTE OIL
BURNER
o
to
• RECOVERED COPPER
EXHAUST
THERMAL
DEGRADATION
CHAMBER
NEUTRALIZER
TANK
TO STACK
QUENCH FEED WATER
•WATER EFFLUENT
Fioure 3.2.1.5-1.
PROCESS FLOW DIAGRAM FDR THERMAL OXIDIZER INCINERATOR AT PLANT 103
-------
for Abatement of PCBs Concentration in Industrial Effluents", February 3, 1976,
pages 71 through 75.
3.2.1.6 Effluent Composition
Effluent flow rates and PCB contents are available
from the three plants which discharge into the rivers and from two plants which
discharge primarily into sanitary sewers. Detailed effluent composition is
available only on Plant 103. This information is given in Tables 3.2.1.6-1 and
3.2.1.6-2, respectively.
The remaining plants in this category which discharge
to sanitary sewers report that their water usage, for reasons other than for
sanitary purposes, is minimal. However, they have no data available on the
quantities and composition of water discharged.
3.2.2 Askarel Transformer Repair Industry
A total of 13 companies repair transformers containing PCBs at
a total of 131 locations. The current industry structure has been identified,
and several potential problems were noted. No estimates have been made of the
pollution which occurs frcm this industry.
3.2.2.1 Transformer Inspection and Maintenance
Askarel transformers are very reliable and have life-
times that range up to 40 years. The failure rate of askarel filled transformers
has been estimated by the manufacturers to be 0.2 percent per year. Failure
occurs primarily due to the degradation of the PCB fluid caused by electrical
arcing within the transformer.
Nine electrical utilities were contacted to determine
their inspection and repair procedures. Ml of these companies have some type
of program, usually informal, for the checking of their transformers. In most
cases this consists of a simple annual inspection which may include a general
cleaning operation of the facilities adjacent to the hardware (e.g., the vaults
may be cleaned and vacuumed) . Inspection involves looking for evidence of
leaks. One utility performs an annual power factor test on the windings, and
if this test indicates a problem in the transformer, then its dielectric fluid
-103-
-------
TABLE 3.2.1.6-1
PCB CONCENTRATION IN EFFLUENTS FROM TRANSFORMER
MANUFACTURING PLANTS
Plant
No.
103
114
115
(1)
116
117
(3)
Discharge
Designation
005
006
None
None
002
003
004
#1
12
13
Batch
discharge
Effluent
Flow Rate
Gal/Day
1,310,000
550,000
50,000,
2,000l
36,000
24,000
150,000
252,000
378,720
504,000
13,500
Effluent PCB Content
Avg/Max
4.9/120
7/75
Unknown
Unknown
2/113
3.4/11
2.1/3.8
8/19.1
Uo /day
Avg/ffek
0.0535/1.311
0.0321/0.344
Unknown
Unknown
<0. 0003/0. 0006
0.0004/0.0226
0.0013/0.0039
0.0071/0.0231
0.0066/0.0120
0.0336/0.0803
Disposition
of Effluent
River
River
Sewer
River
River
River
River
River
River
River
28.6/unknown 0.0032/unknown Sewer
Notes: (1) This plant has other discharges out of their properties. Discharges
listed above are those associated with PCB related operations.
(2) Estimated .
(3) Discharges designated as #1, #2, and #3 are the combined effluents
from their power house, and one each from their two manufacturing
areas, respectively. According to the plants' Corps of Engineers
permit application form, filed in July 1971, this plant has 13
outfalls.
-104-
-------
TABLE 3.2.1.6-2
INFLUBtfT AND EFFLUENT COMPOSITIONS OF PLANT 103
Average flew rate million gpd
pH yearly average
pH min.-max.
Alkalinity, mg/1 14
BOD, 5-day, mg/1 2
Chemical oxygen, mg/1 9
TS, mg/1 69
IDS, mg/1 68
TSS, mg/1 1
TVS, mg/1 34
Attnnnia, mg/1 0.05
(AN)
Kjeldahl Nitrogen, mg/1 0.45
Nitrate AsN, mg/1 ' 0.15
Phosphorus Total, mg/1 0.01
Color (As P) 30
Turbidity, mg/1 <25
Total hardness, mg/1 44
Organic Nitrogen, mg/1 0.5
Sulfate, rag/1 9.0
Sulfide, mg/1 <0.1
Chloride, mg/1 6
Cyanide, yg/1 <0.00
Fluoride, mg/1 0.16
Aluminum - total, yg/1 100
Boron - total, pg/1 70
Calcium - total, mg/1 6.5
Chromium - total, yg/1 <10
Outfall
005
1.31
7.7
6.4-8
Avg/Max
Cone.
25/25
3/3
23/34
70/70
67/67
3/9
19/22
<0. 2/1.0
0.8/1.0
0.55/0.9
0.04/0.05
25/30
<25/<25
31/44
0.6/0.7
14/18
<0.1/<0.1
6/8
0.00/<0.01
-
500/550
-
7.0/7.5
30/30
.0
Avg
Ibs/day
273
28
251
765
735
31
208
<2
9
6
<1
-
-
340
6.6
153
<1.0
61
0.04
-
5
-
77
0.3
Outfall
006
0.55
5.5
3.1-7.1
Avg/Max Avg
Cone . Ibs/da;
15/20 69
27/30 124
75/92 344
364/497 1671
341/483 1565
23/30 106
89/96 408
2.8/3.0 13
4.6/5.1 21
0.98/1.02 5
54/124 248
30/30
<25/<25
33/44 152
1.8/2.0 8
9.0/9.0 41
<0.1/<0.1 <0.5
11/13 50
<0.00/<0.00 <0.02
9.5/12.0 44
200/200 0.9
9/70 0.04
7.7/8.0 35
310/350 1.4
-105-
-------
TABLE 3.2.1.6-2 (CON'T)
Cobalt, total, yg/1
Copper - total, yg/1
Iron - total, yg/1
Lead - total, yg/1
Magnesium - total,
Manganese - total, yg/1
Mercury - total, ug/1
Molybdenum - total, yg/1
Nickel - total, yg/1
Potassium - total, mg/1
Silver - total, y
Sodium - total, mg/1
Tin - total, yg/1
Titanium - total, y
Zinc - total, yg/1
Oil & Grease, mg/1
Phenols, yg/1
Surfactants, mg/1
Chlorinated hydrocarbons, mg/1
(except pesticides)
PCBs, yg/liter
Incoming
Municipal
Water
<7
500
330
<30
7
200
<1
<7
100
1.1
<10.0
5
<7
2
30
1.0
3
<0.02
<1.000
Outfall
005
4/4
20/500
150/330
<10/30
3/7
50/200
-------
is tested - at least this is the theoretical method of operation since the
company has only two PCB-type transformers in use and neither has ever failed
the power factor test. Another company measures the operating temperature of
the units and makes a visual inspection for leaks; this company also claims
that transformers located in the generating facility are inspected daily (visual
inspection) and that units located in vaults are checked at least weekly.
While most major inspections are carried out annually, the range of time
intervals between inspections is 6 months to 18 months, with one company saying
that they inspect at least once every 2 or 3 years, and another saying that
substation transformers are inspected weekly.
These companies perform no sampling and analysis work
on their askarel transformers. Cue company has annual inspection of all trans-
formers, but only the mineral oil-type units have samples withdrawn for
analysis to see if there is deterioration or contamination. A company which
used to perform power-factor tests until about 8 years ago has since abandoned
such tests and does not withdraw askarels for analysis.
Servicing of transformers is only rarely performed
in-house. The response of most companies was that servicing of askarel-type
transformers had yet to be required. One company did its own servicing up until
8 or 10 years ago, but since then, because of the special handling problems
associated with askarels, such work has been farmed out to G.E. and Westinghouse
service centers. The general trend seems to be that major servicing is more
likely to be done at special facilities outside the utility companies while
minor servicing, such as the repair of small leaks is taken care of at the
transformer site by the utility.
More than half of the companies have not scrapped
transformers in the past five years, and most have not scrapped any in the past
10 years. One utility company has had no transformer failures in 20 years
(except for a minor leak of less than 1 gallon ten years ago). These companies
have no specific disposal methods for such instances. One company said that
scrap transformers are handled through a local junk company and that askarel
disposal is the junk company's problem. A company which says it has scrapped
no transformers says that when the PCB capacitors fail they are shipped back to
-107-
-------
the manufacturer; presumably, though it v/as not stated directly, failed trans-
formers would also be returned to their manufacturers. One company which is
proud of its disposal practices has disposed of 200 to 400 gallons of.askarel
per year since 1970 (most of it comes from failed capacitors); until this year
it was all sent to IVbnsanto for incineration, but starting this year they have
been sending it to Sheffield, 111., where it is dumped in a landfill that has
been approved by EPA for the disposal of radioactive wastes. This company
stated that many utility companies dump their PCB-related wastes in local
landfills.
There has been little PCB lost to the environment
through the safety release valve on the transformers. The consensus response
was that if the valve released there would be askarels "all over the place".
The spokesman for one utility did not know whether the transformers they used
had safety valves. One company said that a transformer vented several years ago
when a fuse that was supposed to protect the transformer did not protect it.
Very seldom is a failed transformer scrapped. However,
sometimes the repair work needed in a failed unit could be rather extensive and
very costly. The owner of the unit may request to scrap his unit. If the repair
shops scrap a transformer,'they follow the procedure reconmended by NE1V&. How-
ever, if the owner of the transformer decides to handle the disposal of the unit
himself, the unit is shipped back to the owner. Disposal is then usually made
through a local junk dealer.
3.2.2.2 Repair of Failed Transformers
In talking with a major transformer manufacturing
company which specializes in the servicing of transformers, it was learned that
PCBs used by service shops are primarily for refilling the units which have
failed and have to be repaired. Apparently, very few facilities handle their
own servicing. Major service work is almost always handled by repair shops
while minor service work, such as changing a gasket, to prevent a minor leak,
may be taken care of by the owner of the transformer. Additionally, the repair
-108-
-------
shops often handle askarel conditioning services. In such a case, the service-
man carries the filter press to the costomer's site and performs this service on
site. Several gallons of PCBs are used in this service for topping the unit and
adjusting the level. The procedure for the repair or disposal of failed trans-
formers and the handling of the PCB liquid in those transformers is sunmarized
in Figures 3.2.2.2-1 and 3.2.2.2-r2.
A nurrtoer of potential sources of environmental con-
tamination have been identified, and are discussed in detail in the following
notes to the figures.
1) Testing and analysis of PCB transformer fluid has
been largely discontinued due to the strict re-
quirements imposed on the disposal of the samples.
This change in procedure may be expected to in-
crease the probability of major failures of trans-
formers containing PCBs.
2) Accidental spills of PCBs from transformers can
occur due to leaks, venting caused by short
circuits, or mechanical damage to the transformer
case. In most cases, the transformer is con-
tained in a vault or is surrounded by dikes which
will limit the spill to a controlled area. Only
in the case of railroad transformers would the
leakage resulting from an accident be expected to
be uncontrolled.
3) Transformers which are scrapped by the owner/user
may be a serious potential source of pollution.
Those transformers built during the past several
years are well marked with the hazards of the PCBs
which they contain. Disposal of junked trans-
formers by electrical repair shops is governed by
a detailed specification of the National Electrical
-109-
-------
TRANSFORMER
IN SERVICE
(2)
I
ACCIDENTAL
SPILLS
1
INSPECTION
1(1)
i
TRANSFORMER
REMOVED FROM
SERVICE
l
1
REPAIRED IN-HOUSE SCRAPPED
(VERY SELDOM) BY OWNER
REPAIR SHOP
t
TO JUNK01
DEALER
1 ' '
UAKF-UP ASKAREL
ASKAREL (4) a REFILLIN
ASKAREL'5*6'
SPILLS
•JG
G
REPAIRED OR
SCRAPPED
{8S$r&-*
1
TRANSFORMER
RETURNED TO
SERVICE
FIGUFE 3.2.2.2-1. TRANSFORMER MAINTENANCE & SERVICING
-110-
-------
TRANSFORMER
RECEIVED BY
REPAIR FACILITY
TRANSFORMER
COPPER
WIRING
TO RECOVERY
FINISH
ASKAREL
STORAGE
(UNDERGROUND
OR ABOVE
GROUND) (9)
TRANSFORMER
WASTE DRUM
INCINERATION
OIL
RECLAIMER
(8)
MIXED HYDROCARBON
FUEL
FIGURE 3.2.2.2-2. TRANSFORMER REPAIR
-111-
-------
Manufacturers Association (NEMA) . However, the
disposal of transformers through small local junk
yards may result in significant pollution because:
a) The junk yards are not familiar with PCB
handling procedures.
b) The older transformers are not marked with
special instructions.
c) 90 to 95 percent of the transformers seen by
the junk yards would contain mineral oil, and
the occasional transformer containing PCB
would be noted only as containing non-flam-
mable transformer oil. This would not result
in any special handling of the PCBs.
d) Disposal of PCBs by open burning in a trash
incinerator will not completely destroy the
PCBs, but will vaporize this material and dis-
perse it into the atmosphere.
This is only a potential problem at this time, as
uncontrolled scrapping of transformers has not
been docunented. However, several responses to
the questionnaire claimed that uncontrolled
handling of PCB filled transformers by junk yards
was thought to have occurred in the past.
4) Considerable PCB is shipped in 55 gallon drums to
repair shops and users. The residue in each drum
after it is emptied may contain up to a pound of
PCB. Empty drums which are recycled to drum re-
claiming facilities or scrap yards would introduce
this relatively small, but significant, amount of
PCB into an uncontrolled environment. All drums
presently in use have detailed handling instruct-
ions painted on the drum, and this information
-112-
-------
should minimize any potential problems from this
source.
5) Filter residues and losses are in general treated
as any other waste containing PCBs and are being
placed in drums and held for controlled disposal.
6) Scrap PCB is packaged in 55 gallon drums. The
NEMA instructions are very specific as to the re-
quired disposal procedures for this material.
Small repair shops which do not have access to
controlled disposal sites or services have been
known to mishandle the scrap PCB by disposing into
uncontrolled landfills (note 7) or through oil
recovery services (note 8).
7) Landfills are a satisfactory disposal method for
scrap PCB transformer oil if the leach water is
monitored. In a few cases scrap PCB and PCB con-
taminated material is sent to a municipal dump.
8) At least one case is suspected where PCB trans-
former oil may have been sent to an oil reclaiming
company which mixed it with other hydrocarbon
wastes and sold it to a power company as fuel. It
should be noted that the mineral oil used in 90 to
95 percent of the transformers presently in service.
Problems may result when PCB transformer oils are
mixed with mineral oils and handled in this manner.
9) New and conditioned PCB transformer oil is
normally stored in large surface or underground
tanks at the repair shop. Leakage may occur from
-113-
-------
these tanks into ground waters. No standards
have been established for checking for such losses.
10) The scrapping of unrepairable transformers is
covered by the NEMA standard (ANSI C107.1-1974).
This standard requires that the transformer be
drained and then flushed with solvent to remove
PCB residues before the metal values are reclaimed.
Possible sources of contamination would be
incomplete flushing and the mixture of used
solvent with hydrocarbon rather than with PCB
residues. This is considered unlikely in the
major transformer repair shops.
3.2.2.3 PCB Usage in the Transformer Repair Industry
The PCB usage figures for the transformer manufacturing
and repair industries are summarized below.
PCBs Use, Ibs
1st half-
1971 ' 1972 1973 1974 1975
New PCBs used to repair
transformers 590,000 580,000 440,000 780,000 480,000
PCB reclaimed and reused
in repair of transformers 2,000 64,000 160,000 110,000 78,000
PCB shipped to user to
replace transformer losses 3,000 3,000 4,000 2,000 2,000
PCB disposed in trans-
former repair 570,000*
PCB used in transformer
manufacturing 11,000,000
Total PCB in service in
transf enters 270,000,000
* This figure may include PCBs contaminated wastes as well as PCB.
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3.2.2.4 Transformer Service Life
There have been relatively few failures of PCB filled
transformers, and statistically significant data is not available to support
service life estimates. General estimates by transformer manufacturers indicate
the following expected service life of this equipment:
Service life of substation
transformers 40+ years
Service life of power trans-
formers, including those on
railroad locomotives 30 years
Transformers exhibit a small but significant infant
mortality rate (failure within the first year of service). Overall transformer
failure rate estimates are in the range of 0.2 percent per year.
3.2.2.5 Usage rate of PCBs in Transformer Rspair
The total PCB used in 1974 in the repair of trans-
formers was approximately 0.3 percent of the estimated total PCBs in service in
transformers. This figure is consistent with the estimated failure rate of
0.2 percent per year for in-service transformers.
The usage of PCB in the transformer repair industry
is approximately 7 percent of that of the transformer manufacturing industry.
3.3 Investment Casting
The investment casting industry produces precision-cast metal parts
and shapes for the aircraft and other machinery manufacturing industries.
Approximately 25 of the 135 investment casting foundries in the United States
currently use PCB filled waxes in the manufacture of metal castings. The PCB
incorporated in the waxes is decachlorobiphenyl (deka). The remaining foundries
use either polychlorinated terphenyl (PCT) filled waxes or unfilled waxes. This
section presents a review of the usage of deka filled waxes in the industry, in-
cluding available information on use history, process technology, and potential
-115-
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PCB-bearing waste streams. Currently available information on PCTs usage in
the industry is also included.
3.3.1 Background
There are currently 135 investment casting (1C) foundries and
five investment casting wax manufacturing plants in the United States. The 1C
industry had its start in the United States during World War II when urgent
demands for arms and aircraft parts required more efficient methods of pro-
ducing finished, precision parts than standard machining techniques offered.
Daring the war the waxes used by 1C foundries consisted of a blend of carnauba
wax, beeswax, paraffin, and rosins. However, over the last decade wax
formulations have evolved which consist of a variety of polymeric compounds and
other fillers such as decachlorobiphenyl and PCTs. By reducing the wax content
through low-shrinkage fillers (such as PCBs and PCTs) volumetric shrinkage of
the ceramic mold is controlled. This allows the production of metal castings
with smaller dimensional tolerances than were available with the original un-
filled waxes.
The major wax manufacturing companies are:
1. Yates Manufacturing Company, Inc.
f
2. M. Argueso and Ccrnpany, Inc.
3. Freeman Manufacturing Company
4. J. F. JVfcCoughlin Coirpany
The Yates Manufacturing Company, Chicago, 111., is the sole known U.S. supplier
of deka waxes. The decachlorobiphenyl content is 30 percent of the total wax
by weight (Solomon, P., Yates Manufacturing) . Yates currently imports deka from
Caffaro S.P.A., Italy, at a rate of 300,000 to 500,000 Ibs. per year, which
corresponds to the manufacture of between 1 and 1.5 million pounds of deka wax,
annually. At a cost of $0.70 per pound, (Lewis, W.H., Signicast Corp.) the
annual volume of sales of deka wax should be in the range of $700,000 to
$1 million per year.
All the wax manufacturers listed previously are believed to
use imported PCTs as pattern wax fillers. Since the general properties of the
deka and PCTs are similar, it is believed that the wax production and use
-116-
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processes are similar also. Contacts with industry indicate that the volume
of PCTs in wax is probably about the same as or greater than that of deka PCBs.
Monsanto was the leading (and probably only) U.S. producer of PCTs prior to
their voluntary cessation of production in 1972. Domestic production of PCTs
by Monsanto through 1972 was as follows:
Year Million of Pounds Aroclor 5460
1968 8.87
1969 11.60
1970 17.77
1971 20.21
1972 8.13
It is believed that a relatively small fraction of this pro-
duction was used in casting waxes, probably on the order of a million or so
pounds per year. Aroclor 5460 (Monsanto's trade name for their 60-percent-
chlorine PCTs) was used primarily in adhesives, lubricants and paper coatings.
The current source of imported PCTs is believed to be Prodelec
(France) , which markets the material as Electrophenyl T-60 (60 percent chlorine) ,
which, it should also be noted, may contain PCB contaminants.
In summary, the investment casting process, which is described
more thoroughly in Sections 3.3.2.1 and 3.3.2.2, is a lost-wax casting process
in which the shape to be cast is molded from wax and then invested or surrounded
by a slurry of refractory ceramic. After the ceramic mold has hardened to an
appropriate strength, the wax is melted or burned out leaving a molded cavity.
Wblten metal is then poured into the cavity, and cooled to form the casting.
The major losses of the virgin and used waxes occur during the
dewaxing of the ceramic mold. As the ceranic mold is heated to remove the wax,
a small portion of the wax diffuses into pores of the mold. Later, the mold
with the trapped waxes is fired in a furnace to set the mold and remove the wax.
Depending on furnace conditions, the decachlorobiphenyl in the wax may be
burned or released to the atmosphere. At least several percent of that used
is believed to be emitted via this route.
-117-
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It is a normal practice by many foundries to recover the
drained pattern wax and reuse it several times in sprues and gates. Purchased
wax is apparently used an average of 2.5 titties. During the dewaxing process
the virgin wax (used to form the pattern) and the old wax (used to form the
gates and sprues) are collected as one mixture. Little of the wax is destroyed
in the process; therefore, it is considered probable that the investment
casting foundries store or dispose of relatively large amounts of used PCB-
containing wax.
3.3.2 Investment Casting Technologies
3.3.2.1 Principles of Investment Casting
The principles of investment casting are the same for
both the solid mold and shell processes, but the method of forming the ceramic
mold differs somewhat between the two. Both require a pattern, gating to a
central sprue, removal of the pattern by melting, pouring metal into the cavity
left by the melted pattern, removal of mold material fron the cast cluster, and
cutting of castings from the sprue.
The investment shell process is depicted in Figure
3.3.2.1-1.
The Pattern: The process begins with production of
a one piece heat-disposable pattern. This pattern is usually made by injecting
wax or plastic into a metal die. Dies range from simple, hand-operated single-
cavity tools to fully automated multi-cavity devices, depending on production
quantities and complexity of the parts to be cast.
A heat-disposable pattern is required for each unit
being cast. Each pattern has the exact geometry of the required finished part,
but they are made slightly larger in order to compensate for volumetric shrink-
age during the pattern production stage and during solidification of the metal
in the mold.
The pattern carries one or more gates which are
usually located at the heaviest casting section. The gate has three functions:
-118-
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DIE
PATTERN'
WAX PATTERNS
ATTACHED TO TREE
PATTERN
GATE
POURING CUP
TREE DIPPED INTO
CERAMIC SLURRY
TREE DIPPED INTO
FLUIDIZED BED OF SILICA
AUTOCLAVE DEWAXING
MELTED
WAX
AUTOCLAVE
MOLD FIRING
-FLUE GAS
FURNACE
MOLTEN METAL
w
Figure 3.3.2.1-1. INVESTMENT SHELL PROCESS
-------
(1) To attach patterns to the centrally- located
sprue or runner, thus forming a tree-shaped
cluster;
(2) To provide a passage for the draining of
pattern wax once the mold is sufficiently
hardened and has been heated; and
(3) To guide molten metal entering the nold
cavity in the pouring operation.
Clustering: Patterns are fastened by the gate to one
or more runners. The runners are attached to a pouring cup. All of these parts
are usually made of wax. Patterns, runners and pouring cup comprise the cluster
or tree upon which the ceramic mold is formed. The number of runners and their
arrangement on the pouring cup may vary considerably, depending on alloy type
and the size and configuration of the casting.
Molding: Up to the point of forming the ceramic
mold, all foundries operate in essentially the same manner. After assembling
the pattern to a tree, however, they may form the mold by either the investment
flask process or the investment shall process.
Solid lybld or Investment Flask Process: There are
two investment flask techniques, depending on the type of alloy to be poured.
Ferrous alloys require highly refractory materials and binders. The entire
cluster is dipped into a ceramic slurry, drained and stuccoed with fine ceramic
sand. This step is usually repeated after the first coating has dried. This
coated cluster is then placed in an open-end metal can (the flask) which is
filled with a coarse slurry of ceramic backup material (investment) . The in-
vestment hardens to comprise a green mold. When the flask with its contents are
placed into an autoclave, the whole cluster (consisting of wax patterns, runners
and sprues) melts and runs out through the pouring cup. The resulting mono-
lithic mold contains cavities of the desired casting shape, with passages lead-
ing to them.
Nonferrous alloys are cast in ceramic molds bonded
with plaster of paris. The entire tree (heat-disposable patterns, gates,
runners, and pouring cup) is placed in an open-end metal flask without a first
-120-
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ceramic coating. Investment slurry is poured into the flask, completely sur-
rounding the cluster. Before the binder sets up, the flask is placed under
vacuum to remove all air entrapped during mixing of the investment. When the
investment becomes hard, patterns are melted out exactly as in ferrous casting.
The Investment Shell Process: This technique, as
described in Figure 3.3.2.1-1, involves dipping the entire cluster into a
ceramic slurry, draining it, then coating it with fine ceramic sand. After
drying, the process is repeated several times, using progressively coarser
grades of ceramic material, until a self-supporting shell has been formed.
The thickness of the shell is usually between 3/16 and 5/8 inch.
The coated cluster is then placed in a steam auto-
clave where the wax melts and runs out through the gates, runners, and pouring
cup. The resulting ceramic shell contains cavities of the desired casting
shape, with passages leading to them.
Casting: Monolithic shell molds and solid molds must
be fired to burn out the last traces of pattern material and to attain a degree
of permeability before the molds can be filled with metal. In the case of
solid molds, this heating has to proceed slowly, in a controlled cycle which
stretches over 12 to 18 hours, to avoid cracking of the mold. The shell molds,
made of ceramic material with an extremely lew coefficient of expansion, can
be placed immediately into a hot furnace. Because the shell molds have
relatively thin walls, they can be fired and ready to pour after only a few
hours in the fumaass.
The hot molds may rely on gravity alone to carry the
molten metal into the intricacies of the mold, as is common in sand casting,
or the process may use vacuum, pressure and/or centrifugal force in order to
faithfully reproduce intricate details of the wax patterns.
Melting equipment employed depends on the alloy. For
nonferrous alloys, gas fired or electric crucible furnaces are usually used.
For ferrous alloys, high frequency induction furnaces and indirect arc furnaces
are common.
-121-
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Cleaning; After cooling, mold materials are removed
from the casting cluster with vibrating equipment. Individual castings are
usually•removed from the cluster by means of cut-off wheels, and any remaining
protrusions left by gates or runners are removed by belt-grinding. Generally,
castings are sand blasted for smooth finish, then they are ready for such
secondary operations as heat treating, straightening and machining.
Reclaiming of Pattern Waxes: The present cost of
virgin pattern wax is approximately $.79/U>. In the future, it may be more
economical to reclaim wax for use as pattern waxes, in addition to its present
use in gates and runners. Furthermore, through a precipitation method, it is
possible to remove fillers, including PCBs, from used wax in order to prepare
unfilled wax.
Improvement of Investment Casting Processes: Several
ijtprovements in the investment casting techniques and procedures have been
suggested by TRW Metals in Minerva, Ohio, which developed them through a two-
year Air Force contract (AFML-TR-74-237). The areas of improvement were in wax
pattern formation, mold production processes and metal pouring.
Wax pattern formation techniques were improved
through simultaneous multiple injections of the gates and runners. The usual
procedure requires separate steps.
Two suggestions for improvements were made for the
mold production process: (1) elimination of the drying cycle between slurry
dipping and sand coating, and (2) the use of microwave ovens to melt pattern
wax out of the ceramic mold or shell.
The use of microwave dewaxers would have the ad-
vantage of reducing wax emissions in flue gas and drain condensates of auto-
clave ovens. However, microwave dewaxing may not eliminate wax losses
occurring during mold firing as a result of wax trapped in the pores and
cavities of the ceramic mold.
3.3.2.2 Foundry Process - Use of PCI and PCB_Filled Waxes
A flow chart which typifies the use of PCBs and PCTs
in investment casting is presented in Figure 3.3.2.2-1. PCB filled waxes are
-122-
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I
I-1
LO
ITTERN VIRGIN WAX HEAT
WAX STORAGE *~ EXCHANGER
STEAM rCLARIFIED WAX
1 /
DEWATERING IN t USED WAX
OPEN KETTLES STORAGE
' "WAX"' ••- PACKAG
WAX PODUCTION
DIE PATTERNS
* 1
HOT INJECTION ^ ™^
WAX INTO DIES FRnM n,ES
' HOI
HEAT WAX SPRUES AND GAT
EXCHANGER FORMATION
L-— -BOTTOMS TO DISPOSAL
\ —
(USED .CERAMIC MOLDS 1ST
WAX ,/ , ,
FORMATION OF ' 'A1B '""
BY OIP-COATINP . M ..
DEWAXING / Fi^rPrp —
AUTOCLAVE ?5O(¥>F
11 "' •" ' txctbs
ri-Tiiir ill-mi -. . .•. UFI TINfi » METAL
»
MOLD
REMOVAL
1
SPRUES AND GATES FIN
REMOVAL MACHII
INVESTMENT CASTING PROCESS
NG AND SHIPMENT
PCBs, IN PLASTIC BAGS)
— ADDITION OF
j— SPRUES AND GATES
•ES J COATING WITH
DIP SEAL WAX
ACK GASES
METAL m-.. rnni INK •
INJECTION COOLING
\
• i PACKING AND
7,r;_ *^- DISTRIBUTION
'"'N6 OF CASTINGS
FIGURE 3.3.2.2-1
FLDW CHART OF PCBs USAGE IN INVESTMENT CASTING
-------
purchased from wax manufacturers in bulk quantities of 10,000 or more pounds,
sealed in plastic bags and contained in boxes for shipment. The received
pattern wax is stored in a stockroom at the foundry until melted for the
production of wax patterns. Once melted, the wax is injected into a pattern
die where the wax is allowed to solidify. The pattern die is then disassembled.
and the wax pattern removed. Several wax patterns are produced before forming
the tree. The formation of the tree entails attaching the individual wax
patterns to the sprues and gates, and after the trees are assembled, the sprues
are coated with a dip-seal wax to fill the voids on the rough sprue surfaces.
The next step in the process is the formation of the
ceramic mold. This is accomplished by dip-coating the wax trees in a ceramic
slurry and a fluidized bed of silica, and air drying of the coated tree. This
process is repeated several times before the wax is melted out of the mold.
Dewaxing is accomplished by one of three techniques:
steam autoclave, microwave oven, or flash firing in a mold furnace. MDst
foundries apparently use the autoclave technique, which involves subjecting the
ceramic coated trees to steam until the wax within the mold is melted out,
leaving the ceramic shell. The melted wax is either disposed of or reclaimed
for use as sprues and gate wax. The new microwave technique involves heating
the molds with microwave energy. Microwave units of 5- and 10-kilowatt output
are commercially available for this application. The third technique of flash
firing combines dewaxing and mold firing in one step. The ceramic coated wax
trees are placed in a furnace where all the wax is removed from the tree by
flash firing. Most of the wax is vaporized and leaves the furnace with the
stack gases. It is not known how many facilities use flash firing.
If the foundry dewaxes the trees using autoclave or
microwave techniques, the dewaxed ceramic molds must be fired in the mold
furnace to strengthen the ceramic and to remove wax residues. The ceramic
molds are raised to temperatures of between 1900 and 2000 F for approximately
two hours. The vaporized wax residues leave the furnace with the stack gases.
The foundries clam that only 1 to 2 percent of the wax remains in the molds
before mold firing. This estimate of trapped or wall absorbed wax appears tc
be low for two reasons:
-124-
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(1) The porosity of the ceramic mold can be
as high as 30 percent, and
(2) Trapped waxes in the cavities of the pattern
vary in amount, depending on the pattern's
geometric configuration.
After firing, the ceramics are ready for metal pouring.
The steps involved in pouring, and the subsequent recovery of the castings are
evident in Figure 3.3.2.2-1, starting with metal pouring.
The high cost of pattern wax has stimulated foundries
to reclaim used wax. For example, the PCB filled waxes sell for approximately
70 cents per pound. The average weight ratio between pattern wax and wax in
sprues and gates is about 40:60. Therefore, reclaiming of used wax, especially
for use in sprues and gates, ahs become a very important part of the foundry
process.
Reclaiming involves placing the used wax in open
kettles or tanks and heating it above the boiling point of water until all the
water (from the steam autoclave) is eliminated. After dewatering, the re-
claimed wax is reconstituted by adding paraffin and other additives until
certain melting-point specifications are met. It is claimed that wax fillers
are not added to adjust the filler content (Wurster, W., Consolidated Casting
Corp.).
For those foundries which practice wax reclamation on
their used wax, it is estimated that 5 to 10 percent of the wax is deliberately
disposed of. The major source of the discarded wax is probably the dregs from
the dewatering kettles.
3.3.2.3 Waste Streams
Idealized waste streams (containing PCBs and PCTs)
leaving an investment casting foundry are shown in Figure 3.3.2.3-1. The
broken lines within the process box in Figure 3.3.2.3-1 indicate potential PCB
and PCT escape routes via air emissions from the foundry unit processes. The
solid lines between the processes indicate the production routes of the waxes.
-125-
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FOUNDRY
STACK
I
}->
NJ
I
PATTERN
WAX
AIR
t
s.
hi
p
r~
1
1
1
I
MOLD
PRODUCTION
i
L
WAX
STORAGE
i
k
<1
1
1
1
I
1
1
1
1
L.
r
i
DEWAXING
"
'
WAX
RECLAMATION
T
A
f
b
s *^
»»
K.
r n— H
i
MOLD
FIRING
>
4
r
FOUNDRY
AIR
EXHAUST
DISPOSAL
SEWAGE
3.3.2.3-1
.IDEALIZED FLOW CHART FOR AN INVESTMENT CASTING FOUNDRY, SHOWING WASTE STREAMS.
-------
The solid lines at the top of the figure indicate the two general ambient air
escape routes, namely the stack gas frcm the mold firing furnace and the
foundry exhaust air system. The two solid lines leaving the foundry (at the
bottom of the figure) represent PCB and PCT escape routes: solid waste, which
is usually sent to landfills, and raw sewage, which goes to municipal sewage
treatment in most cases. The broken line outside the facility (at the top of
the figure) indicates the possibility for inadvertent recycling of escaped PCBs
or PCTs in stack gas or foundry air exhaust back into the foundry facility.
PCB-PCT-containing waxes enter the foundry as pattern
wax packaged in plastic lined boxes which are stored until needed in the
casting process. EXiring mold production, when the wax is melted and injected
into metal dies, wax fumes may escape. The type of dewaxing method employed
by the foundries has a direct effect on the amount and mode of PCB or PCT loss
to the environment, not only during dewaxing but also during process steps that
follow. For example, the use of a steam autoclave, in addition to its own
potential emission of PCBs or OCTs, also imparts moisture to the wax, and this
water must be removed before the wax can be reused. Dewatering by evaporation
at high temperature also likely contributes to air emissions. Flash firing,
which ocnibines mold firing and dewaxing into one step, probably emits high
levels of PCBs or PCTs, and so far as is known, emission controls are not used.
Solid wastes can include unreclaimed used wax, excess
reclaimed wax, bottoms from reclamations, and wastes frcm spills, equipment
cleanout, etc. Although process water does not appear to be used, sane plants
may use cooling water. The steam autoclave appears to be a source of water
vapor only.
3.3.3 Wax Manufacturing
To date, very little is known about the wax manufacturing
process. However, it is known that in the process PCB or PCT compounds are
added in powdered form to the wax base. Reduction of PCB or PCT particle size
prior to mixing may be desired. Losses of dust to the environment by air
routes frcm both size reduction and mixing operations would be expected.
-127-
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3.3.4 Itecomnendations
The information presented herein represents the current
knowledge of decachlorobiphenyl and polychlorinated terphenyls usage as wax
fillers in the investment casting industry. This knowledge should be used as
a basis for the development of an accurate assessment of the iirportance of PCB
and PCT waste from the industry, and of the adequacy of available substitutes.
Significant information gathering efforts would be required to establish a
complete picture of the practices, processes and product of the investment
casting foundries and wax manufacturers. Definition of the waste streams and
emissions from the processes used would require sampling and analysis efforts
in addition to the gathering of available process data and other information
from the industry. The objectives of such a plan would necessarily include
the following:
(1) Verification of the magnitude of PCB and PCT wax
filler production and use;
(2) Development of detailed process descriptions,
including waste streams, leading to a complete
mass balance for the production and use processes
(including significant variations);
(3) Definition of quantities and concentrations of
waste streams, including waste form, abatement
techniques, and ultimate disposal methods; and
(4) Evaluation of all reasonable alternatives to the
use of PCBs and PCTs in casting.
A study plan to accomplish the above objectives was developed for GTS under
Task III of this program (Contract 68-01-3259).
3.4 Secondary Fiber Recovery (Paper Recycling)
The secondary fiber recovery industry converts wastepaper from
industrial, commercial, and municipal sources into reusable pulp, which is
subsequently used to produce paper products, either as is or blended with
virgin pulp. In the United States, there are approximately 230 paper mills
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TABLE 3.4-1
PCB CONCENTRATIONS IN WISCONSIN PAPER PLANT EFFLUENTS
Average PCB PCB
No. of Concentration Discharged Aroclor
Plant Determinations (ppb) li/s./day Type
Badger Paper Mills 1 <.l
Scott Paper
Marinette 1 <.l
Oconto Falls 1 <.l
Shawano Paper 1 <.l
John Strange Paper 1 4.00 .037 1242
Bergstrom Paper 4 28.40 1.25 1242
Kimberly Clark 1 0.28 .010 1242
Thilmany Paper 2 <.l
Fort Howard Paper
Mill Effluent 1 2.60 0.158 1242
Deinking 1 6.40 0.586 1242
Deinking & Mill Effluent 3 7.07 1.060 1242
American Can
Sulfite Sewer 1 0.10 0.002 1242
Paper Mill Lagoon 1 0.14 .012 1242
Charmin Paper 1 0.14 .019 1242
Green Bay Packaging 1 0.45 0.006 1242
Note: Effluent flow data for these companies was determined at time of PCB
sampling.
-130-
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which produce pulp completely derived f rcm wastepaper and 550 mills whose
generated pulp contains secondary fiber (typically 10 to 15 percent) .
Wastepaper stands third behind pulpwood and wastes from other forest
products as a source of paper pulp in the United States. In 1974, fiber re-
covery mills removed almost 13 million tons of wastepaper from the nation's
solid waste streams.
The effluent discharges from some of the secondary fiber mills has
been documented by Kleinert to contain Aroclor 1242, an apparent incidental
PCS contaminant occurring in the pulp production process. Table 3.4-1 shows
the PCS (as Aroclor 1242) concentrations and discharge rates for some paper
recovery within the State of Wisconsin. These data were collected in 1975 by
the Wisconsin Department of Natural Resources in an effort to survey PCB dis-
charges.
The following subsections present a review of the historical usage of
Aroclor 1242 in carbonless copy paper production and a brief description of a
secondary fiber recovery process.
3.4.1 Historical Use of PCBs in the Paper Industry
Aroclor 1242 (which appears to be the predominant PCB found in
mill effluents) was used in the manufacture of carbonless copy paper sold by
the Appleton Paper Division of the NCR Corporation during the period 1957 to
1971. Tables 3.4.1-1 through 3.4.1-3 provide data indicating: (1) The magni-
tude of Aroclor 1242 consumption in the manufacture of NCR carbonless paper;
(2) Production quantities of NCR carbonless paper; and (3) The weight percent
of Aroclor 1242 in carbonless paper.
From these tables, several significant facts are derived con-
cerning the magnitude of PCB use in the manufacture of carbonless paper products.
Seme of these facts are:
(1) Approximately 44 million pounds of Aroclor 1242
were purchased (from Monsanto) for the manufacture
of NCR carbonless paper;
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TABLE 3.4.1-1
HISTORY OF AROCLOR 1242 CONSUMPTION
IN THE MANUFACTURE OF NCR CARBONLESS PAPER
FOR THE YEARS 1957 THROUGH 1971^l>
YEAR (THOUSANDS OF POUNDS)
1957 587
1958 779
1959 1019
1960 1149
1961 1643
1962 1953
1963 2281
1964 2705
1965 3489
1966 4246
1967 4355
1968 5801
1969 6278
1970 6611
1971 1266
TOTAL - 1957 through 1971 44162
Note: From data compiled and reported by Appleton Papers Division,
NCR Corporation.
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TABLE 3.4.1-2
HISTORY OF NCR CARBONLESS PAPER PRODUCTION
FOR THE YEARS 1957 THROUGH 1971
YEAR
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
ESTIMATED NCR CARBONLESS
PAPER PRODUCTION - TONS
10010
13264
17434
20703
25504
29708
34583
41762
51.855
60594
69512
83250
87336
91576
88977
TOTAL,(1)1957 through 1970 726068
Note: Total excludes 1971 because use of Aroclor 1242 was
discontinued in May, 1971 but estimated production
of NCR carbonless paper is for full year.
-132-
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TABU: 3.4.1-3
RATIO OF AROCLOR 1242 CONSUMPTION FOR CARBONLESS
TO NCR CARBONLESS ESTIMATED PRODUCTION
(A)
Aroclor 1242
Year Consuitption ,, ,
Thousands of Pounds
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
587
779
1019
1149
1643
1953
2281
2705
3489
4246
4355
5801
6278
6611
1266
(B)
NCR Carbonless
Estimated Production
Thousands of Pounds
20020
26528
34868
41406
51008
59416
69166
83524
103710
121188
139024
166500
174672
183152
177954
PCB Content
{|f x 100
2.9
2.9
2.9
2.8
3.2
3.3
3.3
3.2
3.4
3.5
3.1
3.5
3.6
3.6
_
TOTAL(2) 1957
thru 1970
42896
1274182
Avg. 3.4%
Notes A^ From data compiled and reported by Appleton Papers Division,
NCR Corporation.
'^) Total excludes 1971 because use of Aroclor 1242 was discontinued
in May, 1971 but estimated production of NCR carbonless paper is
for full year.
-133-
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(2) The average weight percent of Aroclor 1242 in
carbonless paper was 3.4 percent;
(3) Of the total PCBs sold in the United States
during 1957-1971, 6.3 percent were sold for the
NCR carbonless paper application; and
(4) 28 percent of the total Aroclor 1242 sold by
Monsanto for plasticizer applications was
purchased for the manufacture of NCR carbonless
paper.
Although NCR developed and sold the product, the actual manu-
facturing step whereby Aroclor 1242 was incorporated into the paper was per-
formed by the Mead Corporation of Dayton, Ohio, who exclusively supplied
carbonless paper to NCR. NCR, in turn, either used the supplied paper to manu-
facture ledger (business) forms or sold and distributed the carbonless paper
to other form manufacturers. Aroclor 1242 is reported to be the only Aroclor
type used in the production of carbonless paper. Specifically, Aroclor 1242
was used as a solvent for certain color reactants which were encapsulated into
microspheres 10-20 microns in diameter and applied to one side of the paper
during the coating process. The walls of the microspheres consisted of a
gelatin-gum arobic formulation which was hardened by treatment with an
aldehyde (such as formaldehyde). Since 1971, alkyl biphenyl compounds have been
used in place of Aroclor 1242 as the dye carrier.
Very little is known about other uses of PCBs in the paper
industry. Past usage of PCBs in paper coatings and adhesives appears likely,
although the quantities used could not have been near the magnitude of PCB
usage in the carbonless copy paper. Almost certainly PCBs were used in some
of the inks, and possibly paper colorants, which can also be expected to occur
in wastepaper. According to Monsanto, the favored Aroclor type used in inks
was 1254, which contains most of the same iscmers as 1242 but at different
relative concentrations.
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In addition, PCBs can enter the pulping process through con-
tamination of intake water and in virgin pulp. Little is known about the
magnitude of any of these sources, or even how much carbonless copy paper
containing PCBs remains in files, etc. to enter the paper recycling processes
in the future.
3.4.2 Fiber Iteoovery Mill Process
The following is a generalized description of the mill process
for recovering paper fiber. Portions of this description was provided by the
Bergstrom Paper Company in Neenah, Wisconsin. Figure 3.4.2-1 depicts the
general process, up to the paper making section, in block form.
The fiber recovery process is a purification process wherein
fibrous materials are deinked and separated from non-fibrous materials through
controlled cleaning and mechanical treatment, followed by washing and cleaning.
The color is next removed from the pulp by a multi-stage bleaching system
accompanied by intermittent washing and centrifugal dewatering.
gulping and Deinking; The fiber regeneration process starts
with feeder crews loading the sorted paper onto a belt conveyor. The conveyor
feeds a bydropulper, where wastepaper is pulped and deinked through the action
of hot water, steam, caustic soda, and deinking chemicals. The breaking down
of the paper stock is accomplished through a combination of mechanical and
chemical treatment. At this point, larger metallic objects and other non-
paper materials mixed with the wastepaper are collected into traps at the
bottom of the pulper. The pulped stock leaves the hydropulper via extrusion
through perforated plates, and goes to blending chests for additional retention
time and agitation. From the blending chests the stock passes over a vacuum
filter which is used for heat and chemical recovery. Much of the filtrate is
recycled to the hydropulper; excess filtrate goes to treatment. The stock is
then diluted and sent to centrifflers where small metallic particles such as
pins and staples are removed.
-135-
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CAUSTIC SODA,
DRINKING CHEMICALS,
STEAM AND WATER
SORTED
WASTEPAPER^
PULPING
AND
DEINKING
WASTE SO LIDS
EFFLUENT
DISCHARGE
PRIMARY
CLARIFIER
(WASTE
TREATMENT)
WATER
HYPOCHLORITE,
CAUSTIC SODA
AND WATER
PULP
PULP
WASHING
WASHED
PULP ^
RECYCLED FILTRATE
EXCESS FILTRATE
EFFLUENT FROM
PAPER MAKING
WATER PLANT
DISPOSAL PLANT MISCELLANEOUS
TO
PAPERMAKING
STORAGE
BLEACHING
WASHED
AND
BLEACHED
PULP
PRODUCT
BLEACHED PULP
I WATER
PULP
WASHING
RECYCLED FILTRATE
SCREENING,
CLEANING AND
DEWATERING
-WATER
WASTE SO LIDS
Figure 3.4.2-1. MILL FIBER RECOVERY PROCESS AND WATER EFFLUENTS
-136-
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Pulpwashing: Accepted stock fron the centrifflers goes on to
the washing stage. Stock washing is accomplished in a four-stage counter-flow
washing system. The first stage consists of cylinder washing, the second and
third stages consist of sidehill washers, and the fourth stage is another
cylinder washer. The cleanest water is used for dilution at the fourth stage,
and the filtrate is fed to the preceding stage, finally reaching the first
stage from which the filtrate is discharged for waste treatment.
Bleaching: Following washing, the stock goes to a three-stage
bleachery. At the first stage the stock is chlorinated by sodium hypochlorite
solution in a tower. After chlorination, the stock is washed on a vacuum
filter. In the next stage the stock is treated with caustic soda and sodium
hypochlorite. After retention in a second tower the stock is diluted and again
washed on a vacuum filter. It is then treated again with sodium hypochlorite
in a third tower.
Screening and Cleaning: After retention in the third tower,
the bleached stock is diluted for the next cleaning process, which is a three-
stage pressure screen system. Accepted stock from the first stage pressure
screen goes to a five-stage centrifugal cleaner system for removal of small-
sized heavy contaminants. Following this, the pulp is sent to a four-stage
system of centrifugal cleaners for removal of lightweight contaminants.
After the cleaning, the stock goes to a final washing stage
and is then dewatered (thickened) and stored in high density towers for paper
making.
Flow Rates and Composition of Discharges: At Bergstrcm the
separate waterborne discharges from the paper and the paper making process are
combined with other facility waste streams and directed to a central waste
treatment system. Only the effluent from the primary clarifier of the waste
treatment system is discharged to the environment. The average effluent flew
rate for Bergstrom during 1975 was 3.9 million gallons per day. This volume
rate is broken down as follows:
-137-
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Volume Rate to Waste Treatment
Prooess Million Gallans/Day
Deinking 2.5
Paper Making .9
Water Plant .3
Disposal Plant and Miscellaneous .2
Table 3.4.2-1 is a tabulation supplied by Bergstrcm of the
1974 averages for various parameters in their raw water source and waste
clarifier effluent. The average Aroclor 1242 concentration in the effluent was
reported to be less than 8 ppb.
Reconmendation (Paper Recycling): The information presented
herein with regard to PCBs in paper recycling processes is based on a very
limited study effort on the secondary fiber recovery industry. It is recom-
mended that a more detailed study be performed of PCBs involvement in this
industry. Important aspects which should be addressed include:
(1) Definition of paper recycling processes and the
PCBs material balance therein (PCBs input versus
PCBs content in effluent and product);
(2) Definition of past PCBs usage in paper and routes
into recycled paper;
(3) Development of present distribution of PCBs
originally used in paper;
(4) Determination of applicable effluent treatment
methodology and associated cost estimates; and
(5) Projecting future contribution of PCBs to the
environment from this industry.
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TABLE 3.4.2-1
OCMPOSITICN CF RflW WATER AND CLARIFIER EFFLUENT (1974 DKTA)
(Bergstrom Paper Go.)
Aldrin, ug/1
Armenia Nitrogen, rag/1
Arsenic, ug/i
Barium, Vig/1
Beryllium, pg/1
Boron, "Pg/1
Cadmium, ug/1
Chloride, mg/1
Chlorine, mg/1
Chromium, yg/1
Cobalt, ygA
Copper, yg/1
Cyanide, mg/1
Dieldrin, yg/1
Fecal Coliform Oount/100 ml
Fluoride, mg/1
Heptachlor, yg/1
Lead, yg/1
Manganese, yg/1
Mercury, ug/1
Nickel, yg/1
Nitrate Nitrogen, mg/1
Nitrite Nitrogen, mg/1
Kjeldahl Nitrogen, mg/1
Oils, Fats, Grease, mg/1
Phenol, yg/1
Phosphorus, mg/1
PCBs, ug/1
Selenium, yg/1
Sulfate, mg/1
Sulfide, mg/1
Sulfite, mg/1
Suspended Solids, mg/1
Thallium, yg/1
Zinc, yg/1
BOD5, mgA
Paw Water
<0.1
0.32
<8
14
<0.3
33
<16
10
<0.5
<4
<14
<5
<0.005
<0.03
4
0.46
<0.07
<42
10
0.7
<33
0.29
<0.005
0.82
<1
4
0.11
<0.5
<8
45
<0.05
<2
<1
<1
67
1.1
Clarifier Effluent
<0.4
1.72
<8
140
<5
235
<16
482
<0.5
26
14
78
0.12
<0.03
<10
0.48
<0.5
85
50
0.5
<33
1.32
0.43
19.0
26.4
26
0.57
8.0 (1242)
<8
74
<0.05
<2
465
<25
420
665
-139-
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3.5 Industrial Use of PCBs as Hydraulic and Heat Transfer Fluids
3.5.1 General
The use of PCBs in hydraulic and heat transfer systems
increased rapidly during the 1950s and 1960s until, in 1970, the maximum sales
by Monsanto for these uses, plus lubricants, were about 11.3 million pounds, or over
15 percent of the total 1970 reported domestic sales. Since 1971, Monsanto has
not marketed PCBs for these uses, and although it should be noted that such
usage of PCBs in deep mining equipment is expressly allowed by the CECD agree-
ment to which the U.S. is party.
When PCBs sales for heat transfer and hydraulic uses were
eliminated by Monsanto in 1971, the affected industries turned to substitutes
or, in a very few cases, imported PCBs. Phosphate esters have found acceptance
in many types of hydraulic systems where PCBs were formerly used. Glycols and
other alcohols have replaced PCBs in some heat transfer systems, and there are
a number of other substitutes used for this purpose (including other chlorinated
hydrocarbons).
It is surmised that there are industrial concerns still using
PCBs in these semi-closed systems. Hesse reported at the National Conference
on PCBs in November, 1975 that a number of such users had been found in
Michigan. Later contacts with these same firms indicated that all had volun-
tarily replaced the PCBs in their systems with substitute fluids. Very little
work has been done to ascertain the magnitude of current PCBs usage for
hydraulic and heat transfer purposes. Of the total reported Monsanto domestic
sales of PCBs over the period 1957-71 for heat transfer fluids, hydraulic fluids,
and lubricants, 81 million pounds, it seems reasonable that at least 95 percent
have been replaced by substitutes or were in systems new obsolete. On this
basis the maximum amount still in use would be on the order of four million
pounds. A figure of two million pounds still in use is probably more accurate.
-140-
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3.5.2 Use of Imported PCBs by Joy Manufacturing
Until recently, Joy Manufacturing Go. (Pittsburgh, Pa.) manu-
factured mining equipment which utilized a PCB motor coolant. Joy imports PCBs»
as a mixture similar to Aroclor 1242, from France (Prcdelec). Presently, the
PCB type motors are no longer manufactured and have been replaced on new units
by an air-cooled motor. However, PCB coolant fluids purchased from France are
being used for servicing the old liquid coolant motors. Currently, there are
approximately 1100 of the old motors in the field, each of which contains an
estimated 3-4 gallons of PCB type coolant fluid. The operating time of these
motors before complete overhaul is between 1 and 2 years. The major benefit
derived from using the PCB type coolant was its fire retardant characteristics.
From the information received by representatives of Joy Manu-
facturing Company, and from available physical properties, it is estimated that
between 40,000 and 60,000 pounds of the imported PCB type coolant fluid would
be necessary to replace and " top off" the fluids in the old motors each year.
3.6 Recent Use of PCBs in Product Development activities
Since the voluntary limitation on the sale of PCB compounds in the
United States by Monsanto, small quantities of PCB compounds have been imported
for new product development by at least one U.S. company. Such a use appli-
cation, by E. I. duPont de Nemours and Co., Wilmington, Del., was for develop-
ment work on a new polymer which is derived from the reaction of decachloro-
biphenyl (deka) and Bisphenol A.
According to duPont representatives, they have imported small
quantities of deka from Caffaro (Italy) for experimental purposes with the
intent to develop a new product called NR-140 polymer. Approximately 2000
pounds of deka were imported in 1974; however, duPont did not import any deka
in 1975. A decision was made not to commercialize the new product because of
the uncertainties associated with the regulation of PCBs.
It is estimated by duPont that, if the new product had been
commercialized, the annual purchase of deka would be in the range of 5-10
million pounds.
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BIBLIOGRAPHY
1. Adduci, V.J., Letter to Mr. Russell Train with attachment entitled,
"Statement of Electronic Industries Association to Environmental Protection
Agency Concerning Proposed Toxic Pollutant Effluent Standards for Poly-
chlorinated Biphenyls (PCB)", June 25, 1975.
2. Air-conditioning and Refrigeration Institute, Letter to Dr. C.H. Thompson,
EPA, March 27, 1974.
3. AFML-TR-74-237, "Mfg. Methods for Production of Quality Superalloy Engine
Parts", DDC Acquisition No. AD B0074 DOL.
4. Blatz, Philip S.D., (E.I. duPont de Nemours and Company, Wilmington,
Delaware), Personal communication, August 14, 1975.
5. Bolin, A.E., (Van Train Electric Corp.), Telephone communication, October 31,
1975.
6. Butner, J., (Sangamo Electric Co.), Personal ccnmunication, October 2,
1975.
7. Clark, R., (Universal Manufacturing Corp.), Telephone ccnmunication,
November 24, 1975.
8. Colder, A.W., (Joy Manufacturing Co., Pittsburgh, Pa.), Personal
oommunication, September 8, 1975.
9. Dornbush, W., (MoGraw-Edison's Power System Div.), Personal comunication,
September 23, 1975.
10. Falk, Bernard H., (National Electrical Manufacturers Association), Letter
to Dr. C. Hugh Thompson, EPA, March 25, 1974.
11. Farnsworth, George B., presented General Electric Testimony, FWPCA(307)
Docket No. 1.
12. Gabel, H.E., Jr., (Niagara Transformer Corp.), Telephone communication,
November 3, 1975.
13. Gunn, R., (H.K. Porter Co., Inc.), Telephone communication, November 3, 1975.
14. Hart, L.P., Jr.; Wright, Gary; Marquis, R.; and McKenzie, W.R. , (General
Electric Co.), Personal cottnunication, October 22, 23, and November 11, 25,
1975.
15. Hesse, J., (Michigan Department of Natural Resources) , paper presented in
Chicago, EPA sponsored symposium on PCBs, November 19, 1975.
-142-
-------
16. Hubbard, H.L., Encyclopedia of Chemical Technology, 1965, Vol. 5_, pp 289-297.
17. Jard Company, Inc., Letter to the Consumer Products Safety Commission,
May 2, 1974.
18. Johnsen, L.A., (Research-Cottrell Manufacturing Division), Personal
conmunication, October 28, 1975.
19. Kleiner, S., Survey of Effluents in the State of Wisconsin in 1974 and 1975
by the Wisconsin Department of Natural Resources, Data presented in Chicago,
EPA sponsored symposium on PCBs, November 19, 1975.
20. Kingsolver, W.S.,(McGraw-Edison Co.), Personal conmunication, December 15 &
26, 1975.
21. Leighton, I.W., "Demonstration Test Burn of DDT in General Electric's
Liquid Injection Incinerator", U.S. EPA Region I, 1974.
22. Leisy, A.E. & Smull, Warren, (Monsanto Industrial Chemicals Co.) Personal
oannunication, October 8, 1975.
23. Leisy, A.E., (Monsanto Industrial Chemicals Co.), Personal conmunication,
November 6, 1975.
24. Lewis, W.H., (President, Signicast Corp., 9000 North 55th Street,
Milwaukee, Wise.), Statements made during lecture of Investment Casting
Institute meeting, October 4, 1975.
25. Monsanto Industrial Co., Testimony, FWPCO(307) Docket No. 1, Presented by
Mr. W.B. Papageorge.
26. National Industrial Pollution Control Council's Report, "The Use and
Disposal of Electrical Insulating Liquids", June, 1971, p. 10.
27. Nelson, J.S., (General Electric) , Letter to Dr. Martha Sager, with
attachment entitled The Impact of a "Ban" on the Use of PCB in Capacitors,
November 21, 1973.
28. Nelson, J.C., and Simon, E.L. (General Electric Company), Personal
communication, September 4, 1975.
29. Oliver, O.M. , (Standard Transformer Co.), Telephone communication,
October 30, 1975.
30. Ortman, J., (Sprague Electric Co.), Telephone communication, November 20,
1975.
31. Papageorge, W.P., (Monsanto Industrial Chemicals Co.), Personal
catrounication, August 27, 1975.
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-------
32. Pierle, A. Michael, (Monsanto Industrial Chemicals Co.), Polychlorinated
Biphenyl Study, Personal communication, November 17, 1975.
33. Report on Power Transformer Troubles, 1969, Edison Electric Institute
Publication No. 71-20 (1971).
34. Rollends, D., (Jard Corporation), Personal cornnunication, October 2, 6,
1975 & January 15, 1976.
35. Rountree, William C., (Assistant General Counsel for Legislation, U.S.
Dept. of Commerce), Letter to Dr. C. Hugh Thompson, EPA, March 26, 1974.
(See discussion of PCB beginning on fourth page of attachment).
36. Salazer, A., (National Electrical Manufacturers Association (NEMA)),
Personal conrnunication, August 19, 1975.
37. Solomon, P., (Yates Manufacturing Co., Chicago, Illinois), Personal
cormunication, September 9, 1975.
38. Stenger, R.A., "Monitoring of the General Electric Company", U.S. EPA
Region II, Surveillance Analysis Div., Edison, N.J. September 26, 1975.
39. Thallner, K.A., (Helena Corporation), Telephone conmunication, October 31,
1975.
40. Thayer, J.H., (General Electric Co.) , Personal communication, October 15,
1975.
41. Tuttle, C.; Teeple, P.L.j Hutzler, J.R.; & Butterworth, N., (Aerovox
Industries, Inc.), Personal comnunication, September 25, 26, 1975.
42. Uptegraff, R.E., (R.E. Uptegraff Mfg. Co.), Telephone conmunication,
November 3, 1975.
43. Vollmar, John R., (Louis T. Klauder and Associates), Letter to Dr. C. Hugh
Thompson, EPA, March 22, 1974.
44. Wblsky, S.P., (P.R. Mallory & Co., Inc.), Telephone communication, November
21, 1975.
45. Wurster, W., (General Manager, Consolidated Casting Corp, 2425 Carolina St.,
Dallas, Texas), November 5, 1975.
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SECTION VI
WASTE TREATMENT TECHNOLOGIES
1.0 INTRODUCTION
This section includes descriptions and discussions of existing and proposed
technologies for the treatment of various types of wastes generated at PCB-
producing and PCB-using plants. Also included are discussions of the presently
available control technologies and technologies to be available within three
years, plus technologies that will not be available for five or more years. The
treatment and control costs included here have been developed and presented in
the Task II report "Assessment of Wastewater Management, Treatment Technology,
and Associated Costs for Abatement of PCBs Concentrations in Industrial Effluents",
EPA Contract No. 68-01-3259, issued February 3, 1976.
1.1 Summary of Waste Management Problem Areas
Based upon detailed plant inspections and examinations of the processes
in the production of PCBs and their use in capacitors and transformers, it has
been determined that there are four major categories of wastes to be considered:
waste liquid PCBs, PCBs in wastewater, PCB contaminated solid wastes, and airborne
PCB emissions. It has also been determined that the characteristics of wastes in
PCBs producing and using operations are similar enough that the same kinds of
control and treatment technologies can be used.
1.1.1 Waste Liquid PCBs and Contaminated Scrap Oil
The users of dielectric materials have strict requirements for
purity. Typical requirements are:
Inorganic chlorides 100 ppb maximum
Acidity, mg KOH/g 0.01 maximum
Water content 30 to 35 ppm maximum
Resistivity, 100°C, 500 V, 100 to 500 x 109 ohm-cm,
0.1 inch gap minimum
Dielectric strength, 25°C 35 kv minimum
- 145 -
-------
When these or other properties cannot be met at the producer's
facility, or by the user during transformer and capacitor filling operations,
and it'is found that the properties cannot be restored to askarel specifications
by filtering and drying,disposal is required. The types of PCB contaminated
liquids requiring disposal are:
1. PCBs contaminated with mineral oil
2. Mineral oil contaminated with PCBs
3. Nonreclaimable contaminated transformer askarels -
arced askarels, askarels from manufacturing spills
and sump accumulations, and askarels from holding
basins, drip and drain pans, washings, sample jars
and containers
1.1.2 PCBs in Wastewaters
The most likely pathways by which PCBs enter wastewater streams
are operator wash-up after PCB handling and groundspills that mix into rainwater
runoff. The significance of the first pathway can be illustrated by the realiza-
tion that sixteen operators (or 4 operators 4 times a day) washing 1 ounce per
day of PCB from their hands, account for one pound per day of PCB discharge.
Other wastewater categories discussed in the industrial character-
ization section of this report are:
1. Incinerator scrubber and quench water
2. Steam jet ejectors in vacuum distillation
3. Capacitor detergent wash solutions
1.1.3 PCB-Contaminated Solid Wastes
Solid wastes can be divided into two categories, burnable and non-
burnable.
1.1.3.1 Burnable Solid Waste Materials Containing PCBs
Burnable wastes can be disposed of by high-temperature
incineration. Such wastes consist of cellulosic materials, rags, pressboard, wood,
sawdust, fuller's earth in bulk or in cloth bags, blotter papers, nitrile or cork
gaskets, and similar materials.
- 146 -
-------
1.1.3.2 Nonburnable Solid Waste Materials Containing, or
Contaminated with PCBs
Nonburnable wastes may consist of capacitor and trans-
former internal components; steel, copper and aluminum components; filter units
of the steel mesh construction type; and askarel drums and cans. Wastes of this
type should be drained, with the liquid collected in drip pans, before disposal.
1.1.4 Air Emissions of PCBs
Although PCBs have very low vapor pressures they can be emitted
to the atmosphere from the following operations and practices:
1. Aroclor scrubbing of air in PCBs manufacture
2. Vapor exhaust from steam jet ejectors
3. Evaporation from accidental spills
4. Evaporation from hot surfaces as part of flood-
filling, inspection or holding operations
5. Vacuum pump exhausts
6. Evaporation from plant wastewater
1.2 Summary of Current PCBs Waste Control Practices
1.2.1 Control of Waste Liquid PCBs and Contaminated Scrap Oils
Plant visits have shown the major control methods to be inciner-
ation and disposal in sealed drums sent to sanitary landfills. Both incineration
and landfilling may be carried out by the facility generating the waste, or the
facility may engage a contractor.
Monsanto, the only U.S. producer of PCBs, has an incinerator
(designed by John Zinc, Inc.) that vaporizes PCB liquids and sustains them in a
turbulent burning gas at more than 2200°F for 2 seconds. One transformer manu-
facturer uses a John Zink designed incinerator that vaporizes PCBs and burns them
at 1600 to 1800°F for 3 seconds or longer; this facility can also destroy PCBs
soaked into transformer internal parts, but cannot routinely handle spent fuller's
earth.
- 147 -
-------
A number of PCB users send their solid wastes to the Rollins
Environmental Services facility at Logan Township, N.J. Rollins uses a specially
designed complex having a rotary kiln and a liquid turbulent burning chamber,
both of which exhaust into an afterburner. Liquids can be burned in either the
liquid chamber or the kiln; in the kiln liquid wastes can help to incinerate
solids. The afterburner is 40 feet long, providing good residence time, and it is
followed by a hot duct of about equal length that allows further combustion.
Rollins claims a residence time of 3 to 4 seconds at a minimum temperature of
about 2400°F at the aft end of the hot duct. The gases then go to a venturi
scrubber and a tower scrubber for cooling and neutralization. For non-PCB incin-
eration, Rollins sometimes lowers combustion temperature to 2200°F and residence
time to 2 to 3 seconds. These residence times and temperatures were chosen experi-
mentally to get 99.999-percent PCB destruction. This facility also handles all
kinds of solids,as will be explained later, and it operates with EPA approval.
Another facility that incinerates liquid PCBs, with New York
State EPA approval, is the Chemtrol Corp.'s facility at Model City, New York.
Liquids going to landfill are sealed in drums and added to land-
fills that have deep clay bases and impervious bulkheads to prevent leaching and
seepage. However, incineration is the preferred disposal method for liquids.
1.2.2 Control of PCBs in Wastewaters
Our plant investigations have revealed that there are no methods
being practiced whereby dissolved or otherwise bound PCBs in water streams are
being either extracted from those streams or destroyed in them.
In the separation of PCBs from wastewaters, PCBs and sludges are
removed from the bottom of water bodies, while oily phases are removed from the
surfaces. However, nothing as yet is being done to treat the water layer itself;
this is the area of PCB wastes control and treatment most needing development.
In general, waste streams contain between 1 ppb and 500 ppb of
PCBs; most levels range between 10 and 50 ppb. PCB concentration of less than 1
ppb are undetectable.
- 148 -
-------
Several plants use methods to keep the quantity of PCB
contaminated wastewaters as small as possible. A few plants planned adsorp-
tion tests with carbons and other adsorbents, but there were no full-scale
operations.
1.2.3 Control of Solid Wastes Contaminated with PCBs
The two current methods of disposal of solid or semi-solid
PCBs wastes are incineration and landfill. Since we found only one PCB-
using manufacturing facility with partial incineration capability, and
Monsanto"s incinerator cannot handle solids, all facilities except one must
ship their solid wastes away from the plant site for either treatment. The
one plant with partial capability can incinerate transformer internals to
recover copper, and also can incinerate paper, rags, cardboard and the like.
However, they do not as yet, incinerate fuller's earth, contaminated dirt, and
similar materials. These are drummed and stored for later disposition.
Although there are a number of experimental facilities through-
out the U.S. that could undboutedly incinerate all types of solid materials,
one commercial venture has received the bulk of the work. Rollins Environmental
Services can handle liquids incineration. For solids incineration of almost
all types, the tumble burner or rotary kiln is used. When PCB contaminated
materials are to be destroyed, the kiln temperature is brought up to 2200°F.
All kinds of solids, packed in 47-gallon lined fiber drums and not posing
unusual safety hazards are accepted. The current (late 1975) fee is about
7-1/2C/pound. Additional charges of $3/fiber-drum handling, plus transporta-
tion charges, and possibly other charges for unusual problems, might be made.
Rollins will not accept impact sensitive, radioactive
materials, or heavy metals concentrations of more than 25 ppm in the PCBs
wastes. For wastes packed in steel drums, Rollins charges a $10/drum handling
charge. As a general rule, anything packed according to the latest ICC tariff
for hazardous materials will be accepted.
As with the liquids incineration, the gases from the kiln at
2200°F pass to the afterburner at a temperature of about 2500°F. Gases exit
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the afterburner to a long hot duct that completes combustion and maintains
the temperature at 2400°F until the gases enter the venturi scrubber, and
thence to the lower scrubber and then the stack. Rollins has experimented
with lower temperatures of 2000 to 2200°F and has not found destruction of
PCBs to be at the 99.999 percent level desired. The residence time for gases
at the 2400°F must be 3 to 4 seconds in a turbulent regime.
With regard to landfilling, one commercial venture has
handled a large quantity of the PCB solid wastes under supervised conditions.
The Chemtrol Pollution Services Co. of Model City, N.Y., operates a landfill
located on the shore of Lake Ontario, under New York State EPA supervision,
in a geologic setting claimed to be ideal for complete containment.
This "scientific landfill" is located entirely above ground
on a bed of 40-feet-thick clay. Constructed on this foundation are cells for
receipt of drummed solid wastes. The cells are lined with 30-mil chlorinated
polyethylene film, and when loaded, are sealed, or covered with 5-feet of clay.
At the bottom of each cell there is a sump, so that all leachate is collected
and removed. That leachate is pH controlled, settled, filtered, and treated
by flow through a carbon bed.- The ground and surface waters are checked
monthly for chemical content by an outside analytical laboratory. The facility
has been approved for usage as a PCB disposal site by the New York State EPA,
and thousands of drums have been landfilled over the last five years. An
inventory is kept of the contents of each cell.
Chemtrol has the capability of converting semisolids and
sludges to solids by using silicate cement powders and proprietary gelling
agents.
Our review and analysis of the industrial situation for PCBs
-solid wastes control shows there are adequate options, at higher prices, for
safe disposal and destruction. There is no longer a justification for open
dumping to the ground or in lagoons.
1.2.4 Control of Air Emissions of PCBs
Most air emissions from ambient temperature PCBs are not con-
trolled or collected for treatment in any way. PCB emissions generally are
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collected as part of the overall plant air exhaust, which frequently is ducted
to roof exhausts without treatment. Several plants used exhaust chilling and/
or fibrous or granular filtration of air; these methods offer the potential
for PCB emission reduction.
The hot flood-filling of capacitors is followed by a cool
down period before the filling tank is opened to the plant atmosphere. How-
ever, the temperature is still between 100 and 150°F; the area of the opening
is several square meters, through which tank gases can reach the plant atmos-
here. The tanks have individual exhaust ducts, but they lead directly to a
roof exhaust system. The PCB-covered capacitors are held in an oven at 100 to
150°F to prevent any moisture condensation before sealing. Vapors from this
storage are ducted to the roof and vented also.
In some cases, waste scrap oils containing PCBs are burned
together with fuel oil in standard boiler systems. In these instances much of
the PCB content is probably vaporized and exhausted to the air, rather than
incinerated.
2.0 CANDIDATE PCBs WASTE TREATMENT TECHNOLOGIES CONSIDERED
As part of the examination phase of this study of alternative methods, we
have contacted a number of equipment suppliers, developers, and researchers,
in both the U.S. and elsewhere.
Key information was obtained on potential methods of PCBs removal from,
and destruction in, wastewaters, by cooperative testing between Versar, Inc.,
and several materials suppliers and process developers. Their assistance is
gratefully acknowledged.
We visited the U.S. producer, IVbnsanto, and several transformer and capac-
itor manufacturers to ascertain the nature, characteristics and quantities of
plant effluents that now contain measureable amounts of PCBs, or might contain
PCBs following a spill or other incident. This has provided the background for
weighing the advantages and disadvantages of all available technology for poten-
tial application to PCBs wastewater treatment. We discussed and evaluated the
control methods now used, possible shortcomings, and ideas for more optimized
systems.
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In order to find the new technology and approaches that might be forth-
coming, we made a computer search of Chemical Abstracts from 1972 to the
present, and focused on degradation, decomposition and waste treatment data.
Searches were also made of the Lockheed Engineering Index, National Technical
Information Service, and Predicasts for information on new developments.
The text reference used as a source of summarized data prior to 1972 was:
The Chemistry of PCBs, by Hutzinger, Safe and Zitko, published in 1974 by
CRC Press.
Candidate treatment technologies have been divided into the same four
categories listed in Section 1.1. Also, as we evaluated technologies, they
were placed into categories, as follows, indicating their level of development:
1. Demonstrated Full-Scale Treatments
2. Pilot-Scale Methods
3. Research Approaches to PCBs Removal or Destruction
Some treatment methods were designed for disposal of compounds similar to
the PCBs, e.g., chlorinated hydrocarbons and other refractory organics.
The full-scale plant treatments are ready for application to PCB waste
problems now. The pilot-scale methods are expected to take one to five years
to be developed to the point where they will be determined suitable, or un-
suitable, for plant-scale PCBs applications.
Methods currently under development are expected to take three years or
more before being ready for plant-scale applications.
Section 2.5 contains a discussion of the applicability of various treat-
ments to the zero discharge objective.
2.1 Treatment of Waste Liquid PCBs and Contaminated Scrap Oils
Only tvro kinds of treatment or disposal methods are considered suit-
able for waste liquid PCBs and contaminated scrap oils, and they are now being
used. However, there are improvements and design features needed to prevent
PCB transfer into the water, air or land.
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2.1.1 Incineration
The standard configuration, long cylindrical steel combus-
tion chamber, having a length to diameter ratio of between 4/1 and 8/1 and
well insulated with high alumina refractory brick, is suitable as a primary
chamber. Two injectors should be provided: one for a high-BTU gas or fuel
oil, and one for the PCB waste liquid. Primary air or steam is provided to
vaporize oils, and secondary air is added to complete combustion and provide
excess air. These feeds should be made tangentially, or with adequate baff-
ling to assure turbulent flow throughout, and to prevent hot or cold spots in
the chamber. It is obvious that almost any residence time may be allowed for
a gas flowing through a cylindrical chamber. However, there is a maximum
residence time above which turbulence is assured throughout the chamber.
Turbulence throughout is assured when wall temperatures are uniform in all
parts of the chamber. Most fuel flames provide adiabatic combustion tempera-
tures of about 3000°F. When the more endothermic PCBs are being destroyed,
the flame can be rapidly cooled to 2200 to 2500°F; for the very high destruc-
tion efficiences desired, 99.999 percent or higher, this is the minimum tem-
perature range required, for a residence time of 3 to 4 seconds. After combus-
tion there should be allowance for afterburning, which may be accommodated in
insulated ducts. These can be of sufficient length to assure total residence
time of 3 to 4 seconds. Following the combustion phase there must be rapid
cooling of the gases, usually by the injection of cold water from a peripheral
ring of sprays or jets. Also, the cooling water should be neutralized so that
hot hydrochloric acid contact with further components is obviated.
In some systems a high energy venturi scrubber is used to
control particulates, if they are expected in the gas stream. In all systems
the gas stream is then washed counter currently with water, or water plus
neutralizing agent, in some form of a packed tower. Usually a demister is the
last element contacted by the gas before it is exhausted through the stack.
The stack gas emissions and the scrubber effluent liquid
should be monitored periodically for PCBs levels, and the incinerator should
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have adequate automatic controls to prevent PCBs from being emitted unde-
stroyed. The chief fail-safe control is a pyrometer that causes burner shut-
down if the combustion chamber or duct temperature drops below about 2150°F.
There are other controls that can warn if such an occurrence might take
place. These flow rate controls on the primary and secondary feeds can be
monitored so that low fuel flow, or high PCBs-to-fuel flow ratio can indi-
cate a temperature drop. Inadequate air flow can also cause temperature
decreases. All such parameters should be monitored, and adequate operator
Warnings provided. And, of course, to prevent destruction of the venturi
scrubber sections, shutdown should automatically take place if cold water
flow is ever insufficient.
2.1.2 Sanitary or Scientific Landfill
Sanitary landfilling is an alternative to incineration for
PCB users who cannot justify incineration facilities just for PCBs, and who
have no waste pickup service organization within reasonable distance. Land-
fills that will adequately contain PCBs should have all the features described
in Section 1.3.3 above, plus there must be assurance that the liquid containers
will be sealed and leak proof, and have long life in the landfill.
2.2 Treatment of Wastewaters Containing PCBs
Treatment of wastewaters containing PCBs has received very little
attention in practice thus far. Our survey has found a variety of methods for
reduction, and even for achieving "zero discharge", of PCBs in wastewaters.
2.2.1 Carbon Adsorption
Carbon adsorption is a well-known water purification and
industrial product purification technique. The use of carbon adsorption is
well-suited to removing PCBs from wastewater since it is most effective in
removing high molecular weight, non-polar, relatively insoluble compounds from
water. All these requirements are met by the PBCs.
As will be discussed later, Versar has conducted tests, in co-
operation with carbon suppliers, demonstrating the relative effectiveness of
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various activated carbon products. PCB concentrations on the order of
1 ppb were taken as a reasonable effluent objective.
The disadvantage of carbon adsorption is that once used,
the carbon may have to undergo destruction by high temperature incineration
rather than be regenerated, as is the usual practice. The great advantage of
carbon treatment is that a wide spectrum of other toxic organics can simul-
taneously be effectively removed from water.
Carbon adsorption is currently being used in large-scale
municipal water purification systems. Thus capital costs, operating costs
and reliability factors are well-known. At the 68th Annual AIChE Meeting in
November 1975, G. Strudgeon of Zurn Industries described design features for
a 30-million-gallon-per-day carbon system to be built for municipal waste-
water treatment at Garland, Texas. This system will cost $5 million, includ-
ing carbon regeneration. Operating costs are expected to be $6,000 per day.
Although carbon adsorption is the only mechanism thus far
proven effective in removing PCBs, three other carbon-based treatment tech-
niques are under study: biodegradation, whereby bacteria-coated carbon
particles break down pollutants in wastewater; catalytic action, wherein a
very active surface holds pollutant molecules while other degradation or
oxidation reactions take place; and chemical reaction, in which carbon is
actually depleted as part of a chemical reaction that removes pollutants. The
techniques were also discussed at the 68th Annual AIChE Meeting.
As an adjunct to this evaluation study, Versar conducted co-
operative laboratory adsorption isotherm tests with Carborundum Company and
ICI-US. These tests have extended the ranges of carbon adsorption data pub-
lished by Calgon Corp. into higher and lower concentrations. Laboratory
adsorption isotherm testing is a reliable technique for determining the feas-
ibility of adsorption treatment for PCBs removal from wastewaters and specifi-
cally indicates:
1. The effluent levels of PCBs concentration
obtainable by adsorption treatment
2. The weight of PCBs adsorbed at the
concentrations being studied
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On the other hand, the laboratory test does not determine
the necessary contact time for granular carbon beds to effect the desired
reduction. This determination is usually performed in small pilot carbon
beds under hydraulic flow conditions.
Laboratory and pilot plant tests involving PCBs must be
designed to prevent losses of PCBs. The root of the problem is the very
low, parts per billion, solubility of PCBs in water. Examples of pathways
of experimental loss are:
1. Evaporation to the air
2. Adsorption on a variety of solid surfaces
and sediments
2.2.1.1 PCBs Adsorption Testing by Carborundum Company
Versar, Inc., together with Carborundum Co., con-
ducted a preliminary study to determine the ability of an experimental, coal-
based activated carbon in removing PCBs from water. This study also provided
an analytical check in that both companies made electron-capture gas chromato-
graph analyses on the same samples, and there was close agreement on results.
The1 coal-based activated carbon had a surface area
of 950 to 1050 square meters per gram. The iodine number was approximately
the same as the surface area, indicating that almost all of the pores had a
diameter greater than 10 to 15 Angstroms.
The control and test samples were filtered before
extraction and gas chromatographic analysis. The removal of PCBs by solids,
surfaces, filter media, and the like, was known and expected prior to these
tests, thus a high PCB concentration in the filtered control and test samples
was the target.
The PCB mixture used was Aroclor 1254. It was solub-
ilized by methanol to give a 1000 ppm stock solution. This was diluted with
distilled water to prepare 1000-ppb test solutions.
Table 2.2.1.1-1 presents the data. The filtered
control level is considered the actual level the carbon was adsorbing, rather
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TABLE 2.2.1.1-1
CARBORUNDUM CD. TESTS OF PCBs (AROCLOR 1254)
REMOVAL FROM WATER BY AN EXPERIMENTAL ACTIVATED CARBON
Prepared PCBs
Concentration (ppb)
Control - 1000
Test 1000
Test 1000
Test 1000
Carbon Dosage v
(mg/D
—
1.0
2.0
10.0
PCBs Cone.
Before Treatment
[Control Cone. After
Filtering] (ppb)
160
160
160
160
Effluent PCB
Cone. After
Carbon Treatment
(ppb)
—
59
20.6(2)
22.0(3)
2.6(2)
2.4<3>
Percent
PCBs
Removal
—
63.1
87.1
86.2
98.4
98.5
NOTES:
(1)
(2)
(3)
Experimental material, coal-based, 950-1050 square meters/gram.
Versar Inc.'s analysis.
Carborundum Co. "s analysis.
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than the prepared level. The filter removed 84 percent of PCBs in these test
runs. •
As shown in Table 2.2.1.1-1, the percent PCBs re-
moved from a concentrated water solution (160 ppb) at low carbon dosages was
quite good. During plant surveys we found PCBs concentrations in wastewater
destined for river discharge to range from 50 to 500 ppb, so the 160-ppb con-
centration treated in this study was an intermediate value; it was, however,
also the highest value treated in the cooperative studies under this program.
Carborundum Co. plans to continue this effort to
determine the effects of other carbon dosage levels on various feed PCBs con-
centrations. The data given here are only considered preliminary.
2.2.1.2 PCBs Adsorption Testing by ICI-US
In a cooperative program with Versar, ICI-US performed
preliminary adsorption tests to determine the ability of powdered carbon in
removing Aroclor 1254 from water. Versar conducted all analytical tests for
this program.
The Aroclor was solubilized with methanol so that a
1000-ppm concentration of Aroclor 1254 in water was achieved. Two types of
granular activated carbon were tested: lignite base, and coal base. Both
types were ground to a fine powder (90 percent through 325 mesh) before adsorp-
tion testing. Prior to grinding, the lignite-base and coal-base carbons had a
surface area of about 650 square meters per gram and 1000 square meters per
gram, respectively.
The test solutions were made up from distilled, de-
ionized water to a volume of 1 liter. Four levels of Aroclor concentrations
/
were treated: 10 ppb, 100 ppb, 500 ppb and 1000 ppb. Both the control and
treated solutions were filtered before analysis. The great affinity of PCBs
for all solid surfaces was not fully anticipated, during these tests. The fil-
tration was uniform for all samples through 2.4-cm Reeve Angel fiberglass
discs (Grade 934AH). As can be seen in Table 2.2.1.2-1, most of the PC3s were
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TABLE 2.2.1.2-1
ICI-US TESTS OF PCBs (AROCLOR 1254) REMOVAL
FROM WATER BY TWO TYPES OF COMMERCIAL CARBONS
Prepared PCBs
Concentration (ppb)
Control, 10
Test, 10
Test, 10
Control, 100
Test, 100
Test, 100
Control, 500
Test, 500
Test, 500
Control, 1000
Test, 1000
Test, 1000
Type
Lignite^
Coal<2>
—
Lignite
Coal
—
Lignite
Coal
—
Lignite
Coal
Carbon
Dosage (mq/1)
4
4
—
30
30
—
100
100
—
100
100
PCBs Cone.
Before Treatment
(Control Cone.
After Filtering)
(ppb)
1.07
1.07
1.07
11.15
11.15
11.15
5.32
5.32
5.32
37.5
37.5
37.5
Effluent
PCBs Cone.
(After Carbon
Treatment)
(ppb)
0.177
0.190
—
0.213
0.111
—
0.09
0.114
—
0.32
0.24
Percent
PCBs
Removal
83.5
82.2
—
98.1
99.0
—
98.3
97.9
—
99.2
99.4
NOTES: Larger pore, 650 square meters per gram.
Smaller pore, 1000 square meters per gram.
-------
removed in filtration. However, by using the filtered "control sample" as an
approximation of the amount the filter removes from all feed samples, we can
get a good preliminary estimate of the PCBs removal ability of the two kinds
of commercial carbons at various wastewater pollutant levels, and at various
carbon dosages.
The results of these laboratory tests indicated
that powdered carbon was highly effective in removing PCBs from water at four
levels from 1 to 40 ppb. There was not a great deal of difference between the
effectiveness of the two carbons. The lignite carbon has relatively large
pores and smaller surface area than the coal-based carbon. The lignite-based
carbon simulates the activity of the coal-based carbon after the latter has a
number of thermal regenerations. Thermal regeneration tends to increase the
pore size, and lower the surface area of any given carbon. These kinds of
activated carbons, however, tend to stabilize at about 550 square meters per
gram, even after many regenerations.
The conclusion from these results is that carbon-
adsorption can be effective in removing PCBs from wastewaters, even after many
thermal regenerations. It is quite significant that in all these tests, the
treated effluent PCBs levels ranged frcm 90 to 320 parts per trillion, which
are well below the target maximum PCB level of 1 ppb.
Further testing is needed to get confirmatory iso-
therm data and column test data. In column tests, the granular form of carbon
was used, and, therefore, some of the interior portions of the carbon were
not as accessible as they would have been in the powdered form. Thus the
tests with powdered carbon, given on a weight fraction basis (i.e., pounds
PCBs removed per pound of carbon), yield the maximum weight fraction of PCBs that
that can be removed in a scaled-up commercial system.
2.2.1.3 PCBs AdsorptionTesting by Calgon Corp.
Adsorption isotherms were run on Aroclor 1242 and
1254. Stock solutions of each compound were prepared in acetone at 100 mg/1.
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(R)
Filtrasorb 300 (FS-300) activated carbon was used throughout. Carbon was
added from a stock suspension of 1 g or 2 g of pulverized FS-300 per liter of
distilled water.
Isotherms of Aroclor 1242 and 1254 were prepared
by the following method. Exactly 1 ml of PCB solution was added to seven
flasks, each containing slightly less than 1 liter of distilled water.
Measured volumes of the 2 g/1 carbon stock solution was added to each flask
to give carbon concentrations of 0,2,5,10,25,50 and 100 mg/1. The total
volume of each flask was 1000 ml. After four hours agitation on a wrist
shaker, each solution was filtered through 0.45 micron millipore pads and
stored prior to analysis in a refrigerator in quart amber glass bottles
having Teflon-lines caps.
A nickel-63 electron capture gas chromatograph was
used for analysis; all samples were extracted and concentrated approximately
100 times before analysis. The method is described in the 1971 EPA report,
"Methods for Organic Pesticide Analysis in Water and Wastewater."
Table 2.2.1.3-1 shows the PCBs removal data, and
gives comparative data for Aldrin. It appears that the Aroclors are removed
as effectively as pesticides. Removal from the 50-ppb level to the 1-ppb
level seems possible.
Figure 2.2.1.3-1 shows the Calgon data plotted to
give the weight percent of PCBs that Filtrasorb-300 carbon can adsorb, at
levels down to 1 ppb. As can be seen, the curves take a downward break at
about 2 to 3 ppb, indicating that the weight of activated carbon required to
remove a unit weight of PCBs is rising rapidly. If this kind of data is con-
firmed with larger-scale column testing, it would mean that removal of PCBs
from water in the parts per trillion range is far more difficult than removal
in the parts per billion range.
Also from the figure it can be seen that the
initial concentrations (C ) of the Aroclors were about 100 ppb. However,
filtration before testing removed PCBs so that the starting concentrations for
the tests were 45 and 49 ppb.
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TABLE 2.2.1.3-1
RESULTS OF CALGON CORP. LABORATORY ISOTHERM
TESTS FOR CARBON REMOVAL OF PCBs
Carbon
Dosage (mg/1)
Residual (ppb)
Aroclor 1242
Control 45
1.0
2.0 7.3
2.5
5.0 1.6
10.0 1.1
12.5
25.0
50.0
Aroclor 1254
49
—
37
—
17
4.2
—
1.6
1.2
Aldrin
48
—
26
—
15
12
—
6.3
4.4
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1.0
o
Q_
I-
I
o
UJ
0.1
0.01
Aroclor 1242
Filtered
0.1 1.0 10.0 100.0
CONTAMINENT CONCENTRATION (PARTS PER BILLION)
Figure 2.2.1.3-1. EQUILIBRIUM CARBON ADSORPTION OF PCB'S FROM WATER AT
LOW CONCENTRATIONS (CALGON DATA)
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Hager and Rizzo of Calgon Corp. have described the
essential elements of full-scale adsorption systems in a paper presented to
the EPA Technology Transfer Session on Treatment of Toxic Chemicals held in
Atlanta on March 19, 1974. Each system is comprised of three basic functional
components:
1. The adsorption treatment of the wastewater
2. The carbon reactivation equipment
3. The carbon/water transport arrangement
For PCBs, the practicality of reactivation must be determined.
2.2.1.3.1 Adsorption Treatment of Wastewater
The adsorbers hold the granular activated
carbon beds through which the wastewater flows. They can be designed for
pressure or gravity flow to achieve the desired contact time of the water with
the carbon. Suspended solids and space limitations also must be considered in
the adsorber configuration. Flow rates usually fall under 10 gpm per square
foot of carbon bed surface area. Contact times for industrial wastewater
mixtures usually are in excess of 60 minutes, which is about twice the time
employed for purification of domestic sewage. When suspended solids are present,
they can be filtered out by the carbon bed; this dual purpose of carbon beds
can be usefully employed as long as the adsorbers are designed to accommodate
periodic backwashing and bed-cleaning procedures such as air scour and surface
wash. For PCBs service, minimum backwashing would be desirable since back-
washing would create large quantities of concentrated wastewater needing incin-
eration or treatment. Some settling and prefiltering would be required for
optimum system performance.
A well designed water distribution system
or underdrain system would insure good backwashing performances, as well as
even distribution of water flow. Well established filtration design practices
can be effectively employed in carbon bed systems. Carbon beds must be periodi-
cally removed via water slurry and obstructions to the flow of carbon from the
adsorber should be avoided in adsorber design.
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Carbon beds are normally in excess of
10 feet deep and usually fall into one of four basic configurations:
1. moving beds
2. beds in series
3. beds in parallel
4. expanded beds
The type of configuration selected depends on a number of variables; principal
among them are total water flow, suspended solids, and degree of contaminant
reduction desired.
2.2.1.3.2 Reactivation of the Granular Carbon
Thermal oxidation, using either multiple
hearth furnaces or rotary kilns, is generally employed to reactivate the
exhausted carbon. The size of the thermal reactivation equipment is based on
the carbon exhaustion rate, i.e., pounds of carbon exhausted per thousand
gallons of wastewater treated, and the weight of contaminant on the carbon.
Excess capacity is designed into the thermal reactivation unit to allow for
variances in carbon use rate due to changes in the wastewater flow and organic
loading.
The exhausted granular activated carbon
is heated to 1600 to 1800°F to effect volatilization and oxidation of the dis-
solved organic contaminants. Oxygen in the furnace is normally controlled at
less than 1 percent to effect selective oxidation of contaminants over activa-
ted carbon. A 5 percent loss of activated carbon per reactivation cycle is an
acceptable bench mark upon which to base granular carbon system economics.
Particularly for the PCBs, which require an incineration temperature in excess
of about 2200°F plus several seconds residence time, the reactivation equipment
must include an afterburner. An air scrubber with HC1 neutralization would be
the last element of the reactivation train. Thus far, the regeneration of car-
bon used for PCBs adsorption has not been proved.
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2.2.1.3.3 Carbon Transport
Granular spent carbon is usually trans-
ported between the adsorbers and the reactivation equipment by water slurry.
Various pumping designs can be employed including centrifugal and diaphragm
pumps as well as hydraulic or pneumatic pressure. The transport piping should
include flush ports and wide radius bends. Typical loading is between 1 and 3
pounds of carbon per gallon of water, depending upon distance and elevation
considerations.
2^.2.1.3.4 Materials of Construction
Special consideration should be given to
the selection of materials of construction with regard to corrosion and erosion.
1. Galvanic Corrosion - Any tendency
toward galvanic corrosion due to water characteristics, such as conductivity
and pH, will be enhanced in granular carbon beds. Mild steel tanks or adsorb-
ers holding granular carbon under water should be lined. Tanks can also be
constructed of cement or reinforced synthetic resins or plastics.
Carbon-in-water slurry piping, which
experiences only periodic exposure, is usually exempted from special corrosion
considerations.
2. Erosion - Periodic replacement of the
carbon beds can cause lining failures at exit ports in carbon tanks and ad-
sorbers. Special grades of stainless steel are usually employed for such wear
points.
2.2.1.4 Carbon Regeneration Alternatives - Wet Catalytic
Oxidation""
For small installations, it might prove feasible to
dispose of spent carbon by incineration. Carbon supply companies also offer
spent carbon removal services and off-site regeneration.
However, there is a new wastewater treatment tech-
nique which might be applicable to carbon regeneration, namely wet catalytic
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oxidation. Several laboratory studies in wet catalytic oxidation are des-
cribed in Appendix C. Lockheed Missiles and Space Co. (Waste Treatment Systems
Section) of Sunnyvale, California, announced in January, 1976, that they have
a process ready for pilot plant evaluation and conmercial scale-up.
In a preliminary look at the PCBs destruction poten-
tial of wet catalytic oxidation, a wastewater sample from an unnamed user of
PCBs was subjected to treatment. The PCB mixture approximated Aroclor 1221
most closely, and was very concentrated to 5 ppm in the wastewater sample.
Since 5 ppm is much higher than that Aroclor's solubility in pure water, it is
believed that solubilizing agents or particulates were carrying most of the
PCBs. Within 20 minutes of treatment time, however, about 90 percent of the
PCBs had been destroyed, and no large quantities of reaction products were
detected. However, this is just one data point and confirmation is needed.
The test reactor was a continuously stirred batch system, with air continuously
sparged in. The test conditions used were: reactor pressure, 1500 psig;
temperature, 550°F; catalyst concentration, 0.5 gram; and reactor volume,
1.5 liters.
The proposed use of wet catalytic oxidation is for
carbon regeneration while in spent water slurry form.
Since the capital and operating costs of the catalytic
system are tied to the hydraulic load, it might be practical to trap PCBs with
carbon in wastewater, and then treat the carbon slurry by catalytic oxidation
to destroy the PCBs. In this way, PCBs would be removed from the wastewater by
the highly efficient carbon adsorption method, while the volume handled by the
catalytic system would be greatly reduced.
Feasibility testing for regeneration of activated
carbon by catalytic oxidation is needed. The activated carbon industry has
long sought alternatives to thermal regeneration of carbon, because of the loss
of carbon by oxidation. With solvent regeneration, or acid or base treat-
ment, the first regeneration only produces about 40 percent of the active sur-
face, which then usually decreases to 30 percent after several more treiitments.
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Such degradation is unacceptable. Thus the questions to be answered are:
a) Can catalytic oxidation destroy adsorbed PCBs on carbon, converting them
to CCL, H20 and HC1? b) Will the regenerated carbon have, say, 90 to 95 per-
cent of its original activity? c) Can the process be operated economically?
The last question must take into account the necessary operation pressures
(500 to 2000 psi), operating temperatures (300 to 650°F), source of oxygen
(air, 0~ or ozone), type and lifetime of catalyst, residence time, and
materials of construction, among other variables.
2.2.1.5 Further Applications Data
ICI-US provides an excellent booklet entitled "A
Symposium on Activated Carbon", providing considerable detail on applications.
ICI also provides information on special graphical procedures helpful in the
scale-up from isotherm to column testing.
2.2.2 Ultraviolet-Assisted Ozonation
Both UV radiation, and ozone, separately, have been used in
water purification for some time. But only in the last five years or so has
the synergism of the combination been appreciated in the destruction of organ-
ics in water.
Two commercial organizations, Houston Research, Inc., of
Houston, Texas, and Westgate Research Corp. of Marina Del Key, California, are
engaged in development of UV-assisted (or catalyzed) ozone oxidation of refrac-
tory organics. Both organizations have cooperated in preliminary tests of PCBs
destruction, and the method has shown great promise as a large-scale, economic
water treatment method. The companies are working mostly with 253.7 nanometer,
near-UV, radiation, but they plan to investigate far-UV mercury radiation at
184.5 nm.
It is of particular significance that these methods promise
destruction of hydrocarbon organics completely to C09 and water. Thus they are
likely candidates for zero discharge and total recycle systems.
Related to this is the work of Lawrence at Environment Canada
(Burlington. Ontario), who is studying the use of near-UV radiation (about
- 168 -
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365 nm) , available frcm sunlight, in conjunction with titania or alumina
photocatalysts rather than the combination of UV and ozone. The ultraviolet
region extends to 380 nm, and then blends into visible violet. Studies using
visible light are described further below.
UV radiation is generally provided by commercially available
tubes, which when operated at low power (and low pressure in the emitting
tube) are quite efficient in transferring UV radiation to water. The range
of effectiveness is quite short, probably of the order of a few inches maximum,
because UV transmissibility in water is poor, and is degraded further by even
small amounts of particulate matter.
Ozone is sparged into the reactor, and vigorous stirring is
provided until increasing turbulence or mixing power input does not further
increase reaction rate.
Various kinds of efficiency values are given to rate different
systems, flows, arrangements, etc. For overall efficiency, the units of measure
are total organic carbon removed per watt-second of UV input, or per gram of
ozone introduced.
Since ozone generation is expensive, work is directed toward
optimum use of the ozone introduced. The cost is almost completely that of the
electric power used in the silent discharge tube method of making ozone from
air. And, of course, UV generation is also an electric power cost factor.
The following subsections discuss UV radiation and its mole-
cular interactions, the photodegradation of PCBs, and UV-assisted ozonation
experiments with PCBs.
2.2.2.1 Molecular Responses to Ultraviolet Energy
Energy absorbed in the ultraviolet region (10 to
380 nm) causes electronic transitions within molecules. The principal charac-
teristics of an absorption band are its wavelength and intensity. The wave-
length of maximum absorption (X max) corresponds to the wavelength of radiation
having energy equal to that required for an electronic transition. A molar
- 169 -
-------
absorptivity at maximum absorption (E max) of 10,000 calories per mole or
greater is regarded as high intensity absorption. Low intensity absorption
is considered an E max of less than 1,000 calories per mole; biphenyl in
alcohol at 250 ran has an E max of 18,000, and in hexane at 246 nm, an E max
of 20,000.
This would seem to indicate that the basic structure
of the PCBs would be readily activated by a mercury lamp generating 253.7-nm
radiation. However, this absorption will be modified by the number of chlor-
ine atoms attached to the biphenyl groups. If at any point in the destruction
of PCBs, saturated hydrocarbons are formed, they will be unresponsive to
253.7-nm radiation. Saturated hydrocarbons contain sigma electrons exclus-
ively. Since the energy required to bring about ionization of the sigma bonds
is of the order of 185 kcal per mole it is only available in the far ultra-
violet, below 200 nm. Single carbon-carbon and carbon-chlorine bonds have
about the same high bond energy, and are similarly resistant to rupture; how-
ever, there is a mercury emission at about 185 nm, which should be capable of
activating those bonds, thus making them highly reactive in the presence of
oxidizers such as ozone.
Thus it appears possible to produce the excited
states in PCB molecules necessary to make them highly receptive to oxidation.
Since ozone is a powerful oxidizing agent, and it too is excited in the same
regions making it even more effective, the possibilities for a wide range of
oxidations are present. This would seem to make complete destruction of PCBs
to GO-, water and HC1 feasible.
2.2.2.2 Photcdegradation of PCBs
Because of the strength of the C-Cl bond, it has here-
tofore been assumed that little photochemical cleavage occurs. Further, in the
photochemical breakdown of DDT and related compounds, cleavage of the aromatic
C-Cl bond is usually not involved. However, Safe and Hutzinger reported in
Nature in 1971, that hexachlorobiphenyl photolyzed readily in organic solvents
when irradiated at 310 nm. The resultant products are formed by stepwise loss
- 170 -
-------
of chlorine, rearrangement, and condensation. Other researchers have found
that certain pure chlorobiphenyls and PCB mixtures can be decomposed by lab-
oratory UV sources and by sunlight, over long time periods.
The wavelength of the UV radiation appears critical
to photochemical decomposition. low-pressure mercury lamps emitting 254 nm
seem to be several times as effective as the UV from sunlight, which is greater
than 295 nm. Studies have been carried out in organic solvents and water, and
in both liquid and vapor states.
Much of the past work has been on organic solvent
solutions of PCBs in order to have high working concentrations. Vapor phase
studies have been run to simulate treatment of atmospheric emissions in environ-
mental studies.
Reductive dechlorination, the main photoreaction of
chlorobiphenyls, is faster in hydroxylic solvents such as methanol and iso-
propanol. Even chlorobenzene loses chlorine rapidly on irradiation in iso-
propanol. Complete dechlorination of a PCB mixture has been observed in 15
minutes in an alkaline isopropanol solution, using a mercury lamp (Anon.,
Chemical Marketing Reporter, Nov. 6, 1972, page 22). Biphenyl and sodium
chloride were identified in the reaction mixture.
Photosensitizers can increase the decomposition rates.
Tryptophan, diethylaniline, benzophenone and triphenylene sensitized the photo-
reaction of dichlorobiphenyl. The reaction was quenched by n-hexyl mercaptan
and di-n-butyl sulfide. Experiments in water solution have been hampered by
adsorption of the PCBs on the walls of reaction containers, particularly ones
made of glass.
Attempts have been made to use surfactants to keep
the PCBs in suspension. Adsorption on such solids as calcium carbonate, silica,
and soils, in water suspension, has been tested as an aid to photolysis. How-
ever, UV radiation will not penetrate deeply into solids, so adsorbed PCB must
be kept close to the surface.
- 171 -
-------
2.2.2.3 Experimental Factors in UV-Assisted Ozone Oxidation
For several decades the advantages of ultraviolet
radiation in the sterilization of aqueous and dry media have been known. Like-
wise, the powerful sterilizing, oxidizing effects of ozone have been known.
Only with the relatively recent advent of requirements for removing refractory
organics from water, and the ability to detect these organics in parts per
trillion and even lower concentrations, has the need for powerful oxidizing
capability been felt. It was quite natural to combine the twD effects into a
single treatment or staged treatments, with the result being a strong synergism
in many cases.
Fjiough data has now accumulated to show that UV/ozone
wastewater treatment is a powerful method for removal of refractory organics.
It has the potential of removing organics to an effective zero discharge level.
However, as the decrease in very small concentrations becomes exponential with
time, the residence time required in UV/ozone treatment equipment becomes a
critical factor. The following variables have been identified as affecting
residence time:
1. Molecular structure of the organic
2 . Concentration
3. UV transmissivity of the wastewater
4. UV intensity
5. UV wavelength
6. Ozone concentration
7. Liquid turbulence and gas- liquid contact
(transfer coefficients)
8. pH
9 . Temperature
The following subsections present experimental find-
ings about the relative significance of these variables.
- 172 -
-------
2.2.2o4 Destruction of PCBs and Refractory Organics at
Houston Research, Inc.
2.2.2.4.1 PCB Destruction Data
In preliminary experimentation on the
feasibility of PCBs destruction, a high pressure 650-watt mercury tube gener-
ating 253.7-nm radiation was used in a 21-liter reactor. Figure 2.2.2.4.1-1
shows the arrangement for a smaller reactor. Oxygen, with an ozone concentra-
tion of 2 percent, was sparged in at 3 liters per minute. This was felt to be
excess ozone usage, but a good starting point for tests. A 1000-ppm solution
of Aroclor 1254 in methanol was used to get a 514-ppb solution of Aroclor 1254
in water. Otherwise the solubility of Aroclor 1254, which is about 50 percent
pentachlorobiphenyl, is only 12 ppb in water. It was theorized that signifi-
cant destruction of this compound would forecast even greater destruction of
the other Aroclors now produced, which are all less chlorinated and more
soluble in water.
Figure 2.2.2.4.1-2 is a plot of the normal-
ized residual concentration of Aroclor versus time of UV-assisted ozonation.
It can be seen that in 1 hour about 2/3 of the PCBs had been decomposed; and
in 3 hours, only about 7 percent of the original PCBs remained.
2.2.2.4.2 Operating Data Obtained from Refractory
Organics Tests
Houston Research has been studying ozon-
ation for water purification for more than four years. Comparison tests have
shown that the addition of UV radiation enhances the reaction rate by 10 to 100
fold. Further it was found that, for the most refractory compound they had
tested prior to the PCBs, acetic acid, there was essentially no reaction without
UV assistance. However, with UV radiation, the oxidation proceeds rapidly at
room temperature.
Figure 2.2.2.4.2-1 shows the effects of UV
and temperature on acetic acid destruction. The ordinate is the fraction of
total organic carbon remaining, showing that for the 30°C or 50°C tests, with
- 173 -
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VARIABLE SPEED
MIXER
UV LIGHT
:s
CTOR
LITER
^CITY)
W»— A
*
EXHAUST
V^.
—
GAS
^~_~~^
c
* 1
1 1 J
TE
CC
P
A
TEMPERATURE
CONTROL
pH MONITORING
AND SAMPLING
OZONE
GENERATOR
AIR
OXYGEN
Figure 2.2.2.4.1-1. LAB SCALE APPARATUS FOR REACTION AND MASS TRANSFER
STUDIES AT HOUSTON RESEARCH, INC.
- 174 -
-------
Normalized Concentration
INITIAL CONCENTRATION OF AROCLOR - 514 ppb
20 40 60 80 100 120 140 160 180
TREATMENT TIME (MINUTES)
Figure 2.2.2.4.1-2 AROCLOR 1254 DESTRUCTION BY UV-ASSISTED OZONATION
- 175 -
-------
CTl
I
1.0
0.8
0.6
TOG
TOCr
0.4
0.2
100
27°C
Reaction Rate Limited Regime
30°C, UV
LIMITING LINE -
Mass Transfer Limited
200 300
TIME (MINUTES)
n
400
Figure 2.2.2.4.2 1. OZONE OXIDATION OF ACETIC ACID, EFFECT OF UV AND TEMPERATURE
(INITIAL CH3COOH - 105 mg/1, O3(l) = 3.5 mg/1)
-------
UV, there is nearly complete destruction to C0~ and water within 4 to 5 hours
The fact that the curves are displaced to the right of the mass transfer limit-
ing line shows that some chemical reaction rate improvement can be sought.
Figure 2.2.2.4.2-2 shows the oxidation
improvement achieved by doubling the UV power input, with near constant temp-
erature. Further description may be found in: "Ozone/UV Process Effective
Wastewater Treatment", by Prengle, Mauk, Legan and Hewes, in Hydrocarbon
Processing, October, 1975.
These are a sampling of the kinds of opti-
mization experiments that must be run with the PCB oxidation system to obtain
good economy of design and efficiency of operation.
2.2.2.5 Destruction of PCBs and Refractory Organics at
WestgateT Research Corp.
2.2.2.5.1 PCBs Destruction Data
Cooperative testing and research between
Versar, Inc., and Westgate Research, Inc., determined the effectiveness of
Westgate's UV-assisted ozonation process in destroying PCBs. The following
experimental conditions were used in the treatment of synthetic wastewaters
containing Aroclors 1254 and 1016:
Reactor volume = 3 liters
Reaction time = 4 hours (excess time used to give
best chance of destruction)
UV Source = one 43-watt, low-pressure Hg lamp
operating at 253.7 ran
Reactor type = vertical, cylindrical, 18 inch long,
3 inch diameter (UV path length =
2 inches)
Pressure = atmospheric
Temperature = 23°C
pH =6.2
- 177 -
-------
1.00
CO
I
0.80
0.60
TOC
TOCr
0.40
0.20
2 w% 03 in gas
100
200
TIME (MINUTES)
300
400
Figure 2.2.2.4.2-2. OZONE/UV OXIDATION OF ACETIC ACID; EFFECT OF INCREASED
RADIATION INPUT
-------
Ozone feed =70 milligrams ozone/minute in 3.4
liters per minute of oxygen; or
about 1.4 percent by weight ozone
in oxygen
Reactant preparation = Pure Aroclor 1254 was mixed
with an equal portion of
methanol, which was then
mixed with distilled water
to get an apparent true
solution. A Hamilton syringe,
with vernier calibration
giving microliter increments
was used to prepare an
estimated 200-ppb concentra-
tion in a beaker. This solu-
tion was added to the reactor
(3 liters). Then a 200-ml
sample was withdrawn to get
the "before" sample.
When preparing the Aroclor 1016 solution,
a more concentrated PCBs solution of about 800 ppb was achieved. The before
and after treatment concentrations of PCBs are shown in Table 2.2.2.5.1-1.
The data show that the destruction was
highly effective in these pioneering tests; more than 99 percent of the
original PCBs were destroyed. In addition, the final concentration was at the
desired level of about 1 ppb. Such an effluent would be expected to be a
reasonable stream for recycle operations and intermediate term zero discharge
Potential.
Of course the contact time and ozone ex-
penditure were overly large, but the goal of this preliminary testing was to
demonstrate destruction of two key Aroclors in use today.
A more comprehensive study of the UV-
ozonolysis of Aroclor 1016 was run, with samples removed from the reactor every
15 or 30 minutes for up to 4 hours. As shown in Table 2.2.2.5.1-2, the initial
PCB concentration was 237 ppb. Within 45 minutes the PCB level had been de-
graded to 1 to 2 ppb, a 99+-percent decomposition. After 2 hours the PCB con-
centration was less than 100 ppt. The last column in the Table labeled
- 179 -
-------
Table 2.2.2.5.1-1
UV Ozonolysis testruction of Typical Capacitor and
Transformer PCBs at Westgate Research
Aroclor 1016 Aroclor 1254
Initial (influent) Concentration (ppb) 790 200
Final (effluent) Concentration (ppb) 0.5 1.5
Table 2.2.2.5.1-2
Destruction of Aroclor 1016 by UV-Ozonation at Westgate Research
Chlorinated
UV-Ozonation Time Aroclor 1016 Cone. Products Cone.
(minutes) (ppb) (ppb)
0 237.0 0.00
15 14.7 33.8
30 7.76 25.86
45 1.73 21.80
60 1.73 18.47
75 0.52 17.63
90 5.2 21.43
120 <0.1 12.64
150 <0.1 16.91
180 <0.1 9.12
210 <0.1 23.07
240 <0.1 12.58
- 180 -
-------
"Chlorinated Products Concentration" is of particular interest. This is the
first time quantitative data on the residual compounds in the reaction mixture
have been compiled. These residual compounds reach a 33.8-ppb level within
15 minutes from the start of the test and then erratically and slowly drop to
about 10 to 20 ppb over the 4 hour period.
The only statements that can be made about
these residual compounds is that they are non-PCBs, but chlorinated materials.
Possibly a different UV wavelength, or ozone concentration, or the use of a
catalyst or other agent could degrade these other products to the non-detectable
level.
2.2.2.5.2 Pilot-Scale Tests of Refractory Organics
Decomposition
Zeff has described pilot-scale tests of
UV-assisted ozonation using 253.7-nm radiation ("UV-OX (TM) Process for the
Effective Removal of Organics in Waste Waters", presented at the 68th Annual
Meeting of the AIChE, November 20, 1975). This work has grown from a patented
invention for a household appliance used to purify tap water. The effectiveness
of the method is demonstrated by the reduction in total organic carbon (TOC) of
500 ml of tap water from 5 mg/1 to 1 mg/1 in 1 minute, using 0.07 mg of ozone
and 0.1 watts of 253.7-nm UV. The bacteria plate count was also reduced by a
significant amount.
In these studies, batch reaction condi-
tions were optimized to get closest to complete TOC destruction with least 0-.
and UV energy input. Then continuous and two-stage operations were investigated.
As shown in Figure 2.2.2.5.2-1, a 6-inch-path length of UV was compared with a
3-inch path. In a batch test, the longer path condition took 3 to 4 times as
long as the shorter path to achieve the same TOC reduction, in approximate
accord with the inverse square law.
The laboratory-scale equipment arrangement
is shown in Figure 2.2.2.5.2-2. Table 2.2.2.5.2-1 presents TOC reductions for
a 5-part organic mixture under two experimental conditions, showing ozone usage
- 181 -
-------
00
ho
Comparison of Effect of UV Depth of
Penetration on 3-part Mixture
oxidized by 72 mg Oymin. at
1.8% O Cone in 0-43 Watt
Innut UV.
M394
D| =3
30
60 90 120 150
REACTION TIME (MINUTES)
180
210
Figure 2.2.2.5.2-1. THE EFFECT OF UV PATH LENGTH ON TOC DESTRUCTION
-------
IMPURE
WATER
SUPPLY
GAS VENT
FLOWMETER
WATER LEVEL
REACTOR
UV LAMP
QUARTZ SHEATH
FLOWMETER
Slllf-
OZONE
GENERATOR
OXYGEN OR
AIR SUPPLY
FLOWMETER
SPARGER
PURIFIED
WATER
Figure 2.2.2.5.2-2. SCHEMATIC OF BENCH REACTION SYSTEM AT WESTGATE RESEARCH CORP.
- 183 -
-------
REACTOR 1
REACTOR 2
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Simulated Two-Stage, Continuous UV-Ozonation of a 5 Component Mix at Westgate Research Corp.
(43 watt UV Input Reactor 1
(28 watt UV Input Reactor 2
-------
efficiencies, and energy usage efficiencies, with a simulated two-stage con-
tinuous operation. Zeff has calculated the prime energy costs for UV-assisted
ozonation based on a scale-up of a pilot reactor. The pilot reactor handled
20 gph, so that 210 of these units in parallel would handle 100,000 gpd. The
plant area needed for this equipment would be only 18 feet square, with a
height of 3 feet.
Based on pilot tests of this reactor, it
might be assumed that it could convert wastewater of 40 mg/1 TOG to less than
5 mg/1, using six 43-watt UV lamps. It is assumed that a UV energy require-
ment of 5 watt-minutes per millgram of carbon oxidized will suffice. Also,
the ozone requirement will be 2 moles per gram-atom of carbon oxidized, but
at a 75-percent efficiency, or 2/.15 = 2.67 moles ozone per gram-atom of
carbon. Assuming a power cost of 1.5C/KWH; the ozone generating power cost
would be $53.40 and the UV power would be $18.93; or a total of $72.33 per
100,000 gal. of water treated.
Zeff points out that the 210 reactor
modules would require«1260 43-watt lamps (six per reactor). This appears to
be a large number of lamps, but it is actually very practical. Such arrays of
lamps are regularly used for room illumination in factories and large offices,
and the low-pressure mercury lamps used here are nothing but fluorescent lamps
without the phosphor coating. An extended array such as this is much more
energy-efficient than fewer high-power high-pressure industrial UV irradiators;
and maintenance and replacement of lamps is much simpler. The life of the low-
power lamps is 7500 hours as compared to 1000 hours for the high-power lamps.
2.2.2.6 Laboratory Test Results from AiResearch Corporation
In the laboratory tests of the AiResearch Corporation,
high-pressure 450-watt mercury lamps were used. The test solutions were very
dilute mixtures of methanol, ethanol, isopropanol, and acetone in water. The
ozone was introduced into the 4-liter organic mixture in an oxygen stream
bubbled in at 2 liters per minute; ozone concentration in the oxygen was
33 mg/liter. With the expenditure of 7.9 grams of ozone, the mixture of alco-
hols and acetone was reduced from 115 mg/1 COD to 10 mg/1 in 2 hours.
- 185 -
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2.2.2.7 Comments on UV^/Ozone Tests
These highly encouraging tests by three different
companies in the destruction of some of the most refractory organics en-
countered in wastewater treatment, give confidence that scaled-up systems can
adequately destroy PCBs in industrial wastewaters. The next step required is
detailed cost effectiveness testing in pilot-scale equipment.
2.2.3 Non-Carbon Adsorbents for PCBs
A variety of non-carbon materials, some well-known for treat-
ing water and some that seem to be quite specific for PCBs removal, have been
found. Limited cooperative laboratory testing of PCBs removal has been con-
ducted in order to gain insight into potential effectiveness.
Materials considered or examined were:
1) Rohm and Haas Arrberlite XAD series resins - These were
laboratory-tested for PCBs removal
2) Polyvinyl chloride - Tested by Canadian investigators
for PCBs removal
3) Clays and Humus - Tested by ffonsanto for PCB removal
4) Polyurethane - Tested by Canadian, Swedish and other
investigators for PCBs removal
5) Sphagnum Peat - Used in commercial water purification,
but has not been tried with PCBs
6) Polyelectrolytes as floccing agent - Not really
adsorbents, but could be aids to removing finely
divided adsorbents from treated wastewaters; have
not been tested
7) Coal - Not tested with PCBs, but being experimentally
used for water treatment
8) Molecular Sieves - Not tried with PCBs, since they
were judged to be of improper character; they would
be expected to preferentially remove water from PCBs,
rather than PCBs from water
9) Miscellaneous Sorbents - A number of proprietary Oil
Sorbents, such as the "3M Brand" series, that were
not tested with PCBs, might have some application
- 186 -
-------
2.2.3.1 The Amberlite XAD Series of Macroreticular Resins
2.2.3.1.1 PCBs Adsorption Testing
Cooperative preliminary experimental work
was carried out between Versar and Rohm and Haas to test the PCB-adsorption
capacity of XAD-4 resins. The tests confirmed the effectiveness of this resin
(see Appendix D).
Since carbon adsorption is the more estab-
lished technology for removal of organics, it was felt that a side-by-side com-
parison of a carbon and an Amberlite resin would be useful.
These tests showed that resin and carbon
are comparable in PCBs removal effectiveness. The resin method includes on-
site regeneration, with the concentrated waste PCBs treated by incineration.
Details on the apparatus and materials used by Rohm and Haas and the results
of their experiments are given in Appendix A.
2.2.3.1.2 Process Concept for Resin Adsorption of
PCBs
Based upon the experiments described in
Appendix A, the Rohm and Haas experience has led them to envision the following
plant-scale process, subject to further experimentation.
The wastewater to be treated is passed
through one or more columns, each containing polymeric adsorbent. Once the
resin is loaded to capacity with PCB, it is taken off line for regeneration.
A water miscible solvent is usually used for regeneration, and is in turn dis-
placed from the adsorbent by water. The stream resulting from this operation
is carefully fractionated to optimize solvent recovery. The final rinse usually
contains a very low level of solvent in water and this must be collected as a
PCBs wastewater.
The distillation column permits solvent
recovery at high purity, leaving water and PCB in the bottoms. To minimize
- 187 -
-------
distillation costs, a patented variation of the process, called "superloading",
is used to maintain a high PCB concentration in the final toxic material to be
disposed. Part of this process includes a separator from which the organic
phase is PCB while the aqueous phase is recycled to "superload" the adsorbent.
A completely enclosed system can readily be designed to insure minimum opera-
tor exposure to PCB. A process concept flow sheet of such a PCBs removal
system is shown in Figure 2.2.3.1.2-1.
The experimental work necessary to plant-
scale design is as follows:
1. MDre extensive leakage data should be gathered
for XAD-4 and other Amberlite polymeric adsorb-
ents, encompassing several influent concentra-
tions of PCBs; other Aroclors should also be
tested.
2. The ability of the Amberlite polymeric adsorb-
ents to be solvent regenerated should be
demonstrated and the optimum solvent determined
3. The capacity of the Amberlite polymeric adsorb-
ents should be determined over a number of
loading/regeneration cycles to see the effect,
if any, of long-term operation on capacity.
The description of XAD-4 resin and its
comparison with other Rohm and Haas resins that might also have application
to PCBs removal are given in Appendix B.
Further descriptions of non-carbon adsorb-
ents are presented in the Appendix C. They contain relevant experimental work
on PCBs and refractory organics, and are included to give a more complete pic-
ture of the options assessed under this program. Also included in Appendix C
are summaries of catalytic reduction, catalytic oxidation, microorganism
studies, ultrafiltration, and reverse osmosis. For the removal of PCBs from
wastewater, all are considered to be in the research stages. Several have
potential for contributing to zero discharge technology.
- 188 -
-------
ADSORPTION
COLUMNS
(2 OR 3)
Figure 2.2.3.1.2-1
PCBs REMOVAL PROCESS CONCEPT FLOW SHEET
BY ROHM AND HAAS COMPANY
- 189 -
-------
2.3 Treatment of PCBs - Contaminated Solid Wastes
2.3.1 Incineration
Incineration has been described in Section 1.3.3. For the
variety of solids ranging from granular particulate, such as fuller's earth,
to large chunks of solids, such as transformer internals, the best destruction
method is rotary kiln incinerator, followed with adequate afterburning to
prevent PCB vaporization.
2.3.2 Sanitary landfill
The best technology for segregation of the PCBs solid wastes
so that spillage, leakage to waterways, or emissions to the atmosphere will not
occur, is described under Section 1.3.3.
2.4 Treatment of Air Emissions
2.4.1 Condensation Methods
Our survey found one plant that was practicing chilling of
exhaust gases from PCBs processing areas. With the low vapor pressure of PCBs
even at room temperature, it might be expected that they could be effectively
swept out of chilled air with the condensing water. Undoubtedly this does
occur to some extent; however, the high activity coefficients of PCBs tend to
keep them vaporized at levels near their pure liquid vapor pressure at that low
temperature. Previous work by Versar has shown that PCBs in stack emissions
from sludge incineration are not removed by water scrubbing (EPA Contract
68-01-1587).
2.4.2 Granular Adsorption Methods
Although no information was uncovered on the collection of
PCBs from air streams by any form of granular filter, it would be expected that
such treatment should be effective. In fact, it would be expected that the
same adsorbents discussed under Sections 2.2.1 and 2.2.3 above would be the
most effective. Activated carbon removal of organic vapors has been practiced
in such widely divergent circumstances and devices as gas masks, kitchen range
hood systems, and submarine air recycle systems.
- 190 -
-------
2.4.3 Catalytic Oxidation of Organics in Evaporated Effluents
Studies of vapor phase oxidation show the potential for PCBs
destruction in air exhausts at lower than incineration temperatures. Catalysts
would have to be resistant to HCl vapors, but fuel savings and insulation
savings would be large. This procedure should be amenable to all proportions
of water and organics in such air streams.
Borkowski passed PCS vapors over a catalyst at elevated
temperatures ("The Catalytic Oxidation of Phenols and other Impurities in
Evaporated Effluents," Water Research (1); 367 (1967)). Copper oxide was the
most active of a large number of catalysts tested and oxidation to carbon
dioxide and water appeared to be complete at temperatures over 300°C and at
residence times of about 0.08 seconds. Without the catalyst, 1000 to 1200°C
was required to achieve the same degree of removal.
Walsh and Katzer studied contaminated air-water vapor streams
over supported copper oxide and showed that the rate was first order in phenol
and relatively rapid between 150 and 270°C ("Catalytic Oxidation of Phenol in
Dilute Concentration in Air", Ind. Eng. Chem. Process Design Develop, (12);
477 (1973)). At 150°C and a space velocity of 4100 hr"1 the phenol conversion
was 99.6 percent, and there was little evidence of any intermediate organics
in the condensate.
These methods of air purification are in the research stages,
and actual testing of PCBs in air is required.
2.5 The Potential for Zero Discharge
The best method of achieving zero discharge, in the face of the prac-
tical problem of defining what a zero concentration is, is to establish total
recycle. This appears feasible for wastewater, but not for solids or air
emissions. Fortunately, for solids, incineration technology promises very high
efficiency of destruction simply by setting the temperature and residence times
high enough.
- 191 -
-------
For air emissions, although vapor pressures are low for PCBs, large
surfaces have the potential for giving off significant quantities of PCBs.
Versar research has found powerful adsorption and destruction methods for
organics in air. If destruction equivalent to that achieved by incineration
can be achieved at lower temperatures through catalyzed reactions, near zero
emissions are possible.
For wastewater recycle, methods of adsorption and catalytic destruc-
tion promise PCBs reduction to levels low enough such that reuse is practical.
Our survey has shown some municipal and fresh waters contain PCB concentra-
tions of 1 ppb or greater, and many river waters can contain many times that.
Thus the recycled water at 1 ppb of PCB would be very suitable for reuse.
3.0 RATIONALE AND SELECTIONS OF CURRENTLY RECOMMENDED WASTE TREATMENT METHODS
Based upon our plant surveys of the PCB-using capacitor and transformer
manufacturers, the single U.S. PCB manufacturer, and waste treatment equipment
suppliers, and upon the analysis and evaluation of all available technologies
whether in commercial use, pilot plant, or research stages, Versar has developed
recommendations for the most practical treatment methods available now. We
have also made predictions of methods applicable over the short- and long-term
future. Our current recommendations are based on technology that is either
currently in use and doing an excellent job of PCB destruction or removal, or
holds great promise of doing that job based upon success in similar but non-PCB,
applications.
3.1 Incineration Recommended for Liquid PCBs and Scrap Oils
For liquid PCBs and contaminated scrap oils, we determined only two
candidate methods: incineration and sanitary landfill. It is possible that
some chemical degradation methods discussed under wastewater treatment might
later become applicable to concentrated PCB liquids, but the prospect is not
clear at this time.
Sanitary landfill is not recommended for liquids when incineration is
available. The potential for liquids escaping in large quantities from ruptured
- 192 -
-------
containers, caused by any of a number of circumstances, and then causing
massive leaching and liquid control problems at the landfill, is felt to be
too great.
Incineration, on the other hand, offers a straight-forward and
physically simple method of final destruction. Incineration facilities that
have successfully handled PCB liquids are available in Massachusetts, New
York, Delaware, Illinois, Texas and Louisiana. Pilot or experimental facil-
ities are available in other parts of the country. With the increase in
requirements for disposing of many other liquid organics, it is expected that
new facilities suitable for PCBs destruction will be added.
Versar therefore recommends incineration, particularly if there is a
choice of the kind of disposal facility to be constructed.
3.2 Carbon Adsorption and UV-Assisted Ozonation Recommended for PCBs in
Wastewater
Our survey of wastewater treatment technology was extensive and excell-
ent potential for current, near- and long-term methods was found. The longer
term pilot- or research-scale methods hold great promise for achieving zero
discharge.
For wastewater treatment, Versar*s recommendation is carbon adsorp-
tion. This technology has been well proved in a wide variety of industrial
adsorption problems. It is constantly being successfully applied to the re-
moval of new organics from water. Our cooperative laboratory work with several
suppliers has confirmed preliminary reports of success in removing PCBs. All
of the aspects of commercial carbon adsorption, from favorable capital and
operating economics to reasonable operating methods, materials of construction,
and lack of transport of pollution to air or land, have been proven for PCB-like
materials. There is every reason to expect commercial success with PCB removal
from wastewater.
Potential problems with carbon adsorption includes the collection of
backwash water and spent carbon for incineration or other treatment. With these
limitations in mind, we studied the various alternatives and have determined
- 193 -
-------
that the UV/ozone method is the best. However, it must be appreciated that
this technology is still somewhere in the pilot-plant and research stage, but
our cooperative testing with two equipment suppliers shows the method to be
effective in destroying PCBs. It offers the potential of degrading breakdown
products all the way to 00,,, water and HCl. Any kind of process that generates
no solids or liquids for later disposal must be considered for application
where no wastewater treatment facilities now exist, and where facilities for
incineration of carbon system wastes are not convenient.
The major factors yet to be determined for the UV/ozone systems are
costs and operating practicality. Separately, UV and ozone systems are being
used in commercial applications, and it is therefore anticipated that the
combination will be practical. Choices of the proper UV-radiation wavelength
and power levels still need to be made, as well as methods of improving ozone-
use efficiency. It appears that commercial UV and ozone generators are suit-
able.
3.3 Incineration and Landfill Recommended for Contaminated Solids
Although incineration is recommended for PCB contaminated solids,
because of its final destruction capability and prevention of any long-term
problems, sanitary or scientifically-controlled landfilling must be considered
a close second choice. At present, the only incineration facilities for hand-
ling the full spectrum of PCB-contaminated solids are those of Rollins Environ-
mental Services in Delaware, Texas and Louisiana. This limitation on locations
for treatment requires that the alternate, landfill, be considered.
Landfill, as practiced by Chemtrol Corp., appears perfectly suitable
for containment of PCB-contaminated solids, at least over a medium term. Our
reservation with this method is that it might be relegating a problem to the
future. Our concern is that some decades in the future, when a landfill might
be closed, no agency will be prepared to handle the sump emptying and maintenance
necessary to prevent leaching. We anticipate that some time in the future, many
landfills will have to be mined, and final destruction or recovery carried out
for land use or hazard reasons.
- 194 -
-------
3.4 Dry Carbon Filter Adsorption Recommended for Control of Air Emissions
For much the same reasons listed in Section 3.2, we recommend that
current emissions of PCBs in plant air be trapped in carbon-containing filters.
It is recognized that other and better adsorbents may emerge from research, as
described in Section 2.2.3, but it is felt that such advances will be readily
applicable to any kind of filter pack, screen or cartridge system already in
use.
The long record of proven capability of carbon adsorption is the
main factor in its choice. However, since contaminated carbon must be either
incinerated or regenerated, over the longer term we see the use of low-
temperature catalytic oxidation methods as described in Section 2.4.3. Catalytic
oxidation methods hold promise for near zero discharge, with the generation of
no solid wastes.
- 195 -
-------
BIBLIOGRAPHY
1. Hutzinger, 0., Safe, S. and zitko, V., The Chemistry of PCBs; CRC Press,
1974.
2. Cam, B., "Upflow - Downflow Carbon Adsorption", Paper #85C; Nov. 19, 1975.
3. "Methods for Organic Pesticide Analysis in Water and Wastewater" , Federal
Register, Volume 38, #75, Part II, 1971.
4. Hager, D.G.; and Rizzo, J.L., "Removal of Toxic Organics from Wastewater by
Adsorption by Granular Activated Carbon", presented to EPA Technology
Transfer Session on Treatment of Toxic Chemicals; Atlanta, Ga., April 19,
1974.
5. "A Symposium on Activated Carbon", ICI-United States, Willmington, Delaware,
Booklet #19897; 1968.
6. Hutzinger, 0., and Safe, S., Nature, 1971.
7. Prengle, H.W., Jr., Mauck, C.E., Legan, R.W., and Hewes, C.G., III., "Ozone/
UV Process Effective Wastewater Treatment" in Hydrocarbon Processing,,
October, 1975, p. 82-87.
8. Zeff, J.D., "UV-OX(TM) Process for the Effective Removal of Organics in
Wastewater", Paper #101C, presented at the 68th Annual Meeting of the
AICHE, November 20, 1975.
9. Brice, C.A., et al., "Final Report on MUST Wastewater Treatment System",
under Contract DADA 17-71-C-1090; July 15, 1973.
10. Borkowski, B., "The Catalytic Oxidation of Phenols and Other Impurities in
Evaporated Effluents", in Water Research 1 367 (1967).
11. Walsh, N.A. , and Katzer, J.R., "Catalytic Oxidation of Phenol in Dilute
Concentration in Air", in Ind. Eng. Chem. Process Design Develop. 12. 477
(1973). ~
12. Musty, P., andNickles, G. , J. Chronat. , 89:185 (1974).
13. Lawrence, J. and Tosine, M.M., "The Adsorption of PCBs from Aqueous
Solutions and Sewage", Progress Report (undated), 1975; Water Chemistry
Section of Canada Center for Inland Wastes, Burlington, Ontario, L7R4A6.
14. Gesser, H.D.; in Analytical Letters, 12:883 (1971).
15. Tucker, E.S., et al. (Monsanto), in Bulletin of Environmental Contamination
and Toxicology 13(1):86 (1975).
- 196 -
-------
16. Hague, R., et al., Environmental Science Technology, 8:139 (1974).
17. Berg, et al., Bulletin of Environmental Contamination Toxicology, 7:338
(1972).
18. Sawai, T., Genshiryohu Kogyo, 18(12):43-7 (1972).
19. Stuart, J.D., et al. (University of Connecticut, Dept. of Chemistry),
preprint paper. Nat. Meet. Div. Air, Water Waste Chemistry, ACS 1972,
12(2, 804).
20. Smith, G., and Chen, J.W. (Southern Illinois Uiiversity), presented paper
#101E at 68th Annual AIChE Meething, November, 1975.
- 197 -
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SECTION: viz
PRODUCTION AND DISTRIBUTION
1.0 PRODUCTION AND CURRENT USE
1.1 Dgrestic _Produc±ion of PCBs and PCTs
Currently there is only one known commercial scale PCB production
installation in the U.S., the William G. Krummrich plant of the Monsanto Chemical
Company in Sauget, Illinois. This facility is specifically designed for
chlorobiphenyls production and has a design capacity of 48 million pounds per
year.
Until 1971 PCBs were also manufactured at Monsanto's Anniston,
Alabama plant which had a design capacity approximately equal to the Sauget
plant. The Alabama operation was discontinued and the plant dismantled in
1971.
PCBs manufactured by Monsanto are marketed under trade name "Aroclor".
Tables 1.1-1 and 1.1-2 present data from Monsanto related to production and
sales of PCBs from 1957-1974 and production of polychlorinated terphenyls (PCTs)
from 1959-1972. The productiori of PCTs were terminated in 1972. Until then
in addition to PCBs (Aroclor series 12) Monsanto manufactured Aroclors 2565,
4465, 5442 and 5460. Aroclors 2565 and 4465 were blends of PCBs and PCTs and
Aroclors 5442 and 5460 were two different grades of PCTs. Also given in these
Tables are breakdowns of domestic sales per use category and by PCB grade.
Detailed information and breakdown on PCB/PCT blends and PCT grades is not
available. However, Monsanto reports that the predominant material produced
was Aroclor 5460. When produced and marketed these materials were used in
plasticizer applications. Figures 1.1-1 through 1.1-3 are graphical represen-
tations of these data.
As can be seen from Figure 1.1-1, the majority of the PCBs produced
in the United States was marketed domestically. Production and sales of PCBs
in 1974 were less than half of those for 1970, where production and sales of
PCBs were at their maximum. The difference between production and sales on
-198-
-------
TABLE 1.1-1
PCB & PCT MANUFACTURE AND PCB SALES
MONSANTO INDUSTRIAL CHEMICALS COMPANY
1957 thru 1964
(Thousands of Pounds)
1957
1958
1959
1960
1961
1962
1963
U.S. PRODUCTION OF PCBs
DOMESTIC SALES OF PCBs
U.S. EXPORT SALES OF PCBs
U.S. PRODUCTION OF PCTs
DOMESTIC SALES OF PCBs BY CATEGORY
Heat Transfer
Hydraulics/Lubricants
Misc. Industrial
Transformer
Capacitor
Plasticizer Applications
Petroleum Additives
DOMESTIC SALES BY PCB GRADE
(1)
32299
(2)
-
(1)
26061
(2)
-
(1)
31310
(2)
2996
37919
35214
(2)
3850
36515
37538
(2)
2322
38353 44734
38043 38132
(2) 3647
4468 4920
1964
50833
44869
4096
5288
-
1612
704
12955
17028
(1)
-
1549
755
5719
14099
3939
-
2685
1569
5984
16499
4573
-
2523
1559
7921
16967
6244
-
4110
2114
6281
15935
9098
157
3915
1681
7984
15382
8924
582
3945
1528
7290
15606
' 9181
929
4374
1692
7997
19540
10337
Arcclor 1221
Aroclor 1232
Aroclor 1242
Aroclor 1248
Aroclor 1254
Aroclor 1260
Aroclor 1262
Aroclor 1268
Aroclor 1016
(1) Production
(2) U.S. Export
23 16
196 113
18222 10444
1779 2559
4461 6691
7587 5982
31 184
72
-
figures and Plasticizer Applications
254
240
13598
3384
6754
6619
359
102
-
103
155
18196
2827
6088
7330
326
189
-
figures unavailable
94
241
19827
4023
6294
6540
361
158
-
during year
140
224
20654
3463
6325
6595
432
210
-
indicated.
361
13
18510
5013
5911
7626
414
284
-
596
13
23571
5238
6280
8535
446
190
-
Sales figures unavailable during year indicated.
-------
TABLE 1.1-2
I
N)
O
O
PCB & PCT MANUFACTURE AND PCS SALES
MCNSANTO INDUSTRIAL CHEMICALS COMPANY
1965 thru 1974
(Thousands of Pounds)
1965
U.S. PRODUCTION OF PCBs 60480
DOMESTIC SALES OF PCBs 51796
U.S. EXPORT SALES OF PCBs 4234
U.S. PRODUCTION OF PCTs 6470
DOMESTIC SALES OF PCBs BY CATEGORY
1966
1967
1968
1969
1970
1971
1972
1973
1974
65849
59078
6852
8190
75309
62466
8124
9450
82854
65116
11231
8870
76389
67194
10624
11600
85054
73061
13651
17768
34994
34301
-
20212
38600
26408
6388
8134
42178
37742
8346
-
40466
34406
5395
-
Heat Transfer
Hydraulics/Lubricants
Misc. Industrial
Transformer
Capacitor
Plasticizer
Applications
Petroleum
Additives
1237
4616
1841
8657
23749
11696
-
1766
4258
1779
8910
28884
13481
-
2262
4643
1426
11071
29703
13361
-
2529
5765
1283
11585
29550
14404
-
3050
8039
1079
12105
25022
16460
1439
3958
7403
1627
13828
26708
19537
-
3060
1552
1155
11134 ,
14141 (
3259
-
752
0
0
25656
0
0
DOMESTIC SALES BY PCB GRADE
37742
34406
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
Aroclor
1221
1232
1242
1248
1254
1260
1262
1268
1016
369
7
31533
5565
7737
5831
558
196
0
528
16
39557
5015
7035
5875
768
284
0
442
25
43055
4704
6696
6417
840
287
0
136
90
44853
4894
8891
5252
720
280
0
507
273
45491
5650
9822
4439
712
300
0
1476
260
48588
4073
12421
4890
1023
330
0
2215
171
21981
213
4661
1725
1
0
3334
171
0
728
807
3495
305
0
0
20902
35
0
6200
0
7976
0
0
0
23531
57
0
6207
0
6185
0
0
0
21955
-------
CO
CXI
M
CL-
OD
M
m
o
o.
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
O
U.S. PRODUCTION
OF PCBs
NOTE' (I) THE DIFFERENCE
BETWEEN PRODUCTION
AND SALES REFLECTS
INVENTORY CHANGES
DOMESTIC
SALES
OF PCBs
X-U.S. PRODUCTION OF PCTs
1963 1965
1967 1969 1971 1973 1975
YEAR
Figure 1.1-1 - U.S. Production of PCBs and PCTs and
Denes tic Sales and Exports of PCBs
-201-
-------
CO
CO
z
o
CO
U)
CO
o
I-
to
UJ
s
o
o
CO
80
70
60
50
40
30
20
10
OPEN END
APPLICATIONS
CLOSED ELECTRICAL
SYSTEMS
57
59
6!
63
65 67
YEAR
69
71
73
75
Figure 1.1-2 - U.S. Dcmsstic Sales of PCBs by End Use Applications
-202-
-------
00
m
m
o
a.
80
70
60
50
40
20
10
57
TOTAL DOMESTIC SALES
1221 S 1232
1262 a 1268
59
61
63
65 67
YEAR
69
71
73
75
Figure 1.1-3 - U.S. Donestic Sales of PCBs by Type
-203-
-------
this graph reflects inventory changes of PCBs. Figure 1.1-1 also indicates
that the production of PCIs increased steadily through 1971 when their pro-
duction was at the maximum. The production of PCTs was terminated in 1972.
Table 1.1-3 shows production, sales and export of PCBs for the first
quarter of 1975. Monsanto reports that sales for Aroclor are expected to
increase at an average annual rate of 6-7 percent over the next few years.
Additionally, exports of Aroclor are expected to maintain the same ratio to
the U.S. production as in the past.
Figure 1.1-2 indicates that prior to Monsanto's voluntary restriction
of sales to all applications with the exception of "closed electric systems",
approximately 13 percent of the PCBs in the U.S. was used in "nominally closed"
applications (heat transfer, hydraulic fluids and lubricants) and 26 percent
was used in "Open End" applications (plasticizers, surface coating, ink,
adhesives, pesticide extenders, and microencapsulation of dyes for carbonless
duplicating paper) where entries of PCBs to the environment are more probable
and PCB emissions are uncontrollable. At present, almost all domestic produc-
tion is being used in "closed electric systems" (transformer and capacitor
applications) where PCB emissions are more controllable.
Between 1957 and 1971 there were twelve different types of Aroclor
manufactured by Monsanto with chlorine contents ranging from 21 to 68 percent.
Aroclor 1242 and grades lower than 42 percent chlorine made about 48 percent of
the total production consumed. U.S. Sale of Aroclor 1242 has dropped drastically
since 1971 and has been replaced by Aroclor 1016. Sales of Aroclor 1254 re-
mained about the same for the period 1957 - 1974. Currently, tnere are four
different types of Aroclor manufactured by the Monsanto Company-Aroclors 1221
and 1016 for capacitor applications and Aroclors 1242 and 1254 for transformer
applications.
Past and current end-use of PCBs by types are presented in Table
1.1-4. In the years prior to 1971 the largest "open-end" use of PCBs and PCTs
has been in plasticizer applications. According to Monsanto, a large percent-
age of the production of Aroclor 1242 and lower chlorine content grades and
the entire PCT production were used for this application. Following Monsanto's
-204-
-------
TABLE 1.1-3
PCB MANUFACTURE AND SALES
MONSANTO INDUSTRIAL CHEMICALS COMPANY
First Quarter - 1975
(Thousands of Pounds)
U.S. PRODUCTION 8532
DOMESTIC SALES 7986
U.S. EXPORT SALES 1538
DOMESTIC SALES
Transformer and Capacitor 7986
DOMESTIC SALES BY PCB GRADE
Aroclor 1221 10
Aroclor 1242 2201
Aroclor 1254 2115
Aroclor 1016 3660
PREDOMINANT UTILIZATION OF AROCLORS
Aroclor 1221 | Capacitors
Aroclor 1016 (
Aroclor 1242 | Transformers
Aroclor 1254 I
-205-
-------
I
N>
O
(Ti
I
Bid-Use 1016
Existing Sales
Capacitors XX
Transformers
Sales Phased-Out
Heat transfer
Hydraulics/
lubricants
. hydraulic fluids
vacuum pumps
gas-transmission
turbines
Plasticizers
rubbers
synthetic resins
carbonless paper
Miscellaneous Industrial
TABIE 1.1-4
END-USES OF PCTs AND PCBS BY TYPE
1221
1232
X
adhesives
wax extenders
dedusting agents
inks
cutting oils
pesticide extenders
sealants & caulking compounds
1242
1248
XX
through 1971
X
XX
XX
XX
XX
X
X
X
X
1254
XX
X
X
X
X
X
X
X
X
X
X
1260
1262
1268
PCTs
through 1971
X
X
X
XX
XX
XX
XX
XX
Notes: (1)X denotes use of a given Aroclor in a specific end-use, while XX denotes principal use
(2)PCTs denote series 25,44 & 54 Aroclors
Source: Monsanto Industrial Chemical Co.
-------
voluntary restrictions in 1972, Aroclor sales for plasticizer applications
dropped to small percentage to that of the previous years. Historically,
capacitors have always been the single largest PCB use category except for the
years 1969-1971 when Aroclor usage for plasticizer applications was higher.
The major uses of PCBs prior to 1969 in order of volume of material used is
listed below:
. Capacitors
. Plasticizers
. Transformers
. Hydraulic fluids and lubricants
. Heat transfer fluids
1.2 Foreign Production and Distribution of PCBs
Known current foreign producers of PCBs are the United Kingdom,
Czechoslovakia, France, Germany, Italy, Spain and the U.S.S.R. Detailed infor-
mation on total production of PCBs outside the U.S. is not available. However,
total foreign production of PCBs was roughly estimated by the Interdepartmental
Task Force to be 80-85 million pounds annually prior to 1971. This value
included 26 million pounds produced by Japan. Foreign production of PCBs has,
however, decreased primarily due to Japanese action on banning the domestic
production of PCBs. In 1973 foreign production of PCBs was estimated to be 43
million pounds, accounting for a 50% reduction. Production, trade and use of
PCBs by OECD member countries for the year 1973 is given in Table 1.2-1. The
combined PCB output of three major European producers, France, Italy and United
Kingdom was about 36 million pounds in 1973. World commerce in PCBs is expected
to decrease further, due to OECD member countries' activities, and to be
essentially confined to capacitor and transformer applications.
1.3 Summary of Recent PCBs and PCTs Imports
A summary of estimated imports of PCBs since 1971 is presented in
Table 1.3-1. Importation of PCBs appears to be steady or increasing, and
currently is in the range of one percent of the domestic sales reported by
Moris anto.
-207-
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Table 1.7-1 ~ Production, Trade and Use of PCBs
OECD Member Countries (1973)
Country
Australia
/-n
Austria1 '
Belgium
Canada
Denmark
Finland
France
(2)
Germany
Greece
Iceland
Ireland
Italy
Japan
Luxembourg
Netherlands
New Zealand
Norway (10>
Portugal
Spain
Sweden'10'
Switzerland
Turkey
United Kingdom
United States
I
ft W
3°
*
0
0
0
21.33
*
5.55
0
0
0
0
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0
0
8.97
42.18
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ti
1
Ef o)
8
1
7
2.38
0.53
0.66
3.53
(2)
7
0.04(9)
0.04
0.70
0
0.01
0.57
"8
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X w
5 a
s
7
0
0
10.12
2.44
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6.53
8.35
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6.48
2.70
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0.075
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0.71(3
S3
S,-,
0)
0.40
0.44(4)
0.44(4)
2.87
3.14(3'4)
7
0
0.05(4)
0.72
6 1.82(
B
H rH
a'"
-
0.41(4)
0
0
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0
0.005
0
9) ^
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(0
7
0
0
0.16
0
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0
0
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7
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M C
Kydra.ul
1 Equipnvs:
7
0
0
0.17
0
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0
0
0
0.04
Vacuum
Punp
7
0
0
0.01
0
?
0.005
0
0
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-P Cn
Lubrica
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?
0
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0.49
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7
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0
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0
0
0
0.25
0.16(6'8>
0
0
0
0
?
Notes:
(1)
(2)
(3)
(4)
(5)
(6)
*
(7)
(8)
(9)
(10)
(11)
(12)
(13)
All quantities are in million pounds
Information is not available
PCS containing 54 wt % chlorine
PCS containing 42 wt % chlorine
PCB containing 64 wt % chlorine
PCS containing 70 wt % chlorine
indicates PCB producer country
"Others" refers to PCBs were used to reseller and in research
"Others" refers to PCBs used as a fire-retardant in plastics
This figure includes about 6 percent from previously imported material
ftnount reported as import and quantities quoted in usage do rot agree
.With regards to the use of PCBs in transformers and capacitors, definitive figures
are not available
Used in investment casting
This figure includes 0.13 million pourris of imported material
-208-
-------
Table 1.3-1
Preliminary Suirmary of PCBs Import Data for
1971-75 Versus Monsanto Production and Sales Data
Estimated Imports (Ib)
Monsanto Domestic Sales (Ib)
Inports as Percentage of Domestic Sales
Monsanto Exports (Ib)
Ratio of Exports to Inports
Year or Portion of Year
1971
550,000
34,301,000
1.6
-
—
1972
700,000
26,408,000
2.7
6,388,000
9.1
1973
480,000
37,742,000
1.3
8,346,000
17.3
1974
450,000
34,406,000
1.3
5,395,000
13.5
1975
450,000 (6 mos)
7,986,000 (3 mos)
-
1,538,000 (3 mos)
~
NJ
O
-------
During 1971 and 1972 most of the PCBs imported into the United
States originated in Japan, ostensibly corresponding to sales of stocks un-
salable in Japan due to pending or established regulatory action. There
apparently has been little or no U.S. importation of PCBs from Japan since
1972. The major importer was Marubeni .America Corp., West Caldwell, N.J.
Since 1972, most of the imported PCBs originated in Italy, with a
small amount imported from Prance (manufactured by Prodelec). This French
material is similar to Aroclor 1242 and is used (40,000-60,000 Ib. per year)
as a coolant in mining machinery by Joy Mfg. Co., Franklin, Pa. Decachloro-
biphenyl (Fenclor DK) is imported from Italy by Yates Mfg. Co., Chicago, 111.,
for use in the manufacture of investment casting waxes. Estimated current
usage is about 400,000 Ib/year.
Polychlorotriphenyls, also used in pattern wax formulations, appear
to be imported at an increasing rate. Estimated amounts are:
1973 1974 1975 (6 mos.)
160,000 Ib. 330,000 Ib. 200,000 Ib.
Major importers of PCTs are Progil, Inc. (formerly Prochimie) and
Intsel Co., both located in the New York City area. Most of the imported PCTs
originate in France (Prodelec).
Use of PCBs and PCTs in casting waxes appears to be generally stable
or increasing slowly, and under conditions of lack of regulatory control in the
future, such use would be expected to continue at least at the current rate.
On the other hand, Joy Mfg. Co. no longer manufactures mining equipment using
PCBs as coolant; the amounts imported by Joy are used to service existing
equipment. However, since Joy imports only 10 to 20 percent of the total, the
overall imports will not be affected greatly by future decreases in imports by
Joy.
r*
2.0 FIFTEEN YEAR EXTRAPOLATIONS FOR PCB PRODUCTION AND USE IN ELECTRICAL
EQUIPMENT
The subject data base was assembled from domestic sales figures for
Aroclors reported by Monsanto — capacitor and transformer sales being summed
-210-
-------
to obtain totals. For certain years (1972-1973), sales data were reported in
aggregate, and in such cases, the reported figures were taken as totals, and
usage breakdown was accomplished by assigning total amounts of Aroclor 1221
and 1016 to capacitors and total amounts of Aroclor 1242, 1248, 1254, and 1260
to transformers. All 1975 totals were obtained by quadrupling the reported
first-quarter sales figures - a process which very likely yields an approximate
lower-bound to the actual yearly totals - and, ultimately, Table 2-1 was
constructed.
Ifonifestly, the available data base is far too limited to form the basis
for any rational statistical analysis. The strong pertubational decrement in
the 1971-1972 interval precludes the application of incremental regression —
even if a fifteen-year extrapolation were not required. In short, then, trend
analysis becomes a generally risky proposition, and the optimum analytical
approach seems to be limited to unbiased extrapolations of least-square linear
fits to grouped subsets of the available data points.
Given this, three data base subsets appear promising:
(i.) the full base — using all reported and 1975-estimated data,
unweighted and unbiased;
(ii.) a singly-deleted base — using all reported data, but
eliminating the 1975 estimates. This tends to weight
the extrapolations (however weakly) with regard to recent
(last-decade) performance only, but the resulting curves
can then be inspected without the bias of the estimated
1975 totals; and
(iii.) triply-deleted base — formed by extracting the depressed
1971 and 1972 totals from the singly-deleted base. This
construction eliminated the bias of the 1975 estimates, and
discounts the effects of the interval decrements caused by
regulatory effects. (A perhaps more realistic picture might
be obtained by placing a decremental weight on 1975 totals —
under the assumption that sane of the roll-back is reactively
-211-
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Table 2-1
Total PCB Breakdown by Use
1966 - 1975
Year
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975 (est.)
Total
(10 5 Ibs.)
37.794
40.774
41.135
37.127
40.536
25.275
25.656
37.742
34.406
31.944
Capacitors
(10 6 Ibs.)
28.884
29.703
29.550
25.022
26.708
14.141
20.321
23.566
22.000
20.644
Transformers
(10 6 Ibs.)
8.910
11.071
11.585
12.105
13.828
11.134
5.335
14.176
12.000
11.300
-212-
-------
induced by the strong depression in the 1971-1972 totals.
This would result, however, in externally biased extrapolations,
and justifying a long-term lag of such effects with the avail-
able data appears difficult.)
These data bases, and the unbiased, least-square linear extrapolations
derived from than, are graphed in Figure 2-1. Inspection of the curves shows
that the 1975 estimate has little effect on the aggregate total; an event
readily accounted for by noting that the singly-deleted base has the effect of
depressing the capacitor total only slightly more than it elevates the trans-
former total. The triply-deleted base, however, provides almost no perturbation
to the transformer total derived from the full base. Inspection of the curves
for the aggregate total and the capacitor total indicate that this arises from
the fact that the ratio of their time-derivatives (slopes) for the triply-
deleted base is almost equal to its value with the full base.
Generally, the developed extrapolations disagree with mid-1975 industry
estimates for the near-term future. Apparently, Monsanto and capacitor manu-
facturers tend to expect 1975 totals to resemble 1974 totals, followed by a
five to ten percent increase in 1976, and a general four to five percent increase
over the preceding year for 1977 on. Obviously, increases by a fixed percentage
over preceding years yields exponentially increasing totals — an event un-
doubtedly strongly desired, but probably wholly Utopian. Transformer manu-
facturers appear to tend toward a more conservative view; General Electric for
example, expecting the demand for power transformers to rise and the demand for
distribution transformers to fall — probably yielding a general saturation of
the sales figures when integrated over all types.
Taking the available information into consideration, the impression
remains that the triply-deleted data bases probably provide the most likely
picture of what might be expected over a 25-year term. Naturally, such
scenarios assume the external status quo as constant; technological, economic,
and regulatory factors being capable of producing strong (and unassessable)
variations in usage patterns. As a matter of fact, very recently, Mbnsanto
has publicly announced that they would support a cessation of the PCB produc-
tion when suitable alternative materials become available.
-213-
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Figure 2-1. Unbiased Extrapolations of Least-Square Linear Curves
for PCB Production and Use in Electrical Equipment
O
Ml
3
o
Ml
45
40 i.
35
• Total (1)
• Capacitor (2)
data base: 66-74 + est. 75
— data base: 66-74
Xformsr C3) data base: 66-70 + 73 & 74
{?. 30
25
20
15
10
1965
1985
1990
-------
3.0 OVERALL MATERIAL BALANCE
Three separate approaches have been taken to obtaining overall data on
total PCBs production, historical usage, and current distribution in the
environment. Most of the uncertainty lies in the period 1930-1960, for which
Monsanto data are lacking. Use of PCBs in transformers, particularly in
electrical distribution systems, apparently began almost simultaneously with
commercial production. Extensive use in capacitors can be traced to the
intensive development and use of electrical hone appliances, starting in the
mid to late 1940's. Use in adhesives, paper, lubricants, etc., probably began
in the early 1950's, and use of PCBs as a heat transfer fluid began early but
increased rapidly between 1950 and 1970.
Using the Monsanto production data for 1960 to 1975, and assuming a
linear increase in total PCBs production between 1930 and 1960, we obtain:
Production 1960 - 75 850 x 106 Ib
Production 1930 - 60 (30 yr x 19 x 106lb/yr ave) 570 x ip6 ib
Total 1,420 x IQ6 Ib
Estimates of total PCBs usage by U.S. industries for the period 1930 -
1975 are given below:
PCBs by use category
Capacitor & transformers 965 x 105 Ib
Heat transfer 20 x 106 Ib
Hydraulics/lubricants 80 x io6 Ib
Misc. industrial 27 x io6 Ib
Carbonless copying paper 45 x 106 Ib
Other plasticizer uses 115 x io6 Ib
Petroleum additives 1 * IO6 Ib
Total from Monsanto 1,253 x 106 Ib
Estimated total U.S. imports of PCBs ' 3 x 106 Ib
Grant total PCBs usage 1,256 x 106 Ib
-215-
-------
Alternatively, we have fitted least square correlations to each of the
sets of Monsanto sales data for various uses, and to the domestic sales data
set from 1957 to 1974, projected each plot back to 1930, and integrated.
These operations, plus the addition of several other well established data
points, produce the following results:
Total Domestic Sales, 1930 - 1970 767 x 106 lb
Domestic Sales, 1971 - 1975 168 x 106 Ub
Total Exports, 1963 - 1974 82 x 106 lb
Estiinated Exports, 1930 - 1963; 1975 70 x 106 lb
Monsanto In-House Use (unreported as sales) 25 x 106 lb
Total 1,112 x io6 UD
As a comparison with the above, the 1973 Foster D. Snell study of PCBs
concluded that the upper bound of U.S. usage of PCBs over 1934-72 was
1.175 x IO9 lb. Adding usage figures for 1973-75 (about 105 x io6 lb), plus
150 x 106 estimated total exports, one obtains:
Estimated Total U.S. Production to Date 1.43 x io9 lb
Estimated Total U.S. Usage to Date 1.28 x io9 lb
Thus, it appears that the approaches taken to obtaining overall pro-
duction and use quantities from various types of estimates yields:
U.S. Production
Maximum 1.4 x io9 lb
Minimum 1.1 x IO9 lb
U.S. Usage
Maximum 1.25 x io9 lb
Minimum 1.0 x IO9 lb
-216-
-------
Sufficient data have been generated to allow an approach to the usage
quantity through estimated quantities now in use or in the environment:
Transformers - 135,000 in service x 2,250 Ib/unit
average content 300 x 10 5 Ib
Fewer Capacitors - 5 x 10 in service x 36 Ib/unit 180 x 10 Ib
average content
Industrial Capacitors - 790 x 106 in service x 6
0.35 Ib/unit average content
Total in Electrical Service 750 x 105 Ib
Total Other Than Electrical 8 x 106 Ib
Grand Total 758 x 106 Ib
Estimated "free" PCBs in
the environment (see Section IX) 150 x 106 to 175 x 105 Ib
Estimated amount degraded or incinerated
(20 x 106 Ib. by contract incineration;
5 x io6 Ib incinerated with sewage sludge
and other solid wastes; and 30 x 1Q6 Ib
degraded mono and dichloro homologs) - 55 x IO6 Ib
Estimated amounts to landfill or dump:
Ten percent of capacitor and transformer
usage as production wastes - 1.06 x 10 9 x 0.10 = 110 x IO6 Ib
Obsolete electrical equipment
(capacitors mainly) - 80 x IO6 Ib
Other sources (paper, plastics, etc.) - 100 x IO5 Ib
Estimated total 290 x IO6 Ib
In summary:
Amount in use 758 x IO6 Ib
Amount in landfills 290 x io6 Ib
Amount "free" in soil,
water, air, sediment 150 x io6 Ib
Amount degraded or
incinerated 55 x io6 Ib
Total 1,253 x I0e Ib
-217-
-------
Thus, using estimates, we can account for the maximum usage of
1.25 x I09lb. calculated previously. Vfe believe that the ranges of production
and usage are well-defined by the maximum and minimum values presented above,
and that the accuracy of the maximum values are sufficient for use in gross
calculations pertaining to the PCBs problem.
-218-
-------
BIBLIOGRAPHY
1. Colder, A.W., (Joy Manufacturing Co., Pittsburgh, Pa.), Personal Comtuni-
cation, September 8, 1975.
2. Environmental, Directorate, Organization for Economic Cooperative and
Development, General Information on PCB Monitoring and Control, Paris,
September 11, 1974.
3. Foster D. Snell, Inc., Market Input/Output Profile, Process Technology
Assessment and Entry Into the Environment of Polychlorinated Biphenyls,
EPA Contract 68-01-2106, December, 1973.
4. Leisy, A.E. and Small, W. (Monsanto Industrial Chemical Co.), Personal
Coitmunication, October 8, 1975.
5. Papageorge, W.P. (Monsanto Industrial Chemical Co.), Personal Communication,
August 22, 1975.
6. Polychlorinated Biphenyls and the Environment, Interdepartment Task Force
on PCBs, Washington, D. C., May, 1972.
7. Solomon, P. (Yates Manufacturing Co., Chicago, Illinois), Personal
Communication, August 8, 1975.
-219-
-------
SECTION VIII
SUBSTITUTES FDR PCBs
1.0 INTRODUCTION
In 1970, the Monsanto Company announced a voluntary restriction on sales
of PCBs for all but closed electrical applications. As a result of this
action, since 1972 the use of domestically produced PCBs has been limited to
the manufacture of electrical capacitors and the manufacture and maintenance
of electrical transformers.
Satisfactory substitutes have been developed for all of the other previ-
ous uses of PCBs except in the manufacture of investment casting wax.
Imported PCBs have been the sole source of material for this application.
There are no complete data available on imports; however current aggregate
information indicates that PCB imports are about one percent of domestic
production.
A number of materials are currently being developed as substitutes for
PCBs. The replacement of PCBs by any of these materials will depend on the
specific technological, economic, and institutional requirements which govern
each specific application. The evaluation of the substitutes must be based
on careful consideration of all of these factors as they apply to each
specific application where PCBs are currently being used.
2.0 ELECTRICAL CAPACITORS
An electrical capacitor is a device which stores electrical energy when
a voltage differential is applied across the device. This stored energy
reappears in the circuit as the voltage is decreased. The capacitor therefore
performs an electrical function equivalent to that of a spring in a mechanical
system. The amount of electric charge (q) which a specific capacitor can store
-220-
-------
is a function of its size, or capacitance (c), and the voltage (v)
q = cv (1)
and the energy stored in the capacitor (w) is a function of the capacitance
and the square of the voltage:
2
w = %cv (2)
This energy is stored in the capacitor in the form of an electric field
and in the dielectric material which is exposed to that field.
2.1 Function of the Dielectric Material
When a material is placed within an electric field there is a ten-
dency for the charges associated with the constituent molecules of the
material to move in the direction of the field (the positive charges move in the
direction of the applied field, the negative charges in the opposite direc-
tion) . If the material is a conductor, the mobile charges, usually electrons,
will move freely under the influence of the field and a current is said to
flow. However, if the material is a non-conductor, the applied electric field
will cause a spatial displacement of the charge centers of the constituent
molecules, with the result that surface charges will be induced on the material.
The charge on opposite faces of the material will be opposite in sign
and will generate an electric field within the material opposing the applied
field. Such a material is known as a dielectric and is characterized by a
parameter defined as the ratio of the electric field that would exist in that
space if the medium were replaced by vacuum to that actually found within the
dielectric - this parameter is referred to as the dielectric constant. The
dielectric constant of most materials, at least at low frequencies, is greater
than unity.
Since the effect of an applied electric field on a dielectric medium
is the generation of a surface charge, it is clear that work must be done in
the separation of these charges. Clearly, the larger the applied electric
field, the larger the surface charge, and conversely, when the electric field
is removed, the surface charge is zero. The energy that is required to es-
tablish the necessary surface charge is stored within the dielectric and can
in most cases be recovered without loss by removing the external electric
field.
-221-
-------
In practice, the external electric field is established by applying
electrical charges to a pair of metal plates placed on the opposite surfaces
of the dielectric. Although the geometry of the conductor-dielectric sand-
wich can take a wide variety of forms, the specific geometry that is of most
interest is that in which conductors are parallel plates separated by the
dielectric. In this case the capacitance of the device is given as
= • * (3)
where e is the dielectric constant, A the area of each plate and d the spacing
(the thickness of the dielectric).
As is stated above, the magnitude of the surface charges that are
formed on the dielectric increases as the applied electric field increases.
Eventually, the external electric field may become sufficiently strong to rup-
ture the bonds that hold together the charges on the individual constituent
molecules with the result that the dielectric breaks down; i.e., conducts cur-
rent. The critical voltage (V ) for a specific capacitor is
c
V = E d (4)
c c
where E is the dielectric strength, i.e. the maximum potential gradient
(_•
(voltage) that the dielectric can sustain without rupture. Clearly, the
dielectric constant and the critical voltage, or dielectric strength, are
essentially unrelated.
The critical voltage of the dielectric material can impose severe
limitations on the maximum voltage at which a capacitor can operate. The
electric field strength in a capacitor is strongest at sharp edges and points
caused by surface roughness and the edges of the conductive plates.
If the electric field at these points exceeds the critical voltage of the
„dielectric, a corona discharge can occur which results in current leakage and
heating of the capacitor and causes chemical degradation of the dielectric
material. This critical voltage for corona discharge depends on both the
geometry of the capacitor and the properties of the dielectric, and is known
as the corona inception voltage. Air has a rather low dielectric strength; the
presence of air bubbles in the dielectric will result in corona discharges if
the capacitor is operated at applied voltages above about 270 volts.
-222-
-------
When several capacitors, say C, and C^, are connected in parallel,
then the voltage across each is the same, V, while the charge on the capaci-
tors is Q, = C,V and Q2 = C^V; hence the capacitance of the parallel combina-
tion is given as
C = C -f C
S ul U2 (5)
On the other hand, if the two capacitors were connected in series, then the
charge, Q, would be the same for each. In this case, the respective poten-
tials would be given as V-L = Q/C^ and V2 = Q/C^, with the result that the
total capacitance is given as
l/Ct = I/CL + 1/C2 (6)
From the above considerations it can be seen that the effect of a
small hole through the dielectric will be to produce a very small reduction
in the overall capacitance, since the resulting structure may be considered
as two capacitors, one with the normal dielectric, the other with air
dielectric, in parallel. On the other hand, the breakdown strength of air
is considerably less than that of most practical dielectric materials, so
that the effect of such a discontinuity in the dielectric will primarily be in
reducing the critical voltage of the resulting structure.
On the other hand, the effect of a gap between the dielectric and
the plates is more serious since the resulting structure will act as if it
were made up of several capacitors in series. From Eq. (6), it can be seen
that the smallest capacitor in a series circuit will determine the total
capacitance of the structure. Thus, a gap between the plates and the dielectric
will have the effect of reducing the capacitance without a reduction in the
dielectric strength.
In most practical devices, the assumption that the sole effect of
the dielectric is the reduction of the internal electric field by the
induction of surface charges is not entirely correct. In all such practical
cases, there is a leakage current that flews through the dielectric. This
leakage current produces heat within the dielectric. This leakage is very
small in useful dielectrics, but the heating effect is not always
-223-
-------
negligible. An additional dissipative process results when the dipole moment
induced within the molecules of the dielectric is not exactly in phase with
the inducing electric field. In those cases where in the constituent molecules
have a permanent dipole moment, i.e. water, the inability of the orientation
processes to follow the changes in the applied field becomes the dominant
energy dissipation process? this is the basis of dielectric heating.
The combination of the mechanism by which energy is dissipated within
the dielectric is called the loss-tangent; the smaller the loss-tangent,
the smaller the energy loss within the dielectric and hence the better the
capacitor.
2.2 Practical Capacitors
In its simplest form, a capacitor is a pair of metal plates separated
by a dielectric material. Depending on the application, a great variety of
structures have been used ranging from parallel plate mica or glass dielectrics
for very small capacitors, through tantalum-tantalum oxide-tantalum structures
which have very large capacitances with very lew operating voltage ratings.
The capacitors which use PCBs as the dielectric material have capacitance
values in the range of a few tenths to tens of microfarads and are usually
spiral wound of two thin aluminum foils and two paper spacers. To illustrate
the utility of spiral winding, a 0.5 itifd capacitor made of two layers of alu-
minum foil 2.5 inches wide by 0.0005 inches thick and alternate layers of
paper (dielectric constant = 2) 0.001 inches thick, would have a diameter of
only 0.9 inches, whereas, in the plane parallel configuration, the structure
would be 2.5 inches by 220 inches. Incidentally, taking the dielectric
strength of the paper to be of the order of 500 kv/cm, the voltage rating of
the above example capacitor would be about 1250 volts.
The manufacturer of spiral would metal/paper capacitors must avoid
the presence of small imperfections in the paper dielectric and must insure
complete and reliable matching of the metal foils to the surfaces of the paper.
As an alternative to the requirement of very high quality control of the
paper and of the forming process, it has been found to be cost effective
to evacuate the spaces within the wound capacitor and to subsequently fill
-224-
-------
the voids with a suitable liquid dielectric material prior to sealing the
completed unit. This liquid displaces any air which may be left in the
capacitor, thereby raising both the dielectric constant and the critical corona
inception voltage.
2.3 Required Properties of Dielectric Liquid
The properties that are essential for the liquid dielectric can be
described in terms of the functions that the liquid must fulfill:
Electrical Properties ~ Should have a dielectric constant
at least as large as that of the solid dielectric spacer,
and a dielectric strength at least as high as that of the
solid dielectric. The liquid must have a low loss factor
to assure electrical efficiency and a high resistance to
the formation of corona discharges.
Physical Properties - Must be liquid at a suitable
temperature to allow processing of the capacitor. Further,
it should be liquid over the operating temperature range
of the resulting capacitor with a sufficiently small
coefficient of thermal expansion so as to fulfill its
function over the entire temperature range. Mast have a
boiling point sufficiently elevated to ensure that the
vapor pressure at the maximum operating temperature of
the capacitor does not cause rupture of the container.
. Chemical Properties - Must be chemically compatible with
the solid dielectric material and with the metal plates.
Specifically, the dielectric liquid must wet both the plates
and the solid dielectric without altering either material
chemically or physically over the entire operating temper-
ature range. The dielectric liquid must also be chemically
stable at elevated temperatures and in the presence of
intense electric fields so that its properties do not change
over time.
-225-
-------
* Flammability - Should be non-f lammable and produce no
flammable breakdown products if electrical arcing occurs
within the capacitor.
' Cost and Availability - Should be inexpensive and readily
available with well defined and standardized properties.
' Toxicity - Should be non-toxic and its possible break-
down products should be non-toxic.
" Environmental Persistence - Should be environmentally
degradable and non-bioaccumulating.
' Legislative Acceptability - Must be acceptable under the
laws of the U.S. and of all other countries to which
capacitors are exported. Should be acceptable under the
relevant electrical codes which govern the use of capacitors.
2.4 The Use of PCBs in Capacitors
PCBs have been the standard dielectric liquid used in almost all
liquid-filled capacitors since 1929. Prior to 1952 the liquid used in
capacitors was Aroclor 1254 (54 percent chlorine); it was then replaced by
Aroclor 1242 (42 percent chlorine), which has better electrical properties.
In September 1971, Monsanto introduced a new capacitor liquid, Aroclor MCS-
1016, which is a modified Aroclor 1242. This material is the standard against
which the properties of any other proposed capacitor dielectric fluid must be
compared.
jL4.j._^ Properties of PCB Capacitor Dielectric Liquid
The relevant properties of Aroclor 1016 are as follows:
Electrical Properties
dielectric constant (ASTM D-150-47T) 5.85 (25°C)
dielectric strength (ASTM D-149-44) >35 KV
resistivity (ASTM D-257-46) >500 x 109
loss-tangent (Dissipation
factor-ASTM D-150-47T) 0.0025
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Physical Properties
melting point (pour point) -19°C
viscosity at 100°F TL-81 SUS
boiling point 325-366°C
specific gravity (25°C) 1.362
coefficient of thermal expansion .00068 cc/cc°C
Chemical Properties
corrosiveness: liquid - noncorrosive
breakdown products - corrosive
solvency: high, but satisfactory materials have
been developed
stability (max. service temp.) 95°C
Flanmability
•
liquid (Cleveland open cup flash point) : 141°c
breakdown products: nonflammable (primarily
HC1 and carbon)
Cost and Availability
cost $5.14/gallon
availability - no problem
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• Persistence
environmental - very persistent
+ (2)
% biodegradation (48 hour activated sludge) 33 - 15%
bioaccumulating - very
• jjegislative Acceptability
banned in Japan, essentially banned in Sweden
2.4.2 Advantages and Disadvantages of PCBs in Capacitors
Aroclor 1016 has a relatively high dielectric constant of
5.85 which is well matched to the dielectric constant of 6.10 of the paper
used in capacitors. This mixture of PCBs is chemically very stable, even in
the presence of high temperatures and intense electrical fields. It is prob-
able that some slight dechlorination of the PCB occurs during the long term
operation of capacitors. The resulting HC1 would lower the dielectric strength
of the PCB. However, the Aroclor 1016 used in capacitors usually contains a
few tenths of one percent of a chemical scavenger (usually an organic epoxide)
which reacts with any HC1 which is formed, and thereby extends the life of the
capacitor.
The only major problems associated with the use of PCBs are
their extreme environmental persistence and chronic toxic properties which are
made more severe by the high degree of bioaccumulation which occurs in the
environment. The recent restrictions imposed by the governments of Japan and
Sweden on the use of PCBs in those countries will require that a suitable sub-
stance be developed for use in electrical equipment which will be exported.
2.4.3 Usage of PCBs in Capacitors
The General Electric Co. reports that approximately 100
million PCB type capacitors are produced annually in the U.S. with a value of
140 million dollars, most of them for first-time use. Total annual PCB
requirement for capacitor manufacturing is 21 million pounds, about 50 percent
of which is used in large power factor correction capacitors.
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Capacitors used in lighting and air conditioning applications
contain 0.005 to 0.09 gals. (0.05 to 1.0 Ibs.) of PCBs. The largest power
capacitors contain about 6.7 gals. (77 Ibs.) of PCBs. The most popular size
contains about 3.1 (36 Ibs.). The National Electrical Code requires that any
installation of capacitors in which any single unit contains more than 3
gallons of combustible liouid shall be in a vault like that required for
(4)
transformers.
The life expectancy of capacitors exceeds 10 years for
lighting applications and more than 20 years in electric utility power trans-
mission application. Although capacitors are considered long-lived products,
they could fail due to poor process control, materials quality and mis-
application. According to G.E., existing PCB capacitors have been developed
to the point that failures are considered essentially negligible. In each
application, the first-year failure rates are less than 0.2 percent. This
level of life and reliability had not been achieved prior to the introduction
of PCBs. Furthermore, the relative non-flammability of askarels significantly
reduces the fire hazard that might otherwise accompany those failures that
result in rupture of the case. Capacitors are not rebuilt and returned to
service after failure. They are disposed of and replaced by new capacitors.
2.5 Alternatives to the Use of PCBs in Capacitors
There are two main approaches that might be adopted in the develop-
ment of substitutes for the PCBs in capacitor applications, (a) a straight-
forward replacement of PCBs that would require minimal alternation of the
present production techniques; and (b) the introduction of new production
techniques designed to eliminate the need for a liquid dielectric. In either
case, the alternative solution must be significantly less environmentally dis-
tressing than the currently used PCBs.
2.5.1 Substitutes for PCBs
So long as the present method of construction of capacitors
is used, the dielectric liquid is required and must necessarily satisfy the
physical, chemical, and toxicity requirements at least as well as do PCBs.
These requirements can be relaxed only i: conjunction with a more or less
severe restriction on the maximum operating temperature of the capacitor. On
the other hand, some sacrifice in the dielectric constant and dielectric
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strength would be possible by increasing the dimensions of the capacitors. In
many applications this increased size would be troublesome, but not so serious
as to be inpractical. Further, there are some applications in which the non-
flammability of the dielectric liquid and of its possible breakdown products
could be somewhat sacrificed. Finally, the cost factor could be considerably
relaxed.
A number of compounds are being developed as replacements
for PCBs in capacitors. The following list of ccmpounds must all be con-
sidered as possible substitutes for PCBs in at least limited applications.
2.5.1.1 Phthalate Esters:
2.5.1.1.1 Dioctyl Phthalate: (POP)
Current status:
Used in capacitors in Japan. Used by General
Electric Co. under the trade name "Econol" in ca-
pacitors manufactured for export to Japan.
Advantages;
Price: one-half that of PCB.
Availability: Widely used as a plasticizer for PVC.
Dielectric Constant: 5.3; similar to PCB.
Disadvantages:
Chemical stability: capacitors are limited to 85 C
max. vs 95°C max. for PCB.
Corona inception voltage: lower than PCB. *• '
Flanmability: Flash point is relatively high (220 C)
but more flammable than PCBs.
Toxicity: Suspected carcinogen. Extensive addi-
tional testing is required.^ '
2.5.1.1.2 Diisononyl Phthlate:
Current status:
Currently being tested by Exxon Chemical under the
trade name "Enjay 2065".(6>
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2.5.1.4 Silioones
Current status: Developmental work is being done in the
U.S. by Dow Corning Co. No information is currently avail-
able, but Dow Corning has indicated that a formal announce-
ment will be made late in 1976.(10)
2.5.1.5 Diaryl Sulfone
Current status: The Monsanto Company has been
conducting extensive tests with a proprietary dielectric
(?)
liquid trade named "MCS-1238". ' Detailed chemical
information is not currently available on this material;
however, an example cited in German and U.S. patent dis-
closures is a mixture of tolylxylyl sulfone, isopropyl
biphenyl, and minor ingredients which may be antioxidants.
Complete information has been promised by Monsanto for the
late first quarter of 1976.
Advantages: (MCS-1238)
Dielectric constant: 6.0
Corona inception voltage: similar to PCB.
Bicdegradation (48 hour activated sludge): 70% + 10%.
Bioaccumulation: does not concentrate in food chain.
Toxicity: Rat oral LDgQ = 3.8 q/kg. Rabbit dermal
LD5Q - 5 to 8 g/kg.
Disadvantages: (MCS-1238)
Flammability: more flammable than PCBs.
Chronic toxicity: lack of data.
2.5.2 Elimination of Dielectric Liquids in Capacitors
Because of the complex and strongly interacting requirements
on a liquid dielectric material, there is considerable interest in the
development of capacitor designs which do not require a liquid dielectric.
The rather advanced technology involved in the production of very thin
plastic films of very high physical integrity, such as is required in many
food packaging applications, has opened the way for the production of plastic
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films of suitable dielectric constant and dielectric strength for capacitor
applications. The parallel development of methods for the deposition of thin,
carefully controlled metallic films on non-conducting surfaces, such as is
widely practiced in the semiconductor industry, suggests that the use of a
liquid dielectric material could be circumvented by metallic films deposited
onto suitable plastic substrates. The resulting metallized film can be
spirally wound into useful capacitors. The essential problems associated with
this approach, aside from the development of suitable high speed processing
equipment, lie in the selection of a plastic substrate that is tractable but
also stable at sufficiently high operating temperatures, and in the complete
elimination of air from the capacitor. An additional problem with this approach
lies in the nature of the polymers that have been studied; nearly all of the
suitable materials are themselves flammable and so are their probable breakdown
products.
A number of different plastic films are used in low voltage
DC capacitors, i^bst of these materials exhibit a relatively high loss-tangent
(dissipation factor) which results in over-heating when subjected to an alter-
nating electric field. Only polypropylene has a loss-tangent sufficiently low
so that it can be used in AC capacitors, and the dielectric constant of this
material is about 2.2 (vs 5.85 for PCB).
The polypropylene film that is used in capacitors is con-
siderably thinner than that used for packaging and decorative applications.
There is no current source of satisfactory capacitor grade polypropylene film
in the U.S. The technology for metallized polypropylene film capacitors
comes from Pye TMC of England which is partially owned by Philips. Represen-
tatives of this company have approached most major U.S. manufacturers.
Currently, this technology has been purchased by one U.S. manufacturer at a
cost of four percent of their capacitor sales for the life of the technology
usage. The failure rate of the dry film capacitors is reported to be 20 times
that of PCB filled capacitors, primarily due to corona discharges into air that
is trapped in the dielectric layers. Present efforts on dry film type
capacitors are directed toward the development of a suitable capacitor design.
Polypropylene capacitors are widely used in Europe at voltages up to 250 volts.
Capacitors suitable for U.S. applications are not expected for 3 to 5 years.
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2.6 The Use of PCB Capacitors in Electrical Equipment:
Each of the specific uses of PCB capacitors imposes special
requirements on the performance of the capacitor and on the properties of the
dielectric liquid. The evaluation of the various substitute liquid dielectrics
and of the dry capacitor designs must be based on the suitability of the
resulting capacitors for each of these uses.
2.6.1 Power Factor Correction
The largest use of PCB filled capacitors is to increase the
efficiency of electrical power distribution by correcting for the power factor
of inductive machinery such as industrial motors, induction furnaces, and
fluorescent light transformers. In general, the load imposed on a power line
by these electrical devices is not purely resistive, but is also partly
inductive. The voltage drop (V,.) across such an inductor is proportional to the
rate of change of current through the device; hence
dt
(7)
where the negative sign expresses the reaction of the inductance (L) to a
change in current (i) through the inductance. If the current is expressed in
the form
Itot
o
(8)
JOJt
where j = /T , e = (cos tot - j sin tot) , to = 2irf, f = frequency.
Then
VT = JtoL i = Zr i (9)
where ZT is the inductive reactance given by
ZT = jtoL .
(10)
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difference
On the other hand, for a capacitance (c), the potential
'i dt 1 .
TT — **_
C " C
jwc
(11)
where Q is the electric charge on the plates of the capacitor. Hence, the
capacitive reactance Z is given by
(12)
If a series circuit containing inductive (L), capacitive (c),
and resistive (R) elements has a potential difference v = v e-1 across it, the
relation between current and applied potential difference is given by
i Hi_ _ v jut
-I-; i — • _L QU — V ci
dt C / O
(13)
A solution of this equation is in the form
6)
(14)
where 9 is the phase difference between the applied potential difference and
the resulting series circuit current. On substitution of the assumed solution
into the differential equation (13) , one finds
(jcoL + R - -1 ) i = V
(15)
which is, in the general (Ohm's Law) form,
Z i = V
(16)
where
Z =
OJC
= Iz
j4>
(16)
where
2
<"*"•;£->
(16")
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and
_i
— coc
= tan ~ ' ""
and, in order to satisfy Eq. (16)
0 = - . (17)
The power dissipated in a series R, L, c circuit is given by
. T
1 /
P =
*/
VI dt (18)
6
where T is the period = -=•
which, on integration, yields
P = I V cos cj) (19)
where cj) is the phase angle given by Eq. (16' ' ').
The importance of the phase angle is best described by noting
that electrical power is generated in such a manner that the voltage and cur-
rent are in phase, i.e. (cos cj)) , . =0.
^ ' T generation
Hence
Power generated - power consumed = Power losses
in transmission
VI - V I cos 6 = V I (1 - cos 6) = newer loss due
oooo oo '
to unfavorable phase angle (20)
Since the voltage is fixed and cos 0 < 1, the transmission
line current must be increased in order to supply the load when there is a
lagging phase angle. However, the resistive losses in the transmission lines
are proportional to the square of the current transmitted. Therefore,
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efficient transmission of electrical energy requires that the net phase angle,
or power factor, of the load be as close to unity as possible, this power
factor correction is achieved by the introduction of a capacitor in series
with the inductive load at the load end of the line.
The function of a capacitor in such a circuit can perhaps be
better understood by examining the interchange of electrical energy among the
various components of the circuit. In an inductive device, such as a motor or
a fluorescent light, which is subjected to an alternating current, a consider-
able amount of energy is stored in the form of a magnetic field and then
returned to the circuit in the form of current when the voltage decreases. In
a purely inductive circuit, this current is transmitted back to the generator
and is lost in the form of heat in the transmission lines. The energy required
to form the magnetic field during the next cycle must then be supplied by the
generator. If a capacitor is placed in the circuit near the inductive load,
the energy from the collapse of the magnetic field is stored in the capacitor
in the form of an electric field when the voltage decreases, and then is
transferred back from the capacitor to the inductive device to reform the
magnetic field during the next cycle. Since the energy to form the magnetic
field is transferred between the capacitor and the inductive device, it does
not appear in the transmission lines. This decreases both the heat losses £11
the transmission lines and the amount of energy required from the generator.
The capacitor used for power factor correction functions as a
temporary storage device for electrical energy. It is important that the
energy losses be minimized, implying a low loss-tangent for the capacitor and
a minimum distance between the capacitor and the inductive device. The other
physical and electrical properties of the capacitor are a function of the
particular application. There are three general types of power factor cor-
rection capacitors: high voltage power, low voltage power, and lighting ballast
capacitors.
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2.6.1.1 High Voltage Fewer Factor Capacitors
Power factor correction can be furnished by the
electric utility by installing capacitors at substation locations. These
capacitors are designed to operate at high voltages of 4800 to 13800 volts,
and are manufactured in a size range from 15 kvar to 200 kvar. Each capacitor
contains about 2 to 2^ gallons of PCBs, most of which is trapped in the
porosity of the paper dielectric. These capacitors are generally installed in
banks in a substation or mounted in groups on utility poles.
The failure rate of high voltage power factor
capacitors is approximately .3% per year. These capacitors are usually
protected by fuses so that the failure of one capacitor in a bank will not
cause failure of other capacitors. Rupturing of these capacitors on failure
is relatively unusual, and even when the case does rupture, loss of PCB is
generally less than ^-gallon as most of the liquid is absorbed by the paper
in the capacitor.
The high voltage power factor capacitors are usually
installed outdoors in non-hazardous locations. Fire resistance is therefore
of minor importance. The dielectric must have a high dielectric constant and
a high resistance to corona formation in order to operate successfully at high
voltages.
2.6.1.2 low Voltage Power Factor Capacitors:
Electrical utilities structure their rates so that
there is an economic advantage to the industrial user to supply the power
factor correction for major inductive loads such as motors, induction furnaces,
and welding machines. The capacitors for these applications are designed to
operate at 250 to 575 volts.
The PCB/paper combination used as the dielectric in
spiral wound capacitors operates most efficiently at a voltage of 400 volts
Per mil. Technological limits on paper manufacturing limit this dielectric
combination to a minimum thickness of about one mil, so the full efficiency
of these capacitors is not achieved at voltages below 400 volts. However,
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capacitors of this type are used for power factor correction for voltage
applications down to 220 volts with the motors in heavy duty whole-house air
conditioners.
Low voltage capacitors are usually built into the
equipment or located close to the inductive machinery in manufacturing plants.
Important requirements of the dielectric and low flammability, low toxicity of
the liquid and its degradation products, are chemical stability to achieve
long service life of the capacitors. Dry film capacitors could find consider-
able use in 220 volt applications where space is not a severe limiting factor,
as in air conditioners.
2.6.1.3 Lighting Ballast Capacitors
Normal fluorescent light fixtures are designed to
operate on 110 volt power circuits. The fluorescent bulbs, however, require
about 300 volts to operate. This high voltage is supplied by a transformer
which is built into the fixture. A small percentage of fluorescent lights are
built with a coil-and-core transformer and no power factor correction. These
units are sold for household use on the basis of low initial price. The power
factor of these lights is about 0.7.
The fluorescent lights which are manufactured for
commercial and industrial applications all have the high voltage supplied by a
ballast. This ballast consists of an auto transformer connected in series
with a 4yf capacitor. The capacitor is of foil-PCB-paper construction and is
sealed into an aluminum can. The transformer and capacitor are packaged in a
steel can which is filled with a mixture of asphalt and sand as a potting
compound. This finished ballast is about 1" x 2V x 12", and has a life
-expectancy of 10 to 15 years in normal service. The lighting fixtures using
this arrangement have a power factor of about 0.9. The capacitor in a
fluorescent light ballast is usually installed very close to the bulbs, and
depending on the design of the fixtures, the ballast operates at temperatures
of 85 to 90°C.
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High efficiency mercury arc and sodium arc lights
are widely used for highway lighting and other high-intensity applications.
The ballast units which supply the high voltage for these lights are similar
to those used in fluorescent lighting, except they supply more power at a
higher voltage.
It should be remembered that the amount of energy
that can be stored in a capacitor is proportional to the square of the voltage,
so that a 110 volt capacitor would require 8 times the plate area of a
capacitor operating at 300 volts.
The major requirements for ballast capacitors are:
small, size, implying a high dielectric constant;
ability to operate at 3 00 volts, which implies a complete
exclusion of air so as to avoid corona discharge problems;
chemical stability when exposed to 90 C for long periods
of time; and
non-flammability because of the use oi the ballasts
in houses and other flammable, hazardous locations.
Aerovox reports that they are developing a dry type
metallized polypropylene capacitor which could be used in fluorescent ballast
applications and that this design would be good for industrial applications
/ ~\ T N
up to 370 volts.Vi ; Application of these units up to 440 volts is considered a
possibility. This substitute, when available, would be suitable for 50 percent
of the current capacitor applications. It would increase the oost of low
voltage power factor capacitors by 20 percent as compared to a PCS
unit but would double the cost of ballasts (separate units would be required
for purposes of start and storage). The film and metallizing equipment used
in these capacitors are manufactured in Europe and currently must be imported.
The use of this technology will require major redesign of the parent products,
particularly when used in fluorescent light ballasts and room size air
conditioners. Because of space and temperature limitations, the dry film
capacitors could not generally be used to replace failed capacitors in existing
electrical equipment.
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It should be noted that the general use of dry film
capacitors in European fluorescent lights is not comparable with U.S. practice.
The European line voltage is normally 250 volts, which is below the corona
discharge voltage into air, but which allows a decrease in size of the capacitor
by a factor of 6 compared to 110 volt applications. In addition, the European
fixtures are usually single bulb, rather than the dual bulb fixtures used in
the U.S., and the auto transformer is much less reactive as it needs only to
increase the voltage frcm 250 to 300 volts. As a result, much less capacitance
is required for power factor correction in European fixtures, and the capacitor,
can operate efficiently at normal line voltages. Finally, the capacitors in
European fluorescent fixtures are installed as discrete components to allow for
their replacement; this is necessary because of the higher failure rate of dry
film capacitors oompared to U.S. capacitors.
In spite of the relative severity of the technical
requirements for U.S. ballast capacitors, industry sources indicate that there
is probably a 50 percent chance that a usable dry film capacitor will be
available ±n the U.S. by the end of 1976.
2.6.2 Motor Starting Circuits
Electric motors for residential use are designed to operate
on single phase current. A number of different methods are used to develop
the rotating magnetic field that is required to start the motor, and these
methods differ in the amount of torque that is developed at low speeds.
Certain applications, particularly compressors in air conditioning units,
require a very high starting torque. This is achieved in a single phase motor
through the use of a capacitive starting circuit.
shewn below:
In a capacitor ran motor, stator windings are connected as
PRIMARY WINDING
ROTOR
LINE
SECONDARY WINDING
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The starting field is connected bo the paver supply
through a capacitor; the result is a starting winding current which leads the
applied voltage. Hence, at standstill, the rotor sees fields nearly 90 apart
in time as well as 90 apart in space. The resulting, effectively rotating,
field results in high starting torque and a high power factor (important
during the period when the back emf due to rotor motion is low so that the
starting current is significantly higher than the running current). Because
of the inductive effect of the starting winding, the capacitor is subjected to
a voltage substantially higher than the line voltage. MDSt 110 volt appliance
motors are designed so that the capacitor operates at an effective voltage of
370 volts, thus making optimum use of the characteristics of foil-PCB-paper
capacitors.
The capacitor not only performs the necessary
function of generating the starting field, but also provides significant power
factor correction. In larger motors — primarily 220 volt air conditioner
motors — the PCB motor run capacitor is sized for optimum power factor
correction and additional capacitance is provided during the first few seconds
of start-up by an electrolytic capacitor in parallel with the PCB capacitor.
The electrolytic capacitors provide very high capacitance in a small package,
but they have a dissipation factor of about 7 percent which causes rapid
temperature increases. The electrolytic capacitor is disconnected by a
centrifugal switch when the motor reaches running speed. This prevents failure
from overheating and results in a configuration with good operating character-
istics and satisfactory power factor.
The motor run capacitor is normally built into the
motor. This results in a requirement for small size, long life, and fire
safety for the capacitor. It is possible that dry film capacitors could be
used in this application. However, the high voltages suggest that a liquid
dielectric capacitor would be more suitable if a satisfactory substitute were
developed for PCBs.
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In sane applications, DC motors can be used in place
of single phase PC motors. Such DC motors are used in some European electrical
appliances where the electronic speed control that can be achieved with the
DC motor results in a savings compared to the more complex speed control
mechanisms required with an AC motor. In these European appliances, the DC
power is supplied by a silicon rectifier. However, the output from the
rectifier must be filtered to eliminate the fC components, and this filter
circuit normally uses a liquid filled capacitor. In addition, the IDC speed
control circuit requires an additional capacitor. While these circuits could
be redesigned to eliminate the use of capacitors, the resulting DC motor would
not appear to be economically competitive with the capacitor run motor except
in a limited number of special applications.
2.6.3 Electronic Filter Capacitors
Eectifier circuits are used to supply DC current to electronic
components. For instance, the circuitry of most U.S. television sets operates at
300 volts DC. The output of the rectifier must be filtered to achieve a stable
DC current. Most television sets use a PCB capacitor operating at 300 volts
to pass the AC components of the current. This achieves the required 300 volt
DC power required by the other components.
Requirements for this capacitor are long life at 300 volts,
small size, and good fire resistance. Either a dry film capacitor or a suitable
liquid dielectric capacitor could be substituted for the PCB capacitor in this
application, although the larger size of the dry film capacitor may limit its
use in repairing existing television sets.
2.7 Institutional Barriers to Substitutes for PCBs in Capacitors
The final choice of an acceptable substitute for PCBs will be made
by the capacitor manufacturers based on the performance characteristics and fire
safety of alternate dielectric materials. This choice will be affected by
performance waranties that are common in this industry and by evaluations of
safety as reflected in the codes and regulations which govern the use of
capacitors. The traditional industry practices and the formal regulations both
impose institutional barriers to the acceptance of a substitute for PCBs.
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These barriers are a major factor in the rapid replacement of PCBs, and should
be carefully considered in the formulation of government regulations and in
the industrial marketing of alternate dielectric materials.
2.7.1 Performance Acdeptability
Capacitors are sold with stringent performance warantees which
cover both the capacitance and the expected life or maximum failure rate of the
capacitors. These warantees are based on various capacitor standards which are
established by industry groups. The wide usage of a particular type of
capacitor will depend on the existence of relevant standards which allows the
user to choose equivalent capacitors from different manufacturers.
Currently, no industry standard exists for dry film capacitors
for AC applications. However, such a standard is being developed by a
committee of the E.I.A. and should be formalized by the end of 1976. This
standard will establish minimum performance criteria for any dry film AC
capacitors which may be manufactured.
Saless of capacitors to performance specifications implies the
acceptance of considerable liability by the capacitor manufacturer. Because
of the expense of repairs to lighting fixtures and appliances which have been
sold to consumers, the liability due to early failures could easily exceed the
cost of the capacitors. A situation of this type occurred during the 1960's
when many fluorescent light ballast capacitors failed prematurely. This group of
failures occurred when the voltage stress on the PCBs was increased, resulting
in a slightly increased rate of degradation by dechlorination caused by corona
discharges. The increased failure rate was not apparent on short term tests;
the replacement of the failed ballasts was very expensive to the capacitor
manufacturer. This problem was solved by the addition of a chemical scavenger
to the PCB.
Because of the occurrence of past performance failures and the
hiqh potential cost of future failures, tfie capacitor industry can be expected to
be very conservative in the introduction of substitutes for PCBs. Substitutes
will be accepted only after the accumulation of substantial long term (3 to 5
years) service testing data. Since the greater biodeqradability of the
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substitutes implies that they will exhibit lower chemical stability than PCBs,
considerable testing at service conditions will be required to support the
general use of any of these materials. This requirement of extensive service
testing would be expected to delay the general acceptance of PCB substitutes
by 3 to 5 years.
2.7.2 Fire Safety
The use of capacitors is governed by several industry
standards which embody the general service experience and risk factors as
perceived by industry representatives and fire insurance underwriters. These
codes and regulations are specific for various applications of capacitors. The
major applications must therefore be considered separately.
2.7.2.1 Utility Use of Power Factor Correction Capacitors
Most of these capacitors are installed in substations
or are mounted on poles. In general, the locations of these capacitors are non-
hazardous, and there is little risk that fire damage or personal injury will
result from the failure of a utility capacitor.
The failure of existing utility capacitors may
result in uncontrolled loss of PCBs into the environment. The frequency of
capacitor rupture is reportedly quite low (estimated to be .02%/year) and the
amount of PCB lost to the environment probably does not exceed 2 to 3 pounds
per capacitor rupture. However, because of the large number of capacitors in
service and the lack of means for containing any leakage, the total environ-
mental load from this source may total several thousand pounds per year.
Current standards for the disposal of failed
capacitors containing more than 2 pounds of PCB requires that they be buried
in supervised dry land fills that meet state requirements.d) in addition, the
standards require that these capacitors be labeled with a warning as to their
environmental hazards. This label must also contain detailed disposal pro-
cedures. The major apparent lack in these standards is in the area of control
and disposal of leakage from failed capacitors. The necessity for such control
may offset the economic penalties associated with the replacement of PCB
capacitors by units which are environmentally less objectionable.
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2.7.2.2 Industrial Use of Power Factor Correction Capacitor
The use of power factor capacitors in industrial
plants is governed by state fire regulations and by the National Electrical
Code (4) which has "been formally incorporated into OSHA regulations.
The National Electrical Code requires that capacitors
that contain more than three gallons of flammable liquid be enclosed in a
vault or installed in a outdoors fenced enclosure. The definition of flammable
liquid is not explicit, but the effect of the Code is to give large PCB
capacitors a significant economic advantage compared to those containing other
liquids. Proposals are currently being considered to define a class of
transformer and capacitor liquids which are self extinguishing. This may
eventually lead to a change in the code so that vaults will not be required
for large capacitors in industrial applications. This code change is unlikely
to be made prior to issuance of the 1981 code.
2.7.2.3 Lighting and Appliance Capacitors
These small capacitors are usually built into the
ballast or appliance. Failure of the capacitor prior to the obsolescence of
the light or appliance is infrequent, and the capacitor is scrapped as part
of the entire assembly. Currently, most of this material ends in municipal
landfills. With growing popularity of reclaiming metal values from municipal
waste, there will be an increasing amount of PCB which appears as contaminants
of scrap steel and is vaporized or burned off in the steel furnace.
The major drawback to the use of substitute materials
is the fire safety of the appliance. Completed ballasts or appliances must
meet mindjrtum safety standards as specified by tests conducted by Underwriters
Laboratories. Because the amount of liquid contained in these capacitors is
small, there is probably little increase in fire hazard if a flammable liquid
is used, especially if the capacitor is fused to prevent rupture of the case.
However, acceptance of flanroable liquids in capacitors will have to await
action by Underwriters Laboratories, and recent conversations indicate that
they have not yet established either specifications or test procedures for
electrical equipment containing flammable liquid capacitors. '
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3.0 ELECTRICAL TRANSFORMERS
Polychlorinated biphenyls are used as liquid coolants in electrical trans-
formers which are located in enclosed or hazardous locations. PCBs have an
advantage over the other major liquid transformer coolant (mineral oil) in that
they are nonflammable. Gaseous coolants are also nonflammable, but gas cooled
transformers have disadvantages which are considered below. Alternative liquid
coolants are probably available, but to date none have been found which have
all the advantages of PCBs. The following analysis includes a summary of the
purposes of transformers in electrical circuits, heat generation in trans-
formers, currently-^used cooling techniques, materials being investigated as
substitutes for PCBs, and institutional barriers to the use of substitute
materials in place of PCBs.
3.1 Heat Generation in Electrical Circuits
In direct current electrical circuits, the power, P, delivered at a
load consisting of pure resistance (e.g., a light bulb) is the product of the
electrical current, i, moving through the load and the voltage, v/ across the
load,
P = (V) (i) (21)
But since current is proportional to voltage for a given resistance,
V = (i) (R) (22)
where R, the resistance, is the constant of proportionality. It follows that
power delivered to the load resistance is the product of voltage, V, and the
square of the current
P = i2R (23)
Since the wires that carry electrical power from the site of
generation (be it a battery or an electrical generator) to the load resistance
also offer resistance to the flow of electrical current, a portion of the power
generated is lost through heating of the wires connecting the load to the
electric power source. For a given wire diameter, electrical resistance is
proportional to the length of the wire. In many circuits (e.g., an automobile
electrical system), the power lost in the transmitting wires is small in
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comparison to the power delivered at the load (such as the headlights) . How-
ever r in transmitting electrical power over long distances, the resistance of
the wires could cause the dissipation of a significant portion of the energy
intended for the load.
In alternating current circuits, the power dissipated in a resistance
(either in the load or in the wires carrying the power to the load) is also
2
given by P = i R. (The relation, P = (V) (i) , always applies to power
dissipated in DC circuits, but in AC circuits the expression only applies when
the voltage and current are in phase with each other, which isn't always the
case. In most practical instances involving purely resistive loads it is a
fairly accurate means by which to calculate the power dissipated.)
2
The expression, P = i R, is not influenced by the phase relation
between voltage and current and thus applies to both alternating and direct
current circuits. It is apparent frcm this expression that the energy
dissipated in a transmission wire having resistance R is proportional to the
second power of the current; thus, if the current being delivered to the load
were to be doubled, the energy losses in the transmission wire would be
quadrupled.
Commercial electrical power is often generated many miles from where
it is to be used. There are hundreds of thousands of miles of power trans-
mission lines in this country, and it is not unusual for the electrical power
generated in one place to be used hundreds of miles away, which means that a
considerable amount of electrical resistance must be overcome in transmitting
electrical energy to the user.
The method used to minimize energy losses in transmission lines is
to reduce the current, i, and thus minimize the i R losses (also known as
Joule heating losses) in the transmission wire. In order to deliver maximum
power to the load, the transmission voltage, V, must be increased since the
power delivered is (as with DC circuits) effectively given by P = (V) (i).
Thus, if the transmitted current, i, is reduced by a factor of 2 - which
reduces the Joule heating losses of the transmission line by a factor of 4 -
the voltage of the transmitted power must be increased by a factor of 2.
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In practice, the electricity which is used in homes at 110 volts is
transmitted at voltages ranging up to more than 700,000 volts - roughly 6500
times greater than common wall-socket voltage. As a result, the Joule heating
2
losses are (6500) , or more than 40 million, times less than if the power were
transmitted at 110 volts.
3.2 The Nature and Purpose of Transformers
The purpose of a transformer in an electrical circuit is to trans-
form electrical power from its high-current low-voltage characteristics at the
generating facility to the low-current high-voltage characteristics needed for
efficient transmission; and then, at or near the site of use, transformers
perform the opposite function, bringing the power back into its low-voltage
(typically llOv or 220v) high-current form.
A transformer consists of two windings which are joined by a magnetic
yoke. An alternating current applied to one winding (the primary winding)
creates an alternating magnetic field in the yoke. This magnetic field
induces an electric current in the other, or secondary, winding. In a simple
transformer,-as shown in the following sketch, the ratio of voltages in the
primary and secondary windings is equal to the ratio of turns in the windings,
or
CORE (IRON)
!i. = !i '
V2 N2
N2TURNS
N,TURNS
There are two types of transformers used in the electrical power
industry: power transformers (used for "stepping up" the voltage at the plant)
and distribution transformers (used for "stepping down" the voltage at or near
the site of power use). Power and distribution transformers operate on the
same principle - they differ only in whether the primary or secondary winding
has the greater number of turns. If the transformer is being used for
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stepping up voltage, then the primary side is the one having fewer turns; for
stepping down, the primary side is the one having most turns.
The lengths of wire in the windings offer resistance to the flow of
electricity, the result being the production of heat in the windings. Heat is
also produced by electrical currents induced in the transformer core by same
mechanism that induces currents in the secondary windings. Since the
electrical resistance of most conducting materials increases with temperature,
the efficiency of the transformer (i.e., the ratio of the output power to the
input power) is maximized if the transformer is kept at a low operating
temperature. Therefore, all transformers used in the electrical industry have
provision for cooling, based on either gaseous or liquid coolant.
The coolants in camion use today are:
mineral oil |
pCB | liquid cooled transformers
air )
* dry type transformers
gas
3.3 Desired Properties for Transformer Heat Transfer Fluids
The purpose of the heat transfer fluid in a transformer is to absorb
the heat produced in the windings and core, to transfer the heat to cooling
fins, and to provide electrical insulation within the transformer. The ideal
fluid should have the following properties:
Heat transfer: Be a liquid with a low viscosity, high heat
capacity, and high boiling point. (The use of low boiling
point liquids or gases would require that the transformer be
enclosed in a pressure vessel.)
Chemical stability: Not degraded by prolonged e:?qposure to
high temperatures. Non-flammable in the event of an electric
arc within the transformer and subsequent case rupture. Non-
corrosive, with non-corrosive products resulting from
exposure to an electrical arc. Low solvency toward other
materials used to construct the transformer.
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Electrical properties: High dielectric strength. Low
loss-tangent (minimized dielectric heating of the fluid).
High resistance to corona formation.
Toxicity: Non-toxic and biodegradable. By-products from
exposure to arc should also be non-toxic.
Cost; Low cost.
Availability: Readily available with reliable properties.
3.4 Use of PCBs in Electrical Transformers
PCB cooled transformers account for about 5 percent of all trans-
formers in service. ' The PCB coolant in these transformers is a mixture
of 60 to 70 percent PCBs and 40 to 30 percent trichlorobenzene. The PCBs
currently used in these mixtures are sold by Monsanto under the trade names of
Aroclor 1242 and Aroclor 1254.
The mixtures of PCBs and trichlorobenzene are commonly known by the
generic term Askarel. Askarel is defined by the National Electrical Code as
"a generic term for a group of non-flammable synthetic chlorinated hydro-
carbons used as electrical insulating media. Askarels of various compositional
types are used. Under arcing conditions the gases produced, while consisting
predominantly of non-combustible hydrogen chloride, can include varying
amounts of combustible gases depending on the askarel type". The most commonly
used askarel compositions are Inerteen (Westinghouse trade name for 60 percent
PCB mixture) and Pyranol (General Electric trade name for 70 percent mixture).
The exact composition of both Pyranol and Inerteen have been changed from time
to time, but they have almost always been mixtures of PCBs and trichlorobenzene.
Prior to the mid-1950's, the insulating liquid used in many trans -
'formers (General Electric formulation) was a 50-50 mixture of Aroclor 1260
(60 percent chlorine) and trichlorobenzene. In the late fifties the benzene
component was changed to a mixture of tri- and tetrachlorobenzenes. In
September, 1971, at Monsanto's suggestion, the Aroclor component was changed
to Aroclor 1254 (54 percent chlorine). The current Westinghouse formulation
(Inerteen) utilizes Aroclor 1242.
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The volume of askarel used in various transformers ranges from 40 to
1500 gallons (440 to 16,500 Ibs), with an average of about 230 gallons (2500 Ibs)
One transformer manufacturer, General Electric, estimates the total number of
askarel filled transformers put in service in the U.S. since 1932 to be 135,000;
virtually all are still in service. Typical lifetime of a transformer is often
greater than 30 years, and units that do fail are usually rebuilt and returned
to service. The current production rate for askarel filled units is about
5,000 per year, requiring some 10-15 million pounds of PCBs.
Liquid coolants in transformers have better heat transfer and heat
capacity characteristics than gaseous coolants. Askarel has the further
advantage of being non-flammable. The other advantages of askarels are their
high dielectric strength, their outstanding chemical stability, and their
relatively low viscosity. Disadvantages , in addition to the environmental
threat, are the highly corrosive HC1 they produce .when arcing takes place and
their cost, which is about eight times as much as mineral oil on a volume
basis.
Most askarel-filled distribution transformers are located inside
public, commercial, or industrial buildings, or on the roof tops of such
buildings. No special enclosures or vaults are required except as are neces-
sary to prevent accidental electrical or mechanical contact of persons with the
equipment. However, the National Electrical Code does specify vaults for the
indoor installation of PCB-filled transformers rated more than 35,000 volts.
Askarel-filled transformers are limited by the dielectric strength of the
liquid to ratings below 69,000 volts.
Most power transformers are situated in remote locations where fire
or explosions are not a threat to property. Mineral oils are cortmonly used in
power transformers in these safe locations. However, seme utilities use
askarel-filled power transformers at generating stations.
Step up transformers used to supply the high voltage electricity to
electrostatic precipitators are usually mounted on or very near the stack.
This minimizes the problems associated with the in-plant distribution of high
voltage power. These transformers are usually askarel filled units to minimize
fire hazard in the usually crowded area of the stack.
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Railroad locomotives which operate on high voltage PC power from
overhead catenaries are used in the U.S. Northeast Corridor. Askarel-filled
transformers are mounted in the engines or under the self-powered passenger
cars, and reduce the catenary voltage to that required by the traction motors.
These electric locomotives are mostly limited to passenger service on the
Northeast AMTRAK routes and on the commuter lines around Philadelphia and New
York. Large askarel-filled transformers are used in the old GG-I locomotives,
under the Metroliner cars, in various commuter cars, and in the new E-60
locomotives. (Twenty-six E-60 locomotives are currently being delivered to
AMTRAK by General Electric; each locomotive contains 710 gallons of askarel).
Perm-Central Railroad operating rules require the use of askarels in all
locomotives using the tunnels and stations in New York. This rule has been
in force as a fire safety measure ever since an early GG-I locomotive con-
taining a mineral oil-filled transformer was involved in a fire inside a tunnel
early in the 1940's.
3.5 Present Alternates to the Use of PCBs in Transformers
Askarel-filled transformers are only used where considerations of
fire safety, reliability, availability, and cost make such a unit preferable
to an oil-filled transformer or to a dry type transformer. These alternative
types of transformers are currently used in 95 percent of all applications,
and could, with proper engineering design, be used to replace most of the
remaining askarel-filled units. Consideration would have to be given to the
specific limitations of these designs that presently make askarel-filled
transformers preferable for certain applications.
3.5.1 Mineral Oil-Filled Transformers
If safety were not a consideration, there is no reason why
oil-filled transformers could not be used in all applications. Askarel-filled
transformers cost about 1.3 times as much as oil filled units of the same
capacity, and thus most users prefer the oil-type where possible. The oil-
filled transformers are the same size as the askarel units, and are considerably
lighter in weight. In addition, mineral oil has somewhat better heat transfer
characteristics than does askarel, and an electrical arc in mineral oil results
in breakdown products that are non-corrosive.
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The major disadvantage to mineral oil is its flarnmability.
Transformer mineral oil has a flash point of 145 C, and if an arc occurs within
the transformer, the breakdown products will be hydrogen and methane which are
also flanmable. Detailed records of such failures are maintained by the
electrical industry. Fire Underwriters do not approve of the use of oils
and other flammable liquids for indoor applications; where oil-filled trans-
formers are not specifically prohibited as on-site replacements for askarel-
filled units, the National Electrical Code imposes certain restrictions upon
their mode of installation.
Oil-filled transformers are used in almost all power trans-
fo?jner applications and for most substation distribution applications where
the high voltage from the transmission lines is reduced to 12.8 kv for local
distribution. Most rural pole mounted transformers which reduce the voltage
to 220 volts are also oil-filled. The issue of flarnmability only becomes
important where the distribution transformer must be buried, as in many urban
applications, or located close to, within or on the roof of the building which
it serves. Askarel-filled transformers are used for most of these hazardous
areas.
Oil-filled transformers can be used in these applications
only if they are suitably isolated from flammable structures or if these
structures are suitably safeguarded against fires. When transformers are
located outside of the building they service, however, the low-voltage power
must be brought into the building via cables or insulated buses, incurring
additional energy losses due to Joule heating in the additional low voltage
transmission lines.
3.5.2 Open Air Cooled Transformers
Transformers can be built without the use of a liquid cooling
medium. One type of dry transformer which is quite successful under limited
conditions is the open air cooled transformer. In this design, the required
cooling is provided by air which passes through the transformer due either to
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thermal convection or forced fan circulation. In those sizes where air cooled
transformers are available, they are about equal in price to askarel-filled
transformers of the same kva rating. However, the following limitations govern
the successful use of open air cooled transformers, and prevent them from being
considered for many applications using askarel-filled transformers.
Heat capacity: The power drawn from a transformer usually varies
over a fairly wide range. The rating of a transformer is basically
governed by the power which it can handle continuously without over-
heating. If a liquid filled transformer is operated at overload
conditions for a short period of time, the liquid will act as a heat
sink, absorbing the excess heat produced in the transformer without
a rapid increase in temperature. The result of this thermal inertia
is that liquid-filled transformers can operate at outputs of up to
200 percent of rated capacity for a period of one to two hours with-
out being damaged.
An air cooled dry type transformer does not have this heat sink
available, and is limited to operating at a maximum service rating
near its continuous rating. Where the current drawn on the trans-
former does not vary greatly during the day, this limitation is no
problem. However, in most cases the variation in load would require
that a dry transformer be sized 20 percent to 30 percent greater in
capacity than a liquid-filled transformer for the same application.
Dielectric strength; The liquid coolant in a liquid-filled trans-
former also provides a significant level of electrical insulation
between the various current carrying components within the trans-
former. Air has a much lower dielectric strength, and open air
cooled transformers are limited to a maximum voltage of 25 to 40 kv.
The problem of electrical insulation is even more severe if the open
air cooled transformer only operates intermittently. When the trans-
former is operating, the heat generated within the windings keeps
their insulation dry, and maintains a high dielectric strength of
this solid insulating material. However, when the transformer is
not operating, the coils cool to ambient temperatures and the
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insulation can absorb moisture fran the air which reduces its
dielectric strength. Therefore, an open air cooled transformer must
be carefully dried before being put into service after each time it
has been allowed to cool.
One final problem with dry air cooled transformers is due to the
tendency of dust to be attracted from the air to the coils by electro-
static attraction. This dust can build up in the coils which
blocks the flow of air and causes overheating, or the dust can form
conductive paths which short circuit the transformer.
Dry open air cooled transformers are generally limited to dry, clean locations
where the load requirements are fairly even and constant, and where the maximum
voltage does not exceed 30 kv. This type of transformer is being successfully
used in large office buildings, particularly tall buildings where the trans-
formers are located every few floors. Even in this application, there are
situations which are beyond the capabilities of the open air cooled transformer;
for instance, in the Sears Building in Chicago, which is over 1400 feet tall,
the electric power is brought into the building and up to the distribution
transformers at 128 kv, which is beyond the voltage limitations of open air
cooled transformers.
3.5.3 Closed Gas Filled Transformers
Transformers can be built which use a dry inert gas (usually
at an elevated pressure) as a heat transfer medium. These transformers avoid
the maintenance problems caused by moisture and dust in open air cooled trans-
formers. However, they are similarly limited in overload capacity because of
their reduced thermal inertia compared to liquid filled transformers.
Closed gas filled transformers must be installed in pressure
tight containers due to the changes in gas pressure caused by changes in
temperature. However, the maximum voltage ratings of these gas filled trans-
formers can be equal to that of liquid-filled units.
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A number of different gases have been successfully used as
heat transfer media in closed gas filled transformers. The most comnon gas
used in the U.S. in this application is the fluorocarbon hexafluoroethane
(C JV). Nitrogen and sulfur hexafluoride have also been used successfully
in certain applications. Helium has not been found to be a satisfactory gas
for this application because its low dielectric strength results in corona
discharges within the transformer. Hydrogen gas is unsatisfactory as any leak
in the transformer would result in a severe fire hazard.
Because of the necessity for the pressure vessel container,
gas cooled transformers are 30 to 40 percent heavier than askarel-filled trans-
formers, and cost two-thirds more than askarel transformers (and twice as much
as oil-filled transformers). In addition, the gas filled transformers must
often be specified in a larger size than the liquid-filled transformers to
allow for the expected heavy load peaks of power consumption.
3.6 Current Alternatives to the Use of PCS Cooled Transformers
The National Electrical Code has detailed specifications for trans-
formers which assure that transformer installations meet both fire and shock
safety requirements. These safety requirements are achieved by the use of
either non-flammable transformers (askarel or dry type) or vaults, or both.
The final choice of the type of transformer to be used in each application
will be a function of the code requirements and their economic consequences.
3.6.1 Vault Usage Requirements for Transformers
The National Electrical Code 1975^ ' considers three types
of transformers in connection with indoor vaults: dry type, askarel insulated,
and oil insulated.
Askarel insulated transformers installed indoors and rated
at more than 35,000 volts must be enclosed in vaults, according to Section 450-
23. This same section specified that askarel transformers installed indoors
and rated over 25 kva must have pressure-relief vents which must either be
vented to the outside of the building, or some other provision must be made
for "absorbing any gases generated by arcing inside the case".
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The 35,000-volt criterion also applies to dry type trans-
formers; they most be contained in vaults when in indoor installations. The
Code also specifies that dry-type transformers rated at more than 112% kva must
"be installed in a transformer room of fire-resistant construction". Thus, if
space is not a consideration, dry-type transformers - which generally occupy
a larger volume than equivalent-capacity askarel insulated units - can directly
replace askarel-insulated transformers.
In cases where space is not available for the larger-volumed
dry-type transformers to replace the askarel-insulated units, or where the dry-
type units might emit too much noise for a given location within a building,
oil-insulated transformers would be required as replacements for askarel units.
Section 450-24 specifies that oil-insulated units must be installed in vaults,
but the following exceptions are made:
1. If the total capacity of the transformer does not
exceed 112% kva, vault walls need only be 4 inches
thick instead of 6 inches as specified in Section
450-42.
2. Where voltage does not exceed 600, a vault shall
not be required if suitable arrangements are made
to prevent a transformer oil fire from igniting
other materials.
3.6.2 Vault Construction Requirements for Transformers
Section 450-42 of the 1975 National Electrical Code specifies
the construction requirements of vault walls, roof, and floor. "The walls and
roofs of vaults shall be constructed of Tnaterials which have adequate structural
strength for the conditions with a minimum fire resistance of 3 hours." (Six-
inch thick reinforced concrete is stated in the Code as being typical 3-hour'
construction.) "The floors of vaults in contact with the earth shall be of
concrete not less than 4 inches thick, but when the vault is constructed with
a vacant space or other stories below it, the floor shall have adequate
structural strength for the load imposed thereon and a minimum fire resistance
of 3-hours."
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Vault doors are specified in Section 450-43. "Each doorway
leading into a vault from the building interior shall be provided with a tight-
fitting door having a minimum fire rating of 3-hours" (as defined by the NFPA) .
"A door sill or curb of sufficient height to confine within the vault the oil
from the largest transformer shall be provided, and in no case shall the height
be less than 4 inches." Locks are required for vault doors, and "doors shall
be kept locked, access being allowed only to qualified persons". The locks
shall be arranged so that vault doors can be easily opened from inside the
vault.
With regard to ventilation openings, Section 450-45 specifies
the following:
Location: "Ventilation openings shall be located as far away
as possible from doors, windows, fire escapes, and combustible materials."
Arrangement: "A vault ventilated by natural circulation of
air shall be permitted to have roughly half of the total area of openings
required for ventilation in one or more openings near the floor and the
remainder in one or more openings in the roof or in the sidewalls near the roof;
or all of the area required for ventilation shall be permitted in one or more
openings in or near the roof."
Size: "For a vault ventilated by natural circulation of air
to an outdoor area, the combined net area of all ventilating openings after
deducting the area occupied by screens, gratings, or louvers shall not be less
than 3 square inches per kva of transformer capacity in service, and in no case
shall the net area be less than one square foot for any capacity under 50 kva."
Covering: "Ventilation openings shall be covered with
durable gratings, screens, or louvers, according to the treatment required in
order to avoid unsafe conditions."
Dampers: "All ventilation openings to the indoors shall be
provided with automatic closing dampers of not less than No. 10 MSG steel that
operate in response to a vault fire."
Ducts: "Ventilating ducts shall be constructed of fire-
resistant material."
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Section 450-46 specifies the drainage requirements for vaults:
"Where practicable, vaults containing more than 100-kva transformer capacity
shall be provided with a drain or other means that will carry off any accumu-
lation of oil or water in the vault unless local conditions make this
inpracticable. The floor shall be pitched to the drain where provided."
Section 450-47 requires that pipes or duct systems "foreign
to the electrical installation shall not enter or pass through a transformer
vault". Piping or other facilities provided for fire protection or for water
cooled transformers shall not be considered foreign to the electrical
installation.
3.6.3 Transformer Vault Construction Costs
In an effort to determine the cost factors in the construction
of transformer vaults, various construction comp-nies in the Washington, D. C.
area were contacted. It was discovered that the incidence of vault construction
in existing buildings is virtually zero; apparently all vaults existing in
buildings built in the last twenty-five years were constructed as integral parts
of the buildings the same as any other room or enclosure in the building. Thus
the cost of constructing a vault cannot be easily broken out frcm the cost of
the entire building structure, especially since the prime contractors in the
construction industry often subcontract the various facets of the construction
work (e.g., concrete forms, concrete pouring, plumbing, ventilation duct work)
and the portion of the work required by the vault is included in the cost of
construction of the entire building. The construction companies were reluctant
to make cost estimates for installing vaults in existing buildings unless
detailed drawings were submitted as a basis for estimation, and of the half
dozen largest contractors contacted, none had any readily available data from
previous such installations, and all claimed such installations were extremely
rare.
The National Electrical Code allows the installation of oil-
insulated transformers in outdoor locations adjacent to the site of power use.
In the Washington area, as in many urban areas, "manholes" are used to house
transformers in outdoor locations.
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Useful cost information on manhole installations was obtained
through the Potomac Electric Power Company of Washington, D. C. Manholes are
precast concrete structures which are commonly installed in public space
directly adjacent to the building receiving electric service. (The steel
gratings seen in the sidewalks of downtown areas frequently cover manholes
containing transformers.)
IVfenholes are supplied usually by precast concrete product
manufacturers. Costs quoted by one manufacturer range from $875 for a
6' x 6' x 6' (inside dimensions) model to $1700 for an 8' x 10' x 7' model.
These costs include delivery to the job site and installation into the excavation.
According to Pepco, manholes are usually installed flush
against the property line of the building being served. In some cities, the
local government pays for the manhole and its installation, but in Pepco's
customer service area, the customer pays the cost. (Pepco customers also pay
the cost for vault construction when transformers must be installed on private
property.) Pepco used to install more than one transformer per manhole, but
experience with fires has led them to put only one unit in each hole.
According to Pepco, there are no specific codes relating to
manhole construction, but it is likely that local codes influence specific
installations. Pepco provides the final 18 or so inches of each manhole
installation in order to blend the entire installation into the surface grade;
in such cases, and when Pepco has occasion to cast its own manholes, the local
building code must be followed.
The average cost of installing a 5V x 17' manhole is $10,000;
no cost-range data were available from Pepco. The labor requirement is
typically 600 to 700 man-hours, and total time is about one week. Cost factors
include:
1. Working day restrictions - for example, rush hours
in sane parts of the city restrict work hours to
9:30 to 3:30, but the laborers must be paid for a
full days work.
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2. Rain time - the laborers do not work in the rain,
but they must be paid.
3. Rocky soil - hand digging (i.e., with pneumatic
drills and hammers) may be required in lieu of
power shovels. In such cases labor costs - which
account for 70 to 75 percent of installed cost -
can more than double.
The only other cost for manhole installation is the "public
space permit fee", a one-time fee to the local government which is about $20
in the Washington, D. C. area regardless of size of the manhole.
Because they are lighter and easier to handle, dry-type trans-
formers are used very often by Pepco, especially in roof-top applications where
noise is not a consideration and ventilation is not a problem. This lightness
and ease of handling, in conjunction with the lack of vault requirements for
dry-type transformers of less than 35,000 volts, might make roof-mounted dry-
type transformers the most cost effective replacement for askarel-insulated
units in areas where the air is relatively free of corrosive gases and dusts
which could affect the transformer.
3.7 Substitutes for PCBs in Transformers
Because of the evidence that PCBs are damaging the environment, con-
siderable work is being conducted to find a satisfactory substitute for PCBs
in askarel-filled transformers. These efforts by various manufacturers are
attracting considerable interest in the business and technical press.' '^
The goals of these efforts is the development of a heat transfer liquid which
will have satisfactory heat transfer properties, be environmentally acceptable,
and be non-flammable. These requirements are basically contradictory; the
chemical stability required for complete non-flammability implies that the
liquid may be non-biodegradable and may accumulate in the environment. There-
fore, each of the liquids that have been developed sacrifices a certain degree
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of fire resistance to achieve environmental acceptability. The following
liquids have been proposed as substitutes for PCBs in transformers installed
in hazardous locations.
3.7.1 Fluorocarbons
Certain fluorocarbon compounds have properties similar to the
PCBs, and some study is being carried out in this area. However, fluoro-
carbons are highly volatile in comparison to PCBs, and they are about six
times as expensive at this time - though, of course, higher production volumes
would lower their cost.
3.7.2 Silicones
Low viscosity silicone fluids (on the order of 50 centistckes)
are also possible replacements for PCBs. Silicones are currently produced by
four companies: General Electric, Dow Corning, Union Carbide and Stauffer.
The silicone fluid recommended by one producer is polydimethyl siloxane,
which has this molecular structure:
f~tr (~v-i /"fJ
(~£1~. L«tl~ kXL-
I3' I3 !3
H3C — Si 0(— Si — 0 —)n Si — CH3
/•"IT (T^T fTT
CH3 CH3 CH3
Heat Transfer; Silicone fluids have the special advantage of
a relatively temperature-independent viscosity. The silicone fluids have some-
what poorer heat transfer characteristics than askarel, but can be substituted
directly for askarel in existing transformers, resulting in only a small
decrease in the transformer rating.
Electrical Properties: * ^
Dielectric Constant 2.72
Dielectric Strength 400 volt/mil
14
Resistivity 7.1 x 10 ohm-cm
Dissipation Factor 1.8 x 10~5 at 100 hz, 23°C
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Flammability: Polydimethyl siloxane has a higher flash point
than conventional, non-PCB transformer coolants: 280 C versus 146 C for mineral
oil (PCBs have no true flash point) . The heat of combustion of 50-centistoke
polydimethyl siloxane is lower than that of mineral oil — 7.67 kcal/gm versus
11.0 kcal/gm — and since the silocones burn more slowly, they are considered
poor fuel.(18)
On the Underwriters Laboratories fire-hazard classification
(in which water is rated as 0 and ether as 100) polydimethyl siloxane is
classified as 4 to 5, which is slightly higher than the 2 to 3 rating given to
(19)
PCBs, but is considerably less than the mineral oil rating of 10 to 20.
Ecological Persistence; These compounds do not biodegrade,
as measured by sewage sludge breakdown to CO-. However, there is evidence that
they partly depolymerize to low molecular weight compounds upon contact with
soil and water. Since ultra-violet light decomposes methyl silicones, sunlight
exposure may be the mechanism for environmental degradation.
Bioaccumulation: No tendency for bioaccumulation or bio-
concentration has occurred in experiments. In the mammals the compound is not
adsorbed through the gastrointestinal tract or the skin.
Toxicity; The PCS substitute developed by Dow Corning for
transformers is called 02-1090. This is a mixture of polydimethyl siloxanes
of various chain lengths which have a viscosity of 50 CS. The literature on
environmental and health characteristics of silicones refers to at least
six fluids, most of which are probably similar to the OZ-1090 but some of
which could be other mixtures with certain additives. By necessity, the
usefulness of published toxicological data depends on the validity of the
assumption that all of these compounds have identical persistance, bio-
accumulation, and toxicity properties.
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A review of toxiaological studies of silioones reported the
following results:
Dietary Toxicity:
LD5Q (rats) >28 gm/kg
Extended Feeding Tests:
Guinea pigs - 47 gm/kg/day for extended period -
no toxic effect.
Mallard ducklings and bobwhite quail - 5000 ppm
for 5 days - no effect.
Rats - 20 gro/kg/day for 28 days - no effect.
Rats - 190 mg/kg/day for 90 days = no effect level.
Beagle dogs - 300 nig/kg/day for 120 days - no
effect.
Mice - 3% in diet for 80 weeks - no effect.
Man - FDA allows silioones as food additives at
up to 10 ppm.
The major deficiency in our knowledge of the silicones
appears to be in their fate in the environment and the toxicity of their break-
down products.
Cost: The silicone transformer fluids currently cost up to
twice as much as PCBs on a volume basis.
Availability: Dow Corning is currently completing evaluation
of polydimethyl siloxane as a high voltage insulating fluid. They report,
though, that a near term 100 percent replacement of PCBs in transformers by
this fluid is not possible. If a transformer market were to develop for
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polydimethyl siloxane, the present domestic capacity could only be adequate
to supply new transformers. The time lag for a 100 percent replacement of PCBs
in transformers by polydimethyl siloxane would be on the order of 5 to 10
years.
3.7.3 High Flash Point Mineral Oils
The flash point of mineral oil is a function of its molecular
weight. Crude petroleuti can be refined to have any required molecular weight
over a wide range. This makes it possible to specify any particular flash
point that is desired for the mineral oil transformer liquid. This approach
has been taken by RTE Corporation in the development of their proprietary
/21)
transformer liquid which has the trade name RTEMP.
RIEMP is a highly refined paraffinic mineral oil which has
a flash point of 296 C, approximately the same as the 50CS silicone liquid
proposed by Dow Corning. To achieve this higher flash point, the oil is
refined to have a higher molecular weight and consequently a higher viscosity
which reduces its effectiveness in convective cooling. It may be possible to
achieve a lower viscosity without sacrificing the fire resistance of the
liquid, but this modification has not yet been demonstrated.
The major current advantage of the high flash point mineral
oils is their low price relative to silicone and askarel, and their inherent
biodegradability and low toxicity.
3.7.4 High Flash Point Synthetic Hydrocarbons
Certain mixtures of synthetic hydrocarbons may result in a
liquid having the high flash point characteristics of RTEMP or silicone
combined with a relatively low viscosity and satisfactory heat transfer
characteristics. The Monsanto Co. is reportedly testing such a mixture
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which has the trade name MCS-1866. No technical details are available on the
liquid except that it is claimed to have flammability and heat transfer
properties equivalent to silicone at a much lower cost, and to be environmentally
acceptable. Monsanto has stated that the technical details will be made public
early in 1976.
3.8 Institutional Barriers to the Use of Substitutes for PCBs
The National Electrical Code recognizes only three classes of
transformers: askarel, mineral oil, and dry. The Code requirements for
askarel and mineral oil transformers differ only in the vault requirements:
for transformers located inside buildings or in hazardous locations, vaults are
required for all mineral oil transformers, but only for those askarel trans-
formers rated at over 35,000 volts. Askarel transformers are economically
attractive for many applications because the savings in vault costs more than
offset their higher price relative to mineral oil transformers, and their
reliability is better than that of open air cooled transformers. In all cases,
technically acceptable alternatives are available to replace askarel trans-
formers; the only limitations are economic.
All of the substitute liquids that have been developed are more
flammable than askarels, but less flammable than mineral oil. These liquids
do not come within the definition of askarel in the National Electrical Code,
and their use is governed by the rules that apply to oil filled transformers.
Thus, there is no economic or technological incentive to use these alternate
liquids under present Code regulations.
If the Code is to be changed to offer an economic incentive to the
use of these liquids, the relative safety of each liquid must be assessed, and
a decision must be made as to "how safe is safe enough". In particular, test
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procedures must be developed which allow a realistic estimate to be made of
the relative safety of each liquid under conditions which may be expected in
service.
Limited testing of the relative fire safety of the various trans-
former liquids has been conducted by RTE Corporation. The properties of the
four liquids that were tested are summarized in Table 3.8-1 which is reporduced
from the test results report prepared by Mr. D.A. Duckett of RTE Corporation. (21)
The KCE test consisted of the following procedure for each liquid:
Four gallons of liquid was heated to 150°C in a
closed container. An electrical arc was then
initiated below the surface of the liquid. Arc
conditions were 4800 amperes at 4800 volts. The
resulting explosion and fire was recorded photo-
graphically .
The results of this test were as follows: In all four cases, the lid
was blown off the container and a fire ball was formed above the container. In
the test of the transformer oil, the liquid remaining in the container continued
to burn after the fire ball dissipated (as would be expected, as the liquid was
heated to its flash point prior to the initiation of the arc). The other three
liquids self extinguished within several seconds. Because the fire performance
of the KIEMP and the silicone liquids were similar to that of askarel under
these test conditions, both REE Corporation and Dow Corning submitted proposals
to the transformer committee of the National Electrical Code to allow the use
of "self extinguishing" liquids where present Code regulations require the use
of askarel. If these proposals were to be accepted, the use of these liquids
would be allowed by the 1978 Code.
There are a number of questions which have not yet been satisfactorily
answered concerning the use of the "self extinguishing", liquids. The most
itrportant question concerns the realism of the test conditions. It has been
suggested that catastrophic arcing is a relatively unusual cause of transformer
failure, and that a more frequent cause is prolonged minor arcing which creates
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TABIiE 3.8-1
PROPERTIES OF TRANSFORMER LIQUIDS
TESTED BY RTE CORPORATION*
FLU 1 D PROPER! 1 ES :
DIELECTRIC
Dielectric Strength (ASTM D-877) kV
(25 C-fluids as received from vendor]
Dielectric Constant
Power Factor 50°C
100°C
150°C
Dissipation Factor (ASTM D-150)
Volume Resistivity (ASTM D-1169)
Ohm-cm
THERMAL
Flash Point °C
Fire Point °C
Pour Point °C
Thermal Conductivity 25°C
cal/(sec-cm-°C)/cm
Specific Heat (cal/gm/°C) 25°C
Coefficient of Expans ion(cc/cc- C)
PHYSICAL
Specific Gravity (ASTM D-1810) 25°C
Interfacial Tension (dyne/cm)
Neutralization Number (mgKOH/gram)
• Viscosity (cent i stokes)
25°C
50°C
100 C
150°C
TRANSFORMER
OIL
31
2-2.5
<.01
1.0
2.5
.0004
1.0 x 1012
150
162
<-57
.000318
• 393
.00063
.883
49-4
<.02
16
8
3
RTEMP
37
2.2
0.6
2.2
10.5
<-05
1.1 x 1013
296
321
-21
.000297
.450
.0008
.883
25-5
.011
800
150
2k
8
SILICONS
DC-200
34
2.74
0.6
0.9
1.5
.0002
5.6 x 10I/4
304
360
-55
.000360
.340
.00104
.961
20.8
<.01
50
30
16
12
ASKAREL
40
4.5
--
.03
5.0 x 1012
-37
.000262
.7.64
.00067
1.545
50.0
<.01
18
10
k
<3
* Reproduced from report:
"Environmentally Acceptable Insulating Fluids May Replace
Askarels", by D.A. Duckett, RTE Corporation; May 8, 1975.
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a flammability problem due to the breakdown products of the transformer oil.
If this were the case, neither silicone oil nor high flash point mineral oil
would be significantly better than the present transformer oils.
Because of the limited test data that is available, it appears
unlikely that the proposals will be approved for inclusion into the 1978 Code.
Since the deadline for submission of proposals for this Code revision has
passed, the most likely date for any Code revisions is the 1981 Code.
The general acceptance of alternate liquids in place of askarels will
only occur after the performance of these liquids has been demonstrated by
prolonged service tests under realistic conditions. The effect of the Code is
to prevent the testing of alternate liquids in transformers which, under the
rules, must be filled with askarels. The inclusion of the Code into the
regulations of the Occupation Safety and Health Administration is an additional
institutional barrier to the accumulation of adequate performance experience.
3.9 Relative Merits of Alternatives to New Askarel Transformers
The relative merits of the various alternatives that have been
proposed are summarized in Table 3.9-1. Special consideration must be given
to the suitability of each of the alternatives to the major types of trans-
formers which currently use askarels.
3.9.1 Distribution Transformers
Very few distribution transformers presently use askarels.
These transformers are generally installed at the site of major generating
plants, and there would be little difficulty in designing these plants so that
mineral oil cooled transformers could be used safely.
3.9.2 Power Transformers
Askarel cooled transformers are used in buildings and
industrial plants without vaults where the maximum voltage is less than 35,000
volts. Currently available alternates in new construction are:
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TABLE 3.9-1
Relative Jferits of Alternatives to the
Use of Askarel Transformers in New Applications
Mineral oil
transformer in vault
Mineral oil
transformer installed
in non-hazardous
location
Dry transformer
Silicone heat*
transfer oil
High flash point*
hydrocarbon oil
r*i
•rH
O
"S
Q
e
excel.
excel.
excel.
excel.
excel.
"oi
'&
S
•H
CM
excel.
excel.
excel.
fair /good
fair/good
.-
V-l O ^
S QJ 5
18 > 1~I °
In § ^ J S
O ^ OJ '^ M
O -P S-l n3 -P
$5000 to
$50,000
more
$5000 to
$50,000
more
1.5x
1.3x
Ix
^1
-P
-H
"le
•Hfc
01 W
K >
good
good
poor
good
good
•H Cfl
-H -P 0)
t! Q) 4-1
§ a 3
Q i_|..| ^_|
U O -P
usually
no
usually
no
usually
no
probably*
yes
probably*
yes
* Use depends on Code regulations being changed to allow self extinguishing
liquids as direct equivalents of askarels.
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• Mineral oil transformer installed in a vault
• Open air cooled trans formers - limited to clean dry
environments with even power requirements. Satisfactory
for most office buildings and shopping centers.
• Mineral oil transformers at a site away from the
building. This will be satisfactory for most trailer
parks and industrial plants except for those locations
where space is extremely scarce.
A possible, future, alternative may be to use a "self extin-
guishing" transformer fluid in those applications where askarels are now
required. This alternative requires that major changes be made to the National
Electrical Code.
3 . 9.3 Precipitator Transformers
These are high voltage step-up transformers which are mounted
on or near industrial stacks. It should be possible to use mineral oil cooled
transformers in all such applications.
3 9 . 4 Railroad Transformers
These transformers use askarel due to Penn-Central Railroad
regulations. However, foreign experience indicates that there is no significant
fire risk from the use of more flammable liquids in these transformers:
European practice has traditionally been to use mineral oil in locomotive
transformers. About ten years ago an experimental transformer was built in
France which used an enclosed gas cooled (sulfur hexafluoride coolant) trans-
(22)
former. Although somewhat limited in peak power output (overload conditions)
compared to oil-filled transformers, it performed satisfactorily during
extensive tests. However, this type of transformer did not gain wide acceptance
because it was more expensive than oil-filled transformers, and there was not
felt to be any significant safety problem associated with the use of the oil-
filled units.
General Motors Corporation recently supplied a demonstration
electric freight locomotive to the Penn-Central Railroad for test. This
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locotiotive is designated a type GM-6. The transformers in this locomotive
were supplied by a Swedish manufacturer, and are filled with mineral oil as
Swedish regulations would not allow the use of PCBs even for test purposes.
As a result of this material choice, this demonstrator locomotive is not
allowed into the tunnels into New York.
Japanese practice over the past four years has been to use
silicone oils in new railroad transformers. No service problems have been
reported.
AMTRAK is presently negotiating the lease of several new
electric locomotives from France. Preliminary specifications call for the
transformers to be able to operate satisfactorily with mineral oil, askarel,
or silicone oil as the coolant.
3.10 Replacement of Askarels in Existing Transformers
There are currently about 135,000 askarel-filled transformers in
service in the United States. These transformers contain an average of
2000 to 2500 pounds of PCBs each, for a total in-service inventorv of about
300 million pounds of PCBs. Accidental losses of askarel may occur due to
failure of these transformers and accidental spills during servicing. It has
been suggested that these losses may be a significant source of PCBs into the
environment, and that this source of pollution could be minimized by refilling
these transformers with an approved "self extinguishing" transformer liquid.
3.1C.1 PCS Losses Due To Transformer Failures
The incidence of failure of askarel-filled transformers has
been estimated to be 0.2 percent per year. No more than 1 percent of these
failures result in a rupture of the transformer case and spillage of liquid.
The usual failure involves only a venting of gases from the transformer safety
valve, followed by irrmediate operation of the circuit breakers to remove the
power from the transformer. Thus the expected incidence of spillage is
probably on the order of 3 transformers per year containing perhaps 6000 Ib of
PCB. However, most askarel transformers are installed in buildings or in
vaults where there is a provision for containing any leakage. It is probably
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reasonable to assume that the cleanup activities following a transformer
rupture are 90 to 99 percent effective in recovering the spilled askarel, which
limits the total uncontrolled loss of askarels from transformer ruptures
total of 60 to 600 Ib per year. If it is assumed that the venting of vapors
during a transformer failure results in the loss of an average of two Ib of
PCB due to evaporation, the total losses from this source will be about 540 Ib
per year. Thus, the total annual entry of PCB into the environment due to
transformer losses is on the order of 4 Ib per million Ib of PCB in service.
3.10.2 Environmental Effects of An Askarel Replacement Program
The proposal to drain the existing askarel transformers and
refill them with an environmentally acceptable heat transfer liquid pre-
supposes the availability of sufficient quantities of a liquid having satis-
factory fire resistant properties and heat transfer properties equal to askarel.
No such material is currently available. The use of either silicone oil or a
high flash point hydrocarbon material would require a change in the National
Electrical Code regulations which govern the installation of transformers. In
*
addition, all of these materials have poorer heat transfer characteristics than
askarels, which may require the derating of all the transformers.
Assuming that a satisfactory substitute liquid were available,
the retrofitting of the existing transformers still faces a number of practical
problems. The most difficult problem is the achievement of thorough draining
of askarels from the existing transformers. Much of the liquid is held in the
insulation of the transformers by capillary action; simple draining of a trans-
former only removes 80 percent to 90 percent of the liquid. Therefore, it will
be necessary to flush each transformer 2 or 3 times with a liquid which will
dissolve the remaining askarel, and which is compatible with the liquid used
to refill the transformer. This requirement of compatibility could be a major
problem; for instance, askarels are immiscible in silicone foils.
It can reasonably be expected that the draining and flushing
of each askarel-filled transformer will result in an average of 800 gallons of
askarel and PCB contaminated liquid. This liquid must be shipped to an
incinerator and burned under controlled conditions. Disposal of the liquid
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oould be expected to cost $700 plus the cost of the shipping containers and
transportation.
The result of this draining, flushing, and refilling pro-
cedure will be a transformer which is filled with 300 gallons of an environ-
mentally acceptable liquid that is contaminated with 10 to 20 Ib of PCB. This
reduction in the amount of PCBs in service will reduce the severity of
potential transformer failures, but will not eliminate the need for careful
handling or eventual disposal of the contaminated liquid.
A more serious concern would be the amount of accidental
spillage which would occur when the scrap askarel and flushing liquid is
shipped to the incinerator for disposal. The current lack of sufficient
incineration facilities would require that much of this liquid be stored in
drums or tanks for an extended period of time. In addition, the accidental
leakage from broken drums and other accidents which can be expected to occur
during transportation can be expected to release PCBs and flushing solvent
to the environment.
3.10.3 Effect of Leaving Askarel Trans formers in Service
The alternative of leaving the askarel in the transformers
until they become obsolete or fail is probably to be preferred to retrofitting
these transformers with a less toxic liquid. The existing askarel should last
the life of the transformers; only infrequently is it necessary to filter the
liquid to remove the degradation products of minor internal arcing, and askarel
losses during this filter cycle should not exceed 1 percent of the total
liquid in the transformer. Askarel for makeup of these losses will not be
available once it is no longer used in new transformers; Monsanto has announced
its intention of closing the only U.S. PCB manufacturing plant as soon as
satisfactory substitutes are available for PCBs in electrical equipment. This
should not prove to be a major problem in the maintenance of askarel trans-
formers, as minor losses of liquid can be replaced with pure trichlorobenzene.
The resulting mixture will be suitable as long as the concentration of the
PCBs is above 50 percent; below this concentration of PCBs, solvent attack on
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the solid insulation may occur. Complete replacement of the transformer
required by lack of askarel should be infrequent and should not impose a
significant economic burden on the electrical industry.
The decision to leave existing askarel transformers in
service also gains time for the solution of the problem of scrapping failed
or obsolete transformers. Current specifications require that transformers
be drained and flushed before being scrapped. This, however, cannot be
expected to remove more than 95 to 98 percent of the PCBs from the trans-
former internals.
It is currently very unusual for transformers to be
scrapped, but when they are scrapped the value of the metal is sufficient
to make recycling attractive. There is currently no acceptable facility for
the recovery of metal from failed transformers. Special procedures would
have to be used to prevent PCB residues from being carried through into the
scrap furnaces. This will eventually be a significant problem. Better
solutions to the problem can be expected if the problem is delayed by leaving
existing transformers in service.
4.0 INVESTMENT CASTING
The investment casting process is a lost-wax casting process in which a
pattern is molded from wax and then invested or surrounded by a slurry con-
taining a refractory ceramic. After the ceramic mold is dried to an appropriate
strength, the wax pattern is melted or burned out leaving a molded cavity.
Molten metal is then poured into the cavity, and solidified by cooling to form
a cluster of metal castings. Maintenance of close dimensional tolerances
requires that the shrinkage of the wax be carefully controlled during the
initial pattern step. This control requires either slow cooling of the pattern
while the wax is solidifying or the use of a wax material which shrinks very
little upon solidification.
4.1 Function of the Filler Material
One method of modifying the wax to achieve minimal shrinkage is to
fill the wax with a finely powdered material that is insoluble in the wax and
remains solid at the temperature at which the wax is cast into the molds.
-277-
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Because this filler does not change state (frcm a liquid to a solid) on cooling,
it exhibits very low shrinkage, and the resulting slurry of wax and filler will
be much more dimensionally stable than will be the pure wax.
The second step in the casting process is to burn the wax residues
out of the ceramic mold so that the mold will be completely empty when metal
is cast into it. This requires that the filler be volatile at the temperatures
used to fire the molds, and that the vapors be non-toxic.
4.2 Use of PCBS in Investment Casting
Some of the pattern waxes, especially those used in the casting of
metal parts requiring tight dimensional tolerances, contain decachlorobiphenyl
(deka) as the wax filler. Decachlorobiphenyl waxes contain approximately 30
(23]
percent (perhaps up to 40 percent) of the decachlorobiphenyl filler.v
Pattern waxes are recovered and reused several times to form the sprues and
gates of the patterns. Wax is apparently used an average of 2.5 times.
During the dewaxing process the virgin wax (used to form the pattern) and the
old wax (used to form the gates and sprues) are collected as one mixture.
Little of the wax is destroyed in the process; therefore, it is probable that
the investment casting foundries store or dispose of relatively large amounts
of used PCB-containing wax.
It is estimated that approximately one to 1.5 million pounds of deca-
chlorobiphenyl-filled wax is purchased yearly by U.S. investment casters. The
(24)
cost of the PCB-filled wax is in the range of $0.70 per pound. Imported
polychlorinated terphenyls, which exhibit properties very similar to deca-
chlorobiphenyl, is also used as a pattern wax filler. There is only one U.S.
producer of deka-filled wax, and this company also produces PCT-filled
pattern wax.
4.3 Advantages and Disadvantages of the Use of Deka PCBs in Investment
Casting
The deka PCBs have nearly ideal properties for fillers in investment
casting waxes. These materials are only slightly soluble in the wax, remain
solid at the wax casting temperatures, and volitilize completely at the firing
temperatures without charring or burning.
-278-
-------
The only disadvantage to the use of deka PCB is its suspected
possible environmental persistence and, by analogy to the other PCBs, its
toxicity. Ho direct evidence of environmental damage fron this compound
has been found to date.
4.4 Alternatives to the Use of Deka PCBs
Potentially acceptable process alternatives for the deka PCBs could
utilize either a replacement filler material or an unfilled wax.
4.4.1 Replacement Filler Materials
Properties required for a filler are: high melting point
(over 300 C), high heat transfer coefficient, low thermal coefficient of
linear expansion, and minimum ("zero") ash. The following materials have
been suggested as possible replacements for deka PCB.
4.4.1.1 Isophthalic,Acid
Isophthalic acid has been used as a filler material
to a limited extent, but the grade of material that was previously available
(25)
left an ash residue on firing. A new grade of isophthalic acid, only
recently commercialized by AMOCO Chemicals Corp., exhibits much lower ash and
metal contents. The various grades of material available from AMOCO are as
f ,, (26)
follows:
Cost in Bulk Comments
$0.24/lb High ash
$0.27/li> Previous use history
IPA 110 $0.31/lb Being phased out
EPA 220 $0.35/lb New - low ash
Although there is a considerable body of literature on phthalic acids and
phthalate esters, their environmental fates are not known. Degradation routes
properties of degradation products, etc., which are of great importance to an
assessment of environmental acceptability have not been studied in depth. It
can be surmised that this will be the case for most filler substitutes.
-279-
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4.4.1.2 Polystyrene
Polystyrene plastic is available from a number of
suppliers including Dow Chemical Co., ffonsanto, and Foster-Grant. If this
plastic were reduced to a sufficiently fine powder, it would have physical
properties equivalent to deka PCB and should perform satisfactorily as a wax
filler. The bulk cost of polystyrene pellets is $.40/lb, and the size
reduction should cost an additional $.08/lb of filler.
Upon firing, the polystyrene could be expected to
depolymerize to styrene which would be volitilized. Styrene vapor has known
toxic properties. This potential problem may limit the serious consideration
of polystyrene as a wax filler.
4.4.2 Unfilled Waxes
Prior to the use of PCBs or PCTs as fillers, unfilled waxes
were used. Industry sources claim that reverting to the use of unfilled waxes
would increase production costs by about 10 percent. However, new types of
unfilled waxes have recently been introduced to the market, and it is claimed
that their properties are equivalent to the filled wax and their cost is
I?T\
slightly lower ($0.60 to $0.65/lb). ; Although the exact formulation of
these waxes is not known, they reportedly contain no chlorinated additives.
4.5 Conclusions - Substitutes for PCB in Investment Casting
Technically adequate substitutes for decachlorobiphenyl filler in
pattern waxes appear to be available. Maximum increases in costs would be
about 10 percent. The only producer of wax containing PCBs could probably
change to other types with very little technical difficulty or economic
impact.
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SUVMARY
SUBSTITUTES FOR PCBs
Capacitors
PCBs are used as the dielectric liquid in almost all PC capacitors used
by the electrical utilities for power factor correction and in various
industrial applications including appliance motors, fluorescent light ballasts,
and power supply circuits in television receivers. PCBs are uniquely suited
for capacitor applications because of their high dielectric constant, chemical
stability, and non-flammability.
A number of different chemicals are being developed as replacements for
PCB capacitor fluid. There is not yet sufficient data available on the
electrical performance, chronic toxicity, or environmental effects of any of
these liquids.
Dry film AC capacitors are also being developed. These capacitors are
significantly larger than liquid-filled capacitors and are limited to a
maximum of 280 volts.* Satisfactory dry film capacitors will not be available
until there are two separate technological breakthroughs: 1) the development
of a plastic film that combines a high dielectric constant with a low loss-
tangent; 2) the development of winding techniques that exclude all air from
the winding of the capacitor.
Although it is probable that satisfactory substitutes for PCBs will be
developed within the next 5 years, no such material is presently available and
much additional research remains to be done.
Transformers:
PCBs are used as a major component of the non-flammable transformer
liquid known as askarel. Only about 5 percent of all transformers are cooled
with askarel. These are the transformers which are located in buildings and
other hazardous locations where fire resistance is of great importance.
Most transformers are cooled with mineral oil. This liquid is flammable
and the National Electrical Code requires that oil-filled transformers be
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installed in fire proof vaults when they are used in buildings. Vaults
are not required for askarel-filled transformers that are rated at less
than 35,000 volts. Although the askarel-filled transformers are 20 percent
to 30 percent more expensive than oil cooled units, the savings on vault
construction costs more than offsets the difference.
Other currently available substitutes for askarel-filled transformers
are open air cooled transformers, which are limited to lower voltaqe
applications in clean, dry environments, and closed gas cooled transformers
which are more expensive than askarel units. Both of these dry transformers
have lower overload capacity than do askarel and oil-filled units.
Technically satisfactory alternatives are available to the use of trans-
formers containing PCBs. The present choice of PCB units is based on the
relative costs of the alternatives.
Several substitute liquids have been suggested which are less flammable
than the currently used mineral oil, but which are more flammable than askarel.
These liquids are characterized as being self extinguishing — i.e., they do
not continue to burn after being ignited by a momentary electrical arc.
Proposals have been submitted to the National Electrical Code to allow the
use of these self extinguishing materials under those conditions where
askarels are presently specified. Because of the relative lack of service
experience with these liquids, it is unlikely that these proposals will be
accepted. The next Code revision (1978) will probably continue to recognize
only askarel and "oil filled" transformers.
It is likely that the "self extinguishing" liquids will prove to be
satisfactory alternatives to PCBs. Substantial experience on the performance
of the liquids will be required before the Code requirements will be changed
to allow their use. The restrictive Electrical Code, which has been incorpor-
ated into the OSHA Regulations, may act to inhibit the accumulation of this
data and thereby act to postpone the general acceptance of these substitutes
for PCBs.
It has also been suggested that PCBs be drained from existing trans-
formers and replaced with a less toxic material. Analysis of this alternative
suggests that it may have a worse effect on the environment than would the
continued use of PCB in the transformers.
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SUMMARY
INVESTMENT CASTING
Dekachlorobiphenyl is used by one manufacturer in the formulation of
investment casting waxes. The deka PCB acts as an inert filler which reduces
the shrinkage which occurs when the wax solidifies. Other manufacturers use
polychlorinated terphenyls (PCTs) for the same purpose. All of the deka PCB
and PCTs used in investment casting waxes are imported.
Several substitutes are available for deka PCB waxes. These include the
replacement of the PCB with isophthalic acid, or the use of new low shrinkage
non-filled waxes. Complete elimination of deka PCBs from this application
should be possible without causing significant problems.
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REFERENCES
1. Guidelines for Handling and Disposal of Capacitor-and Transformer-Grade
Askarels Containing Polychlonnated Biphenyls, ANSI C107.1 - 1974, American
National Standards Institute, Inc., N.Y., N.Y., January 9, 1974.
2. Wood, David, Chlorinated Biphenyl Dielectrics - Their Utility and Potential
Substitutes, (Presented at the National Conference" on Polychlorinated
Biphenyls, Chicago, II., November 19-21, 1975), Monsanto, 1975.
3. Nelson, J.D., (General Electric Company), "Effluent Limitations for Items
on Toxic Substances List; Economic Impact of a Bar in PCB," Contained in
Communication to Dr. Martha Sager, Chairman, Effluent Quality Information
Advisory Committee, November 21, 1973.
4. National Electrical Code - 1975, National Fire Protection Association,
Boston, MA, (NFPA No. 70-1975; NASI Cl-1975), 1974.
5. Personal coitmunications with knowledgable individuals in the electrical
equipment industry.
6. Inchalik, E.J., (Exxon Chemical Co.), Verbal Presentation, National
Conference on Polychlorinated Biphenyls, Chicago, II., November, 1975.
7. Rey-Coguais, Bruno, (Prodelec, S.A.), Verbal Presentation, National
Conference on Polychlorinated Biphenyls, Chicago, II., November, 1375.
8. Branson, D.R., Health and Environmental Properties of Dow XFS-4169L
Capacitor Fluid^(Oral Presentation to the U.S. E. P. A./Washington, D. C.,
October 16, 1975), Dew Chemical Co., October, 1975.
9. Branson, D.R., (Dew Chemical Co.), Verbal Presentation, National
Conference on Polychlorinated Biphenyls, Chicago, 11., November, 1975.
10. Montgomery, Richard, (Dow Corning Corp.), Verbal Presentation, National
Conference on Polychlorinated Biphenyls, Chicago, II., November, 1975.
11. Tuttle, Cliffton, (Aerovox Co.), Personal Communication, September, 1975.
12. McAllister, John F., (General Electric Co.), "Benefits of PCB Use".
Letter to Dr. Edward J. Burger, Jr., Executive Office of the
President, Office of Science and Technology, December 30, 1971, 36 pp.
13. Report on Power Transformer Troubles, 1969, Edison Electric Institute,
Publication No. 71-20, 1971.
14. "The Rush to Market for PCB Substitutes", Business Week, January 19, 1976,
pp 30E-31E.
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15. Bloorguist, W.C., "What is the Future for Askarel", Power, Vol. 120, No. 2,
February, 1976, pp 68-70.
16. Interdepartmental Task Foroe on PCBs, Polychlorinated Biphenyls and the
Environment, Washington, D. C., May, 1972.
17. Burrow, R.F. & Orbeck, T. (Dow Corning Corporation, Midland, Michigan)
Silicone Fluid Filled Transformer - An Alternative to Askarel and Dry-
Type Transformer?, (Presented at the Doble Engineering Client Conference,
Boston, MA., Aprin 9-13, 1973) , Dow Corning Core., 1973.
18. Burrow, R.F., & Vincent, G.A., Silioone Fluids vs Hydrocarbon Oils:, a
Comparison of Thermal and Electrical Performance Capabilities, (Presented
at the 1974 Winter Meeting, IEEE Power Engineering Society, N.Y., N.Y.,
January 31, 1974), IEEE Paper No. C 74-258-0.
19. Report on Dielectric Medium Under the Classification Program - File MH9466,
Underwriters Laboratories, Inc., May 26, 1972.
20. Rowe, V.K.; Spencer, H.C.' Bass, S.L; "Toxioological Studies on Certain
Conmercial Silicones", The Journal of Industrial Hygiene and Toxicology,
Vol. 30, No. 6, pp 332-352.
21. Duckett, D.A., Environmentally Acceptable Insulating Fluids May Replace
Askarel (Presented at the General Meeting, Edison Electric Institute
Transmission and Distribution Committee, Minneapolis, Minn., May 8, 1975),
RTE Corporation, May, 1975.
22. "Transformateur dans le gaz", Chemins de Fer, No.246, 1964-3, p 96.
23. Solomon, P. (Yates Manufacturing Co., Chicago, Illinois), Personal
Conmunication, September 9, 1975.
24. Lewis, W.H. (President, Signicast Corp., 9000 North 55 St., Milwaukee,
Wise.), Statements during Lecture of Investment Casting Institute Meeting,
October 4, 1975.
25. Edwards, Dan (Chicago Laboratory - Standard Oil Co., Amoco Chemical
Corporation, Joliet, 111.), Personal Conmunication, October, 1975.
26. Connelley, J. (New York Office, Standard Oil Co., Amoco Chemical
Corporation, Joliet, 111.), Personal Communication, October 1975.
27. Davidson, R. (Freeman Manufacturing Company, Inc., 1315 Maine Ave.,
Cleveland, Ohio), Personal Communication, November 1975.
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SECTION IX
PCBs RELEASE AND CUMULATIVE EWIIOSMENTAL LOADS
1.0 ESTIMATES OF FREE PCBs IN THE ENVIRONMENT
1.1 PCBs Losses to the Environment Since 1930, by Use and by Chlorine
Content of Molecule
This section includes an analysis of the estimated amounts of PCBs
which have escaped to the environment, by molecular chlorine content. The
approach and results are summarized below.
Loss factors, which include spillage losses during manufacture or
use of the end products and losses due to inadequate disposal methods, are
estimated on the following basis:
% of Yearly PCB Use
Use Category Lost to Environment
Closed electrical systems
(transformers and capacitors ) 5%
Hydraulic and heat exchange fluids 60%
Plasticizers 25%
Miscellaneous industrial applications 90%
Each of the assigned loss percentage factors can be the subject of
considerable controversy. Suffice it to say that the choices made appear to
be reasonable based on the widely varying information considered.
The following data have been computed on the basis of the production
and sales data released by Monsanto on the PCBs. Since by far the largest
production has been in the form of Aroclors 1242, 1248, 1254, and 1260, these
data are based only on those four mixtures.
"Proportional Use Factors for PCBs" were computed from the Monsanto
PCB manufacturing and sales data utilizing the domestic sales by category
information. Since the detailed breakdown for the period 1930-1957 was not
available, it was assumed that the pattern for this period followed the average
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for the period 1957-1959. Estimates were then prepared of the actual produc-
tion and use of the individual Aroclors listed above. Table 1.1-1 is a
tabulation of the estimated amounts of Aroclors that have escaped into the
environment, assuming that 5% of the PCBs used in capacitors and transformers
escaped; 60% of that used for hydraulic media, and heat exchange media
escaped; 25% of that used for plasticizers escaped; and, finally that 90% of
that used in miscellaneous industrial uses has escaped.
These data may be expressed in terms of chlorine content, based on
published Monsanto data on the isomers typically present, by chlorine content,
in each Aroclor type. The results from such an exercise are presented in
Table 1.1-2. The totals in the right-hand column represent the cumulative
totals of all escaped PCBs by the year listed at the left.
The computed spectrum of chlorine contents based on the cumulative
data on Table 1.1-2 is presented, for selected years, on Table 1.1-3.
The average chlorine content for the set termed "average values" is
4.38 chlorine atoms per molecule, compared to:
Aroclor Chlorine Content (atoms/molecule)
1242 3.67
1248 4.22
1254 5.35
Thus, the distribution as is comes closest to Aroclor 1248. How-
ever, if it is assumed that all mono- and di-chloro biphenyl were biodegraded
or otherwise destroyed, then the average chlorine content of the "wild" PCBs
would be 4.67, intermediate between 1248 and 1254. If the trichloro isomers
were also subtracted out, then the composite average chlorine content would
be 5.0, which begins to compare favorably with 1254.
1.2 Total PCBs Accumulation and Current Rates
As a rough estimate of the total PCBs currently available to the
biota (in active transport, in biological systems, etc.) in the United States,
the total of 172,800,000 Ih. from Table 1.1-1 may be reduced by a factor
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TABLE 1.1-1
PCB ENVIRONMENTAL LOAD BY AROCLOR TYPE
1930-56
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
'1974
1242
18709
1991
1431
2298
2955
4082
3992
3648
4597
5928
7010
7442
7789
9182
10072
3232
48
310
310
[In
1248
5395
704
1065
1597
1226
1745
1452
2062
.2160
2260
1932
1794
1881
2190
1536
112
-
-
—
Thousands
Aroclor
1254
5003
676
917
1142
989
1295
1222
1166
1224
1456
1247
1158
1615
2172
2575
717
229
399
309
of Pounds]
Type
1260 1016
3559
932
783
1118
1191
1347
1258
1503
1664
1096
1041
1111
954
997
1044
266 167
20 1045
1177
1098
Total
PCBs
32466
4303
4196
6155
6361
8469
7924
8379
9645
10740
11230
11505
12239
14541
15227
4494
1342
1886
1717
Grand Total - 172.8 x 106lbs.
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TABLE 1.1-2
CUMULATIVE ENVIPCNMENTAL PCB LOAD
BY CHLORINE CONTENT
[In Thousands of Pounds]
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
Cl
561
621
664
733
822
944
1064
1173
1311
1489
1699
1922
2156
2431
2733
2837
2881
2938
2992
Cl
^>
2540
2813
3020
3351
3760
4326
4874
5389
6030
6846
7796
8799
9850
11088
12428
12880
13073
13324
13561
C13
O
6210
6894
7487
8417
9465
10922
12301
13693
15369
17436
19747
22154
24674
27639
30735
31723
32131
32663
33165
^4
— 4
8221
9174
10130
11584
13070
15135
17048
19095
21473
24315
27328
30406
33673
37543
41462
42624
43086
43700
44272
^5
D
8936
10070
11311
13086
14805
17128
19279
21575
34160
27123
30097
33080
36376
40368
44523
45657
45782
46046
46265
C^
D
4017
4709
5419
6388
7344
8529
9640
10835
12153
13391
14568
15754
17053
18625
20362
20840
20928
21076
21193
ci7
— «— /
1759
2182
2558
3085
3632
41'62
4751
5437
6192
6728
7230
7755
8243
8782
9365
9517
9539
9563
9582
Sifi
— o
285
360
423
512
607
715
816
936
1069
1157
1240
1329
1405
1485
1569
1590
1592
1592
1592
Cln
_?
36
45
53
64
89
89
102
117
134
145
155
166
176
186
196
199
199
199
199
Total
32,565
36,868
41,064
47,219
53,580
62,049
69,973
78,352
87,997
98,735
109,966
121,471
133,710
148,251
163,478
167,972
169,314
171,204
172,821
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TABLE 1.1-3
COMPUTED SPECTRUM OF CHLORINE CONTENT
FOR WILD PCBs
[In Percent]
Weight Percentage of Isomers Containing Cl_
1.7
1.5
1.5
1.7
1.7
7.8
7.0
6.9
7.6
7.8
19.1
17.7
17.7
18.8
19.2
25.2
24.4
24.6
25.4
25.6
27.4
27.6
27.5
27.2
26.8
12.3
13.7
13.6
12.5
12.3
5.4
6.8
6.8
5.7
5.5
0.9
1.1
1.2
1.0
0.9
0.1
0.1
0.1
0.1
0.1
1956
1960
1965
1970
1974
Average 1.6 7.4 18.5 25.0 27.3 12.9 6.0 1.0 0.1
Values
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accxmnting for environmental degradation of less chlorinated isomers and
other destruction processes. Based on Table 1.1-2, this should be about 20
to 30 million pounds, resulting in a total of free PCBs of about 150 million
pounds.
Estimates by Nisbet and Sarofinr ' in 1972 for total PCBs available
through air and water dissipation amount to 180,000,000 Ib. since 1932. This
value is within four percent of the above estimate of about 173million pounds
based on the loss factors specified.
Application of the five percent loss factor to the 1974 Monsanto
donestic sales yields an estiitiate of 1,720,000 Ib. lost to the environment
during 1974, to which should be added a maximum of 50,000 Ib. lost from
imported materials. The 1974 total of 1,770,000 Ib. entering the environment
in available forms represents about 1.5 percent of the total amount estimated
above to be available to the biota in the U.S.
The 1,770,000 Ib. per year amount may be compared with estimates for
(7}
1974 by Peakarr ; as follows:
Industrial leaks and disposal - 880,000 to 1,100,000 Ib.
Disposal in dumps and landfills - 15,000,000 Ib.
Total - 16,000,000 Ib.
The figure of about 10 percent loss from the above required to match
the 1,770,000 Ib. per year loss rate does not appear unreasonable. However, it
should be pointed out that the 16,000,000 Ib. per year figure for leaks and
disposal from Peakall represents almost half of Mfonsanto's reported 1974
domestic sales, and must be questioned.
1.3 Current PCBs Disposal in Landfills and Dumps
The most important current sources of land-disposed PCBs are:
(1) Solid wastes from the manufacture of PCBs and electrical
equipment (including reject capacitors and transformer
internals);
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(2) Failed capacitors;
(3) Capacitors in obsolete equipment; and
(4) Municipal solid wastes other than electrical (obsolete
equipment, sewage sludge, paper, plastics, etc.)
One relatively minor source is the transformer service industry.
3try handles about 2 x 10 Ib. of PCBs annually (roughly half nev
Assuming that 5 percent of the PCBs handled ends up as solid wastes (from
filtration
landfills.
This industry handles about 2 x 10 Ib. of PCBs annually (roughly half new PCBs)
ar
filtration, etc.), results in 0.1 x 106 lb./yr. of solid material entering the
The major sources are treated below. Land-destined solid wastes
from production of PCBs, capacitors, and transformers are estimated to con-
tain about 1.2 x 10 lb./yr. of PCBs. Reject capacitors and transformer
internals add about 0.7 x 10 lb./yr. to landfills. Since most PCBs used in
investment casting are eventually land disposed, this adds 0.4 x 10 lb./yr.
Aiding in 0.1 x 10 lb./yr. for transport and other losses brings the total
of land disposed PCBs from production and first tier use to 2.4 x 10 lb./yr.
The failure rate for PCB-irrpregnated capacitors is estimated at one
percent per year. On this basis, and assuming that the failed equipment
enters a landfill or dump, then about one percent of the approximately
450 x 10 Ib. of PCBs estimated to be in service in capacitors, or 4.5 x 10
lb./yr., can be expected to be landfilled.
Capacitors which have not failed but are contained in obsolete
equipment (TV sets, light fixtures, etc.) also end up in land disposal sites.
This applies to small capacitors only, and it is estimated that one percent
of the total are discarded in this manner each year. The amount of PCBs in-
volved is (0.01 x 270 x 106), or 2.7 x 106 lb./yr.
The amount of PCBs currently contained in land-disposed municipal
and industrial wastes other than that assignable to transformers and capacitors
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is difficult to estimate. Approximately 160 million pounds of PCBs have been
used in plasticizer and other "open end" applications or in "semi-closed"
applications such as hydraulic or heat transfer systems. Most of this usage
occurred between 1960 and 1972, and it is likely that up to 80 percent of the
total is either free in the environment or already in land disposal sites.
The rest of this material, estimated to be on the order of 30 million pounds
can be thought of as being literally "in service" or used and awaiting dis-
posal. A prine example of the latter is used carbonless copy paper currently
residing in files and awaiting disposal or recycling. It is estimated that
about seven percent of this 30 million pound reservoir, or 2.1 million pounds,
enters land disposal sites each year.
In addition, it is estimated that 0.3 million pounds of free PCBs
in the environment are added to land disposal sites each year from a variety
of sources (sewage sludge, dirt, garbage, etc.). This brings the total for
municipal and non-electrical wastes to 2.4 x 10 Ib./yr.
PCBs Added to Landfills
Source and Dumps, Ib./yr.
Wastes from Production and First Tier Use 2.4 x 106
Failed or Obsolete Capacitors 4.5 x 106
Capacitors in Obsolete Electrical Equipment 2.7 x 106
Other Municipal and Industrial Wastes 2.4 x 106
Wastes from Transformer Service Industry 0.1 x 106
Total 12.1 x 106
(2^ fi
Peakall'sv ' estimate of 16 x 10 lb. of PCBs for leaks and disposal in 1974 is
about 30 percent higher than the above total. Peakall^ also estimated a
total of 50 x 10 Ib- for leaks and disposal during 1970, which is over
two-thirds of Monsanto's 1970 reported domestic sales of about 73 x 106 lb.
In the absence of no other comparable data, we estimate a current land disposal
rate of between 10 x 106 and 15 x 106 lb./yr.
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It should be noted that several large first-tier users of PCBs are
not currently land-filling their solid wastes, but are storing the drummed
wastes on-site in anticipation of potential regulations on disposal of such
wastes. The wastes being stored are estimated to contain at least 0.5 x 10
Ib. per year of PCBs; this is included in the above analysis as being finally
disposed of in landfills.
1.4 Release of PCBs via Industrial Effluents (Waterborne)
Based on data obtained fron industry, the following average PCBs
waste loads for water effluents were estimated:
PCBs Production 1117 Ib./yr.
Capacitors 2139 Ib./yr.
Transformers 62 Ib./yr.
Total 3318 Ib./yr.
This number is very small in comparison to the estimated 10 x 10 to
15 x 10 Ib. per year of PCBs going to landfills.
The above values for industrial discharges do not include PCBs dis-
charged to municipal systems for those plants having discharges to rivers (ten
plants) . In the production category, all discharge is to a municipal system.
It should be noted that the above waste loads represent current
industrial practice. It may be assumed that, prior to knowledge of the adverse
environmental effects of PCBs, much of the types of material currently land-
filled was not disposed of properly and thus entered the environment directly.
1.5 Spills of PCBs During Transport
The most complete set of transportation spill data for PCBs avail-
able to us are for the period 6/74 to 6/75. The spills during transport and
the quantities involved are as follows:
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Location Gallons Spilled
Trion, Ga.
Lawrence, Ala.
Erie, Pa.
Unknown
Total 937 (10,213 Ib.)
In addition, during this period, three railroad capacitors failed
in the New York City area, spilling on the order of 50 Ib. each, or a total of
150 Ib. Since this occurred during transit, we chose to add this amount to
the above total, for a grand total of 10,363 li>. spilled in the transportation-
related incidents. This probably represents a minimum figure, since transport
of defective product units (capacitors and transformers) and of PCBs containing
wastes can be expected to release PCBs.
On the basis of the above, a tentative number of 10,000 Ib. per year of
transportation-related spills of PCBs is advanced.
*Capacitor shipment via truck overturned; leading units and soaked dirt
removed from site for subsequent incineration.
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REFERENCES
(1) Nisbet and Sarofim; Environ. Health Perspect., ~L_, 21, (1972).
(2) Peakall, D.B., "PCBs and Their Environmental Effects", CRC Review, 5_,
Issue 4, 1975.
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SECTION X
INADVERIENT AMBIENT REACTIONS AS ROUTES OF ENTRY
OF PCBs INTO THE ENVIRONMENT
1.0 INTRODUCTION
This is a report of a preliminary investigation into the ways that PCBs
could enter the environment even if they were no longer manufactured, imported,
used or disposed of in the U. S. The work focused on the reactions of aromatic
compounds, particularly the biphenyls, and how the conditions found in ambient
surroundings in the environment could lead to the inadvertent and undesirable
synthesis of PCBs. Specifically the major question addressed was whether
chlorination water treatments could convert biphenyl contamination into PCBs.
Beyond that, there are questions of the likelihood of the breakdown of
compounds such as DDT, followed by recombination to produce a PCB; the break-
down and rearrangement of dyestuffs to form PCBs; and other potential routes to
the inadvertent synthesis of PCBs.
When a candidate route is identified, one needs then to determine the
probability of that reaction proceeding, and the reaction rate. Also, the
determination of what relevant pollution loads and concentrations occur in
wastewater or clean water systems is an obviously important factor. For this
study, the objective was primarily the identification of PCB formation routes
which could be significant. Studies to determine kinetics of these reactions
have not, to our knowledge, been performed.
2.0 COMMERCIAL BACKGROUND, PRODUCTION AND PROPERTIES OF BIPHENYL
2.1 Origins and Commercial Usage Background
Biphenyl (previously known as diphenyl and phenyl-benzene) was first
reported in 1862 by Fittig. In 1867 Berthelot identified it as the main product
generated when benzene vapors were passed through a hot tube. During 1925-1926,
Dr. Herbert H. Dow carried out experiments with diphenyloxide, using it as a
heat transfer fluid in a steam power process. In 1927, Theodore Swarm of the
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Federal Phosphorus Co. was asked to supply biphenyl in commercial quantities
for use as a heat transfer fluid in the refining of lube oils. He set up a
pilot plant for this purpose.
Soon after, the Swann Corp. developed the "Aroclor" series of PCBs.
Early in the 1930's, Monsanto took over this production. About that time Dow
also entered into the field, developing "Dowtherm A", a eutectic of 73.5%
diphenyloxide and 26.5% biphenyl. Dowtherm has been a popular heat transfer
fluid since that time.
During the 1950's, the advantages of using biphenyl as a mild fungi-
cide in individual fruit wrappers were appreciated. later, biphenyl was used
as a kraft paper and boxboard impregnant and as a coating in closed fruit
packages. In the 1960's, the usage as a carrier for dispersed dyes began. All
of these biphenyl applications have continued to be important up to the present.
Hydroxybiphenyls are also used as preservatives, and aminobiphenyls are used
as dye intermediates.
2.2 Production Methods and Rates for Biphenyl
The two principal producers in the U. S., Dow and Monsanto, both synthe-
size biphenyl by the thermal dehydrogenation of benzene.
At temperatures of 700-850°C, benzene reacts by a homogeneous gas-
phase reaction (in which a benzene molecule joins with another benzene molecule
or with a polyphenyl molecule, liberating hydrogen and forming diphenyl or
higher polyphenyls), or by a heterogeneous gas-solid reaction giving carbon and
hydrogen. Most process development work has been directed to repressing the
second reaction, which is known to be catalyzed by metals, particularly nickel,
iron, and copper.
In 1964 biphenyl appeared on the U. S. market as a by-product of phenol
produced by the partial oxidation of benzene. Benzene can be oxidized to phenol
and biphenyl with hydrogen peroxide as the oxidant. Other more recent sources of
biphenyl are as a by-product of the hydrodealkylation production of naphthalene,
and as a by-product of the dealkylation of toluene to benzene. The latter stream,
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one of the bottoms from the benzene plant, lias a fuel value of 1 to 2er year.
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On balance, a "best estimate" of 50 million pounds pen' year current
biphenyl use would seem appropriate.
2.3 Properties and Characteristics of Biphenyl
Biphenyl is a rather stable organic compound, and it is resistant to
thermal and radiation degradation. Some of its properties are given in Table
2.3-1.
TABLE 2.3-1 PHYSICAL CONSTANTS OP BIPHENYL
Solubility in water at 20°C., mg/1 7.5
Melting point, °C 69.2
Freezing or congealing point of commercial product,
°C 68.5-69.4
Boiling point at 700 mm, °C 255.2± 0.2
Flash point, °C 113
Fire point, °C 123
Ignition temperature of dust cloud, °C 650
Temperature, °C
100 200 300 350
Vapor pressure, atm 0.251 2.436 5.509
Liquid density, g/cm3 0.970 0.889 0.801 0.751
Heat capacity, cal/g 0.427 0.509 0.590 0.631
Heat of vaporization, cal/g 95 82 68 60
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3.0 PROVEN BIPHENYL REACTIONS YIELDING PCBs
The two categories of biphenyl reactions examined in this section are
the direct chlorination of biphenyl and the joining of two chlorinated
phenyl groups into the biphenyl configuration.
3.1 Chlorination of Biphenyl
Although conflicting statements can be found in the literature, it
is accepted that biphenyl is more easily chlorinated than benzene due to less
resonance stability in the biphenyl. The behavior of biphenyl is complicated
by the non-coplanarity of the two rings. Because of repulsion between the
2 and 2' hydrogen atoms, the rings of biphenyl itself have an angle of about 45°
between their planes. This non-coplanarity greatly diminishes the resonance
interaction between the rings, and is believed to make biphenyl more prone to
reaction than benzene.
Since benzene can be brominated with bromine at 0 °C in the presence
of iron, and also chlorinated with chlorine in the presence of iron at 50°C,
we can expect significant reaction of biphenyl with chlorine in the presence
of iron below 50°C. Also, solid biphenyl reacts with bromine vapor to give
first 4-bromobiphenyl, and then 4, 4'-dibromobiphenyl. Biphenyl melts at
about 70°C. The commercial production of PCBs by chlorination of biphenyl in
the presence of an iron catalyst is conducted above 70°C in order to obtain
and maintain the molten state for ease of transport and for better mixing with
the added chlorine. The higher temperature conditions may also be important
in the formation of the higher chlorinated homologs, but this is also dependent
on contact time. The chlorination is exothermic.
The ease with which biphenyl may be chlorinated to two isomeric mono-
chlorobiphenyls is best illustrated by an early description of a pilot plant
synthesis by Jenkins, McCullough and Booth, of the Federal Phosphorus Company,
in 1929. They used a temperature just high enough to melt the biphenyl, and
achieved iron catalysis by using iron filings. Schmidt and Schultz and Kramers
(2 3)
had shown that antimony pentachloride was a catalyst for the reaction. '
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The method used by Jenkins and coworkers led to the formation of
2-chlorobiphenyl and 4-chlorobiphenyl. In this reaction some dichloro-
biphenyl is always produced, with the amount depending on the temperature of
chlorination and on the quantity of chlorine added. Higher temperatures
during the chlorination produce higher percentages of dichlorobiphenyl. When
the theoretical amount of chlorine for monochlorobiphenyl is added, consider-
able dichlorobiphenyl is formed.
The general conclusion derived from this synthesis evaluation is
that it is quite reasonable to expect that chlorine contact with biphenyl at
ambient temperatures will yield PCBs at a measurable rate. The effects of
temperature, dilution by air or water, lack of iron catalyst, presence of
other catalytic compounds, presence of UV radiation, and other reaction con-
ditions present in the environment are not known.
3.2 Reactions Combining Phenyls to Produce Biphenyls
Two aromatic nuclei can be joined to form a biphenyl by interaction
of a diazonium salt and a hydrocarbon (benzene) under the catalytic influence
of metallic copper or zinc (Gatterman procedure). In the method developed by
Ullmann, many biphenyl derivatives are made by the treatment of aryl halides
with copper powder. The halogen atom must be reactive. N02 is an example of
an activating group. These two procedures are of special interest because
reactants similar to the above reactants, or their progenitors, have been
found in public water supplies. Examples are mono-, di-, and trichlorobenzene
and chlorinated nitrobenzene.
Hutzinger, Safe and Zitko synthesized twenty-three chlorobiphenyls
(4)
using a number of different routes. The compounds ranged from mono- to
decachlorobiphenyl. The general procedure used involved the use of diazo
compounds. The specific chloraniline, selected to give the desired PCB, is
heated in concentrated hydrochloric acid to about 50°C, then cooled to -5°C
and diazotized with a solution of sodium nitrite in water. The mixture is
stored for 30 minutes at this low temperature, then filtered. The filtrate is
added to cold, vigorously stirred benzene, and a solution of sodium acetate (or
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sodium hydroxide) in water. The mixture is stirred for 12 hours at 25°C., and
then the PCB is recovered from the benzene layer. As an example, by this
method, starting with 2, 3, 4, 5 - tetrachloroaniline, they synthesized 2, 3,
4, 5 tetrachlorobiphenyl.
They also prepared decachlorobiphenyl by the exhaustive chlorination
of Aroclor 1268. The Aroclor was mixed with twice its weight of antimony
pentachloride, and heated for four hours at 150°C.
Wolf and Kharasch showed that irradiation of orthoiodophenol in
benzene gave 2-hydroxybiphenyl with a 65% yield.
The conclusion drawn from this review of the reactions of a number
of aryls is that there are a number of low temperature reactions (0-50°C.)
that are capable of yielding biphenyls. In addition, some of the reactants
have already been identified as present in water supplies.
4.0 BIPHENYL USAGE IN HEAT TRANSFER FLUIDS, DYES AND PACKAGING
Although the prime usage for biphenyl is the production of PCBs, it also
has important use in heat transfer fluids, as a dye carrier, and as a paper or
paperboard impregnant.
4.1 Heat Transfer Fluids
In heat transfer fluids, for the temperature range 250-360°C, biphenyl
is used alone, or in combination with other compounds. Dowtherm "A", or Diphyl
in Europe, is the combination of biphenyl with diphenyloxide. A mixture of bi-
and terphenyls was used as a coolant-moderator in the AEC prototype organic-
liquid cooled nuclear reactor at Piqua, Ohio.
4.2 Dye Carriers for Polyesters and Polyolefins
Disperse dyes (dye and carrier combinations) are the most widely used
dye type for unmodified polyesters. Dye uptake is rather slow, and frequently
pressure-dyeing above 100°C is used. Also, carriers or accelerants like
biphenyl are used to cause the fiber to swell and allow more rapid penetration
of the dye into the fiber.
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Polyolefin fibers are also difficult to dye. Their non-polar
nature and impermeability are the problem properties. However, dye carriers
such as biphenyl penetrate these fibers and leave the insoluble dye residue
within the fiber. Of course, most of the carrier would be expected to leave
the fabric in dye-setting and washing processes. Disperse-dyed polypropylene
fibers generally lack the bright colors sought in apparel, but they are used
in tufted carpets and upholstery fabrics.
4.3 Biphenyl as a Mold Preventative in Packaging
Biphenyl itself has been used for many years as a mild fungicide in
citrus fruit wrappers and packaging. The 2-hydroxybiphenyl sodium salt has
also been used as a preservative, germicide and fungicide.
The use of biphenyl as one ingredient in impregnated tissue for
wrapping citrus fruit began in the Middle East, then grew in the U.S. An odor
control agent was added since biphenyl has such a pronounced odor.
Practically all of the biphenyl containing coating is now applied to
the inside of the corrugated cardboard cartons used for shipping citrus fruit;
or the biphenyl is applied to a pad of sheets placed inside the carton.
It would be impossible to ship citrus fruit across the U.S. in
cartons, without a blue mold preventative like biphenyl. Years ago, "orange
crates" of open lattice wood were used to let air circulate through and reduce
mold formation. However, this exposed the fruit to the drying effects of air,
external molds, water, dirt, etc. The new sealed cartons prevent all these
problems, but absolutely require a mold retardant. The coating on cardboard
or in tissue consists of a petroleum jelly or similar base with about 15-20%
of biphenyl.
During the mid-1950"s, the FDA investigated the toxicity of biphenyl,
and some of the results of this investigation emerged as a threat to the future
of the $40 million/yr. segment of the kraft paper industry devoted to making
the cardboard cartons, liners, wrappers etc. for citrus fruit shipping. The
Institute of Paper Chemistry (IPC) was chosen to determine methods of analysis,
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and to referee an investigation of the potential problem. As a result of the
work by IPC, biphenyl was given a clean "bill-of-health" by the FDA and has
continued in use.
4.4 General Biphenyl Occurrence in the Environment
The above descriptions of biphenyl usage indicate a potential for
its widespread occurrence. Of particular interest here is the occurrence of
biphenyl in industrial usages where water treatment by chlorination is
practiced, as in paper recycling and dyeing operations.
5.0 PCBs GENERATION AND WASTEWATER EXPERIMENTS IN A MAJOR U.S. BIPHENYL
USAGE LOCALITY
For the past three years, Dr. Peter Gaffney of the Biology Department of
Georgia State University has been investigating the problems of biphenyl and
PCBs contamination of a watershed in northwest Georgia. He has also conducted
experiments on the conversion of biphenyl to PCBs. Support was provided by
the Georgia Environmental Protection Division. He estimates that this locality
uses about 22 million pounds per year of biphenyl as a dye carrier in carpet
dyeing. This relatively small geographical area accommodates 250 to 300 mills
representing 65% of the world's carpet and rug industry.
Also, W. C. Tincher of the Environmental Resources Center of Georgia
Institute of Technology has been studying the problem of biphenyl effluents
from polyester carpet manufacturing in Georgia. Other workers have been
concerned with the residual odor of biphenyl in carpets.
In New England, R. A. Kites of MIT has been analyzing river water for
biphenyl wastes from dyeing processes.
Dr. Gaffney originally became interested in the problems of biphenyl and
PCBs in water when he was called to investigate a BOD problem at a municipal
waste treatment plant. Two-thirds of the flow to that plant (4 million gpd
out of a total of 6 million gpd) came from a carpet dyeing mill. When looking
for agents that might affect the bicmass in the activated sludge portion of
the plant, two questions arose:
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1. Could the biphenyl (used as a dye carrier) discharged from the
mill be affecting the biota, since biphenyl is a known mold
suppressant?
2. Could the biphenyl be converted to PCBs during waste treatment
chlorination, and could the PCBs exert a harmful affect on the biota,
as well as contribute toxic organics to downstream water supplies?
Although these studies are still underway, preliminary data indicate
that PCBs can be formed in the suspected manner.
The original report of Gaffney's work told of finding 18 ppm of PCBs in
the scrapings from the surfaces of trickling filter rocks in the municipal
treatment plant. At the time, no PCBs were detected in the influent.
This seemed a strong indication of PCBs formation within a municipal
treatment plant. The plant was using about 350 pounds per day of chlorine
for influent odor control and effluent disinfection.
When it was later discovered that there was an upstream transformer plant
using PCBs, further testing indicated there were detectable PCBs in the intake
water to the mill and the town.
Dr. Gaffney continued his previous work on chlorination of organics as
they pass through municipal treatment plants. The tests and data are consid-
ered preliminary at this time, and further reaction and analytical data are
highly desirable.
In laboratory tests, detectable levels of PCBs were formed when 10 mg/1
of biphenyl were added to deionized water, held at 20°C, and then 1 mg/1 of
chlorine was added and the reactants kept in contact for one hour. Fifteen
peaks were formed in the electron capture chromatogram (a hexane in water
control gave four peaks with the same treatment). When iron was included in
the reaction mix, four more peaks were formed (total of 19). It is believed
that these peaks are largely chlorobiphenyls. Addition of an Aroclor to the
pure water resulted in the growth, by 50 fold, of the peak height for dichloro-
biphenyl due to chlorination.
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VJhen municipal wastewater was analyzed before and after laboratory
chlorination, as described above, the dichlorobiphenyl peaks increased in
height by ten-fold.
Although the tentative conclusion from this work was that PCBs can be
formed through chlorination of biphenyl in wastewater under laboratory con-
ditions, extrapolation of the results to actual wastewaters from industrial
sources is probably premature. Even more tenuous, but of equal interest, is
the possibility of further chlorination of PCB molecules via chlorination.
However, it should be noted again that the use of biphenyl as a dye
carrier leads less to its dissipation in products than to its eventual des-
truction or discharge as waste. Assuming that half of the biphenyl so used
appears as waste, a biphenyl to PCB conversion of even 0.01 percent during
chlorination treatment for the 22 million pounds per year of biphenyl in
northeast Georgia corresponds to the generation of over 1,000 Ib/year of
chlorinated biphenyls in that area.
6.0 POTENTIAL DEGRADATION AND SUBSEQUENT REACTION OF DDT AND RELATED
COMPOUNDS IN THE ENVIRONMENT TO FORM PCBs
It appears possible that there are a number of compounds in the environ-
ment that could be partially decomposed and then reacted with their own de-
composition products, or with other reactants, to produce PCBs.
As early as 1969, Plimmer and Klingebiel reported that DDMU, dichloro-
benzophenone, and dichlorobiphenyl, were all products of the photolysis of DDT
or DDE in methanol at 260 nm ultraviolet radiation. This conversion may be
sensitive to reaction conditions. In the same year, Mosier, Guenzi and Miller
did not observe formation of PCBs or DDMU when they subjected solid DDT or DDT
(9)
in hexane to UV irradiation at 254 nm.
Since that time, most researchers publishing on this topic have suggested
the possibility of conversion of DDT to PCBs. Peakall and Lincer stated that
the possibility that PCBs could be derived from DDT should be considered. '
They did not believe this could occur in metabolic processes in tissues. How-
ever, they felt that UV catalyzed free radical reactions to form dichlorobiphenyl
from DDT could be expected in the atmosphere.
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Although they could envision tautameric shifts leading to various isomers
of dichiorobiphenyl, they could not theorize a route to more highly chlorin-
ated biphenyls by these DDT reactions. They also pointed out that PCBs extract-
ed from biological materials matched well with the PCBs found in Aroclors like
1254 (one-half pentachlorobiphenyl, and about one-quarter each of the tetrachloro
-ind hexachloro horologs). Thus, if DDT degradation to dichlorobiphenyl were
taking place, further chlorination would also have to take place, by some other
reaction, to lead to the material found in biological specimens. Peakall and
Lincer also point out that the ethane component between the two rings in DDT
is the weakest part of the structure and is the site at which most transforma-
tions of DDT take place. The PCBs, not having that weak point between the two
benzene r.ings, thus are expected to be more stable than DDT, which is the case.
Maugh again reported on the DDT conversion potential, apparently unaware of
the Plimnier and Klingebiel report, and showed the potential for vapor phase
photolysis.v
Peakall, in his recent comprehensive review, "PCBs and Their Environmental
Effects", does not cite other references for other mechanisms of DDT conver-
(12)
sioris. However, Kothny, in a letter to the editor of Chemical and Engineering
News, states a case for the formation of gaseous chlorine from particulate
chlorides under the influences of ozone and solar radiation. He states that
the chloride loss from particulates, formed by the evaporation of water from
sea spray, "has been known for some time". Kbthny then goes on to attribute
PCBs formation to the reaction between a wide range of aromatics that could be
present in the atmosphere, and chlorine, formed as described above. He also
suggests potential PCBs formation from all manner of waterbome aromatics by
action of municipal and industrial chlorination of pure and wastewater.
7.0 COMPARISON OF POTENTIAL INADVERTENT AMBIENT REACTIONS
Of the types of reactions cited in this section as holding potential for
inadvertent ambient production of PCBs, the possible chlorination of biphenyl
during industrial and rouncipal water and waste treatment appears to the authors
to- have the most significance. In general, the other reactions cite3 would
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Subcategory
No.
2
3
4
5
6
7
8
9
10
11
12
Note: (1)
TABLE 8-1
PCBs Concentration in the Effluents of the
Machinery & Mechanical Products Manufacturing
Manufacturing Operations
Casting & Molding of Nonf errous
Metals
Mechanical Material Removal
Material Forming - All
Materials Except Plastics
Physical Property Modification
Assembly Operations
Chemical-Electrochemical
Operations
Material Coating
Smelting and Refining of Non-
ferrous Metals
Molding and Forming - Plastics
Film Sensitizing
Dockside Ship Building
Activities (2)
Lead Acid Battery Manufacture
PCBs Concentration
mg/1 (1)
Min.
Max.
Avg.
0.2 5.1 2.1
0.2 63.3 6.997
0.2
0.2
0.2
0.5
0.2
0.2
-
0.3
63.3
100.0
104.4
2.8
224.8
18.0
None
123.9
9.867
12.842
15.553
1.65
18.241
9.1
-
28.136
None
7.5 30.0 18.75
Information obtained from the Development Document for Effluent
Limitations Guidelines for the Machinery & Mechanical Products
Manufacturing EPA Contract No. 68-01-2914, Vol. 3, June 1975.
(2) No water effluent; all solid wastes.
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effluents; however, evidence of the presence of chlorinated hydrocarbons
was found. Effluent Guidelines study on Subcategory 10, Film Sensitizing
Industry, is currently underway. According to the information presented in
Table 8-1, this subcategory was demonstrated as having the highest levels
of PCBs concentration in the outfalls. Verification sampling work to be
conducted on these effluents will provide a further test of the validity of
the data in Table 8-1.
It, is considered quite likely that effluents from industries other than
those directly involved with the production and process usage of PCBs may
exhibit significant amounts of PCB contamination. Much of this contamination,
if found, could be attributed to past usage of PCBs and products containing
PCBs, although, as stated elsewhere in this report, current usage must also
be considered a possibility. To our knowledge, no significant effort to
determine the extent of PCBs contamination from such sources has been made.
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require two steps (chlorination plus condensation of aryls or decomposition
of DDT followed by recombination of selected fragments); they also would be
expected to involve compounds present in relatively low concentrations corn-
pared with potential biphenyl concentrations in some industrial waste streams.
For all of these reactions, however, mono- and dichlorobiphenyls would
be the expected products. Although these are believed by many researchers to
be significant (especially in an aquatic environment), it is generally
accepted that they are more easily biodegraded and less bioaccumulative in
comparison to the more highly chlorinated PCB homologs. The possible forma-
tion of more highly chlorinated PCBs from mono- and dichlorobiphenyls is thus
also of interest to the environmental PCBs problem.
8.0 PCBs FOUND IN THE EFFLUENTS OF THE MACHINERY AND MECHANICAL PRODUCTS
MANUFACTURING INDUSTRY
For some time it has been suspected that PCBs could be found in the
effluents of other industrial categories which are not recognized as being
sources of PCBs entry into the environment. A review of data presented in the
draft Development Document For Effluent Limitations Guidelines for the Machin-
ery and Mechanical Products Manufacturing Point Source Category (EPA Contract
No. 68-01-2914, Volume 3, June, 1975) indicates high concentrations of PCBs,
in the order of 2 to 28 mg/1, in the effluent of the plants grouped in this
category.
This group of industries encompasses .173 different product group segments
manufacturing over 4000 different products in over 100,000 separate plants.
These products include such varied goods as wire, tractors, x-ray equipment,
sporting goods, automobiles, television picture tubes, and jewelry.
Because of the variations in manufacturing operations from plant to plant,
categorization of this industry was based on the manufacturing processes
utilized, whereby a specific plant was defined by the applicable process sub-
categories which describe its overall operation. Rationale used in subcate-
gorizing this group of industries was that the manufacturing processes, not the
product, generate the effluent discharge.
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Based on the above, this group of industries was divided into
the following twelve general manufacturing subcategories:
Subcategory 1 Casting and Molding - Metals
Subcategory 2 Mechanical Material Removal
Subcategory 3 Material Forming - All Materials Except Plastics
Subcategory 4 Physical Property Modification
Subcategory 5 Assembly Operations
Subcategory 6 Chemical-Electrochemical Operations
Subcategory 7 Material Coating
Subcategory 9 Molding and Forming - Plastics
Subcategory 10 Film Sensitizing
Subcategory 11 Dockside Ship Building Activities
Subcategory 12 Lead Acid Battery Manufacture
The PCBs concentrations in the raw waste from the overall machinery and
mechanical products manufacturing point source subcategories, as abstracted
from the abovementioned draft Effluent Guidelines Document, are presented
in Table 8-1. This table shows the minimum, maximum and mean PCBs
concentrations as found from sampling and analysis work conducted by the con-
tractor on 240 raw waste streams in the point source category. As reported in
this document, all samples were taken downstream of the manufacturing processes,
but prior to any treatment.
It can be seen from Table 8-1 that PCBs concentrations in the effluent from
this group of industries are much higher than those reported for the major PCBs
user industries (capacitor and transformer industries). Within the machinery
and manufacturing industries PCBs could be used in paints, inks and plastics,
as wax fillers in casting operations, as hydraulic and heat transfer fluids,
and in lubricants.
It should be mentioned, however, that there are questions as to the valid-
ity of the analytical techniques used during this study. Subsequent studies
conducted by Versar Inc. on Subcategory 12 (lead acid battery manufacture) under
EPA Contract 68-01-3273 have indicated no detectable levels of PCBs in the
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REFERENCES
1. Jenkins, R.G., McCullough, R., and Booth, C.F. (Federal Phosphorus
Company), Ind. and Eng. Chem., 22^ 31 (January, 1930).
2. Schmidt, H., and Schultz, G., Ann. Chem., 207, 338 (1881).
3. Kramers, K., Ibid, 189, 142 (1877).
4. Hutzinger, 0., Safe, S., and Zitko, V., Bull, of Env. Contamination
and Toxicology, 6_, 209 (1971).
5. Wolf, W., and Kharasch, N.; J. Qrg. Chem., 26_, 283, (1961).
6. Gaffney, P.E., Science, pg. 367, February, 1974.
7. Ingols, R.S., Gaffney, P.E., and Stevenson, P.C., J. Water Pollut.
Control Fed., 38, 629, (1966).
8. Plimmer, J.R., and Klingebiel, U.I., Chemical 'Communications, 1969,
p. 648.
9. Mosier, A.R., Guenzi, W.D., and Miller, L.L., Science, 164, 1083 (1969)
10. Peakall, D.B., and Lincer, J.L., Bioscience, 20_, 958, (39"?0).
11. Maugh, J.M., Science, May 11, 1973, p. 578.
12. Peakall, D.B., "PCBs and Their Environmental Effects", CRC Reviews, 5,
Issue 4, 1975.
13. Kothny, E.L., Letter to the Editor of Chemical and Engineering News,
January 19, 1976, p. 5.
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SECTION XI
MOVEMENT OF PCBs IN THE ENVIRONMENT
GENERAL DISTRIBUTION MODEL
1.0 INTRODUCTION
Thus far in this report, the history and current status of PCBs
production and usage, treatment and disposal aspects, and gross estimates
of current environmental distribution have been presented and discussed.
Transport of PCBs within the environment is extremely important in the
assessment of future environmental distribution of PCBs. In turn, knowledge
of future PCBs distribution will allow the assessment of potential regulation
of PCBs production and usage. Projection of future biological effects also
depends upon the distribution of the substance of interest.
Transport of PCBs between soil, water, sediments, the biota, and
the atmosphere is of obvious Incal environmental importance. Measurable
amounts of PCBs have been found in Antarctic ice, showing that atmospheric
transport over long distances does occur. Transport phenomena at the various
phase interfaces are of obvious importance to the mobility of any environ-
mental contaminant, but in most cases, and this is particularly true of PCBs,
such transport properties are not known and have not been treated success-
fully in a theoretical manner; On the other hand, analysis of the transport
and distribution of a given contaminant requires sufficient knowledge of basic
transport processes on which to base reasonable estimates; the estimates can
then be evaluated using an internally consistent model and available experi-
mental data.
A. simple, first-order mass balance model has been constructed to
treat the overall PCBs economy of an artificially bounded region of the
lithosphere. In order to test the validity of the model, it was applied to
lake Michigan and the associated drainage basin. Lake Michigan was selected
for tills p-vdication because of the existence of a considerable tody of
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recent data on PCBs concentrations, because of the environmental and commer-
cial significance of PCBs contamination in Lake Michigan, and because this
lake, in spite of its size, represents a relatively closed system (estimated
water retention time of 90 years).
The total environmental load of PCBs, and its variation with time,
represents a very important input to the mass balance model. An analysis of
available data was performed to provide this input, one important result of
which was an estimate of the variation of atmospheric fallout rate with time.
Atmospheric fallout appears to be the most important source of PCBs
entering Lake Michigan, although this may not be the case for other areas (the
lower Hudson River is one possible exception). For example, in 1974, atmos-
pheric fallout onto the lake and its drainage basin accounted for approximately
85 percent of the PCBs input to the lake.
The rationale for the model is described in Section 2.0 below. Sub-
sequent sections describe the application to Lake Michigan and the results and
conclusions therefrom. The development of the model is presented, in full, in
Appendix D to this report, and the supporting data used are tabulated in Appen-
dix E.
2.0 RATIONALE FOR MODEL DEVELOPMENT
The first order model derives basically from the assertion that the
total of PCBs entering a bounded region of the lithosphere must be fully ac-
counted for by: (1) Incorporation into specific phases of the bounded region;
(2) Loss from the region via mass transport; and (3) Degradation by processes
operating within the region.
In application, the region under study is selected to be sufficiently
large and well defined that adequate averaging can be accomplished. The Lake
Michigan area, which meets the above criterion, was selected as a suitable
region for study. The region included the nominal drainage basin of the lake
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in order to provide an estimate of the PCBs entering the lake from runoff.
After suitable boundaries were defined, an overall mass balance
was constructed. The source function was constructed so as to account
for all point and non-point sources. The distribution over the various
internal phases of the system (aqueous solution, biota, and sediment) was
then estimated. Additional terms were introduced to account for PCBs loss
from the region due to mass outflow and surface evaporation. There was ap-
parently no need to introduce a term to account for degradation since such
processes are thought to be of small importance for PCBs. The form of the
mass balance was then as follows:
B(t) At = AM + AMD + AM + AM + AM_ (2-1)
W B S O E
where:
B(t) is the source or driving function which describes the
input rate for PCBs;
AM is the change in the mass of PCBs dissolved in the aqueous
phase of the region;
AM^ is the change in the mass of PCBs contained within the biota
of the region;
AM is the change in the mass of PCBs contained within the sedi-
ment of the region;
AM is the mass of PCBs carried out of the region by (water)
mass transport; and
AM^ is the mass of PCBs carried out of the region by evaporation
(codistillation).
2.1 Time Dependence of the PCS Input Rate [B(t)]
The distribution of PCBs between phases within the region is governed
by processes which are assumed to act independently of the actual concentrations
involved. The time dependence of equation 2-1 is therefore contained in the
driving function, [B(t)].
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Sensitive analytical methods for PCBs have been available only for
a few years; consequently a sufficiently reliable and detailed data base to
allow the direct determination of B(t) is not available. In view of this/
it was necessary to construct a model which could be fitted to a direct esti-
mate of B(t) for a specific time, in order to approximate the appropriate
time dependence of B(t) . The details of the computation by which B(t) was
determined are contained in Appendix D (Section 2). For the purposes of this
summary/ it is sufficient to state that the major input of PCBs to the region
selected (Lake Michigan) was from atmospheric fallout; thus the time dependence
of B(t) was estimated from knowledge of the time dependence of the fallout.
Table 2.1-1 is a summary of the input PCB from all sources during the
period 1973-1974 and is a summary of the detailed data which are presented,
along with suitable citations to the sources of these data, in Appendix E of
this report.
Table 2.1-1
Summary of PCB Input Sources (1973-1974) to
Lake Michigan
Point Sources 1.6 x 10 Ibs/yr
Lake fallout 6.4 x 103 Ibs/yr
Basin fallout* 5.4 x 103 Ibs/yr
Then B(t) = B(1973-1974) = 13.4 x 103 Ibs/yr
* It is assumed that 50 percent of the basin
fallout actually enters the lake as input(1)
3.0 APPLICATION OF THE MDDEL TO LAKE MICHIGAN
The results of an analysis of PCBs distribution within Lake Michigan
are summarized in Table 3.0-1 (The details of the computation are given in
Section 3 of Appendix D).
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Table 3.0-1
Overall PCBs Balance for Lake Michigan Area
During the Period 1930-1975
Total Input 1.49 x 105 Ihs.
Total in Solution (Water) 1 x 10 Ibs.
Total in Biota 3.64 x 103 Ibs.
Total in Sediment 1.7 x 10 Ibs.
Total in Outflow 9.07 x 103 Ihs.
4
Total Evaporated 1.93 x 10 Ibs.
The last entry in Table 3.0-1 indicates that some 13 percent of the
total input to the lake has been lost by evaporation (codistillation) from
the surface.
The concentration of PCBs in the aqueous phase and the (average)
concentration in the biota were calculated; the results are displayed in
Table 3.0-2.
Table 3.0-2
Date
1930
1935
1940
1945
1950
1955
1960
1965
1970
1975
*The average biotic concentration is taken as 4 x 10 C ,
water
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Derived PCB Concentrations in Lake Michigan
Water and Biota Over the Period 1930-1975
water
(ppt)
0
-4
4.9 x 10
1.34 x 10~2
7.12 x 10~2
0.28
0.68
1.60
2.92
5.35
9.10
ID iota*
(ppt)
0
1.97
5.36 x 102
2.84 x 103
1.12 x 104
2.72 x 104
6.4 x 104
1.17 x 105
2.14 x 105
3.64 x 105
-------
The values presented in Table 3.0-2 are lake-wide averages so that
considerable variations from these values are to be expected from point to
point within the lake; for instance between the northern portions and the
heavily contaminated regions on the southwestern shore. In addition, because
of the considerable spread in species-specific concentration factors (and
the wide variation in intra-species concentration factors) it can be surmised
that PCB concentrations in higher predators could easily have exceeded the ppm
level by 1960.
4.0 RESULTS AND CONCLUSIONS
4.1 Results
Even though the model used is only first order, it is apparently able
to describe the relative significance of the natural processes which control
the distribution of PCBs. The strong focus on fallout as the primary input
source of PCB to Lake Michigan suggests the need for further study of the nature
of the processes by which PCBs become airborne and thus become part of the
available atmospheric reservoir.
The attempt to model the atmospheric reservoir of PCBs, discussed in
Appendix D (Section 2), yields results that indicate significantly greater cumu-
lative atmospheric loads than the preliminary estimate, made by Nisbet and
(2) 4
Sarofim, of a cumulative atmospheric reservoir of 3 x 10 tons up to 1970.
The estimate of Nisbet and Sarofim leads to a half-life, from the model, for
PCBs in the atmospheric reservoir on the order of eight years. This value is
considerably in excess of the reported lifetime measurements, on the order of
20 to 40 days, for atmospheric PCBs. However, the observation that signifi-
cant levels of PCBs are found in present snowfalls and in packed snow in the
Antarctic suggest that the applicable half-life may indeed be considerably
longer than 20 to 40 days.
It is suggested that further refinement of the environmental distri-
bution model presented in Appendix D (Section 2) will lead to a resolution of
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this apparent discrepancy. This refinement will focus attention on the
nature of the physical processes involved in atmospheric transport of PCBs
and may suggest methods of reducing PCB fallout in the future.
The observation that evaporation and/or codistillation seems to be
a significant process by which PCBs are returned to the atmosphere is of im-
portance. It should be noted that the magnitude of the evaporation rate con-
stant necessary to achieve mass balance in Lake Michigan is in excellent agree-
ment with that computed from the simple kinetic theory of gases and also with
that computed from the theory of codistillation discussed by Mackay and
Wolkoff(5
subject).
Wolkoff (see Section 4 of Appendix D for a detailed treatment of this
The observation that the PCB input to Lake Michigan from point
sources seems to be a rather small part of the total input suggests that re-
duction of point source PCB effluents may only slowly correct the present
problem.
4.2 Conclusions
The first order mass balance model described herein seems useful in
describing the historical situation as it explicitly addresses the question,
"How did we get here?" The model requires refinement before it can be used to
allow a reasonable estimate of future conditions. Significantly more detailed
data are required as to the temporal variation of inputs and concentrations as
well as on the internal transport processes by which localized concentrations
are smoothed and distributed over the whole body. While the present model
seems to deal very well with the situation that obtains during an interval of
rising aqueous concentrations, there seems to be little experimental or
theoretical guidance as to what will happen if, in the future, aqueous con-
centrations begin to fall. It is not known whether the biota and the sediments
will act as reservoirs to return their PCB loads to the system. The processes,
if any exist, which will eventually remove or inactivate the PCBs already in
the lithosphere are not known.
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The application of this model to the situation in Lake Michigan
seems successful. It will be of interest to apply it to regions which are
more complex or of larger scale.
5.0 BIBLIOGRAPHY
1. Ruttner, F., Fundamentals of Limnology, Univ. of Toronto
Press (1952). ~~~
2. Nisbet, C. T. and A. F. Sarofim, Environmental Health Pro-
spectives, Exp. 1:21-38 (1972).
3. a. Sodergren, A., Nature 236;295-397 (1972).
b. Risebrough, R. W., et al; Nature (12/14), 1098-1102 (1968).
c. Harvey, G. R., et al; J. Marine Research 32(2):103-118 (1974).
d. Harvey, G. R. and W. G. Steinhauer, Atmospheric Environment,
8(8):777-782 (1974).
4. Peel, D. A., Nature 254 (3/27):324-325 (1975).
5. Mackay, D. and A. W. Wblkoff, Env. Sci. & Tech. 7(7):611-614 (1973)
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SECTION XII
REGULATORY ACTIONS ON PCBs
1.0 INTRODUCTION
The risk of increased accumulation of PCBs in the environment as well as
appreciation of the difficulties involved in imposing workable environmental
controls in most end-use manufacturing operations have led some manufacturers
and a number of government agencies to take steps to regulate PCBs or
to restrict some uses of PCBs where emission risks are obviously quite uncon-
trollable.
1.1 Measures Taken by the Manufacturers
In 1971, Monsanto Company, the major producer of PCBs, instituted a
program which led to voluntary restriction on sales by the Monsanto of PCBs for
all uses except the manufacture of sealed electrical equipment (transformer and
capacitor applications). Sales for heat transfer applications were phased out
in 1972 while sales for other non-electric applications were discontinued in
1971. As a result, current production related to point source discharges of
PCBs are more controllable than in years prior to 1971 when PCBs were widely
used in thousands of "Open-End" and "nominally closed" operations.
Furthermore, by 1971, at Monsanto's suggestion, the capacitor and
transformer industries formed a standards committee. The members of the
committee include representatives from the three affected industries, EPA,
Department of the Army, Department of Agriculture, the Tennessee Valley Author-
ity, the National Bureau of Standards, and the General Services Administration.
Also represented were the Certified Ballasts Manufacturers Association, the
Electronic Industries Association, the Institute of Electrical and Electronic
Engineers, and the National Electrical Manufacturers Association. In the fall
of 1972, under the auspices of the American National Standards, this committee
published PCB handling and disposal guidelines (ANSI-C107-1-1974). This docu-
ment establishes procedures for labelling, shipping, general handling and
proper disposal of liquid and solid materials containing PCBs. This standard
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has been proposed also by NEMA and is currently being used voluntarily by the
transformer and capacitor industries.
The above measures taken by the manufacturers could be effective in
PCB control if they were supported, inrplemented and enforced by the Federal
Government.
1.2 Measures Taken by the U.S. Government
The Government of the United States has taken a number of steps with
the objective to reduce the PCBs content in foodstuffs and reduce emissions
from all sources. The following Federal laws are relevant for the regulation
of PCBs.
1.2.1 Food, Drug and Cosmetic Act (21 U.S.C. 301 et seg.)
The Food and Drug Administration has set tolerances for PCBs
contamination of animal feeds, foods, and food packaging in its final rule-
making document published on July 6, 1973 (Federal Register, Vol. 38, No. 129).
These tolerances, expressed as parts per million are as follows:
(1) Mlk (fat basis) 2.5
(2) Dairy products (fat basis) 2.5
(3) Poultry (fat basis) 5.0
(4) Eggs 0.5
(5) Complete and finished animal feeds
for food producing animals 0.2
(6) Animal feed components 2.0
(7) Fish and shellfish (edible portion) 5.0
(8) Infant and Junior food 0.2
(9) Paper food - packaging material 10.0
The Food and Drug Administration provides, upon request, the
analytical methods used for enforcing these tolerances.
The FDA enforces the FDC Act by various means, including
inspections of food establishments to determine whether the provisions of the
Act are being violated. These inspections include the collection and analysis
of food samples. Some of the samples are taken by FDA on a routine surveillance
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basis to determine the presence of specific contaminants. However, the actual
number of FDA conducted routine sample and analyses is few and this agency
relies heavily on information on the known or suspected existence of specific
instances of food contamination.
1.2.2 The Egg, Meat and Poultry Acts
The Consumer and Marketing Service of the U.S. Department of
Agriculture (USDA) administers three acts relevant to the PCB problem: the Egg
Products Inspection Act (P.L. 91-597); the Wholesome Poultry Products Act
(P.L. 90-492); and Wholesome Meat Act (P.L. 90-201).
These authorities apply to meat, egg or poultry products from
the time they reach the processing plant until they are purchased by the
consumer. Once they leave the plant, they are also under the FDC Act.
The Department of Agriculture uses FDA guidelines for its Egg,
Meat and Poultry Acts.
1.2.3 The Clean Air Act (42 U.S.C. 1857 et seg.)
Mr. David Young of the Southern California Coastal Water
Research Project in a report prepared as part of an ORD (Environmental Research
Center - Corvallis) contract acknowledges that the air contributes about one-
third of the total PCB loading of the ocean. His conclusion that air is a sig-
nificant route of PCB transport is based on effluent and aerial fallout measure-
ments made in the coastal areas of Southern California.
The current understanding is that air transport of PCBs is a
contributor to the PCB loading of other media. However, the conclusion reached
by the pollutant strategies board of the Strategies and Air Standard Division is
that the air act of 1970 is not an effective legislative measure for control of
PCBs; but that monitoring for PCBs should be considered for control. The
recommendation made at that time was to control PCBs by regulating the produc-
tion, use and disposal of PCB-containing products.
The general authorities contained in the clean air act are not
applicable to the majority of PCB discharges since PCBs from most PCB applications,
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such as for closed electric systems, are not emitted into the air by the opera-
tion of industrial and municipal facilities. In these applications, PCB
emissions are associated with accidental losses and waste disposal in landfills.
Additionally, PCBs enter the air via the burning of refuse containing PCB waste
products. These types of air emissions can be controlled only by preventing
PCB products from being incorporated into the refuse. Control of emissions
from landfills may require specifications on how waste is covered and, in some
cases, the application of plastic materials to prevent sublimation. However, in
the case of PCB applications for the investment casting category, PCBs can
enter directly into the environment from the operation of furnaces which are
used for purposes of setting the mold and removing the wax from the mold. In
this latter application, the air act can be used as an important tool for the
regulation of PCB entry into the environment.
1.2.4 Federal Water Pollution Control Act (33 U.S.C. 466 et seg.)
Section 304 (a) of FWPCA
Section 304(a) of the Federal Water Pollution Control Act
(FWPCA) authorizes the Administrator of EPA to enforce state water quality
standards established by the States and approved by the Federal Government, if
the State is not adequately enforcing the standards.
In 1973, water quality criteria were proposed to limit PCBs to
2 ppt in ambient waters. The 1973 proposed level has been more recently reduced
to 1 ppt due to evergrowing concern on the health and ecological effect of PCBs
and on the basis of further review of available data.
Section 307 (a) FWPCA
A national effluent standard for PCBs has been proposed under
Section 307(a) of FWPCA.
Section 311 of FWPCA
In 1974, the Office of Air and Water Programs acted to minimize
accidental spills of PCB through the enforcement of Hazardous Substances Section
of the Water Pollution Control Act. Currently, pursuant to Section 311 of this
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act, proposed guidelines on the levels of harmful quantities of PCBs accident-
ally released into navigable waters and rates of penalties for such spills are
being developed.
Section 304(d) of FWPCA
Section 304(d) of the effluent guidelines promulgated for
several industrial categories contain limitations on PCBs. For example,
effluent guidelines promulgated for the steam electric power generating cate-
gory contain limitations of "No Discharge" for PCBs. Furthermore,, EPA reports
that NPDES permits limiting PCB discharges have already been issued for several
facilities.
1.2.5 The Refuse Act of 1899 (33 U.S. C.4071
Section 13 of the 1899 Refuse Act forbids the discharge of any
wastes, other than municipal wastes, into navigable waters without a permit.
This act would be an effective tool in the control of PCB discharges into the
waterways if the permit program required the reporting of PCBs as a separate
item. Presently this is not a requirement.
1.2.6 The Occupational Safety and Health Act (29 U.S.C. 651-678)
Chemical hazards in the workplace are regulated under the
Occupational Safety and Health Act (OSHA). The Secretary of Labor, in coopera-
tion with the Secretary of Health, Education and Welfare, is authorized to set
and enforce occupational safety and health standards applicable to businesses
affecting interstate commerce.
In Title 29, Section 1910.93, the limits set for chlorodiphenyl
compounds as an air contaminant are 1 mg per cubic meter for Aroclor 1242 and
0.5 mg per cubic meter for Aroclor 1254, based on 8 hours average exposure.
The Department of Labor could enforce these limits on PCBs.
1.2.7 Act to Pegulate Transportation of Explosives and other
Dangerous Articles (18 U.S.C. 831-835)
The Department of Transportation (DOT) regulates the transport
of hazardous substances under the Act to regulate transportation of explosives
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result, PCB is being imported by a few companies for use in several "open-end"
or "nominally-closed" applications.
In 1972, with hopes to bring about a multi-national understanding on
PCB uses, the United States asked the Organization for Economic Cooperation
and Development (OECD) through its Environment Committee to review national
policies on PCBs and also identify products moving in international trade
which contained PCBs. In October, 1972, OECD, whose members include all major
western industrialized countries plus Japan and Australia, met to discuss the
U.S. proposal to control manufacturing and trade of PCBs.
In the October meeting the OECD Council decided that for adequate
protection of health and environment, PCBs should be controlled by the actions
of individual member countries. It was agreed that in order to insure that
home production was not substituted by imports, control action by governments
through licensing or other means was essential. It was further recognized
that means to insure proper collection of used materials, safety in transport
of raw PCBs and assessment of substitutes for PCBs were of utmost importance.
*
Details on the council's decisions were issued on February 14, 1973.
The major thrust of the decision was:
A. PCBs should be used for industrial or commercial purposes in
the following applications:
- As dielectric fluids in transformers and capacitors
- In heat transfer applications (other than that for
applications in foods, drugs, feeds and veterinary
products)
- As hydraulic fluid in mining equipment
With respect to the above uses, the OECD Council recommended that PCBs
should only be used if adequate environmental controls were exercised and when
the requirement for non-inflammability outweighed the needs.
B. Manufacture, use, recovery, disposal, import and export of
PCBs should be controlled and regulated. Special labelling
for bulk PCBs and PCB-containing products should be instituted
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and safety specifications on containers and transport
should be established.
C. Manufacture, import, and export of PCB-containing products
should be controlled and efforts should be directed to
eliminate the use of PCBs in "open end", "nominally-
closed", and small capacitor applications.
D. Annount of material manufactured, exported, imported,
incinerated and consumed by PCB type should be reported
and any substitute used for PCB should be identified,
characterized and defined.
The decision of OECD leaves it to the member countries to go beyond
the council's agreements and it further encourages the governments to phase
out PCB uses wherever possible. OECD council's decision or even more stringent
measures are currently being exercised in all member countries.
1.4 Measures Taken by Foreign Governments
The measures taken by foreign governments are, in some instances,
quite severe; especially in Japan, where a large scale poisoning episode,
resulting in the disease syndrome "YUSHO", occurred in 1968 (after a heat
transfer fluid leaked in a rice-oil pasteurization plant). In other countries,
like the Netherlands, the control measures are quite informal. The main thrusts
for PCB control are found in two main areas; those taken by the manufacturers
and those required by the legislative process.
1.4.1 Measures Taken by Manufacturers - Limitations of Sales
Several nations have voluntarily limited sales of PCBs. The
spectrum of limitation ranges from restrictions to specific fields of manufac-
ture that are considered to be non-polluting or controllable to total suspen-
sion in the manufacturing process.
Since 1972, Japan has banned production and importation of
PCBs; the United Kingdom has restricted sales of PCBs to all applications with
the exception of their usage as a dielectric fluid, while Germany has lessened
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and other dangerous articles. Under CFR Title 49, Subpart G amended February
27, 1973, DOT classifies poisonous substances into three categories:
Class A - highly poisonous material
Class B - moderately poisonous material
Class C - irritating material
The responsibility for insuring that this standard is met
remains with the manufacturer and the shipper.
1.2.8 Federal Insecticide, Fungicide, and Rxienticide Act (FIFRA)
(7 U.S.C. 135-135K)
On October 29, 1970, the Pesticides Regulation Division, admin-
istered then by the Department of Agriculture, issued a notice (PR Notice 70-25)
to all pesticide manufacturers and distributors to eliminate the use of poly-
chlorinated biphenyls and polychlorinated terphenyls from their formulation and
products. Presently, there should be no pesticides on the market or in use
containing PCBs.
Under the FIFRA act, all pesticides shipped in interstate
commerce must be registered with the EPA. Presently, EPA can refuse to register
a product if it will cause injury to humans or the environment if used as direc-
ted. A product already registered with EPA can be cancelled if it is found that
it no longer meets the criteria of registration.
Congress is currently considering bills to renew the FIFRA act.
More than 20 amendments to FIFRA are pending in the House and Senate. One of
these amendments, if adopted, will give the Secretary of Agriculture the power
of veto over EPA by requiring USDA concurrence in procedures leading to pesti-
cide cancellation or changes in classification or regulation. This amendment
will loosen EPA's controls on dangerous pesticides.
1.2.9 Needs for Federal Control
It can be summarized that currently four government agencies,
the Monsanto Company and NEMA comprise the regulatory forces restricting the use
and distribution of PCBs. EPA, OSHA, FDA and USDA have authorities to regulate
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and monitor food levels, disposal into waterways and housekeeping and safety
practices in the work place. EPA forbids the use of PCBs in pesticides and
regulates their discharges into the waterway. OSHA can regulate PCB hazards
in the work place. FDA forbids PCB use in food processing machinery and limits
PCB levels in food, feeds and paper food-packaging material. USDA follows FDA
guidelines in egg, meat and poultry products. Monsanto manufactures more
degradable PCBs and sells them only for selective uses, and NEMA recommends
standards and guidelines for handling and disposal of PCB containing materials.
Each of these available authorities has a limited focus and is inadequate to
prevent more PCBs from entering the environment.
Both Monsanto's and NEMA's actions are voluntary and have no
law behind them for enforcement. The government has no power to control and
restrict imports of PCBs and if it desires to restrict the use of PCBs in
selected applications, it has no authority to impose this restriction on any
manufacturer.
Ihe above actions can only be implemented through the proposed
Toxic Substances Control Act (TSCA). TSCA would give EPA the needed authority
for formal banning of certain PCB uses and sanctioning National Standards and
Guidelines for handling and disposal of PCB containing products. Thus EPA could
deal with the PCB problems in a far more orderly and effective manner. Addition-
ally, the TSCA would enable EPA to require testing for health and ecological
effects of new chemicals which are being proposed as substitutes for PCBs.
Thus, this measure could prevent new chemicals from creating health and ecologi-
cal problems similar to those from PCBs. This preventive approach of controlling
chemicals is a more reasonable and cost effective method than the current approach
of corrective measures after the damage has been done. Therefore, the passage of
the Toxic Substances Act by Congress is an important step in dealing with problems
such as PCBs.
1.3 International Decisions and Agreement
There are currently no regulations to restrict the importation of PCBs
as a chemical for use in applications banned by the Monsanto Company. As a
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this restrictive measure to include the heat-transfer and hydraulic-fluids
industries.
1.4.2 Measures Taken by Seme Governments
1.4.2.1 PCB Producing Countries
Actions taken by governments differ widely, ranging
from acceptance of the measures taken by the manufacturers to a more strict
regulation.
France
The government has taken no active legislative
action and has accepted the local manufacturers decisions. These include:
- Complete cessation of sales for heat transfer
purposes, in pharmaceutical and food industries,
paper production of carbonless copying paper,
marine paints and cutting oils.
- Providing information to manufacturers about the
dangers of PCB, with a view to cancelling their
use in or on products in contact with foodstuffs.
Germany
The government is taking the approach of supporting
the manufacturers' decision to stop selling PCB and is pursuing the voluntary
signing of bilateral agreements to restrict the amount of imports. Additionally,
tolerances of PCB in foodstuffs are being established.
PCBs have been under governmental control since 1972.
There have been practically no production, import or export of PCBs in this
country since 1972. The two companies, Kanegafuchi Chemical and Mitsubishi-
Monsanto, which had been producing PCBs in Japan ceased their operation and sus-
pended their sales in 1972. One exception has been the production of PCBs for
railroad transformers which was discontinued in September, 1973. The use of
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existing stocks in railroad transformers is permitted, subject to the condi-
tions that there be no discharge to the environment. Beginning in 1976, paper
plants will be prohibited from accepting PCB contaminated paper for recycling
purposes and they will be required to build treatment facilities to meet the
general discharge standards.
Imports of equipment using PCBs have been decreased
drastically since 1972. For these products importers must cooperate with the
users to ensure that the components containing PCBs are properly disposed.
Manufacturing of PCBs are rigidly controlled by the
Ministry of International Trade and Industry (MITI). Any company who desires
to manufacture PCBs must apply to MITI for a permit. The Japanese government
anticipates a total ban on PCBs in 6 to 10 years.
These efforts have had remarkable results, and the
environmental levels of PCB in Japan have subsided and are expected to continue
diminishing.
United Kingdom
The government is taking no official action and is
accepting the decisions of the manufacturers. Additionally, there is a high
duty on imported PCBs (about 23%).
1.4.2.2 Non-Producing Countries
Canada
Initial activities are under way to collect necessary
data for restricting PCBs pursuant to a new Environmental Contaminants Act
which should be enacted by 1976.
Finland
The use of carbonless copying paper is totally banned
and legislation is being proposed to require prior authorization for the use of
PCBs by the Ministry of Social Affairs and Health. Furthermore, compulsory
labelling and disposal instructions are being introduced.
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Netherlands
A gentleman's agreement is in effect that PCBs will
no longer be used in the manufacture of paints, inks, lacquers, adhesives,
resins, wire and cable coatings, lubricating oils, hydraulic fluids and copy-
ing paper.
Norway
Since October 1971, only the Ministry of Social
Affairs can authorize the use of PCBs.
Sweden
Since June 1, 1972, only the environmental protection
board can authorize the use of PCBs or compounds containing PCBs. Furthermore,
compulsory labelling and identification of PCB content on the wrappings have
been introduced.
Switzerland
Since October 1972, PCBs or products containing PCBs
may not be sold to the public or to light industry. Heavy industrial use is
subject to prior authorization.
1.5 U.S. Customs Regulations
Pursuant to Customs Bureau Directive CIE 36-72, July 4, 1975, the
field offices of the Customs Bureau have been specifically monitoring the inflow
of PCBs and this information is forwarded to EPA. The information is not public.
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BIBLIOGRAPHY
1. Bauman, R.D., EPA's Pollutant Strategies Branch, Polychlorinated Biphenyls.
Private Communication to Mr. Lindsey, A.W.; Office of Solid Waste Manage-
ment Program, November 20, 1973.
2. Ooleman, J.H., Acting Director Duty Assessment Division, Polychlorinated
Biphenyls. Private Communication to Mr. Barden, J.D., Versar Inc.,
October 15, 1976.
3. Environment Directorate, Organization for Economic Cooperative and Develop-
ment, "Polychlorinated Biphenyls, Their Use and Control", Paris, 1973.
4. Op. Cit., September 11, 1976.
5. Op. Cit., February 7, 1975.
6. Environmental Regulation Handbook EIC-Environment Information Center, Inc.,
New York, New York.
7. Polychlorinated Biphenyls and The Environment, Interdepartmental Task Force
on PCBs, Washington, D. C., May (1972).
8. Steigerwald, B.J., Director, EPA's Office at Air Quality Planning and
Standards, "Air Transport of Polychlorinated Biphenyls (PCBs)". Private
Conntunication to Mr. Strelow, R., Assistant Administrator for Air and
Water Management, September 29, 1975.
9. Stottlenyer, J.N., Department of Transportation, "Transportation Regu-
lations for Toxic Substances". Private Conmunication with Contos, G.,
Versar Inc., September 10, 1975.
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APPENDIX A
PCB ADSORPTION TESTING BY XAD-4 RESIN
Experiments and Results
The apparatus and materials used by Rohm and Haas were:
Two glass columns - 1/2 inch in diameter
Adsorbent volume - 50 ml in each column
Adsorbent bed height
XAD-4 Amberlite polymeric adsorbent - 16.5 inches
Activated carbon (Filtrasorb 300) - 15 inches
PCB material used - Aroclor 1254 (manufactured by IVfonsanto)
A feed solution representing a PCB contaminated waste stream was prepared
containing approximately 160 ppb of PCB. Because Aroclor 1254 is very viscous,
it was solubilized in methanol prior to dispersion in water. Methanol increases
the solubility of PCBs in water. In order to maintain a constant flow through-
out the experimental run* two batches of feed solution had to be prepared. The
composition of each solution is presented in Table A-l.
Table A-l
Composition of Feed Solutions
Feed Solution A - 13.25 liters
0.0022 gm of PCB or 166 ppb
2 ml of methanol or 119 ppm
Feed Solution B - 13.25 liters
0.0029 gm of PCB or 218 ppb
2 ml of methanol or 119 ppm
The influent solution was passed simultaneously through the column of
Amberlite polymeric adsorbent and the column of activated carbon at a flow rate
of 2 bed-volumes per hour (0.25 gpm/ft resin). Samples were collected from
each column daily, so that each sample nominally represented 48 bed volumes of
A-l
-------
effluent. Liquid passed through both columns for five days, or until 240 bed
volumes of effluent (12 liter total volume) were collected from each column.
Prior to analysis, the PCS in each effluent sample was extracted into a
volume of hexane equal to one-tenth the volume of the original sample. The
influent material, which was sampled four times during the run, was likewise
extracted into the same proportion of hexane. This single stage extraction
removed more than 95 percent of the PCBs present in the aqueous samples. The
extracted effluent samples were then evaporated to 5 mis, further concentrat-
ing the PCBs present. These evaporated samples were then sent to Versar Inc.,
for analysis. The results are given in Table A-2.
Table A-2
Reductions of PCB (Aroclor 1254) Concentrations Through Use Of
Day
1
2
3
4
5
Amberlite
Nominal
Throughput (BV)
1-48
49-96
97-144
145-192
193-240
Polymeric Adsorbents
Influent
Concentration (ppb)
25 (Feed A)
none detected
21.1 (Feed B)
0.69
0.69
and Activated Carbon
Effluent Concentration (ppb)
Amberlite Adsorbent Carbon
0.246
0.031
0.023
none detected
3.478
0.050
0.055
0.025
none detected
0.045
A significant amount of PCB was adsorbed onto the walls of the influent
container, as can be seen with Feed A, which originally was prepared with 166
ppb of PCBs. This loss by adsorption on equipment surfaces also has been
detected in other tests, and must be taken into account.
Both the Amberlite polymeric adsorbent and the activated carbon reduced
"the concentration of PCBs in water to less than 0.05 ppb. The higher concen-
tration of PCBs for the first day's passage of effluent through the resin beds
could be due to an incomplete conditioning of the beds, resulting in some
material leaching out of the resin. The high concentration of PCBs in the
last sample from the polymeric adsorbent must be viewed with some suspicion,
A-2
-------
particularly since it indicates an effluent having a concentration higher
than that in the influent.
Amberlite polymeric adsorbents can usually be solvent regenerated,
because the energy of adsorption is much lower for resins than it is for
carbon. Hence, adsorbed solute can be removed simply by passing an appro-
priate solvent through the resin. Work performed by Musty and Nickles
(J. Chromat., 89:185 (1974)) with PCBs and a solution of 10 percent diethyl
ether in hexane as a regenerant indicates that 76 percent of the PCBs adsorbed
on an Amberlite polymeric adsorbent can be recovered using this mixed solvent.
In addition, Rohm and Haas have found that simple alcohols or ketones are
effective solvents for these resins. Undoubtedly, a more efficient solvent
could be found that would quantitatively remove PCBs from polymeric adsorbents.
Activated carbon, which has a much higher energy of adsorption than do
these resins, requires a more energy intensive process of regeneration, such
as thermal rejuvenation.
The ability to solvent regenerate Amberlite polymeric adsorbents in situ
would provide the advantage of generating only the more-readily-handled-by
incineration liquid phase PCBs wastes.
A - 3
-------
APPENDIX B
MACRORETICULAR RESINS FROM ROHM AND HAAS CO.
Description
Ion exchange resins have the capacity to selectively recover ionic
constituents, both inorganic and organic, from water through an ion exchange
mechanism. Organic compounds are often exchanged or adsorbed irreversibly
onto an ion exchange resin. This may cause a decrease in capacity so that
the operating life of the resin is diminished. The more recently developed
jnacroreticular type of ion exchange resins are polymeric adsorbents used
specifically for adsorbing aromatic and aliphatic compounds from water.
Structures
The macroreticular structures are characterized by having unusually large
surface areas as compared with those of conventional gel structures.
Using the newer macroreticular polymerization technique, it is possible
to widely vary the particle pore size, pore size distribution, and surface
area. Polymers with very small pores (5 nm or less) and high surface areas (in
the range of 800 square meters per gram) can be prepared. At the other end of
the spectrum, pore sizes on the order of 30 micrometers, visible under modest
magnification, are possible.
The macroreticular polymerization technique is applicable to a wide variety
of monomers. It is possible to introduce functional groups onto the surface of
the preformed macroreticular polymers. Thus, a great range of surface types is
possible, limited only by the availability of monomers or the applicability of
reactions to introduce functionality. The full line of macroreticular adsorbent:
constitutes a spectrum of surfaces from the least polar to the most polar. For
PCBs removal, the nonpolar and intermediate polarity adsorbents should be used.
The chemical structure of Amberlite XAD-2 and Amberlite XAD-4 (see Figure B-l)
is representative of the nonpolar adsorbent series. Figure B-2 shows the
acrylic-ester composition of Amberlite XAD-7 and Amberlite XAD-8, the inter-
mediate polarity adsorbents. The physical properties of these Amberlite XAD
adsorbents are summarized in Table B-l
B-l
-------
CHa - CII - CH2 - CH - CHZ - CH
i i i
- CH - CII2 - CH
i
Structure of Araberlite XAD-2 and Arriberlite XAI>4
Figure B-l
B - 2
-------
en.
1
- CI!2 - C - CH2
t
c=o
1
0
1
R
i
0
1
c=o
1
- CH2 - C - CH2
i
CH3
C1I,
t
- C -
1
c=-o
1
0
1
II
1
0
1
c=o
1
- C -
1
CH3
Structure of Araberlite XAD-7
CH3
i
- CH2 - C -
C =.0
i
0
I
R«
vn^
1
- CHj - C -
•
C — 0
CH3
t
i
C = 0
t
0
1
R
i
0
1
C = 0
1
CH2 - C -
i
/Ml
CH3
i
CH2 - C -
t
O •_
I
0
t
R«
vll^
1
CH2 - C
i
C -
0
0
Structure of ftiriberlite XAD-8
Figure B-2
B - 3
-------
Table B-l
Typical Properties Of Amberlite Polymeric Adsorbents
Chemical Nature
Helium Porosity
Volume %
cc/gram
Surface Area
mVgram
Average Pore Dia.
Angstroms
Skelatal
Density
grams/cc
Nominal
Mesh
Sizes
Nbnpolar
XAD-1
XAD-2
XAD-4
Polystyrene
Polystyrene
Polystyrene
37
42
51
0.69
0.69
0.99
100
330
750
200
90
50
1.06
1.08
1.09
20 to 50
20 to 50
20 to 50
Intermediate Polarity
XAD-7
XAD-8
Acrylic Ester
Acrylic Ester
55
52
1.08
0.82
450
140
80
250
1.25
1.26
20 to 50
25 to 50
to
I
*>.
-------
Macroreticular Adsorption Phenomena
An important aspect of the Artiberlite adsorbents is the nature of the
different surfaces. The phenomenon of adsorption on solids involves van der
Waals' forces which bind the adsorbate on to the solid surface. Many types
of interactions, such as hydrophobic bonding, dipole-dipole interaction and
hydrogen bonding, are important. It is not possible to predict accurately
which materials will be adsorbed well by a given adsorbent; however, from a
practical point of view, a useful concept is that hydrophobic or nonpolar mole-
cules or portions of such molecules are attracted to hydrophobic surfaces,
while hydrophilic or polar materials are attracted to hydrophilic or polar
surfaces. Examples of these interactions are presented in Figure B-3. If each
organic molecule is thought of as having both a hydrophobic and a hydrophilic
end, then the hydrophobic end will be attracted to hydrophobic adsorbents such
as Amberlite XAD-2 and Amberlite XAD-4, while the hydrophilic end will be
attracted to hydrophilic adsorbents. This type of reaction is particularly
true when the adsorption takes place from aqueous solution.
For PCBs, it would be expected that the biphenyl portion would be typically
aromatic and hydrophobic, and thus attracted to an aromatic resin. Increasing
the chlorination of a biphenyl would reduce its water solubility and thus reduce
what little polar character the PCB might have. Thus, the PCB would not have a
"polar end" and would be strongly repelled by the water phase and strongly
attracted by the resin.
A recent study by James Fritz, et al, of Iowa State University, reported a
macroreticular resin method for extracting trace organic contaminants from
water. He also demonstrated the feasibility of selective desorption of these
contaminants, using appropriate eluants, so that the contaminants could be
identified. He also established the performance or retention efficiency of the
**
resin in isolating these compounds. A summary of these results is given here:
B - 5
-------
SORPTION OK AROMATIC SOHHCK'TS fRO.M POLAR SOLUTIONS
MicnospHtnc
tn rrtvr.m
PHASE
SORPTION ON ALIPHATIC SORUENTS FROM POLAR SOLUTIONS
UlCROSPHCnE
POLAR SOLVENT
PHASE
SORPTION ON ALIPHATIC SOROf-NTS FROM NON - POLAR SOLVENTS
NON-l'Ol All
SOI.Vf Kt
Figxire B-3
B - 6
-------
Adsorbent: Arriberlite XAD-2 unless otherwise indicated
Particle Size: 100 to 150 mesh
Flow Rate: 10 BV/hr. (1.25 gpm/ft3 of adsorbent)
Retention
Test Compounds Influent Effluent Efficiency %
Benzene 100 0 100
Benzene sulfonic acid 3.0 2.1 31
Phenol 0.4 0.22 45
Phenol (Amberlite XAD-7) 0.4 0.06 86
Aniline (Amberlite XAD-7) 4.0 0 100
Naphthalene 0.05 0 100
It can be seen that Amberlite XAD-2 and Amberlite XAD-7 were 100 percent
efficient in recovering the nonionic organic compounds. These results predict
good success with PCB adsorption. On the other hand, ionic solutes as well as
strongly ionized compounds, such as benzene sulfonic acids and p-toluene sul-
fonic acids, were not retained with the same high efficiency. It was noted
that retention efficiency of a contaminant increases with increasing molecular
weight in a homologous series, indicating that the higher chlorinated PCBs
would be the best adsorbed.
B - 7
-------
APPENDIX C
NON-CARBON ADSORBTION AND OTHER RESEARCH STAGE
PCB TREATMENT TECHNOLOGIES
1.0 POLYVINYL CHLORIDE (PVC) AND POLYURETHANE FOAMS
John Lawrence and oo-workers of Environment Canada have reported prelim-
inary tests using PVC, polyurethane foams, carbon, and the XAD resins for
removal of PCBs from both synthetic wastewater solutions and actual raw sewage.
H. D. Gesser (in Analytical Letters 12:883 (1971)), reported that a poly-
urethane foam column quantitatively adsorbed PCBs from water. Lawrence found
that carbons, polyurethane foams and XAD-2 strongly adsorbed PCBs from aqueous
solutions, but were much less effective with raw sewage. He found that PVC,
however, was very effective in removing PCBs from raw sewage.
Dr. Lawrence is the only investigator known to have worked with PVC for
adsorbing PCBs. Following is a summary of his test procedures and results.
1.1 Experimental Method for PCBs Adsorption Tests, by Environment Canada
Two stock solutions of Aroclor 1242 and 1254 were prepared by vigor-
ously mixing an excess of each Aroclor with water for 8 hours, allowing the
solutions to stand overnight and carefully decanting off the true aqueous phase.
The water used was double distilled, the second distillation being from an all-
glass system. The concentration of these solutions, determined by gas chroma-
tography, was 45 * 10 ppb, which is consistent with the published solubility
for Aroclor 1254 of 56 ppb.
All solvents used were glass distilled pesticide grade (Caledon
laboratories, Inc.). The activated carbons employed were lignite-based hydro-
darco 400 (ICI-United States) and anthracite-based Filtrasorb 400 (Calgon
Corporation). These were pretreated by heating to 300°C for 12 hours, cooling,
and twice extracting each 500 gm with 2 liters of hexane. The extracted carbon
was then filtered and air dried. The polyurethane foams used were DiSPo plugs
(Canlab Supplies Ltd.) and Foams 1115 and 2328 (B.F. Goodrich Ltd.). (The first
C - 1
-------
two digits in the Goodrich products relate to the density, i.e., 1.1 and 2.3
Ib/ft and the second two digits to the hardness). The foams were shredded
and successively washed with n-hexane (several times), acetone and distilled
water. They were then air dried. This pretreatment was developed to remove
trace organic contaminants from the surface of the foams. The macroreticular
polystyrene resins Amberlite XAD-2 and XAD-4 (Eohm and Haas Company) were
pretreated by successively washing each 500 gm of resin with 1-liter batches
of water, methanol, and water. The cleaned resins were stored in sealed glass
containers under methanol to prevent them from drying. Polyvinyl chloride
chips (lYbnsanto Company) were washed several times with n-hexane and air dried.
To determine the adsorption characteristics, 100-ml aliquots of stock
Aroclor solutions were stirred rapidly for 30 minutes with weighed amounts of
adsorbent and then the adsorbent was removed by filtration through a Millipore
prefilter pad. Five milliliters of n-hexane were then vigorously stirred with
the filtrate for 45 minutes and the organic extract withdrawn. These extracts
were analyzed with a gas chromatograph (Varian series) equipped with an
electron capture detector (Ni ). The gas column (1.8m x 1.5 mm i.d.) was
80
packed with 4 percent OV-101 and 6 percent OV-210 on Chromosorb W HP A on mesn-
Nitrogen was used as a carrier gas at 50 ml/min. The injection port, column and
detector temperatures were 250°C, 200°C, and 300°C, respectively. Extraction
and analysis of water samples spiked with known amounts of Aroclor indicated
that greater than 98 percent of the PCBs were detected by this method.
Wastewater was collected from the Hamilton Sewage Treatment plant at
the raw sewage inlet pipe. Sampling was carried out using all-glass containers
to insure against adsorption of PCBs onto container walls. The samples were
stored at a constant temperature of 3°C and in all cases were treated and/or
extracted within 24 hours of collection. In the evaluation of PCB adsorption
from sewage, the procedure described above for pure Aroclor solutions was
followed, except that 100-ml samples of raw sewage were stirred vigorously with
the adsorbent for 1 hour, and then the adsorbent was separated by filtration
through a 60 mesh, stainless-steel screen. After washing, the screen did not
retain any raw sewage and, with the exception of activated carbon, 100 percent
C - 2
-------
separation of adsorbent was achieved. The filtrates were then twice extracted
with 50 ml of n-hexane in 500-ml separatory funnels. The aqueous portion was
discharged and the organic phase, after being dried through 15 g of Na2S04, was
reduced in a rotary evaporator to approximately 3 ml. The sample was purified
by liquid-solid chromatography on a florisil support column using petroleum
ether to elute the PCB fraction and then the eluate was evaporated to 3 ml.
Prior to injecting the sample into the gas chromatograph, it was shaken with
0.2 ml of mercury to remove residual sulfur compounds.
The PCBs in the samples were identified by comparison of their
chromatograms with chromatograms of standard Aroclors. The total concentrations
of PCB in raw sewage usually averaged 9.8 * 4 ppb.
1.2 Experimental Results of PCBs Adsorption from Sewage and Synthetic
Wastewater
Adsorption data for Aroclor 1254 and 1242 on PVC, activated lignite
carbon, anthracite carbon, two polyurethane foams, and Amberlite XAD-2 and
XAD-4 resins are shown in log-log form in Figure C-l. The weight of PCB
adsorbed per unit weight of adsorbent is expressed as a function of the equil-
ibrium concentration of PCB remaining in solution. The sets of data do not
*
follow any of the common isotherm expressions (e.g., Langmuir, Freundlich, BET),
and consequently a theoretical interpretation of the results has not been
attempted. It is evident that the two carbons and XAD-2 have the greatest
adsorptive capacities; however, a residual concentration of less than 3 ppb
could not be obtained with lignite carbon. Both polyurethane foams appear to
be good adsorbers, with relatively nigh adsorptive capacities and low residual
levels. DiSPo polyurethane foam plugs are also evaluated but these have identi-
cal adsorptive properties to the Goodrich Foam 1115. The lower efficiency of
XAD-4 is surprising in view of the similarity between it and XAD-2 (they differ
only in pore diameters: 9 ran for XAD-2 and 5 nm for XAD-4). The lower efficiency
of PVC, which has no macroreticular structure, can be explained by its lower
2
surface area. The surface area per unit weight is reported as 500 to 2000 m /gm
for carbon, 750 m /gm for XAD-4, and 330 m2/gm for XAD-2, but only 2 x 10~3 m2/gm
for PVC chips - there being no macroreticular structure in PVC. This gives an
area ratio for XAD-2/PVC of approximately 10 .
C - 3
-------
UJ
8
O
to
Q
I
H
tr
o
IT)
g 01-
co
o
D.
O)
E
ooH
.0001-'—
A PVC
O LIGNITE CARBON
A GOODRICH 1115 FOAM
0 GOODRICH 2328 FOAM
XAD -4
XAD-2 *
ANTHRACITE CARBON *
1
10
100
1000
PCB REMAINING (ppb)
Figure C-l. Adsorption of Aroclor 1254 on P.V.C., Lignite Carbon,
Anthracite Carbon, Polyurethane Foams and Amberlite XAD-2 and XAD-4,
* Indicates adsorption of Aroclor 1242 rather than 1254
C - 4
-------
There are two complicating conditions associated with adsorbing
PCBs from raw sewage rather than from synthetic aqueous solution: (a) sewage
contains other hydrophobic organic matter vvhich competes for the active sites
on the adsorbent, and (b) much of the PCB has already adsorbed onto the sus-
pended solids by the time the sewage reaches the treatment plant. Condition
(b) can be demonstrated easily by filtering raw sewage and monitoring the
change in PCB concentration. With typical raw sewage containing 10 ppb PCB,
vacuum filtration through a Millipore prefilter pad results in the removal of
about 75 percent of the PCBs. It is therefore necessary to find an adsorbent
which is not only relatively specific to PCBs, but which also has sufficient
affinity for the PCBs to reverse the PCB-suspended-solid equilibrium.
Table C-l shows the percentage of PCB (including both Aroclor 1254
and 1260) adsorbed from raw sewage by five different media. With the exception
of the PVC, approximately 1 gm of each media was stirred with 200 ml of raw
sewage for 45 minutes; approximately 10 gm of PVC were used to compensate for
its lower surface area. To minimize the inconsistency of raw sewage, the data
have been averaged over several determinations on different days and with
different sewage samples. The data indicate that PVC and XAD-4 are more
effective than carbon or polyurethane foams in terms of percentage of PCB
removed from raw sewage. This is surprising since the graphs for PCB adsorp-
tion for pure Aroclor solutions (Figure C-l) predict the opposite. Lawrence
believes the reasons for this apparent anomaly are: (a) the active sites on
carbon are preferentially occupied by hydrophobic species other than PCBs in
the sewage, and (b) suspended solids adhere to the surface of carbon and foam
acting as a barrier to further adsorption. These results indicate that PVC is
superior to the other media for removing PCBs from sewage.
Lawrence's work is continuing, with studies of methods of scale-up
and continuous or multistage operations with PVC. Optimum retention time, and
methods for continuous addition of fresh PVC and removal of spent PVC are under
study.
The strong competition between organic solids and non-organic media
is emphasized further in the following discussion.
C - 5
-------
Table C-l. Adsorption of PCBs from Raw Sewage
ADSORBENT % PCB
ADSORBED*
Lignite Carbon 46
Polyurethane Foam 35
Amberlite XAD-2 23
Amberlite XAD-4 60
PVC 73
* Includes both Aroclors 1254 and 1260. Data are averaged over several
determinations to minimize the variations in raw sewage.
C - 6
c
-------
1.3 PCBs Adsorption on Clays and Qrganics in the Soil
E. S. Tucker and co-workers at Monsanto reported on studies of
migration of PCBs (Aroclor 1016) through various soils as induced by perco-
lating water (Bulletin of Environmental Contamination and Toxicology
13 (1):86 (1975)). The results were to be used for estimating PCBs leached
from landfills. Their tests first led them to believe that the higher the
clay content of a soil, the better its retention of PCBs.
The experimental procedure employed consisted of percolating water
through a column packed with soil coated with Aroclor 1016 and then monitoring
the effluent water for PCBs. The soil columns employed were approximately
3 inches in diameter by 12 inches high, and were dry packed in layers. Each
soil layer was 3 inches thick, with the first layer being uncoated soil,
followed by a layer coated with 2.5 percent (w/w) of Aroclor 1016, and then
another layer of uncoated soil. An acetone solution of Aroclor 1016 was used
to coat the air-dried soil, followed by removal of the acetone in a rotary
evaporator.
Three different types of soils were used in this study. The charac-
teristics of each are shown in Table C-2. The intent was to simulate the
various soil types which could be encountered at different landfill sites.
The soil types and the procedure employed have been used previously to evaluate
the soil mobility of agricultural chemicals.
Distilled water was fed from a reservoir at a constant pressure to
each soil column. The effluent flow rates were observed to increase the first
few days, then decrease, and finally level out. Apparently, after the wetting
phase some channeling occurs until the soil becomes compressed in the column.
This effect was most pronounced with the silty soils. The average flow rates
for Norfolk Sandy Loam, Ray Silty Loam and Drummer Silty Clay Loam were 0.26,
0.53 and 0.32 liters per day, respectively. The effluents then were quantita-
tively adsorbed on polyurethane columns, then extracted and analyzed by electron
capture gas chromatography.
C - 7
-------
Table C-2
COMPOSITION OF SOILS USED IN THE MONSANTO STUDY
Soil
% Sand
% Silt
% Clay
% Organic Carbon
Norfolk
Sandy Loam
82.5
11.0
5.5
1.0
Ray
Silty Loam
6.2
83.2
9.6
1.0
Drummer
Silty Clay Loam
2.8
55.4
35.8
6.0
C - 8
-------
1.3.1 PCBs Adsorption Results
PCBs adsorption results are given in Table C-3. These results
indicate that clay was a strong adsorbent for PCBs. This would be in agree-
ment with the work of R. Hague and co-workers (Environmental Science Technology,
8:139 (1974), in which clay was found to have a high affinity for PCBs. How-
ever, in later work with pure clays, the retention was found not to be as good
as expected. Attention was then directed to the organic portion of the soils,
and Tucker, et al, have tentatively decided that the organic fraction is more
important to the adsorption of PCBs; it can be seen from the data that the
high-clay-content soil was also the high-organic-content soil.
Further investigation of some clays might be warranted.
S. Pearson of Hercules, Inc., in a personal communication, stated that bentonite
clay was very effective in removing other pesticide wastes from water. The
finely divided clay was then rapidly removed from the water with "Hereofloc".
1.4 Spahgnum Peat (Lignin-Cellulose) as an Adsorbent
The above work by Tucker, and the general finding that in sewage sludge
the solid phase contains many times the amount of PCBs the water phase contains,
leads to the conclusion that natural organic materials from the earth might make
good adsorbents for PCBs.
Although it has not yet been tested for removing PCBs, there is a
commercial method of continuous wastewater treatment, called the Hussong/Couplan
Water Treatment System, that uses sphagnum peat. The peat is formed into a
continuous mat on a mesh belt through which wastewater is sprayed. The system
has shown high effectiveness in removing certain organics and metals from waste-
waters .
Capital costs for this system average about 60C per gallon of daily
capacity. Operating costs, when treating a dye house .effluent, were 7£ to 14C
per 1000 gallons.
2.0 CATALYTIC REDUCTION
In the literature review, two approaches were found for modifying the chem-
ical structure of PCBs in order to aid in waste control. One approach was the
C - 9
-------
Table C-3
PCBs FOUND IN PERCOLATING WATER
Norfolk
Sandy Loam
Total
Effluent
Volume (I)
1.3-8.1
10.1
13.5
25.5
48.1
ppb
PCBs
ND
ND
23
63
63
Ray
Silty Loam
Total
Effluent
Volume (£)
2.7-16.4
20.7
27.6
51.9
98.1
Drummer
Silty Clay Loam
ppb
PCBs
ND
65
92
153
136
Total
Effluent
Volume U)
1.6-9.9
12.5
16.6
31.4
59.2
ppb
PCBs
ND
ND
ND
ND
ND
ND = None detected, < 1 ppb
C - 10
-------
complete chlorination of PCBs, to give decachlorobiphenyl, the rationale being
that the completely chlorinated biphenyl would have the least solubility in
water of any PCB, and thus would be much easier to adsorb and remove. However,
decachlorobiphenyls are also the most refractory PCBs.
A better approach is the dechlorination of PCBs to give biphenyl or bi-
cyclohexyl. Berg, et al (in the Bulletin of Environmental Contamination
Toxicology 7:338 (1972) state that PCBs can be dechlorinated quantitatively
with hydrogen over platinum or palladium catalysts to give bicyclohexyl.
T. Sawai of Japan (in Genshiryohu Kogyo 18(12):43-7 (1972)) reported the
degradation of PCBs using the cobalt 60 isotope. Gamna irradiation at a level
18
of 10 ev/gram produced chain dechlorination in an alkaline propanol solution
saturated with nitrogen. Alkaline concentrations of 0.01 molar gave about 40
times the dechlorination that a neutral solution gave.
A process of reductive dechlorination, more amenable to low-cost operation
and commercial scaleup, is being developed by Sweeny, Saltonstall and co-workers
at Envirogenics Systems Co. of El Mbnte, California.
2.1 Reductive Dechlorination of PCBs at Envirogenics Systems Corp.
Envirogenics, originally working in chlorinated pesticides, has devel-
oped catalyzed reduction process methods for the following compounds:
DDT aldrin Aroclor 1221
ODD Chlordane Aroclor 1242
Kelthane dieldrin Aroclor 1254
Perthane endrin Aroclor 1232
Methoxychlor heptachlor Aroclor 1248
Lindane toxaphene Aroclor 1260
The reductive dechlorination reaction has been run at ambient tempera-
ture and pressure, by flowing the liquid chlorinated hydrocarbon through a column
containing metallic iron granules coated with a metallic copper and blended with
sand. The copper exerts a catalytic action. pH is maintained at nearly neutral,
since with low pH, say 2.0, the iron conversion rate to ferrous chloride
increases 10 times, but the dechlorination reaction is not much faster. The
chlorinated hydrocarbon is converted to a hydrocarbon. PCBs, in this process,
seem to lose chlorines stepwise, leaving unidentified PCB homologs.
C - 11
-------
Envirogenics is now under EPA contract (68-03-2364) to develop and
demonstrate an effective bench-scale (1-3 gpm) low-cost process for the treat-
ment of dilute (ppb to 1 ppm) aqueous manufacturing and processing wastes
containing PCBs. Specific objectives and guidelines include:
1. Reduction of PCBs to 5 ppb or less, with levels of < 1 ppb
desirable
2. Sufficiently low projected treatment cost to be economically
attractive
3. Low expected toxicity of all effluent products, including both
degraded PCBs and any added reagents
4. Use of readily available materials, both in construction and as
reagents
The process entails simply pumping the liquid to be treated through
the catalytic column. Process characteristics that might be proposed for the
scaled-up PCB operation, based on what has been learned about the other pesti-
cides thus far, are:
catalyst; 100-mesh metallic iron granules coated with 0.1 milli-
equivalents of copper per gram of iron
support: 60 to 100 mesh (approx.) sand
number of beds: 4, operable in series or parallel
bed composition; 500 pounds of iron catalyst, plus 3500 pounds
of sand
flow rates; 2 to 10 gpm /ft2
pressure drop: about 10 psi
pH: kept neutral, through caustic addition
piping: 304 ss, with teflon tape seals
tanks: Steel with epoxy coating inside
pretreatment: Wastes are assumed to be free of undissolved solids
and oils and are fabric filtered before entering process
The expectations for wastewater PCB reductions with such a pilot plant
are based on small 1- to 2-inch-diameter column lab tests that gave reductions
of PCBs from 50 ppb to less than 0.1 ppb.
C - 12
-------
The capital cost of the equipment to process 100 gpm is estimated
at $65,000, plus tank storage and construction costs. Operating costs,
including amortization of capital, is estimated at 72* per 1000 gallons of
effluent.
3.0 CATALYTIC OXIDATION AND MISCELLANEOUS REACTIONS
The catalytic oxidation of PCBs includes oxidation by: air, oxygen, ozone,
hydrogen peroxide and chlorine dioxide. The reaction is usually assisted by
catalysts or reaction sensitizers.
PCBs are very resistant to chemical attack. Monsanto states that they
are not affected by boiling sodium hydroxide, or by long contact, say 10 days,
with concentrated sulfuric acid at ambient temperature. There is no apparent
reaction in a bomb of oxygen at 250 psi and 140°C.
3.1 Strong Acids
Russian workers have reported nitric acid decomposition of PCBs.
They used nitric acid at a specific gravity of 1.4, and refluxed two PCBs, a
pentachloro and a heptachloro homolog, for periods ranging up to 100 hours.
They found di- and trichlorobenzoic acids from the former, and tri- and tetra
*\.
chlorobenzoic acids from the latter. Less concentrated nitric acid would not
oxidize these compounds, nor would potassium permanganate or chromic acid.
However, mono-, di- and trichlorobiphenyls can be oxidized to the corresponding
chlorobenzoic acids with chromic anhydride and acetic acid. The less rigorous
conditions can also produce a large mixture of nitrated chlorobiphenyls.
3.2 Electrochemical Oxidation
Notwithstanding these examples of oxidative resistance, J. D. Stuart
and co-workers at the Dept. of Chemistry of University of Connecticut have con-
ducted laboratory electrochemical oxidations of PCBs at ambient temperature and
pressure. They oxidized PCBs having one to ten chlorine atoms, using very high
anodic potentials in a dry methylcyanide solvent. They hypothesize a series of
reactions starting with hydrolysis from traces of water present and ending with
oxidation.
C - 13
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A number of other catalytic oxidation investigations of refractory
organics are being conducted in the U.S., with some being sponsored by EPA.
Although PCBs have yet to be tested in these investigations, the methods have
sufficient power and flexibility to indicate PCBs could be destroyed. In
addition, these methods have the potential for zero discharge of pollutants
since they have converted refractory organics to CO- and water.
3.3 Catalytic Ozonation and Ultrasound Decomposition of Organics
Gerard Smith and J. W. Chen of Southern Illinois University have
presented results (68th annual AIChE Meeting in November, 1975) of catalytic
ozonations of non-PCB organics in aqueous systems. They have tested catalysis
with oxygen, and ozonation without catalyst, and neither method had the
effectiveness of catalytic ozonation. An Fe-0., catalyst was used, and phenol
and ethyl acetoacetate were used as model compounds in water. The liquid re-
tention time in their flow reactor system was 25 minutes, and the gas flow
(using 30 mg/liter concentration of ozone) was 0.1 liter per minute. Under
these conditions, TOC was decreased 95 percent for an initial TOC of 100 mg/1,
and 85 percent for an initial TOC of 400 mg/1. The packed reactor had the
aqueous solution flowing down, and the ozone flowing up.
In experiments comparing the effectiveness against refractory organics
of ozone plus Raney nickel and ozone plus ultrasound, Smith found that the
reactions were similar. Also, he found that ultrasound and oxygen gave similar
2
reactions. Ultrasound was applied at 800 KHz, and 4 to 5 watts per cm . It
appeared, however, that these effects were not additive; for example, adding
ultrasound to an ozone catalytic reaction did not materially change the re-
activity of the ozone and catalyst alone. He also found that at these ambient
temperatures and pressures, phenol disappeared rapidly, but other organics,
including oxygenated aromatics, resulted rather than compounds expected from
rupture of the aromatic ring.
3.4 Wet Catalytic Oxidation of PCBs
L. W. Ross at Denver Research Institute has studied the wet catalytic
oxidation of strong wastewaters having COD values of 3,000 to 15,000. Tests
C - 14
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showed that reacting Fe2 (S04)3, Cu S04, and H202 at a pH of 5.0, and Fenton
catalyst at a pH of 2.5 reduced COD concentrations by 95.4 and 96.0 percent
respectively after 2 hours at 400°F. Platinum oxide as a solid catalyst also
gave good results. Most of the organics were cellubiosics.
3.5 Wet Catalytic Oxidation and Catalyst Durability
J. F. Katzer and co-workers at University of Delaware have been
studying elevated pressure and temperature catalytic air-oxidation of refrac-
tory organics. They are currently being supported by EPA in a study of the
durability of catalysts in wastewater environments. In a paper soon to be
published in the Journal of the Water Pollution Control Federation, Katzer
reports on studies of the complete oxidation of phenol to C02 and water in an
aqueous medium using a supported copper oxide catalyst. Rapid degradation rates
were found, and the rate data were used to run preliminary design and costs for
conmercial-scale waste treatment plants. His conclusion is that catalytic oxi-
dation of wastewaters is cost competitive with other physical chemical treatment
techniques.
Katzer found that pressures of 10 to 20 atmospheres, and temperatures
of 100 to 200°C, were required to get adequate reaction rates yielding up to
99 percent conversion of organics to CO- and water. It was found that ambient
temperature and pressure generally caused more adsorption on a variety of
catalysts than did any reaction.
3.6 Dye-Sensitized Visible Light Photo-Oxidation of Organics
R. L. Sanks and co-workers at the Civil Engineering Dept. of Montana
State University are working on the dye-sensitized, aerobic, photo-oxidation of
refractory organics. They were able to rapidly break apart the benzene ring of
cresol using such dyes as methylene blue and bengal rose. The key to the process
is that in the presence of sunlight and air, methylene blue can produce singlet
oxygen from the 0- in air. There are two forms of this singlet oxygen, with a
half life of only a millisecond, but with the ability to easily shatter benzene
rings. Sanks visualizes a process whereby a lagoon containing wastewater with
refractory organics, could have the dye molecules attached to a long chain alkyl
15
-------
or a floe of some kind to keep them at the surface. The sun would provide the
photolysis, and little dye would be consumed as it is a catalyst in the reaction.
Such a process, if it can be developed, suggests a route to a very low-cost
method of obtaining zero discharge, and water recycle systems.
3.7 Chlorine Dioxide Oxidation
International Dioxide, Inc., of New York City is offering a stabilized
chlorine dioxide, which is being used by municipalities for taste and odor con-
trol of water. It is used as an adjunct to chlorination and can decompose
chloramines. It oxidizes and destroys phenol and does not chlorinate. Un-
stabilized CIO- is a dangerous explosive, thus stabilization offers a very
powerful oxidizing agent for potential degradation of organics.
4.0 DESTRUCTION OF PCBs BY OTCBQORGftNISMS
The Chemistry of PCBs by Hutzinger reports only two pure cultures of micro-
organisms showing metabolic activity on individual chlorobiphenyls. One
culture, Rhizopus japonicus only converted the mono- or dichlorobiphenyls to
chlorohydroxybiphenyls or possibly multi-hydroxybiphenyls.
More promising results were obtained with two species of achromobacter,
isolated from sewage effluent. Under aerobic conditions, 4-chlorobiphenyl was
converted to 4-chlorobenzoic acid. The organism was apparently able to attack
the nonchlorinated benzene ring. Most of these degradations take a number of
hours to occur. More recently, chlorinated biphenyls up through pentachloro-
biphenyl have been oxidized by achromobacter. Monsanto was able to demonstrate
a significant reduction in the mono-, di, and trichlorobiphenyls of Aroclor 1242
after 72 hours of treatment with activated sludge. The higher chlorinated
homologs did not seem to be affected.
The degradation of PCBs by microbial action from sludges and from pure
cultures of bacteria seemed to give results similar to animal metabolism studies.
The lower chlorinated species, again up through the trichloro homolog, were de-
composed to phenols, catechols and related compounds.
C - 16
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The importance of oxidative conditions was demonstrated in tests with
silage containing PCBs. After several months of storage of Aroclor 1242 with
silage that had undergone fermentation reactions under anerobic conditions, no
change in any of the PCBs had taken place.
The use of DDT degradation as a model for PCB degradation conditions may
not be helpful. Results of a study by Johnsen (PCB Newsletter, January, 1973)
showed that when di- to hexachlorobiphenyls were incubated for one month with
soil and with soil containing cattle manure, no indication of PCB metabolism
was found. Under these conditions, p,p" DDT degrades almost completely.
It has also been found that biphenyl itself is more easily degraded or
hydroxylated than any of the chlorinated biphenyls.
5.0 REVERSE OSMOSIS AND ULTRAFILTRATION
No tests for PCBs removal by reverse osmosis or ultrafiltration were found
in our literature survey. Generally, these methods have found most success in
removing dissolved salts from water. However, E.I. DuPont reports, in a
private communication, that they have achieved 90 percent removal (rejection)
or organics in water at the 1000 to 2000 ppm level. They accomplished this
through the development and use of a hollow-fiber permeator system having
fibers of aromatic polyamides. The system is reported to work well on organics
having molecular weights greater than 100. This would indicate probable success
with the PCBs, all of which have molecular weights in the range of 200 to 400.
Based on their experimental work with wound polyamide membranes operating
on chlorinated hydrocarbons in water, U.O.P.'s Fluid System Division predicts a
95 to 97 percent removal of aqueous PCBs at 50 ppb concentrations. They point
out however, that the reject water stream of concentrated PCBs would contain 10
to 20 percent of the original volume of wastewater so that a certain amount of
recycle would have to be built into the system to reduce the generation of con-
centrated wastewater. Reverse osmosis systems cannot tolerate suspended solids
in the feed wastewater; under optimum conditions they can operate for six month
to one year before any maintenance or cleaning is required.
C - 17
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W. L. Short of the Chemical Engineering Dept. of the University of Mass.
reports that with ultrafiltration, 50 percent rejections of phenols and
chlorinated phenols has been achieved. He believes that rejection of a given
compound can be improved by attaching some of that compound, or a similar
material, to the membrane to act as an electronic barrier.
C - 18
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APPENDIX D
MASS BALANCE MODEL FOR PCB DISTRIBUTION
1.0 INTRODUCTION AND MASS BALANCE EQUATION
In order to discover the effect of various possible regulatory efforts on
the distribution of refractory organics in the general environment, an attempt
has been made to determine the manner by which a specific group of such com-
pounds, PCBs, has become so widely dispersed, to determine the dynamics of the
distribution process and to determine the changes in specific distribution that
may be expected to result from several regulatory alternatives. Specifically,
the effect of the voluntary ban introduced by Monsanto in 1970-71 can be
demonstrated.
It would be most useful to construct a mathematical representation of a
suitable segment of the environment based on the existence of large quantities
of valid analytical data taken over a sufficiently long time interval so as to
allow the reliable extrapolation of the important time effects. Unfortunately,
the necessary data are not available. The recognition that PCBs were an environ-
mental hazard came after their prolonged and widespread use in industry. In
addition, the ability to analyze environmental samples for very low levels of
PCBs is also a recent development. There has been too little time since the
development of these sophisticated and exceedingly sensitive analytical techniques
to have allowed anything like a complete spatial and temporal study of the levels
of PCBs in any given region.
In view of the serious lack of a truly adequate data base, and because of
the need to have at least a first order understanding of the physical processes
involved in the transport and distribution of PCBs, an attempt has been made to
construct a mathematical model which should contain at least a germ of the true
situation. Specifically, the model serves to indicate something of the nature
of the problem, and of the types of measurements that will be required to con-
struct a truly satisfactory model to guide future regulatory activities.
To make what follows specific, the derived model is applied to a study of
Lake Michigan where a considerable body of information, of late origin, is
available.
D-l
-------
1.1 Mass Balance Model
In order to construct a mass balance model to be applied to a body
of water such as Lake Michigan, it is appropriate to determine the manner in
which an incremental increase in PCB content is distributed within the various
processes available. In what follows, it is explicitly assumed that:
(a) There are no effective mechanisms for the degradation
of PCBs which are operative over the time scale
involved.
(b) The PCBs that remain in the body of water are
distributed between that portion in solution
in the aqueous phase, that in "solution" in the
biota and that contained within the sediments.
(c) The essential loss mechanisms are evaporation
from the lake surface and carry off due to the
outflowing waters (in this case - through the
Strait of Mackinac).
In terms of these assumptions, a differential equation can be developed that
describes the time rate of change of the concentration in the various phases in
terms of the input rate of PCBs. This equation may be integrated under various
assumptions as to the time dependence of the input rate to yield alternate expres-
sions for the concentration of PCB within the separate phases as a function of
time.
1.1.1 Model Development
Let B(t) be the rate of injection (Ib/yr) of the PCBs from
all sources at a reference time t [where t (years) = 0 in 1930]. Then, within
the interval t to t + At, an incremental amount of PCBs equal to B(t)At will be
injected into the system. This quantity of PCBs will be partially partitioned
into the various phases, with the balance removed by evaporation and/or outflow.
If Q(lbs) is taken to represent the total water mass in the
Lake (assumed to be constant) and C (t) the concentration of PCBs in the water
D-2
-------
at time t, then
AC
Cw(t + At) = °w(t) + AlT At
which, in terms of the definition of concentration, causes an increase in soluted
PCB of magnitude
AC
Q At. (1-1)
In a wide variety of environmental situations there appears
to exist a rather definite relationship between the concentration of PCBs within
the sediment and/or the "average" member of the biota and that of the water in
which they are immersed. These relationships are herein defined as
_ sed
p = c—
water
(1-2)
_ Cbiota
n =
water
and are assumed to be independent of C and of time.
watzer
Using the relationships expressed by Eg. (1-2), the incremental
increase in the mass of PCB stored in the biota is given as
ACw
" ^ At" At' (1'3)
where it is assumed that the concentration of PCB within the biota was in equilib-
rium with that in the water at time t and that G(lbs), the total mass of the
exposed biota, is constant over the period of interest.
Similarily, if the rate of deposition of sediments is taken
to be D(Ibs/mVyr) and the area of the lake to be A(m2), then, assuming that the
principal exchange processes between water and sediment occur within the aqueous
phase during the settling out process, the incremental PCB pickup by the sediments
is given as:
= ADpCw(t)At (1-4)
D-3
-------
[where the additional term (1/2) — At is considered small, especially as At ->• o].
If the rate of outflow from the lake (through the Strait of
Mackinac) is taken as S (Ibs/yr) , then the loss of PCB due to this outflow may be
taken as:
Am , „ = SC (t) At (1-5)
outflow w
Finally, the mass of PCB carried out of the system by evapora-
tion is given as:
Am = KC (t)At (1-6)
evap w
where K is the evaporation rate constant which will be discussed below.
Now, the principle of conservation of mass requires that all
the injected PCB be accounted for, (note that np_ effective degradation processes
are considered to be operative) from which it follows that
B(t)At = Am + Am, . , + Am -, + Am . „ + Am
v ' w biota sed outflow evap
Introducing the definitions of each of the incremental mass loads, and proceeding
to the limit At •> o and dropping the subscript w since the only concentration
appearing is that of the PCB in water, the operative differential equation becomes
(Q + Gn) + (S + K + ADp)C = B(t) (1-7)
which, for convenience in what follows, may be rewritten using the substitutions,
1
(1-8)
S + K + ADp
X E Q + OH
^+ XC = YB(t). (1-81)
D-4
-------
The general solution of Equation (1-81) takes the form
where C(tf) is the concentration of PCB in water at the reference time tf
(tf = 0, 1930).
To solve Equation (1-9), it is necessary to evaluate the
various constants [Equation (1-8)] and to discover an appropriate form for the
driving function B(t).
2.0 PCB PRODUCTION, SALES AND ENVIRDNMENTAL LOAD
In the following section, an attempt is made to evaluate the production
(2)
and sales of PCBs during the period 1930-1975. Data published by Monsanto'
have been presented elsewhere in this report. From the derived empirical expres-
sion for the total sales as a function of time, as well as from the empirical
expressions for transformer, capacitor and other use categories, it will be possi-
ble to estimate the total environmental load of PCBs as a function of time. From
this analysis, it will be possible to estimate that portion of the total environ-
mental load that is, in fact, free and which therefore is responsible for the
widespread distribution of these refractory compounds. As a final step, it will
be possible to estimate the time dependence of the free (wild) PCB input to a
closed system such as Lake Michigan.
2.1 Empirical Representation of PCB Sales, General and in Specific
Use Categories
2.1.1 Period 1930-1970
From the Monsanto sales data for PCBs, it is possible to fit
an empirical expression for each category which, to a satisfactory degree, rep-
resents the time dependence of that parameter. In each case, it is assumed that
the relation is of the general form:
In Q(t) = a + n In t (2-1)
D-5
-------
(a) Total Production
The derived empirical expression for the yearly pro-
duction takes the form, for the period 1930-1970,
") ^ • _7rr X -LU t. J.JDS/yiT \^~4&/
The appropriate empirical expression for the yearly sales, for the period
1930-1970, takes the form
Qsales(t) = 311 t3'39 Ibs/yr (2-3)
The corresponding expressions for capacitor sales and for transformer sales are
(for the period 1930-1970)
Capacitor sales: Q (t) = 2.03 x 102 t3'289 Ibs/yr (2-4)
Cclp
Transformer sales: Q. (t) = 2.02 x 103 t2'37 Ibs/yr (2-41)
In the above expressions, it should be noted that it is
explicitly assumed that
(a) the given Monsanto data are accurate and
represent the great preponderance of PCB
production and sales within the U.S.
(b) the trends noted in the interval 1954-1970
are simple continuations of earlier trends,
so that the curves which fit the period
1954-1970 can, in fact, be used to cover
the entire interval, 1930-1970.
Information reported elsewhere in this report suggests that
the second assumption above might result in low estimates for total U.S. sales;
therefore, the results derived from this analysis must be considered as a lower
bound on the actual situation.
D-6
-------
In any case, numerical evaluation of expressions (2-3) and
(2-4) suggest that a weighted average for the proportion of PCB sales that were
employed in electrical applications is of the order of
3 = 0.62 (i.e., 62%) (2-5)
The remainder of the sales during the period 1930-1970 was
for non-electrical applications.
2.1.2 Period 1971-1975
In 1970, Jyfonsanto instituted a voluntary ban on the sales
of PCBs restricting their use to electrical applications. As a result of this
ban, the empirical relationship appropriate for sales in the post 1970 period is
Q' sales (t) = 3'31 x 10? ^/yr (2~6)
In addition, during this period essentially 100 percent of
PCB production was used for electrical applications; i.e.
3 = 1.00 (1970-1975) (2-7)
To determine the total sales and total electrical system
usage for the period 1930-1975, Equation (2-3) may be combined with Equation (2-6)
Integration over the appropriate time frame yields
'EQsales = 9.33 x 10 8 l±>s
1930 saj-es _________
and for total electrical system usage, Equations (2-4) and (2-6) with (2-7) may
be combined and, on integration, yield,
1975
Q n 4. • i (t) = 7.12 x 108 Ibs
o electrical
The balance, 2.21 x 108 Ibs, were used in non-electrical applications.
D-7
-------
2.2 Environmental Load of PCBs
2.2.1 Introduction
PCBs, or for that matter any other refractory chemical com-
pound, may exist in the environment in two distinct states: (a) that material
which is in a form such as to remain localized and thus is not actually available
to enter the sensitive portion of the environment, i.e., the biota; and (b) that
material which is not so constrained and is thus free to enter the sensitive
portion of the environment. This latter portion of the environmental load will
be referred to as "free" or "wild" PCBs. The significance of the first category
lies in the fact that the containment is not of infinite life and thus material
in category (a) can and will eventually become a component of category (b). For
those compounds for which there exists relatively high rates of degradation with-
in the environment, the category (a) is of somewhat lesser importance than for
those refractory compounds for which the only inactivation mechanism is the en-
trapment with non-available forms, for example, in deep ocean sediments.
In order to estimate the rate of accumulation of PCBs in
category (b), it is first necessary to determine the rate of entry of PCBs into
the category (a). This will be followed by an analysis of the processes by
which this total environmental load eventually becomes wild PCBs.
2.2.2 Total Environmental PCB Load, M (t)
c V
It is assumed that, in any time interval t to t + At, a
fraction a < 1 of the total sales during that interval was directly lost to the
environment. It is further assumed that a fraction g < 1 of the total sales
was used in the manufacture of long lived electrical components. If the average
lifetime of these electrical components (time of service prior to their being
discarded as obsolete) is Y! years, then during the time interval t to t + At,
an amount
3 C> (t-y) At (2-8)
o *•
D-8
-------
will enter the environment as part of category (a). In addition, the direct
entry is given as
a Q (t) At (2-9)
ID
The remaining sales (l-a-3) Q(t) was used in the production
of relatively short-lived products, such as carbonless paper, hydraulic fluids,
etc., which are assumed to have an average lifetime y2 years. Thus, the entry
of this material into the total environmental pool is given by
(l-a-3) Qs(t-Y2) At (2-10)
If the three components of the total environmental load,
t
the limit as At -> o
M (t) are summed, the resulting differential equation for M (t) becomes, in
dM (t)
at = a Qs(t) + U-a-3) Qs(t-Y2) + 3 Qs(t-Yl) (2-11)
or /-t rt rt
^(t) =a/ Q«(t)dt + (1-a-B) / Q_(t-Y,)dt + 3/ Qc(t-y1)dt (2-11l
tlv I O I G *- I O
o o o
In order to obtain a numerical evaluation of Equation (2-111)
it is appropriate to note that 3, the fraction of initial sales utilized for
electrical applications, is given by Equation (2-5) for the period 1930-1970,
and by Equation (2-7) for the post 1970 period.
An estimate of the factor a, the fraction of direct losses,
can be obtained by noting that
(a) approximately 10% of the electrical material
was lost during transport, production and
processing.
(b) approximately 30% of the non-electrical
material was lost during transport, pro-
(4)
duction, processing, and use.
D-9
-------
Hence,
a = (0.1)(0.62) + (0.30)(.38)
a = 0.17 (2-12)
It is further assumed that
Y! = 20 years(5)
A (O ) / 'I 1 'I 1 \
Y2 = 4 years (2-12 )
If the expression of Q (t) given by Equation (2-3), coupled with the estimated
values of a, 3, ^l, and j2, is introduced in Equation (2-11), the total environ-
mental load M (t) may be computed. The integrated form of Equation (2-11) is:
Mev(t) = 71.07 0.17t't'39 + (0.21) (t-4)"'39 + (0.62) (t-20)"'39 (2-13)
The numerical results are summarized in Table 2.2.2-1. It should be noted that,
in contradistinction to equations such as Equation (2-3) , which represent the
yearly sales, Equation (2-13) represents the cumulative load in pounds.
2.2.3 Effect of Monsanto's Voluntary Ban on PCB Sales
In the actual situation, as a result of the voluntary
Monsanto ban on PCB sales, the expression M (t) given by Equation (2-13) must
be modified to account for post 1970 levels. Thus, for the period 1971 and
later,
M (t) = M (40) + 0.1/ Q1 (t)dt -t- (l-a-3)/ Q(t~Y9)dt
ev ev I I z
•'O 40
,t ,t
+ (l-a-3)/ Q'(t-Y2)dt + 3/ Q(t-Yl)dt (2-14)
t=tO+Y2 40
D-10
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TABLE 2.2.2-1
M (t) = Envirorarental PCB Load
ev
Without Partial Ban
[From Equation (2-13)]
With Partial Ban
[From Equation (2-13/2-15) ]
Date
1930
1935
1940
1945
1950
1955
1960
1965
1970
1975*
1980*
t(yrs)
0
5
10
15
20
25
30
35
40
45
50
M (t) (Ibs)
ev
0
1.42 x 104
3.35 x 105
2.32 x 106
9.1 x 106
2.62 x 107
6.23 x 107
1.31 x 108
2.54 x 108
4.58 x 108
7.79 x 108
M (t) (Ibs)
ev
0
1.42 x 104
3.35 x 105
2.32 x 106
9.1 x 106
2.62 x 107
6.23 x 107
1.31 x 108
2.54 x 108
3.76 x 108
4.66 x 108
*Equation (2-13) is not actually valid for the post 1970 period, but if the
voluntary ban had not been imposed, the estimated M (1975) would have been as
recorded in Table 2.2.2-1.
D-ll
-------
Substitution of the appropriate forms of Q (t) and Q ' (t) and integration
s s
results in
M (t>44) =
ev
+ a'51(t-40) +
(l-a-3)6(t-Y2)4-39
4739
i* • 39
4.39
(2-14')
which, on introduction of the appropriate numerical values [note a' - 0.1, i.e.,
after 1970, the only use of PCBs was in the manufacture of electrical equipment
from which some 10 percent of the material used is discarded as scrap]; becomes
Mev(t>44) = 2.99 x 108 + 3.31 x 106 (t-40) + 44.1 (t-20)"'39 (2-15)
This latter Equation (2-15) has been used to compute the 1975, 1980 entries in
the fourth column of Table 2.2.2-1. By comparison of the last two entries in
Table 2.2.2-1, the direct effect of the voluntary ban in 1970 becomes obvious.
2.3 Mobile or Free Environmental PCBs, m (t)
2.3.1 General Considerations on Mobile PCBs
To consider the processes by which the general environmental
load of PCBs I M (t) 1 becomes free, i.e., the processes by which m (t) is
generated, it is necessary to consider that some fraction of the direct losses
are in a form such that the lost material immediately becomes mobile; i.e.,
spills and/or evaporation losses. Further, the non-mobile material is usually
encased or enclosed in some sort of container which will eventually be degraded
thus allowing the subsequent escape of the component PCB.
The fraction of the total sales that is waste occuring in all
production uses of PCBs is aQ (t) of which some fraction e is directly mobile.
o
D-12
-------
Thus, in the tine interval t to t + At, this component introduces an amount
eaQ (t)At (2-16)
s
into the free environmental pool. The remainder (l-e)aQ (t) which enters the
S
environmental reservoir is contained in a state such that the PCB content is
gradually released with a time constant TZ = 1/A2. Thus, within the reference
interval t to t + At, an amount
A (l-e)oQ (t)At (2-17)
2 S
enters the mobile pool.
Further, a fraction 3 of the yearly sales was used to manu-
facture long lived electrical components, assumed to have a useful life of yx
years, after which the components are scrapped. Thus, the contribution of this
source to the general environmental pool is
0 Qgtt-y^At (2-18)
The electrical containers in which the PCB is enclosed will eventually decay,
with a half life T = I/ A . The additional component entering the mobile res-
ervoir will be
A^ Qs(t-Y1)At (2-19)
Finally, the remainder (l-a-B)Q (t) was used in the construction of products
iD
assumed to have a useful life of y2 years, after which they are discarded, thus
contributing a component to the general environmental pool:
(1-a-B) Qs(t-Y2)At (2-20)
If it is further assumed that these products have a lifetime i2 - 1/A2 against
decay, then the contribution to the mobile environmental pool will be
A n-a-g) Q (t-yJAt (2-21)
D-13
-------
On combining Equations (2-16), (2-17), (2-15) and (2-21) , in
the limit At •> o, the differential equation for m (t) becomes
dm (t)
at = eoQs(t) + X2(l-e)oQs(t)
A2d-a-3)Qe;(t-Y9) (2-22)
9
£-
= [ea + X2(l-e)aJ
ea + X(l-e)a Qs(t) + X2(l-c g
but, from Equation (2-3), Q = 311t3'39 = 5t3'39
s
If the parametric values given in Table 2.3.1-1 are substituted
into Equation (2-22) , the equation becomes
r rt r
= 24.321 t3'39 dt + 6.53/ (t-4)3'39 dt + 1.93 /
J n J r-\ "^ r»
t
3.39
m (t) = 24.32 / t3'39 dt + 6.531 (t-4)3'39 dt + 1.93 / (t-20)J' " dt
o •'o
_ 24.32 .^. 39 6.53 ,, .^.39 . 1.93 ,. on> ^. 39
Tl?9" ^ + 4~lQ" (t-~^> + I~W ^~^u^
T: • _J_/ *i • >J_/ ri • Jv
Thus,
m (t) = 5.54t't'39 + 1.49(t-4)'t'39 + 0.44 (t-20) ^'39 (2-23)
The results computed from Equation (2-23) are tabulated in
Table 2.3.1-2
2.3.2 Effect of 1970 Ban on Mobile PCBs
It is now appropriate to discover the effect that the partial
ban established in 1970 can be expected to have on the mobile PCB load, m (t).
D-14
-------
TABLE 2.3.1-1
Parameter Values for Equation (2-22) and Equation (2-24)
a = 0.17
3 = 0.62
1-a-B =0.21
e = 0.40
1-e = 0.60
a' = 0.1
6 = 311
6' = 3.3
X ~ °'1' T2-i/2 = 6.9 years
2
\l = 0.01, T1_1/2 = 59 years
Y2 = 4 years Yx = 20 years
D-15
-------
The operative change occurs as a result of the substitution of Equation (2-6)
for Equation (2-3) in the time interval after 1970. The resulting expression
for m (t>40) is given as (recalling that the ban also stopped sales for non-
electrical applications):
m (t > 40) =
ev
eaS/ t3-39dt + ea'61/
•Jr^ * /->
dt + A2(l-e)a6
f 40
J t3>39dt
(t-Y2)dt
(2-24)
which, on integration and evaluation of the coefficients, becomes, using the
parametric values listed in Table 2.3.1-1,
m (t>45) = 7.59 x 107 + (0.44) (t-20)"'39 + 1.32 x 106 (t-40) . (2-241)
fci v
Numerical values derived from Equation (2-24l) are listed in column 4 of Table
2.3.2-1. Again, the effect of the voluntary partial ban of 1970-71 is apparent.
It will be useful in what follows to express the numerical
relationship given by Equation (2-24l) in the approximate empirical form
mev(t<40) = 4.83t't"5
m (t > 40) = 1.69 x 10bt
ev
64.1 • 0 2
(2-25)
2.4 Atmospheric Reservoir of PCBs, m (t)
a
Suppose that some fraction 6 of the instantaneous addition to the
mobile environmental material is vaporized. Then within the interval t to t + At
dm (t)
cl
~ dt
dt
At
D-16
-------
TABLE 2.3.2-1
Estimated Total Environmental PCB Load [M (t) ]
and Mobile Environmental PCB Load [m (t) ]
ev
Date
1930
1935
1940
1945
1950
1955
1960
1965
1970
1975
1980
1990
t
(years)
0
5
10
15
20
25
30
35
40
45
50
60
m (t) ^ m (t) corrv"'
evv ' ev
(Ibs) (Ibs)
0 0
6.49 x 103
1.40 x 105
8.62 x 105
3.14 x 106
8.54 x 106
1.89 x 107
3.86 x 107
7.01 x 107 7.01 x 107
1.19 x 108 8.31 x 107
1.90 x 108 9.04 x 10?
4.30 x 108 1.07 x 108
M (t) corrv '
ev
(Ibs)
0
1.42 x 104
3.35 x 105
2.32 x 106
9.1 x 106
2.62 x 107
6.23 x 107
1.31 x 108
2.54 x 108
3.76 x 108
4.66 x 108
8.41 x 108
Notes: (1) From Equation (2-23)
(2) From Equation (2-241)
(3) From Equation (2-15)
D-17
-------
Further, suppose that the material contained within the mobile pool is vaporized
with a time constant T 3 = l/\3, then the additional component of the atmospheric
reservoir is given by
dm (t)
Si
dt
= X3mev(t)
Finally, suppose that the lifetime, T^ = I./X , of the atmospheric reservoir
results in a decay of m (t) given as
dm (t)
d.
dt
= -\ ma(t)'
The total change in m (t) with time is then given as
a
dm (t)
a
dt
dm (t)
a.
~~dt
dm (t)
cl
dt
dm (t)
a.
~~dt
(2-26)
which on substitution of the appropriate expressions yields the differential
equation for m (t) as follows:
dm (t)
dm (t)
(2-27)
for which the general solution is
m (t) = e
a
dm (t)
ev
dt
(2-28)
After substitution from Equation (2-25a) and integrating by parts, the interim
result is
m (t) = 1^
a A,,
- 4.!
.5 3.5tz'
2 • 5
(3.5) (2.5) t!.5 _ (3.5) (2.5) (1.5) &-\t I to.se\tdt
(2-29)
D-18
-------
It now becomes important to evaluate the parameters, ^3, ,4, and 0
which appear in (2-29). First, it is noted that the cumulative total of material
entering the environment from 1930 to some time t is given by the sum
dt (2-30)
since the two terms in the integral are simply source terms. On substitution for
m (t) from Equation (2-25) and carrying out the integration, Equation (2-30)
becomes, after simplification,
t P X3 1
ma(t) = 4.83t"-5 e + __ t (Ibs) (2-31)
930 L J
1930
It is important at this point to indicate the essential difference
between Equation (2-29) and (2-31) . The latter, Equation (2-31) , represents
the cumulative FOB load to the atmosphere in the time from 1930 to the time
t > 1930. On the other hand, Equation (2-29) , which contains the time constant
for decay of the atmospheric PCB load, represents the instantaneous PCB load in
the atmosphere at time t.
To return to Equation (2-30) , Nisbet and Sarofim have estimated
that the cumulative load of vaporized PCB in the period 1930 through 1970 was
3 x 10 tons or 6 x 10 Ibs. If it is assumed that 6, the fraction of free PCB
directly vaporized, is 0.1, then Equation (2-31) may be used to evaluate AS as
follows :
19 7<> f 40A3 1
Y> (t) = 6 x 107 = 4.83(40)4'5 0.1 + ----
1930 a L D>D J
\3 = 0.0918 yrs"
and (T3)1/2 = 7.55 yrs. (2-311)
D-19
-------
In view of the results displayed in Equation (2-31 J) and with the
additional assumptions that A » A , A > 1, Equation (2-29) may be approxi-
4 o H
mated as
m_(t) = ~ t3'5 U»t + 4.56
(2-32)
By definition of a(t), the fallout,
a(t)A = Xum (t) - 4.83t3'5 JX t + 4.59
a f 3
where A = '8.66 + 1013 ft2 as the area of continental United States. Solving for
a(t),
a(t) =
4.83t3'5
A
3
At + 4.59 (2-33)
where upon, in 1974, a(t) = 1.06 x 10 Ihs/ft2/sec, (2-33) yields a value of
a(t = 1974) = 1.3 x 10~7 Ibs/ft2/yr.,
a result clearly not consistent with the known value. The obvious suggestion to
account for this discrepency is that the Nisbet value of the cumulative at-
mosphere load from 1930 through 1970 is incorrect. However, no conclusion as to
the reason for this can be reached at present.
2.4.1 Time Dependence of g(t) and of B(t)
From Equation (2- 33) and the known value of a (t) in 1974
(1.06 x 10~8 Ibs/ft2/yr), it is apparent that Equation (2-33) yields the correct
value if the term A3t « 4.50, so that, it is appropriate to take, where 6 = 0.1
o(t) = a0(t)t3'5 Ibs/ft2/yr (2-34)
and, since fallout constitutes the predominant PCB input source to Lake Michigan
(see Section 3), the forcing function B(t) will be taken to be of the form
B(t) - at3'5 (2-35)
D-20
-------
The coefficient a will be evaluated in terms of the specific application for
which Equation (2-35) is the driving function.
3.0 DERIVATION OF PHYSICAL CONSTANTS FOR LAKE MICHIGAN
/o\
3.1 General Properties '
From various atlas and other sources, for Lake Michigan
A - 2.24 x 104 mi2 = 6.24 x 1011 ft2 = area of lake.
S = 1.2 x 1014 Ibs/yr [6 x 10 ft3/sec in average flow
through Straits of Mackinac]
Q = 1.1 x 10 Ibs = total water mass in lake.
A1 = 5 x 104 m2 = 1.29 x 1012 ft2 (average drainage area)
3.2 Proportioning Constants
In order to determine the most appropriate values for the propor-
tionality constants, p*and r\, in the absence of a well-founded theoretical ex-
planation of the physical processes which determine them, it is necessary to
rely on in-situ measurements of concentration over wide regions of the target
water body to establish reasonable statistical reliability. Actually, such a
body of data does not exist for Lake Michigan at this time. On the other hand,
such data do exist for Lake Ontario which should allow at least a reasonable
estimate of the appropriate values for Lake Michigan.
3.2.1 Concentration Ratio of Biota to Water, r\
Sampling of Lake Ontario, conducted in 1972 at several near-
(9)
shore and mid-lake sites, indicated the following:
a. PCB in fish (alewives, smelt, slimy sculpin) = 2.35 - 5.13 x 10° ppt
b. PCB in water (total cone, dissolved + particulate) = 55 ppt
c. Average PCB in sediments = 1.2 x 10 ppt
d. Average PCB in wet plankton = 7.2 x 10 ppt
e. PCB in the benthos = 4.7 x 10 ppt
D-21
-------
In view of these data, it appears that a realistic value for
the constant n, considering the nature of the food chain, is
[n ~ 4 x 10"]
for Lake Ontario which, by inference, should also apply to Lake Michigan. It
should be noted that n is taken as an average concentration ratio over all mem-
bers of the biota; thus, there will be specific species showing considerable
variation from the assumed value.
Since the basic physical processes that account for this
partitioning of PCB-like materials should be independent of the actual concen-
tration of PCBs in the aqueous phase (so long as the aqueous solution is less
than saturated), it is reasonable to assume that n is independent of time.
3.2.2 Concentration Ratio of Sediment to Water, p
From a number of measurements of sediment levels within Lake
Michigan (24 sites) , ' an average PCB concentration of 38.2 ppb was calculated;
this is the presence of an average water concentration of 20 ppt. Since these
specific points were taken from the southern part of the lake, where the con-
tamination is known to be higher, an average value of p has been taken to be:
p = 2 x 103
The deposition rate for the lake, D, is(
D = 5.7 x 106 Ibs/mi2/yr
3.3 Biota Mass, G, for Lake Michigan
A representative value for the biomass in Lake Michigan, recognizing
the relatively limited data that are available on specific species and the ab-
sence of a detailed ecological pyramid, may be obtained from the estimates con-
tained in Table 3.3-1.
In addition, the relatively polluted nature of the southernmost por-
tion of the Lake results in large masses of benthic species, such as tubifex
D-22
-------
TABLE 3.3-1
Estimates of Biota Mass for Lake Michigan
Estimates for the Fish Mass
a. Lake trout (from Michigan waters of the Lake) - 11.2 x 106 Ih (1972)
b. Whitefish (in Northern Lake Michigan) - 55 x 10 Ib (1972)
c. Chubs (those available to bottom trawls) - 15 x 106 Ib (1973)
(note: decline in chubs from 139 x 10 Ib
in 1963-65)
d. Alewives (those available to bottom trawls +
Q
estimate of the midwater individuals) - 2 x 10 Ib (1973)
e. Coho Salmon (estimate based on the number stocked) - 7.6 x 10 Ib (1972)
Total - 2.1 x 109 Ib (1972-73)
Estimates for the Plankton Biomass:
a. Assume 300 kg plankton/hectare of lake
b. Area of Lake = 22,400 mi2 = 5.8 x 106 hectares
c. Plankton biomass = (5.8 x 106) (300 kg) = 1.74 x 1012g = 3.8 x 109 Ib
D-23
-------
worms. In view of this, it is assumed that the benthic biomass is of the order
of 4 x 109 Ibs.
Finally, in terms of the above, a representative value for the total
biotic mass, G, appears to be of the order of 1010 Ibs which, in view of its
approximate value, is taken to have been constant over the time interval of
interest.
3.4 Input Rate [B(t)] for the Period 1973-1974
The PCS inputs to Lake Michigan consist of three parts:
a. that due to fallout on the lake;
b. that due to fallout on the drainage area and subse-
quent extraction by ground waters; and
c. that due to point sources, industrial and sewage
treatment plants.
3.4.1 Point Source Inputs
Data on PCB concentrations are available only for eight of
the tributary streams in Michigan. In addition, historical data collections
seldom extend back beyond 1970-1972. These data, for the St. Joseph, Kalamazoo,
Grand, Muskegon, Marristee, Broadman, Elk and Portage Rivers indicate that,
during the recent period, the yearly load of PCBs from these rivers was about
1000 Ib/yr. Using these limited data on stream concentration due to industrial
and sewage treatment plants, the following estimates of yearly load can be
, (14)
made:
Michigan - 217.2 Ib/yr (1974, STPs)
Wisconsin - 1,150.0 Ib/yr (1974-75, paper plant effluents)
Wisconsin - 130.3 Ib/yr (1974-75, STPs)
Wisconsin - 20.1 Ib/yr (1974, misc. industry)
Indiana - 123.3 Ib/yr (1972, STPs)
Illinois - 3.1 Ib/yr (1971, STPs)
1,644.0 Ib/yr - 1.6 x 103 Ib/yr
D-24
-------
3.4.2 Fallout on Lake Michigan
A variety of fallout rate measurements have been reported^
indicating rates as high as 0.5 Ibs/mi2/yr = 87 yg/m2/yr in the heavily indus-
trialized portion of Sweden^ ' to the other extreme of 17.5 vg/m2/yr observed
in Iceland. In view of the rather heavy concentration of industry in the
Lake Michigan area, it will be assumed that the average fallout in the 1974 era
was 50 yg/m2/yr.
Thus, taking the area of the lake to be 5.8 x 10l° m2, the
annual fallout should be of the order of
B- ,, .,. ^ ~ 6.4 x 103lbs/yr in 1974.
fallout direct /jr
3.4.3 Fallout onto Drainage Basin
In order to compute the contribution of PCB input to the lake
due to fallout on the drainage basin, the separate contributions from each of
the adjourning states is computed in Table 3.4.3-1.
3.4.4 Total Input to Lake (1974)
From Table 3.4.3-1 and the data in Sections 3.4.1 and 3.4.2,
the contributions to the PCB input are taken to be:
Point sources 1.6 x 10 Ibs/yr
Lake fallout 6.4 x 103 Ibs/yr
Basin fallout 5.4 x 10 Ibs/yr (where it is assumed
that 50 percent of
basin fallout actually
enters the lake)(12)
6(1973-74) = 13.4 x 103 Ibs/yr
From Equation (2-35),
B(t) = at3'5
D-25
-------
TABLE 3.4.3-1
PCBs Inputs to Lake Michigan - 1974
(18)
a. For the Michigan portion of the drainage basin:
7 in? i ?
PCB load = (50 yg/m /yr)(6.0 x 1(TU nT) = 3 x 10 yg PCB/yr
= 6.6 x 103 UD PCB/yr
(19)
b. For the Wisconsin portion of the drainage basin: '
7 in 7 19
PCB load = (50 yg/m/yr)(3.7 x 10 u mz) = 1.9 x 10 yg PCB/yr
= 4.1 x 103 Ib PCB/yr
c. For the Illinois portion of the drainage basin:^ '
PCB load = (50 yg/m2/yr)(8.0 x 10 m2) = 4.0 x 1010 yg PCB/yr
= 88.1 Ib PCB/yr
(21)
d. For the Indiana portion of the drainage basin:
PCB load = (50 yg/m2/yr)(1.85 x 108 m2 = 9.3 x 109 yg PCB/yr
= 20.4 Ib PCB/yr
e. Total annual fallout from all four sectors of the basin:
= 1.08 x 104 Ub PCB/yr
D-26
-------
which for the reference year, 1974, was estimated to be
13.4 x 103 = a (44)3'5
a = .0237
so that, in what follows,
B(t) = 0.0237t3'5 (3-1)
4.0 APPLICATION OF THE MASS BALANCE EQUATION TO LAKE MICHIGAN
4.1 Physical and Hydrologic Constants for Lake Michigan
The values used for the various physical and hydrologic constants
(23)
for Lake Michigan are listed below:
11 2
A = surface area of the lake = 6.24 x 10 ft
14
S = outflow through Strait of Mackinac = 1.2 x 10 Ib/yr
Q = water mass in lake = 1.1 x 10 Ibs
2
D = sedim&nt deposition rate = 0.204 Ibs/ft yr
ri = biota/water concentration ratio = 4 x 10
p = sediment/water concentration ratio = 2 x 10
B (1974) = PCB input rate in 1974 = 1.34 x 104 Ibs
14
K = evaporation rate constant = 2.2 x 10 Ibs/yr
[this assumption will be discussed below]
Then, from the data above, the various factors appearing in Equation (1-9 M may
be evaluated as follows:
ADp = 2.25 x 101" Ibs/yr
Q + Gn = 1.14 x 1016 (Ibs), (Q + On)"1 = 8.77 x 10~17 (Ibs)
S + K + ADp = 5.7 x 10llf Ibs
X = S + K + ADp
Q + Gn
D-27
-------
4.2 Integration of the Mass Balance Equation
In terms of the parameters for the lake and the assumed form for
B(t) from Equation (3-1), the differential equation for C(t), Equation (1-9)
becomes:
C(tf) - 2.08 x l(f18 e t' e- dt (4-1)
o
where the PCB concentration is taken to be zero in 1930, i.e., at t = 0.
Equation (4-1) cannot be directly integrated in terms of simple
algebraic functions so that recourse must be had to numerical integration to
yield the results tabulated in Table 4.2-1.
For convenience in what follows, the relationship between C (tf)
and t will be assumed to be of the form:
cw(tf) = btn
where b, and n are determined by a least squares fit to the data in Table 4.2-1.
The results of this analysis may be summarized in the equation
C (t.) = 4.56 x 10~19t/'"16 (4-2)
w f r
From Equation (4-2) , the change in C (t) over a one-year period is found to be
Thus, for the reference year, 1974, the average water concentration was about
— 12
* 8 x 10 and the change in concentration during the reference year was
0.80 x 10 . From these data, it is possible to determine the material balance
during 1974 as is shown below:
D-28
-------
4
Total input 1.34 x 10 Ibs
Increase in solution 8.81 x 10 Ibs
Increase in biota 0.32 x 10 Ibs
Increase in sediinent 1.8 x 10 Ibs
Increase in outflow 0.96 x 10 Ibs
Net loss due to evaporation 1.52 x 10 Ibs
From Equation (1-6) , it is now possible to estimate the evaporation
rate constant K,
K = ^W = 1.52 x 103 _ l,
To discover the material balance over the entire period, 1930
through 1975, the total PCB input to the Lake is given by
r 45
Qinput =' B(t)dt = °-0237/ t3'5 dt
= 1.49 x 10s Uos (4-3)
The average concentration C (t) over the reference period is
w c
t 5
TT-TTT _ 4.56 x IP"19 . .4.416,,
Cw(t) 45 ' t dt
= 1.68 x
The cumulative loads in Lake Michigan in the various phases are
surttnarized below:
Total input (1930-1975) = 1.49 x 105 Ibs
Total in water = 1 x 10 Ibs
Total in biota = 3.64 x 103 Ibs
4
Total in sediments = 1.7 x 10 Ibs
Total in outflow = 9.07 x 103 Ibs
4
Net loss due to evaporation = 1.93 x 10 Ibs
D-29
-------
TABLE 4.2-1
Concentration of PCB in Solution in Lake Michigan*
Date tf Cw(tf) Cw(tf)(PPt)
1930 00 0
1935 5 4.94 x 10~16 4.94 x 10~14
1940 10 1.34 x 10~14 1.34 x 10~2
1950 20 2.79 x 10~13 0.28
1960 30 1.60 x 10~12 1.60
1965 35 2.92 x 10~12 2.92
1970 40 5.35 x 10~12 5.35
1975 45 9.10 x 10~12 9.10
*Maasurements in 1970 indicate a range of aqueous concentration of 1 to 7.5 ppt
D-30
-------
From the net loss of PCB due to evaporation frcm the above data,
and the defining equation for the evaporation losses, Equation (1-6), the evap-
oration rate constant K may be evaluated,
K = evaP = 1'93 x 10' = 2.56 x 1014 Ibs/yr (4-5)
The several values of K, from Equation (4-5) and the earlier value
determined from the 1974 situation, are averaged to yield a useful value
K = 2.2 x 1014 Ibs/yr (4-6)
4.3 Temporal Variation of Concentration of PCB in the Various Phases
of the Lake
It is now possible to combine the relationship expressed by
Equation (4-2) with the definition of the biotic concentration factor r\ from
Equation (1-2), to determine the variation of biotic concentration with time.
The data enumerated in Table 4.3-1 indicate the trends. When it is noted that
the concentration data in Table 4.3-1 are given in parts-per-trillion, it is
clear that the average biota concentration neared the one part-per-million level
on as early as 1965. It is also evident, because of the considerable spread in
specific biotic concentration factors for specific species, that the higher
predictors could easily have exceeded the one ppm level as early as 1960.
D-31
-------
TABLE 4.3-1
Temporal Variation of Biotic Concentration
w oiota
Date ippt) (ppt)
1930 0 0
1935 4.9 x 10~4 1.97
1940 1.34 x 10~2 5.36 x 102
1945 7.12 x 10~2 2.84 x 103
1950 0.28 1.12 x 104
1955 0.68 2.72 x 104
1960 1.60 6.4 x 104
1965 2.92 1.17 x 105
1970 5.35 2.14 x 105
1975 9.10 3.64 x 105
D-32
-------
4.4 Physical Interpretation of K, the Mass Evaporation Constant
4.4.1 Kinetic Theory
(24)
Experimental data on the evaporation rate of Aroclor 1254
indicates that, at 100°C (373°K) , the evaporation rate is 1.47 x 10~8 gm/cm2/sec
and the vapor pressure is 5 x 10 mm Hg. From elementary kinetic theory of
rat
1/2
(25)
gases, the relationship between evaporation rate and vapor pressure is given
m(gm/cm /sec) =
P (4-7)
12TTET
where 5 = the measure of the probability that a collision with the
surface does not result in the molecule sticking to the
surface
R = the gas constant per mole [8.31 x 10 erg (*K) ]
T = the absolute temperature t°K]
m = the molecular weight [gms]
2
P = the vapor pressure [dynes/cm ]
(24)
From Equation (4-7) anS the known evaporation rate, the numerical value of
6 may be computed as follows:
1/2
1.47 x 10-8 = 6 [ 325 1 5_xlO:2 x 1()e
[2u x 8.31 x 107 x 373J /bu
or 6 = 5.47 x 10~5 (4-8)
If it is assumed that 6 is not temperature dependent at
temperatures considerably removed from the normal boiling temperature, and that
Equation (4-7) may be applied to a solution as well as to the pure liquid, then
at ambient temperature (298°K) where the vapor pressure of Aroclor 1254 is
7.7 x 10~5 mm Hg,(24)
1/2
m(gm/cm2/sec) = 5.47 x 10~5 — 7'7 *J^ x 106
2rr x 8.3 x 107 x 298 /bu
or m = 2.53 x 10 gm/sec/cm
D-33
-------
Now the area of the lake is 5.8 x 10 1 ** cm2 , hence
m(lbs/year) = 2.08 x 10 14 (Ibs/yr) (4-9)
The value of m from Equation (4-9) is in excellent agreement with the value of K
empirically determined to be 2.2 x 10 14 Ihs/yr.
4.4.2 Application of the Theory of MacKay and Vtolkoff ( '
Following MacKay and Vtolkoff, the rate of material loss
for a slightly soluble solute from a water-air interface is given, for a system
wherein the solute concentration is less than the saturation concentration, by:
c ,4-10,
11 2
where: A = area of the lake surface (6.24 x 10 ft )
E = mass evaporation rate of water (1.38 x 10 lb/yr)^11'
P. = equilibrium vapor pressure of pure solute (7.7 x 10 mm Hg)' '
M. = molecular weight of solute (325-Aroclor 1254)
G1 = mass of water from which evaporation occurs
M = molecular weight of water (18)
w _o CY~I\
C. = saturation concentration of solute (6 x 10 )
is
P = equilibrium vapor pressure water (23.7 mm Hg)
C. = concentration of solute in the evaporation layer
1 3
p = density of water (62.5 Ibs/ft )
Equation (4-10) must be modified for the present situation to take into account
the effect of fallout on the solute concentration. Thus, for the case in point,
dC. ,,,, EP. M.
1 = g(t)A _ is i c (4-11)
~dt G' G'M P C. i ( '
w w is
D-34
-------
The expression a(t) which occurs in Equation (4-11) is taken
to be of the form [from Equation (2-34)]
a(t) = 1.67 x 10~lltt3'5 (4-12)
Further substitution of G1 = ApC, where £ is the thickness of the layer from
which evaporation is occur ing, and E = Apl', where 1 is the evaporation rate in
ft/year, reduces Equation (4-12) to the form
dC. , In~1't4-3-5 IP. M.
i _ 1.67 x 10 t _ is x . r4-i?
dt fp MP c. Cl (4 12
^p ^ w w is
which is now applicable to a unit area of the lake.
The solution of Equation (4-12J) is complicated by the fact
that £, the layer thickness, is unknown. To obtain some idea of the magnitude
of £, it is reasonable to assume that
Ci(t) = ^w^ (4~13)
where y may be a function of time. Substitution of Equation (4-13) and the
appropriate numerical values with Equation (4-12) and evaluating for t = 44
years (1974), yields [after using Equation (4-2) for C (t)]
— 10
-13 —1 0 Y 1 51 X 10
8.22 x 10 Y + 2.66 x 10 ± = * — (4-14)
IP. M.
Now, ^ = - 1f| ^— Y from the definition of K. Hence, from this last relation,
A cJYL ir w •
W W IS
evaluated at t = 44 years,
^ = 10.92 (4-15)
Substitution of (4-15) into (4-14) yields
Y = 0.57
(4-16)
C = 0.052 ft(28)
D-35
-------
It is apparent, from Equations (4-16) and (4-13) , that this analysis suggests
that the average concentration in the layer is less than that in the bulk water,
i.e., y < 1. The reason for this apparent anomaly can be seen by recognizing
that Equation (4-12) is in the form
<«-»>
= 617 yrs
W W IS
is the effective decay constant for the surface layer concentration. In terms
of the half-life
(T.) ~10 hours (4-17 l)
1 V2
Equation (4-17) may be integrated from a time t to t + I/A to
yield, where the interval is sufficiently short that a(t) may be assumed to be
constant ;
C. = 0.37 C. + 3.34 x 10~12 (4-18)
i 10
If the assumed relationship between C. and C , given by Equation (4-13) is
introduced as (C. = PCBs concentration at time t)
10
Co = ^Cio
then 3 14 x 10~12
y(l -r 0.37) = J-J4-X ±U
Y - 0.74 (4-19)
This shows good agreement with the results expressed in Equation (4-16) .
D-36
-------
5.0 RESULTS AND CONCLUSIONS
5.1 Results
Even though the model used is only first-order, it is apparently
able to describe the relative significance of the natural processes which control
the distribution of PCBs. The strong focus on fallout as the primary input
source of PCBs to Lake Michigan suggests the need for further study of the nature
of the processes by which PCBs become airborne and thus become part of the
available atmospheric reservoir.
The attempt to model the atmospheric reservoir of PCBs, discussed
in Section 2, yields results that indicate significantly greater cumulative at-
mospheric loads than the preliminary estimate, made by Nisbet and Sarofim, of
a cumulative atmospheric reservoir of 3 x 10 "* tons up to 1970. The estimate of
Nisbet and Sarofim leads to a half-life, from the model, for PCBs in the atmo-
spheric reservoir on the order of eight years. This value is considerably in
excess of the reported lifetime measurements, on the order of 20 to 40 days, for
(29)
atmospheric PCBs. However, the observation that significant levels of PCBs
are found in present snowfalls and in packed snow in Antarctica^ ' suggests that
the applicable half-life may indeed be considerably longer than 20 to 40 days.
It is suggested that further refinement of the environmental distri-
bution model presented in Section 2 will lead to a resolution of this apparent
discrepancy. This refinement will focus attention on the nature of the physical
processes involved in atmospheric transport of PCBs and may suggest methods of
reducing PCB fallout in the future.
The observation that evaporation and/or co-distillation seems to be
a significant process by which PCBs are returned to the atmosphere is of impor-
tance. It should be noted that the magnitude of the evaporation rate constant
necessary to achieve mass balance in Lake Michigan is in excellent agreement
with that computed from the simple kinetic theory of gases and also with that
computed from the theory of co-distillation discussed by MacKay and Wblkoff.
D-37
-------
The observation that the PCB input to Lake Michigan from point
sources seems to be a rather small part of the total input suggests that reduc-
tion of point source PCB effluents may only slowly correct the present problem.
5.2 Conclusions
The first-order mass balance model described herein seems useful
in describing the historical situation as it explicitly addresses the question
"How did we get here?". The model requires refinement before it can be used to
allow a reasonable estimate of future conditions. Significantly more detailed
data are required as to the temporal variation of inputs and concentrations as
well as on the interval transport processes by which localized concentrations
are smoothed and distributed over the whole body. While the present model seems
to deal very well with the situation that obtains during an interval of rising
aqueous concentrations, there seems to be little experimental or theoretical
guidance as to what will happen if, in the future, aqueous concentrations begin
to fall. It is not known whether the biota and the sediments will act as
reservoirs to return their PCB loads to the system. The processes, if any
exist, which will eventually remove or inactivate the PCBs already in the
lithosphere are not known.
The application of this model to the situation in Lake Michigan
seems successful. It will be of interest to apply it to regions which are more
complex or of larger scale.
5.3 Discussion of Results
With regard to Lake Michigan, the mass balance indicates that this
fresh water system (water, sediment, biota) serves as a significant sink for
PCBs; this must also apply to many other fresh water systems. In the case of
toxic metals, the oceans are generally recognized as an important ultimate sink,
but this may not be the case for PCBs.
/o/-\
The theory developed by MacKay and Wolkoff, as applied to Lake
Michigan conditions, yields a lifetime against (until) evaporation of about
D-38
-------
ten hours. For seawater, this lifetime is greatly reduced by Icwer solubility
of PCBs and higher evaporation rate, so that the calculated lifetime of PCBs
in seawater against evaporation may be as low as ten minutes.
Although attachment to organic and living material may well be a
factor, the above result indicates that PCBs tend to evaporate from salt water
much more quickly than from fresh water. Then, on this basis, the terrestrial
systems, such as fresh water lakes, forests, etc., must be regarded as partial
sinks for PCBs in fallout; the PCBs lost from these systems reenter the atmos-
phere via direct evaporation or transport by rivers to salt water from which
further evaporation occurs. New PCBs are added to the atmospheric load by direct
evaporation, through inadequate incineration processes, or via water from runoff,
industrial discharges, landfill leachate, etc.
D-39
-------
6.0 GLOSSARY OF SYMBOLS USED
A Surface area of reference body of water (ft2)
B(t) PCB injection rate with reference body of water (Ibs/yr)
C (t) Aqueous PCB concentration
D Sediment rate in reference body of water (Ib/ft2/yr)
G Mass of biota in reference body of water (Ibs)
K PCB evaporation rate constant (Ibs/yr)
M (t) Cumulative environmental PCB load (Ibs)
m (t) Cumulative free environmental PCB load (Ibs)
m (t) Instantaneous atmospheric reservoir of PCBs (Ibs)
a.
Q Mass of water in reference body of water (Ibs)
Q0,1_(t) Cumulative PCB sales for capacitor application (Ibs)
(—-cil_)
Q -,..-,(t) Cumulative PCB sales for electrical application (Ibs)
0 ^^(t) Cumulative PCB sales for production application (Ibs)
Q,es(t) Cumulative PCB sales for all applications (Ibs)
Q, (t) Cumulative PCB sales for transformer application (Ibs)
"Crans
S Water outflow rate from reference body of water (Ibs/yr)
t Time (yrs), (t = 0 in 1930)
a Fraction of PCB sales directly lost to the environment
3 Fraction of PCB sales devoted to electrical applications
,Y1 Average in-service life of electrical components (yrs)
Y2 Average in-service life of non-electrical products (yrs)
e Fraction of production waste initially free
9 Fraction of initially free PCBs that are vaporized
D-40
-------
Xj Decay constant for discarded PCB-containing electrical
components (yr~l)
\ Decay constant for discarded PCB-containing non-electrical
2 products (yr""1)
A Decay constant for vaporization of free PCBs (yr""1)
X Decay constant for fallout of atmospheric PCBs (yr"1)
4
n Ratio of biota PCB concentration to aqueous PCB concentration
p Ratio of sediment PCB concentration to aqueous PCB concentration
a(t) Fallout rate per unit area (Ibs/ft2/yr)
T Half-life of containment of discarded PCB-containing electrical
components (yr)
T Half-life of containment of discarded PCB-containing non-
electrical components (yr)
T Half-life of free PCBs for vaporization (yr)
T Half-life of atmospheric PCBs against evaporation (yr)
D-41
-------
7.0 BIBLIOGRAPHY
The literature resulting from analytical measurements on a wide variety
of biological and geological specimens has become very large. The following
list, while in no sense complete, represents those sources used in this work.
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Can., 30, 595, 1973.
Anonymous, "Chemicals Found in Lake Fish: State PCB Ban Urged." Michigan
Out-of-Doors, July, 1975.
Bailey, S., P.J. Buryan, and F.B. Fishwick. Chemistry and Industry 22:
705, 1970.
Bowes, G.W. and C. Jonkel, in PCB in the Environment, Marcel Dekker Inc.,
New York, 1974.
Carey, A.E., G.B. Weirsma, H. Tai, and W.G. Mitchell. Pesticides
Monitoring Journal 6(4): 369-376, 1973.
Crump-Weisner, H.J., H.R. Feltz, and M.L. Yates. Pesticides Monitoring
Journal 8(3): 157-161, 1974.
Doguchi, M., New Methods in Environmental Chemistry and Toxicology.
Proceedings of the International Symposium, Susono, Japan, 1973;
Coulston, F., Korte, F., and Goto, M., Eds., International Academic
Printing Co., Tokyo, Japan, 1973.
Duke, T.W., J.I. Lowe, and A.J. Wilson, Jr. Bulletin of Environmental
Contamination and Toxicology; 5(2): 171-180, 1970.
Edwards, R. "Polychlorinated Biphenyls, Their Occurence and Significance:
A Review." Chemistry and Industry (No Volume) Issue 47: 1340-8
(21 November, 71), 1971.
Fog, M., and I. Kraul, Acta Vet. Scand., 14, 350, 1973.
Frank, R., K. Ronald, and H.E. Braun, J. Fish Res. Board Can., 30, 1053,
1973.
Giam, C.S., M.K. Wong, A.R. Hanks, and W.M. Sackett, Bull. Environ.
Contam. Toxicol., 9, 376, 1973.
Greichus, Y.A., A. Greichus, and R.J. Emerick, Bull. Environ. Contam.
Toxicol., 9, 321, 1973.
Gustafson, C.G., Environmental Science and Technology 4(10): 814-819,
1970.
Harvey, G.R., H.P. Mlklas, V.T. Bowen, and W.G. Steinhauer. Journal of
Marine Research 32(2): 103-118, 1974.
D-42
-------
Heppleston, P.B., Mar. Pollut. Bull., 4, 44, 1973.
Hidaka, K., T. Ohe, and K. Fujiwara, Shokuhin Eiseigaku Zasshi, 13, 523,
1972: C.A., 79, 028100, 1973. '
Huschenbeth, E., Schr. Ver. Wasser-, Boden-, Lufthyg., Berlin-Dahl, 37,
103, 1972.
Hem, W., R.W. Risebrough, A. Soutar, and D.R. Young. Science 184 (4142).
Interdepartmental Task Force on PCBs. "Polychlorinated Biphenyls and the
Environment." COM-72-10419. 1-192. National Technical Information Service,
Springfield, Virginia (U.S. Dept. of Agriculture, Commerce, Health-Education
and Welfare, EPA, and other agencies), 1972.
Lunde, G., J. Gerber, and B. Josefsson. Bulletin of Environmental
Contamination and Toxicology 13(6): 656-661, 1975.
Law, L.M., and D.P. Oberlitz. Pesticides Monitoring Journal 8(1): 33-36,
1974.
Martell, J.M., D.A. Rickert, and F.R. Siegel. Environmental Science and
Technology, 9: 872-75, 1974.
Oloffs, P.C., L.J. Albright, and S.Y. Szeto. Canadian Journal of
Microbiology 18(9): 1393-1398, 1972.
Oloffs, P.C., L.J. Albright, S.Y. Szeto, and J. Lau. Journal of Fisheries
Research Board of Canada, 30(11): 1619-1623.
Panel on Hazardous Trace Substances. "Polychlorinated Biphenyls-
Environmental Impact." Environmental Research 5(3): 249-362. 1972.
Peel, D.A., Nature, 254: 324-325, 1975.
Risebrough, R.W., P. Reiche, D.B. Peakall, S.G. Harman, and M.N. Kirven,
Nature (12/14): 1098-1102, 1968.
Risebrough, R.W., and B. deLappe. Environmental Health Perspectives
Exp 1: 39-45, 1972. :
Saschenbrecker, P.W., Can. J. Comp. Med., 37, 203, 1973.
Smith, W.E., K. Funk, and M.E. Zabik, J. Fish. Res. Board Can., 30, 702,
1973.
Walker, W.H., "Where Have All the Toxic Chemicals Gone?" Ground Water
11(2): 11-20, 1973.
2. Monsanto Industrial Chemicals Company, "PCB Manufacture and Sales-Monsanto
Industrial Chemicals Company - 1957 thru 1964." (unpublished data), 1974a.
Monsanto Industrial Chemicals Company, "PCB Manufacture and Sales-Monsanto
Industrial Chemicals Company - 1965 thru 1974." (unpublished data), 1974b.
D-43
-------
3. Ruopp, D.J. and V.J. DeCarlo, U.S. Environmental Protection Agency,
Washington, D.C. - Private cormunication.
4. Nisbet, C.T. and A.F. Sarofim, Environmental Health Perspectives, Exp 1,
21-38, 1972.
5. Section V, "Industrial Characterization" and Section IX, "PCBs Release
and Cumulative Environmental Loads" of this report.
6. Section V, "Industrial Characterization" and Section IX, "PCBs Release
and Cumulative Environmental Loads" of this report.
7. Nisbet, C.T., and A.F. Sarofim. Environmental Health Perspectives Exp 1:
21-38, 1972.
8. Annon., World Almanac, Washington Star News, Washington, D.C., 1975.
9. National Water Quality Inventory. Report to the Congress. Vol II.
EPA-440/9-74-001. Office of Water Planning and Standards. Appendices
C-l to C-69, D-l to D-55, E-l to E-76., 1974.
International Joint Commission on the Great Lakes. Pollution of Lake Erie,
Lake Ontario and the International Section of the St. Lawrence River,
Vol 3, 1969.
10. Hesse, J.L. Status Report on Polychlorinated Biphenyls in Michigan Waters.
Report to Michigan Water Resources Commission., 1973.
11. Annon, World Almanac, Washington Star News, Washington, D.C., 1975.
12. Great Lakes Fisheries. Summary of United States and Canadian Landings
(Preliminary Data)., 1974.
Michigan Department of Natural Resources Fisheries Division, Estimates of
Biomass of Principal Fish Species in the Great Lakes (first report).
Fisheries Research Report No. 1813., 1974.
13. State of Michigan Water Resources Commission, Bureau of Water Management.
Polychlorinated Biphenyl Survey of the Kalamazoo River and Portage Creek
in the Vicinity of the City of Kalamazoo, 1972.
State of Michigan Water Resources Commission, Bureau of Water Management.
Monitoring for Polychlorinated Biphenyls in the Aquatic Environment.
Report to Lake Michigan Toxic Substances Committee, May, 1973.
Haile, C.L., G.D. Veith, G.F. Lee, and W.C. Boyle, Chlorinated Hydrocarbons
in the Lake Ontario Ecosystem., 1975.
14. Veith, G.D. Environmental Health Perspectives Exp 1: 51-54, 1972.
D-44
-------
Veith, G.D., and G.F. Lee. Water Research 5(11): 1107-1115, 1971.
Schmidt, T.T., R.W. Risebrough, and F. Gress. Bulletin of^Environmental
Contamination and Toxicology 6: 235-243, 1971.
15. Panel on Hazardous Trace Substances. Environ. Res., 5, 1972.
16. Bengston, S.A., Ambio, ^ No. 2, p. 84, 1974.
17. Revenue, A., J.M. Ogata, and J.W. Hylin. Bulletin of Environmental Con-
tamination and Toxicology 8(4) : 238-241, 197T.
Bidleman, T.F., and C.E. Olney. Science 183 (4142): 516-518. 2nd Copy,
1974.
Bidleman, T.F., and C.E. Olney. Bulletin of Environmental Contamination
and Toxicology 11(5): 442-450, 13W.
Harvey, G.R., and W.F. Steinhauer. Atmospheric Environment 8(8); 777-782,
1974.
Holden, A.V. Nature 228(12/19); 1220-1221, 1970.
Sodergren, A. Nature 236: 395-397, 1972.
Tarrant, K.R., and J.O.G. Tatton. Nature 219: 725-727, 1968.
18. United States Geological Survey. Water Resources Data for Michigan.
Part 1. Surface Water_jRecords, 1974. ~~ ~~
19. United States Geological Survey. Water Resources Data fpr_Wisconsin.
Parti. Surface Water Records, 1974. " " "~" ~' ' ~~
20. United States Geological Survey. Water Resources Data for Illinois.
Part 1. Surface Water_jtecords, 1974. ~~ "
21. United States Geological Survey. Water Resources Data for Indiana.
Part 1. Surface Water Records, 197T:
22. Ruttner, F., Fundamentals of Limnology. University of Toronto
Press., 1952.
23. Saylor, J.H., and P.W. Sloss . Water Volume Transport and Oscillatory
Current Flow through the Straits of Mackinac. (Contribution No. 38,
Great Lakes EnvironnEntal Research Laboratory)., 1975.
24. Hutzinger, O., S. Safe, and V. Zikto. "The Chemistry of PCBs."
CRC Press, Cleveland, Ohio, 1974.
25. Kennard, E.H., "Kinetic Theory of Gases", McGraw-Hill, N.Y., 1938.
Langmuir, "Phenomena, Atoms and Molecules", Philosophical Library, N.Y.
Chapt. 15., 1950.
D-45
-------
26. Mackay, D., and A.W. Wolkoff. Environmental Science and Technology
7(7): 611-614, 1973.
27. Haque, R., and D.W. Schmedding. Bulletin of Environmental Contamination
and Toxicology 14; 13-18, 1975.
Haque, R., D.W. Schmedding, and V.H. Freed. Environmental Science and
Technology 8 (2); 139-142, 1974.
Wallnofer, P.R. , M. Koniger, and 0. Hutzinger. Analabs, Inc. Research
Notes 13(3): 14-16, 1973.
28. Duce, R.A., J.G. Quinn, C.E. Olney, S.R. Piotrowicz, B.J. Ray, and
T.L. Wade. Science 176(4031); 161-163, 1972.
29. Sodergren, A., Nature 236: 395-397, 1972.
Risebrough, R.W., et al; Nature (12/14), 1098-1102, 1968.
Harvey, G.R., et al; J. Marine Research 32(2): 103-118, 1974.
Harvey, G.R., and W.G. Steinhauer, Atmospheric Environment, 8(8): 777-782,
1974.
30. Peel, D.A., Nature 254(3/27): 324-325, 1975.
D-46
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APPENDIX E
BACKGROUND DATA USED TO CONSTRUCT
THE MDDEL FOR PCBs IN LAKE MICHIGAN
Table E-l
Concentration of PCBs in Sediments
Along the Southwestern Shore of Lake Michigan (1970-1971)
(1)
Sample Locations
Along SW shore of lake;
sampling 1-3 mi. off-shore*
(see Figure E-l).
PCBs (ppb)
13.09 A
6.73 A
11.81 ?
26.07 A
87.89 A
130.27 ?
26.61 B
64.32 A
3.72 A
3.87 A
35.8 A
8.31 A
15.24 B
16.09 ?
12.69 ?
23.53 A
17.53 A
36.7 ?
58.81 A
41.06 A
132.61 A
80.63 ?
29.29 A
13.34 A
Total = 896.01
Ave. [PCB] = 37.3
NOTE: Estimated location of sampling sites with respect to
thermocline: A - above thermocline
B - below thermocline
? - questionable
* Sampling sites are located in an area with several known STP discharges.
Data were not available on PCB concentrations in these STP effluents; how-
ever, judging from PCB data for other area STPs, it is probable that these
plants discharge PCBs, thereby producing higher concentrations in the
adjacent sedimsnts.
E-l
-------
___
Illinois
Kel logg Croek .1
Bull Creek \?,z. I
Oo«d River,
Unnamed Chr.nncL,
. 2 13.34-
HSSD Waukegnn STP
10
Waukogan River ' « 5
S'05'.
. USSO Horth Chicago STP
Scal(J ,„„,,,„
Pcttlbono Creeb
S.8a %
Ravine Park Ravine,
8 41. 06
NSSD Lake Bluff STP 58.81
LAKE II I CHI CAN
Woodland Drive Ravine
ferry Hall School Ravine
Stone Gate Lane Ravine
11.22 Barat fiavhio'V '
STP I ?. 5 3
.18
. . .
Park Avc. Ravlne*l\,NSSD Highland Park @ Park Ave . STP 25.
. 3 8 Ravine Drive Ravine A.USSO Hkhlnnd Park f? Ravine Dr. STP
Cary Ave. RavlneX »2l I 5. ,2-V
C_pun_t^ ________ ^Oi-^l-ii^- - IJSSD Highland Park 6 Cary Ave. STP
Cook County
• 60 13. OS
FIQTRF, E-l. IDCATICNS OF SEDIMENT SAMPLING STATIONS
PCBs in sediments of Lake Michigan & Tributary streams,
ravines sediments.
E-2
-------
Table E-2
Concentration of PCBs in Michigan Streams
Tributary to
PCB
ppb; mean 1971-72)
0.013
0.065
0.041
0.010
0.014
0.017
0.012
0.47*
Lake Michigan (2/3'4)
Stream
Discharge (1974)
(CFS) (MGD)
4,204 2,716
2,162 1,397
5,814 3,756
2,489 1,608
2,047 1,322
187 121
575 371
18 12
Ib/day
0.29
0.75
1.28
0.13
0.15
0.02
0.04
0.045
PCBs
105.9
275.1
466.5
47.5
54.8
7.3
14.6
16.5
Stream
St. Joseph
Kalamazoo
Grand
Muskegon
Manistee
Boardman
Elk
Portage
TOTAL 17,478 11,291 988.2
*One-tinne measurement taken in 1972.
E-3
-------
Table E-3
PCBs Entering Lake Michigan From
Known Industrial and STP Discharges*
State PCB Load (Ib/yr) Source
Michigan 217.2 STPs
Wisconsin 1170.1 Industries
Wisconsin 130.3 STPs
Indiana 122.3 STPs
Illinois 3.1 STPs
Total 1643
*See Tables E-4 - E-9 for tabulations of the individual waste discharges.
E-4
-------
TABLE E-4
Concentration of PCBs in Reported
Mi chicr an
STP location
Albion
Battle Creek
Benton Harbon,
St. Joseph Plant
Menominee
Muskegon
Niles
Portage
East Lansing
Escanaba
Holland
Jackson
Kalamazoo
Lansing
STP Effluents Tributary
Design Flow
(MGD, 1974)
4.0
22.0
13.0
1.2
10.0
10.0
3.6
8.5
2.2
4.5
20.0
34.0
34.0
to Lake Michicranu' ' ' ;
[PCB]
(ppb, 1971-72)
0.44
0.39
0.65
0.35
0.28
0.68
1.9
0.5
0.29
0.6
<0.1
0.66
0.18
PCB Load
(Ib/day)
0.015
0.017
0.070
0.004
0.023
0.056
0.057
0.035
0.005
0.022
0.186
0.051
Total
147.0*
0.595*
PCB Load = 0.595 Ib/day = 217.2 Ib/yr.
* Total does not include flows with [PCB] <0.1 ppb.
E-5
-------
TABLE E-5
Gonoentration of PCBs in Reported Wisconsin ,,..
Paper Plant Effluents Discharging to Green Bay (1974-75)
PCB Load
Plant Flow (mgd) [PCB] (ppb) (Ib/day)
3ac3ger Paper Mills 4.78 <.l
3cott Paper
Marinette 5.91 <.l
Oconto Falls 11.03 <.l
Shawano Paper 2.43 <.l
John Strange Paper 1.11 4.00 0.037
Bergstron Paper 5.22 28.40 1.26
Kimberly Clark 4.30 0.28 0.010
Thilmany Paper 25.1 <.l
Fort Howard Paper
Mill Effluent 7.3 2.60 0.158
Deinking 11.04 6.40 0.586
Deinking & Mill Effluent 18.1 7.07 1.06
Anerican Can
Sulfite Sewer 2.23 0.1
Paper Mill Lagoon 10.35 0.14
Charmin Paper 16.3 0.14
Green Bay Packaging 1.77 0.45
Total* 77.65 3.15
PCB load =3.15 Ib/day - 1,150 Ib/yr.
* Total does not include flows with [PCB] <0.1 ppb.
E-6
-------
TABLE E-6
Concentration of PCBs in Reported Wisconsin
Miscellaneous Industrial Effluents Discharged to Lake Michigan
(5)
Plant
Motor Casting Co.
Grey Iron Foundry, Inc.
Hownett, Corp. - Crucible Steel
Maynard Steel Casting Corp.
Milwaukee Solvay Coke Co.
Briggs & Stratton
Wehr Steel Co.
EST Co.
Milwaukee Die Casting Co.
Meta-Mold Daton Malleable Inc.
Babcock & Wilcox Co.
Tubular Products Div.
Total**
Flow (mgd)
0.22
0.339
0.796
0.133
4.3
1.523
0.228
0.069
0.012*
0.033*
[PCB] (ppb)
<0.2
PCB Load
(Ib/day)
<0.2
<0.1
2.95
32.2
170.3
0.9
0.001
0.003
0.047
PCB load - 0.055 Ib/day =20.1 Ib/yr.
* Average of two readings.
** Total does not include flows with [PCB]<0.1 ppb.
E-7
-------
TABLE E-7
Concentration of PCBs in Reported Wisconsin
STP Effluents Discharged to Green Bay (1974-75)
(5)
STP Location
Marinette
Portage
Oshkosh
Neenak-Menash
Appleton
Kaukauna
DePere
Green Bay
Kewaunee
Two Rivers
Manitowoc
Sheboygan
Port Washington
Milwaukee (South Shore)
Milwaukee (S. Milwaukee)
Racine
Kenosha
Total
low (mgd)
2.5
0.736
8.49
12.75
11.05
1.25
23.45
30.64
0.315
2.28
9.3
11.04
1.59
66.7
2.42
16.92
18.88
[PCB] (ppb)
<0.1
5.0
0.1
0.16
0.12
<0.1
0.5
<0.1
0.18
0.2
<0.1
1.1
0.2
0.29
0.12
<0.1
<0.1
PCB Load
(Ib/day)
0.031
0.007
0.017
0.011
0.01
0.001
0.004
0.11
0.003
0.160
0.003
119.8*
0.357*
PCB load = 0.357 Ib/day = 130.3 Ib/yr.
* Totcu, dees not include flows with [PCB]<0.1 ppb.
E-8
-------
TABLE E-8
Concentration of PCBs in Reported Indiana
STP Location
Michigan City
Valparaiso
Hobart
Hammond
East Chicago
Chestertown
Gary
South Bend
Mishawaka
Elkhart
Goshen
Nappanee
Kendallville
La Grange
Ligonier
Angola
Syracuse
Total*
STP Effluents Tributary to
Flow (mgd)
12.2
4.0
2.9
42.6
18.7
1.6
50.5
35.8
10.39
17.5
4.8
0.9
1.2
0.185
0.434
0.784
0.305
Lake Michigan
[PCB] (ppb)
1.32
0.24
0.23
<0.1
0.1
<0.1
0.38
<0.1
0.13
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
0.17
0.13
PCB Load
0.134
0.008
0.006
0.016
0.159
0.011
99.8
0.001
0.0003
0.335
PCB load = 0.335 Ib/day = 122.3 Ib/yr.
* Total does not include flows with [PCBl<0.1 ppb.
E-9
-------
TABLE E-9
Concentration of PCBs in Reported ,.,,
Illinois STP Effluents Discharging to Lake Michigan
PCB Load
STP Location Flow (mdg) * [PCB1 (ppb) ** (Ib/day)
N.S.S.D., Waukegan 0.002 2.635 .00004
N.S.S.D., North Chicago Plant 1.2 0.831 .0083
Total 1.202 0.00834
PCB Load = 8.34 x 10~3 Ib/day = 3.04 Ib/yr.
* Data for 1975
** Data for 1971
E-10
-------
TABLE E-10
Lake Michigan Basin Hydrology (7'8'9'10'i:L)
Total mean river discharge (1974) of the 4 states (Michigan, Illinois,
Wisconsin, and Indiana) into Lake Michigan ~ 34,508 cfs
= 1.1 x 1012 cf/yr
Total flow of water in the basin =9.4 billion gpd
Flow diverted from Lake to Chicago = 2 billion gpd
Flow diverted through Straits of Mackinac = 67,000 cfs
Other withdrawl's from the Lake =11.7 mgd
Volume of STP effluents entering Lake:
from Illinois =27.6 mgd
from Indiana - 110.5 mgd
from Michigan = 161.6 mgd
from Wisconsin = 183.4 mgd
E-ll
-------
TABLE E-ll
CL2)
Estimates of Fish Bionass in Lake Michigan (1972-73) ^ '
Michigan Waters of Lake Michigan - 11.2 x 10 Ib. of lake trout
(age group II & older); 1972
Northern Lake Michigan - 55 x 10 Ib. of whitefish
(age groups I-VI); 1972
From bottom trawls of the Lake - 220 x 10 Ib. of alewife
(age groups I & over); 1973
- 15 x 106 Ib. of chubs
(age groups I & over); 1973
Total (1972-73) - 3x 108 Ib.
9
If midwater alewives are included, the total could be in the range of 2.3 x 10 Ib.
E-12
-------
BackgroundCalculations Used to
Construct the Model for PCBs in Lake Michigan
The concentration and total weight of PCBs in Lake Michigan at the present
was calculated on the basis of PCB input to the lake from the following sources:
1) atmospheric fallout directly on the lake, 2) atmospheric fallout over the
drainage basin of the lake, and 3) documented point source discharges from
tributary industries and sewage treatment plants (STPs). The derived concen-
tration in the water of 0.078 ppb PCB (or 8.4 x 10 Ib.) represents the expected
maximum amount of the chemical in the water, assuming a constant annual input
PCBs over the past 40 years, and no loss of PCB from the lake.
A. Estimation of PCBs in the Lake Water Phase.
1. PCB load from atmospheric fallout directly on the lake surface:
area of lake = 22,400 mi2 = 5.8 x 1010 m2 (13)
Assume that the atmospheric fallout of PCBs has a constant annual
p
rate of 50 mg/m /yr., that PCBs are evenly distributed across the
lake surface, and that the total accumulation over the past 40 years
represents the present load;
then the annual PCB fallout on the lake = (50 mg/m2/yr)
(5.8 x 1010 m2)
= 2.9 x 1012 yg/yr.
= 6.4 x 10 Ib/yr of PCB
The total fallout on the lake after
40 yrs = 2.6 x 105 Ih. of PCB.
2. PCB load from atmospheric fallout on the lake drainage basin:
2
Assume that fallout (at a constant annual rate of 50 yg PCB/m /yr)
over the basin contributes the majority of the PCBs to the lake via
runoff, and that all of the PCBs falling on the drainage basin
eventually enter the lake,
2
then the annual PCB load = (50 yg/m /yr)(area of drainage basin)
For the Michigan portion of the drainage basin -
? in? 12
PCB load = (50 yg/m /yr)(6.0 x 10 m ) = 3 x 10 yg PCB/yr
= 6.6 x 103 Ib PCB/yr
E-13
-------
(8}
For the Wisconsin portion of the drainage basin -
PCB load = (50 yg/m2/yr)(3.7 x 1010 m2) - 1.9 x 1012 yg PCB/yr
= 4.1 x 103 Ib PCB/yr
(9)
For the Illinois portion of the drainage basin -
9 o o in
PCB load = (50 ug/m /yr)(8 x 10 in ) = 4 x 10 yg PCB/yr
= 88.1 Ib PCB/yr
For the Indiana portion of the drainage basin -
PCB load = (50 yg/m2/yr)(1.85 x 108 m2) = 9.3 x 109 yg PCB/yr
= 20.4 Ib PCB/yr
Total annual PCB fallout from all four sectors of the basin =
1.08 x 10 Ib/yr and total fallout on the basin after 40 yrs =
(1.08 x 104 UD/yr)(40) = 4.3 x 105 Ib PCB.
3. Total annual PCB load in the lake due to fallout = PCB load from
drainage basin + PCB load from lake surface
= 1.08 x 104 Ib/yr + 0.64 x 104 Ib/yr
= 1.7 x 104 Ib PCB/yr
4. Total fallout load of PCB after 40 years = (1.7 x 104 Ib/yr)(40 yrs) =
6.9 x 105 Ib PCB
5. PCB load entering the lake via tributary stream discharges:
Assume that the concentration of PCBs in the streams has remained
constant over the past 40 years, with an annual PCB load equivalent to
that in the most recently recorded data.
Data on PCB concentrations are available only for eight tributary
streams from the state of Michigan (see Table 2). PCB measurements
along the St. Joseph, Kalamazoo, Grand, Maskegon, Manistee, Boardman,
Elk, and Portage Rivers indicate a total of 988.2 Ib PCB/yr. 2'3'4^
E-14
-------
6. PCB load entering the lake from reported industrial and STP discharges:
Assume that the concentration of PCBs in the industrial and STP
effluents has remained constant over the past 40 years, with an annual
PCB load equivalent to that in the most recently recorded data, and
that all the PCBs in the discharges eventually enter the lake.
The annual PCB load from the four tributary states is as follows:
(see Tables 4-9):(2'3'4)
Michigan - 217.2 Ih PCB/yr (from STPs)
Wisconsin - 1150.0 Ib PCB/yr (from paper plant effluents)
- 130.0 Ib PCB/yr (from STPs)
20.1 Ib PCB/yr (from misc. industry)
Indiana - 123.3 Ib PCB/yr (from STPs)
Indiana 3.1 Ib PCB/yr (from STPs)
TOTAL - 1644.0 UD PCB/yr = 1.6 x 103 Ib/yr
7. The total PCB load in the water phase from all the above sources
4
(i.e., fallout, industry, STPs, Michigan streams) = 1.98 x 10 Ih/yr.
= 7.9 x 10 Ib PCB after 40 years of constant accumulation at this
annual rate.
8. Concentration of PCBs in the lake water phase:
Calculation based on the lake water volume = 4.91 x 10 1.
Annual concentration of PCBs =
(1.98 x 104 Ib PCB/yr)(454 x 105 ug/lg) = 0.002 ppb/yr-
4.9 x 1015 1
Total maximum concentration of PCBs at present (after 40 years of
constant accumulation) =
(7.9 x 105 Ib PCB) (454 x IP* _y.g/flb) = 0.073 ppb PCB
4.91 x 1015 1
E-15
-------
9. The above calculations estimate PCB fallout over the drainage basin
based on the size of the drainage areas as computed from USGS stream
10 2
flow data, and totaling 9.8 x 10 m . These data were obtained from
flow gaging stations, which were not all located at the mouths of the
tributary streams; therefore, the calculated size of the drainage basin
may be underestimated.
As an alternative to the above, the same calculations were per-
il 2
formed, but using a value of 1.76 x 10 m for the area of the
drainage basin (this area was estimated by the Lake Michigan Federation.
Then, the annual PCB fallout over the basin =
76_
^6
(50 yg PCB/m2/yr)(1.76 x 1Q11 m2)
454 x 10
4
= 1.9 x 10 Ib PCB/yr.
After 40 years of constant accumulation at this rate, PCB load =
7.6 x 105 Ib PCB (from fallout)
For this larger basin, the total PCBs in the water phase (i.e.
fallout + industrial & STP discharges)
= 1.9 x 104 Ib/yr + 0.16 x 104 Ib/yr
= 2.1 x 104 Ib/yr of PCB
After 40 years of constant accumulation at this rate, the PCB
load would be 8.4 x 105 Ib.
The PCB concentration in the water phase is:
on an annual basis = (2.1 x 10 ) (454 x 10 ) = 0.002 ppb
4.91 x 1015 1
After 40 years of constant accumulation at this rate =
(8.4 x 105)(454 x 106) = 0.078 ppb
4.91 x 1015 1
E-16
-------
B. Estimates of PCB Transport in Lake Ontario, with Application to Lake
Michigan.
Sufficient data were not available for Lake Michigan to determine the
relationship of PCB concentrations between the water, sediment, and biotic
phases. Adequate data were available to determine this relationship for Lake
Ontario, and due to the similarities between the two lakes, the calculations
were then used to estimate the present situation in Lake Michigan.
1. Sampling of Lake Ontario, conducted in 1972 at several near-shore and
mid-lake sites, indicated the following: '
PCB in fish (alewives, smelt, slimy sculpin) = 2.35 - 5.13 x 10 ppt.
PCB in water (total concentration dissolved + particulate) = 55 ppt.
Average PCB in sedircents - 1.2 x 10 ppt.
Average PCB in net plankton = 7.2 x 10 ppt.
Average PCB in benthos = 4.71 x 10 ppt.
It was assumed that these concentrations are the result of PCB accumu-
lations at a constant rate for the past 40 years.
*
2. Determination of the rate of PCB deposition in the sediments:
The average sedimentation rate of Lake Ontario is 1.2 mm/yr (as
compared to a rate of 1.0 mm/yr for Lake Michigan.
Therefore, the thickness of sediment today in Lake Ontario, after
40 years of deposition = 48 ram.
At this constant rate of deposition, PCBs accumulate in the
sediments at a rate = 1.2 x 10 ppt PCB/40 yrs = 2.5 x 10 ppt PCB/
48 mm sediment/40 yrs sediment
= 3 x 103 ppt PCB/yr.
3. Annual accumulation of PCBs in the biota =
PCB + PCB +
fish Plankton
(3)(40 yrs)
= (5.13 x 106 ppt) + (7.2 x 106 ppt) + (.471 x 1Q6 ppt)
(3)(40 yrs)
= 0.11 x 106 ppt/y::.
E-17
-------
4. Annual accumulation of PCBs in the water = 55 ppt = 1.38 ppt/yr.
40 yrs
5. Concentration ratios of PCBs in the three phases are:
[PCBsed. ]_ 3 x 103 ppt/yr = 2.2 x 103
[PCBwater] 1.38 ppt/yr
°-n x l fc/r 36
[PCBsed. ] 3.0 x 10 ppt/yr
fPCB, . , -| 0.11 x 10 ppt/yr 8 x
L ruotaj= ~—gr -'••*- =
fPCB . 1 1.38 ppt/yr
L waterJ tv /1 „ ._ -,^4
Therefore,
[PCBwater]
2.8 x 10
6. Applying these ratios to Lake Michigan:
[PCBbiotaJ=[PCBwater](8xlo4)
'= (.078 ppb) (8 x 104)
=6.24 ppm
[PGBsed.] ^[PCBwater] (2.2 x 103)
= (.078 ppb)(2.2 x 103)
= 0.172 ppm
C. Estimates of Plankton Biomass in Lake Michigan:
1. Assume a density of 300 kg. plankton/hectare of lake
*") a
Area of lake = 22,400 mi. = 5.8 x 10 hectare
Therefore, plankton bionass = (5.8 x 106) (300 kg) = 1.74 x 1012g.
= 3.8 x 109 Ib.
E-18
-------
D. EstJjaate of Flow of PCBs Through the Straits of Mackinac;
1. Water flows out of the lake via Straits at a rate = 67,000 cfs.
= 1.3 x 1014 lb of
water/yr.
(17)
Using the concentration of PCB in the water as 0.013ppb, the loss
14
of PCBs through the Straits is: = (1.3 x 10 Ih/yr)(0.013 ppb)
= 1.7 x 103 lb PCB/yr.
4
Assuming a constant loss over the past 40 years, 6.8 x 10 lb of
would have been lost through the Straits.
E-19
-------
BIBLIOGRAPHY
1. Schacht, R.A.; Pesticides in the Illinois Waters of Lake Michigan,
Project #16050 ESP., 1974.
2. State of Michigan Water Resources Commission, Bureau of Water Management,
Polychlorinated Biphenyl Survey of the Kalamazoo River and Portage Creek
in the Vicinity of the City of Kalamazoo 1972.
3. Hesse, J.L.; Status Report on Polychlorinated Biphenyls in Michigan
Waters. Report to Michigan Water Resources Coittnission, 1973.
4. State of Michigan Water Resources Commission, Bureau of Water Management,
IVbnitoring for Polychlorinated Biphenyls in the Aquatic Environment.
Report to Lake Michigan Toxic Substances Committee, May, 1973.
5. Kleinert, Stan; Chief of Water Quality Surveillance Section, CNR Wisconsin,
Personal Coimtunication, 1975.
6. Winters, John; Acting Chief of Water Quality and Standards Branch of
Illinois EPA, Personal Communication, 1975.
7. United States Geological Survey, Water Resources Data for Michigan.
Part 1. Surface Water Records, 1974'.
8. United States Geological Survey, Water Resources Data for Wisconsin.
Part 1. Surface Water Records, 1974.
9. United States Geological Survey, Water Resources Data for Illinois.
Part 1. Surface Water Records, 1974.
10. United States Geological Survey, Water Resources Data for Indiana.
Part 1. Surface Water Records, 1974.
11. Saylor, J.H., P.W. Sloss; Water Volume Transport and Oscillatory Current
Flew through the Straits of Mackinac. (Contribution No. 38, Great Lakes
Environmental Research Laboratory), 1957.
12. Michigan Department of Natural Resources Fisheries Division, Estimates
of Biomass of Principal Fish Species in the Great Lakes (first report).
Fisheries Research Report No. 1813, 1974.
13. The Lake Michigan Federation, "The Lake Michigan Basin", March, 1975.
14. International Joint Commission on the Great Lakes. Pollution of Lake
Erie, Lake Ontario and the International Section of the St. Lawrence
River, Vol 3, 1969.
E-20
-------
15. Haile, C.L., G.D. Veith, G.F. Lee, W.C. Boyle; Chlorinated Hydrocarbons
in the Lake Ontario Ecosystem, 1975.
16. Ruttner, F., 1952. Fundamentals of Liitmology. University of Toronto
Press. 295 p., 1952.
17. Nealy, Brock; Chemist with Dow Chemical Co., Midland, Michigan. Personal
Gorttnunication, 1975.
E-21
-------
APPENDIX F
TOXICOLOGICAL ASPECTS
1.0 TOXICOLOGICAL ASPECTS OF POLYCHLORINATED BIPHENYLS (PCBs)
1.1 Introduction
A critical biological effect of polychlorinated biphenyls (PCBs) is
the induction of tumors in mice and rats, which implies potential human activity.
Cancer is typically progressive and irreversible, in the absence of medical inter-
vention. Virtually all chemicals known to cause cancer in man have been shown to
cause tumors in animals, including mice and rats. The use of experimental animals
to test chemicals is generally accepted as a reliable basis for estimating potential
carcinogencity to humans. Pathological development of chemically induced tumors
in experimental animals and in humans is very similar, and most of the major types
of human cancer can be reproduced in animals by chemical induction. Mice and
rats are generally the preferred experimental animals because their relatively
short lifespan permits lifetime testing within two to three years, whereas chem-
ical carcinogenesis in humans is usually manifested by a latent period of 30 to
40 years between exposure and the appearance of symptoms. This long latency period
coupled with the lack of adequate human data, and the lack of identifiable con-
trol groups for widespread agents such as PCBs, make it difficult to identify PCBs
as a "human" carcinogen by conventional epidemiological studies. However, most
experts in chemical carcinogenesis, including researchers at the National Cancer
Institute of NIH and the Ptorld Health Organization, accept animal data as pre-
dictive of potential human activity.
To date, no minimum effective dose or maximum safe dose has been estab-
lished for carcinogenic chemicals in man or animals; therefore in approaching the
problem of formulating regulatory action all mammalian systems are considered
sensitive and man must be considered the target system.
Although in at least one positive study on PCBs the dosage level used
would be considered low, high levels are generally used in animal tests because
the limited number of animals may render the tests relatively inconclusive. In
addition, the strain or species used may also render the tests comparatively
insensitive. Failure to demonstrate response at low doses of an oncogen is not
an adequate basis to establish a "no-effect" level.
F - 1
-------
Virtually no chemical that has been adequately studied is known to
cause only benign tumors. Furthermore, oncogens may cause tumors at different
sites in different animals species or strains depending upon factors such as
routes of metabolism and excretion.
In considering the current status of medical knowledge, a lack of
understanding of the carcinogenic mechanism within cellular biochemistry is
evident. One issue that must be resolved in order to establish effective control
legislation is whether or not there is a level of carcinogenic exposure below
which there are no effects.
The two points of view are known as the "threshold" and the "no-threshold"
concepts. The threshold concept is based on the theory that there is a dose level
below which no effect will occur regardless of the number of test animals exposed;
since this no-effect dose level would be higher than any resultant legally-established
exposure limit, humans would not be harmed by doses at or below the limit. The
assumption is made that the number of animals affected will decrease at a greater
rate than the rate of decrease in the dose until a zero-point is reached. This
assumption is unverified. Proponents of the threshold concept believe that for
every toxic chemical there is an exposure level below which no effect can occur
in a given organism, and that no effect, or possibly even beneficial effects at
subthreshold doses, gives way to undesirable effects as the dose is raised. No
valid data have been developed to support the concept of safe levels of exposure
to carcinogens since the extremely large numbers of animals needed for such ex-
periments preclude such testing, and extrapolation of animal data to man is tenuous.
The no-threshold proponents insist that any substance which is carcino-
genic at any level must be regarded as such at all levels. They further insist
that it is not possible to predict safe levels of carcinogens based on an arbitrary
fraction of the lowest effective animal dose, regardless of how many test animals are
used. For those chemicals which have been shown to be carcinogens in experimental
animals, no thresholds have been demonstrated. Thus neither the no-threshold theory
(or zero-dose concept) nor the threshold concept can be demonstrated or disproved
at the present time.
F - 2
-------
In the development of a standard for a carcinogen, the following
recommendations, taken from the April 22, 1970 renort to the Surgeon General by
the Ad Hoc Committee on the Evaluation of Low Levels of Environmental Chemical
Carcinogens, National Institutes of Health, should be considered:
1. No level of exposure to a chemical carcinogen should be
considered toxicologically insignificant for man. For
carcinogenic agents, a 'safe level for man' cannot be
established by application of our present knowledge.
The concept of 'socially acceptable risk' represents a
more realistic notion.
2. The principle of a zero tolerance for carcinogenic exposures
should be retained in all areas of legislation presently
covered by it and should be extended to cover other exposures
as well. Only in the cases where contamination of an
environmental source by a carcinogen has been proven
to be unavoidable should exception be made to the principle
of zero tolerance. Exceptions should be made only after
the most extraordinary justification, including extensive
documentation of chemical and biological analyses and a
specific statement of the estimated risk for man, are pre-
sented. All efforts should be made to reduce the level of
contamination to the minimum. Periodic review of the degree
of contamination and the estimated risk should be made
mandatory.
3. A basic distinction should be made between intentional and
unintentional exposures.
(a) No substance developed primarily for uses involving
exposure to man should be allowed for wide-spread human
intake without having been properly tested for carcino-
genicity and found negative.
F - 3
-------
(b) Any substance developed for use not primarily
involving exposure in man but nevertheless re-
sulting in such exposure, if found to be carcino-
genic, should be either prevented from entering
the environment or, if it already exists in the
environment, progressively eliminated.
The same report states:
The production of specific carcinogenic chemicals for uses
that do not primarily involve an intentional exposure of
man, but which result in such environmental contamination
that extensive human exposure becomes inevitable, must also
be controlled. The most effective prevention of exposure
in man is the elimination of carcinogen production, or
control of entry into the environment.
More recently, the Subcommittee on Estimation of Risks of Irreversible,
Delayed Toxicity to the Department of Health, Education and Welfare Committee to
Coordinate Toxicology and Related Programs published their report (Hoel et al,
J. Toxicol. Environ. Health 1., 133, 1975).
The Subcorrmittee suggests (on an interim basis only) a
computational procedure to assist in setting levels of
qualitatively unavoidable chemicals (both natural and
manmade) in the environment compatible with a socially
acceptable level of risk. It includes a simple arithmetic
procedure to compute an exposure dose of a chemical for
humans so that there will be a high probability that this
dose will give a risk equal to or below the specified level.
Data from experiments designed to detect irreversible self-
replicating changes (carcinogenesis) in experimental animals
will be used. Through this arithmetic, the results will be
translated to appropriately low levels for humans. In
F - 4
-------
addition, human exposure data need to be considered. All
the knowledge necessary to evaluate these factors does
not yet exist. We suggest here an interim procedure to
be used until research points to better procedures such as
methods for obtaining direct or best estimates of risk at
a given dose with their corresponding confidence limits.
Some of this research is now under way. These suggestions
must be reviewed as new research is available, but not
longer than within two years.
Specifically, the so-called linear straight-line arithmetic
method combined with a 99% confidence level for extrapola-
tion to very low levels works this way:*
1. Say an experiment at a dose, d, using 100 animals has
shown no induced tumors, for example, in the animals,
that is, 0/100=0%.
2. The upper 99% confidence limit on this result (which
can be found in standard statistical tables) is 0.045,
that is, 4.5%.
3. For a dose, d , that will produce, as an upper limit,
S
fewer than 1 in 1,000,000 tumors, divide 1/1,000,000 by
_c
.045. This gives (in standard notation) 2.22 X 10 d
as the appropriate dose. If one were to aim for fewer
* For certain compounds, some knowledge of the carcinogenicity process may be
available, such as with renal concretions resulting in bladder tumors. In these
instances, models other than the linear model may be more appropriate.
For illustration we consider only the case of one experimental dose. In practice,
however, it is expected that several dose levels will be available and their treat-
ment can be found in the literature (Gross et al., 1970; Mantel and Bryan, 1961;
Mantel et al., 1975).
F - 5
-------
than 1 in 100,000,000, (i.e., 1 X 10~8), the appro-
priate dose would be 2.22 X 10~ d; for fewer than 1
in a hundred thousand (1 X 10 ), the appropriate dose
is 2.22 X W'^d, etc. If 10 of the 100 animals showed
a response (i.e., 10/100 = 10%), then the 99% confidence
limit is 0.19, that is, 19%. The appropriate dose for
1 in a million is then 5.3 X 10~6d and for 1 in 100,000,000,
the dose would be 5.3 X I0~8d.
For corrections to a 'natural' incidence, the normal distri-
bution is used to approximate a 99% confidence interval on
the difference between the response at dose d and the back-
ground. Suppose at dose d 60 of 200 (30%) animals were
affected while the natural incidence gave 20 of 200 animals
(10%). The upper 99% confidence limit is then approximately
.3 - .1 + 2.327[.3(.7)/200 + .1(.9)/200]1/2 = 0.29
where 2.327 is the 99% point of the standard normal distribu-
tion. For a dose, d , that will produce as an upper limit of
s
fewer than 1 in a million changes in excess of the natural
incidence, 1/1,000,000 is divided by 0.29. This gives
3.4 X 10 d as the dose, and for 1 in 100,000,000 excess changes
the dose is 3.4 X I0~8d.
Two questions need to be answered in converting results in
animals to man:
1. In what units should the dose conversion be made (i.e.,
weight basis, surface basis, etc.)? At present it
appears that the appropriate dose unit is the 'surface'
unit, that is, use the 2/3 power of the weight of the
two species (test animal-man) as the surface area con-
version factor. For example, if a 25-g mouse receives
a dose stated on a milligram basis, then the corres-
F - 6
-------
ponding dose (mg) for a 70-kg man would be (70
2/3
kg/25g) ' = 200 times the mouse dose. Thus, on a
mg/kg basis, the use of surface units would require
that the corresponding relative dose become
(70 kg/25 g) =14 times the mouse dose. Dose
expressed in concentration (ppm) should lead to
approximately the same levels as dose expressed in
surface area units.
2. Should any additional safety factor be added in
going from animals to man? Yes, but not the same
factor for all substances. This species conversion
factor should be determined substance-by-substance
using appropriate biological considerations (and
allowing for any safety factors implicit in other
parts of the calculation).
A statutory provision exists, however, which provides some sanction to the no-
threshold concept. This is, of course, the "Delaney clause", Section 409(c) (3)
(A) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 321 et seq.), which
became law in 1958. This clause provides "... that no additive shall be deemed
to be safe if it is found to induce cancer when ingested by man or animal, or
if it is found, after tests which are appropriate for the evaulation of the safety
of food and additives, to induce cancer in man or animal..."
In spite of all of the furor concerning this clause, it is interesting
to note that since its introduction in 1958, it has been invoked only twice to
ban food additives and both of these were trivial components of food packaging.
The Food and Drug Administration, in addition to its responsibility
for regulating food additives, is also supposed to protect the public from carcino-
gens which appear naturally or incidentally in our food. These substances are not
covered by the Delaney clause. Aflatoxins, DDT, aldrin, nitrosamines, and vinyl
chloride are examples. Presently, these problems are handled on the basis of
practicality and not on any assessment of risk. That PCBs presently exist in our
diet has been amply demonstrated. But the pressure to eliminate such carcinogens
from entering our food must fall upon other regulator agencies such as EPA.
F - 7
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In summary, there is no generally accepted toxicological basis upon
which to establish a no-effect level for any carcinogenic material. Methods which
arrive at estimates of acceptable exposure levels for carcinogens in man are, there-
fore, based on the concept of a "socially acceptable level of risk." In general,
the methods employ statistical extrapolation of laboratory aniinal test data to
man, whereupon a political decision as to the socially acceptable incidence of
tumors is made. Such estimates of socially acceptable level of risk to determine
human exposure tolerances to ionizing radiation have been employed by the Atomic
Energy Commission and adopted by the Environmental Protection Agency. Estimates
based on acceptable level of risk are only conceptual and must not be taken as
calculated no-effect levels.
1.2 Mammalian Toxicity
"The current knowledge of the interaction of PCBs with life forms will
not be reviewed in detail in this report; an exhaustive review will be submitted
in the final report on Task I. This report will highlight only those data re-
lating tumor induction. This review, however, is complete in the sense that major
adverse effects are mentioned including those within the major target organs.
PCBs have low acute toxicity. But because of their near complete ab-
sorption, high lipid (fat) solubility, low water solubility, and relative chemical
inertness, PCBs tend to concentrate in the food chain, accumulate in body fat,
persist in biological tissue, and show persistent toxicity. Consequently, short-
term studies are not adequate indicators of the long-term effects of PCB exposure.
Latent effects, those effects that occur some time after exposure has ceased, and
cumulative effects, those effects that occur only after a threshold level of PCB
or tissue damage has been reached, may be easily missed over the short term. Since
most toxicity studies with PCBs have been short-term, there is limited scientific
evidence establishing or predicting the chronic effects.
1.2.1 Subacute and Chronic Toxicity
"No-effect" levels of PCBs in rats and dogs fed three Aroclors
for two years were reported by Monsanto in 1971. A summary of their results is
presented here.
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Rats - Method
A two-year chronic toxicity study was conducted using rats
fed diets containing Aroclors 1242, 1254 and 1260. The animals employed in the
test were Charles River strain albino rats. Four hundred rats (200 male and 200
female) were selected for each of the experiments.
Outline of Each Experiment
Group
Control
T-I
T-II
T-III
Number of Animals
Male
50
50
50
50
Female
50
50
50
50
Dietary Level
(ppm)
None Administered
1
10
100
Rat Results - Aroclor 1242
At sacrifice after 3, 6 or 12 months on test, organ weights,
organ to body weight and organ to brain weight ratios disclosed several randomly
occurring intergroup differences. The lack of any consistent dose-related res-
ponse and the absence of any deleterious tissue changes confirm that these
differences were not related to the ingestion of Aroclor 1242.
At the final sacrifice after 24 months on test, the liver weights
and liver to body weight or brain weight ratios were significantly elevated in
females from the T-III group. Histologic examination of the livers from the T-III
group revealed several animals with vacuolar changes indicative of fatty degenera-
tion. Specific fat stains confirmed the presence of fat in these vacuoles. Focal
hypertrophy and focal hyperplasia were also found in the livers from animals fed
Aroclor 1242.
Hyperplasia of the urinary bladder was found in animals from
the control group and from each of the test groups. This hyperplasia was usually
associated with cystitis.
F - 9
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The incidences and types of all tumors were about the same in
all groups, including the control group, and are considered normal for rats of
this age.
Rat Results - Aroclor 1254
At sacrifice after 3, 6, or 12 months on test, organ weights,
organ to body weight and organ to brain weight ratios disclosed several randomly
occurring intergroup differences. The lack of any consistent dose related res-
ponse and the absence of any deleterious tissue changes confirm that these
differences were not related to the ingestion of Aroclor 1254.
At the final sacrifice after 24 months on test, the absolute
liver weight and liver to body weight or brain weight ratios were significantly
elevated in both T-III males and females. Histologic examinations of the livers
from the T-III group revealed several animals with vacuolar changes indicative
of fatty degeneration. Specific fat stains confirmed the presence of fat in these
vacuoles. Focal hypertrophy and focal hyperplasia were also found in the livers
from anirals fed Aroclor 1254.
Hyperplasia of the urinary bladder was found in animals from
the control group and from each of the test groups. This hyperplasia was usually
associated with cystitis.
None of the tumors found could be related to the ingestion of
Aroclor 1254 and are considered normal for a random population of rats this age.
Rat Results - Aroclor 1260
At sacrifice after 3, 6, or 12 months on test organ weights,
organ to body weight and organ to brain weight ratios disclosed several randomly
occurring intergroup differences. The lack of any consistent dose related res-
ponse and the absence of any deleterious tissue change confirm that these differences
were not related to the ingestion of Aroclor 1260.
At the final sacrifice after 24 months on test, the liver weights
and liver to body weight or brain weight ratios were significantly elevated in the
rats from the T-III group. Histologic examination of the livers from the T-III
P - 10
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group revealed several animals also with vacuolar changes indicative of fatty
degeneration. Specific fat stains confirmed the presence of fat in these vacuoles.
Focal hypertrophy and focal hyperplasia were also found in the livers from animals
fed Aroclor 1260.
Hyperplasia of the urinary bladder was found in an animal from
the control group but not in any of the test animals.
The incidences and types of all tumors were about the same in
all groups, including the control group, and are considered normal for rats of
this age.
Dogs - Method
The two-year toxicity study utilized an untreated control group
and three test groups, each consisting of eight purebred beagle dogs (four males
and four females). The beagles were all eligible for A.K.C. registration and
had been previously immunized.
The material to be tested, Aroclors 1242, 1254,aand 1260 were
incorporated into a stock diet and fed to the dogs seven days a week in three
graded dietary levels. The levels were 1, 10 and 100 ppm.
An outline of the test organization is presented here:
Outline of Each Experiment
Group
UC
I
II
III
Number of Animals
Males
4
4
4
4
Females
4
4
4
4
Dietary Level
(ppm)
None
1
10
100
Dog Results - Aroclor 1242, 1254 and 1260
No significant abnormalities were observed in the following
parameters:
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Body Weight
Food Consumption
Behavioral Reactions
Hematology
Urine
Animals receiving 100 ppm of Aroclor 1260 exhibited increases
in serum alkaline phosphatase activity at the conclusion of the investigation.
A female receiving 100 ppm of Aroclor 1242 was sacrificed in
extremis after 60 weeks of testing; gross and histologic examinations revealed
severe chronic peritonitis. A male receiving 10 ppm died after 32 weeks of testing;
death was attributed to chronic pneumonia. Histologic examination revealed no
abnormalities related to the test material ingestion.
Two fatalities occurred during the Aroclor 1254 study: a 100
ppm female after 33 weeks of testing and a 10 ppm female after 37 weeks. The
female receiving 100 ppm died from injuries received in a fight. Gross and
histologic examinations of the 10 ppm female revealed chronic peritonitis.
Two fatalities occurred during the Aroclor 1260 study: a 100
ppm female after 29 weeks and a 100 ppm male after 33 weeks. Gross and histologic
examinations revealed severe chronic peritonitis in the female and acute pneumonia
in the male.
All animals receiving- 100 ppm of Aroclor 1260 exhibited elevations
in liver to body weight ratios.
Gross and histologic examination of all remaining animals re-
vealed no significant abnormalities.
Work by Dr. James Allen (U. of Wisconsin) on simians is dis-
cussed in the following paragraphs.
Simians - Method
The hazards to simians of low level PCB exposure have been
demonstrated only very recently. Allen in 1974 reported the results of feeding
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six adult female rhesus monkeys a diet containing 25 ppm of Aroclor 1248 for two
months. The average total intake of PCBs for five animals fed for two months
was approximately 250 mg, or 0.78 mg/kg body weight per day. The sixth monkey
consumed a total of 450 mg at 1.34 mg/kg/day; this animal died 68 days after
feeding was stopped.
The effects in all six animals included facial swelling, severe
hyperplastic gastritis and liver necrosis. All but one of the surviving were un-
able to conceive. The one live birth was a smaller than average infant.
The surviving monkeys continued to have high adipose tissue
levels, acne, tissue swelling and hair loss two years after this short term, low
level exposure. As will be seen, these signs were similar to those encountered
in humans during the "Yusho" intoxication in Japan (described later in this report).
1.2.2 Reproduction
PCBs have been shown to affect reproduction in several different
species. Egg production, egg hatchability, and shell thickness were decreased by
feeding low levels of various PCB formulations to chickens. Female rats fed 20
ppm of Aroclor 1254 (1.5 ivg/kg/day) had a decrease in the number of litters and
in litter size. In a two-generation study, 5 ppm was the no effect level for rat
reproduction. Higher dietary levels caused decreased rat offspring survival and
decreased mating performance. Even at 1 ppm, male rats were born with enlarged
livers. In a more recent study, Allen has reported that levels in the diet as
low as 2.5 ppm resulted in a marked decrease in the ability of monkeys to conceive.
1.2.3 Pathology
One of the most studied toxic effects of PCBs has been in liver
pathology in rats and rabbits. PCBs cause similar damage when administered by
injection, inhalation, or by mouth. In cases of PCB poisoning, early liver damage
has been noted. Many researchers have described the now classical pathological
changes in the liver of animals exposed to PCBs. These include infiltration by
fat, increased cell and liver size, degeneration of cellular contents, and ulti-
mately cell death. The latent nature of these effects is demonstrated by the fact
the most severe histopathology known occurred 5 to 13 weeks after PCB ingestion
had ceased.
F - 13
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Additional pathological changes have recently been noted.
These were classified as adenofibrosis and are often seen in association with
liver carcinoma. Abnormal growth and development of the gastric mucosa has
also been reported and is further evidence of the carcinogenic potential of PCBs.
For reasons completely independent of any possible association
with cancer, the significance of fibrosis, adenofibrosis, and liver necrosis are
very grave. These lesions may be associated with carcinomas in rodent liver.
1.2.4 Carcinogenicity
Unfortunately, statistically sound dose-carcinogenic response
studies necessary to treat many environmental problems, including PCBs, are
currently not available. A review of the world scientific literature reveal
only six studies pertinent to carcinogenesis. These are listed and discussed
below.
1. Kimbrough, R.D., Linder, R.E., and Gaines, T.B.,
"Morphological Changes in Livers of Rats Fed Poly-
chlorinated Biphenyls", Arch. Envon. Health _25_,
354 (1972) .
An extensive chronic study of Sherman rats, using
Aroclors 1260 and 1254, with dietary levels of 0,
20, 100, 500 and 1000 ppm, documented a variety of
histopathological effects after 8_ months of ex-
posure. Degenerative liver changes observed in
both male and female test animals at all dosages
of both PCBs included hypertrophy of individual
liver cells, hyperchromatic pleomorphic nuclei,
cytoplasmic lipid vacuoles, and porphyria, all
characteristics of chlorinated hydrocarbon (DDT,
dieldrin) intoxication. In some cases, adenofibrosis
(uncertain significance) was observed. All of the
mortalities that occurred during exposure to the
Aroclor 1260 were female. In nearly all gross
F - 14
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pathological examinations, males demonstrated
enlarged livers, while females did not; liver
effects of Aroclor 1254 were adjudged more pro-
nounced than those of Aroclor 1260.
The short duration of this study is a drawback
for its inclusion in evaluation of carcinogenic
effects.
2. Kimura, N.T. and Baba, T., "Neoplastic Changes in
the Rat Liver Induced by Polychlorinated Biphenyl",
Gann 64, 105 (1973).
Following the observation, by electron microscopy,
of specific morphological alterations (previously
observed with other carcinogens) in liver cell
nucleoli of animals ingesting PCBs, a preliminary
study on PCB carcinogenic activity was instituted.
Using rats of the Donry strain, Kanechlor 400 mixed
in oil was fed at dietary levels ranging upwards
from 38.5 ppm. Ten male and ten female rats were
in the experimental group with five of each sex in
the control group. Using body weight gains (com-
pared to controls) the concentration of the Kanechlor
was increased or decreased according to the following
schedule.
Concentration of
Period of Kanechlor-400
Feeding (days) (ppm)
26 38.5
57 77
21 154
21 308
56 616
39 462
29 0
98 462
28 0
82 462
Total 400
F - 15
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Multiple adenomatous nodules were observed in
all livers of the female experimental group
ingesting more than 1200 rags of Kanechlor 400.
In sharp contrast, however, the liver specimens
of the male experimental rats revealed no such
changes even in animals receiving comparable or
higher amounts of Kanechlor 400 than females.
Although these authors refer to this lesion as
benign in nature, further discussion of this
lesion is presented later in this report.
The variable dosage schedule and the small numbers
of animals used present drawbacks for its inclusion
in evaluation of carcinogenic effects.
Ito, N., et al. "Histopathologic Studies on Liver
Tumorigenesis Induced in Mice by Technical Poly-
chlorinated Biphenyls and its Promoting Effect on
Liver Tumors Induced by Benzene Hexachloride", J.
Natl. Cancer Inst., 51, 1637 (1973).
This paper reports the histopathologic and ultra-
structural observations of livers of dd mice fed
PCBs in their diet for a period of 32 weeks. Twelve
male mice were used at each of three dosage levels.
Three PCBs were investigated, Kanechlor 500, 400,
and 300. The results indicate hepatocellular carcinomas
and nodular hyperplasia were induced by Kanechlor
500 but not by the two other PCBs, as seen below:
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PCBs Cellular Nodular Hepatocellular
Diet (ppm) Hypetrophy Hyperplasia Carcinoma
Kanechlor 500 (500) ++ 7/12 5/12
Kanechlor 500 (250) + 0/12 Q/12
Kanechlor 500 (100) ± 0/12 0/12
Kanechlor 400 (500) ++ 0/12 0/12
Kanechlor 400 (250) + 0/12 0/12
Kanechlor 400 (100) ± 0/12 0/12
Kanechlor 300 (500) ± 0/12 0/12
Kanechlor 300 (250) ± 0/12 0/12
Kanechlor 300 (100) - 1/12 0/12
Control - 0/6 0/6
The effect of PCBs on neoplastic changes induced
by isomers of benzene hexachloride (a, 3 and y) in
the livers of mice fed a diet containing BHC with
and without PCBs for 24 weeks was also studied. The
authors concluded that in addition to the carcinogenic
activity of PCBs, these materials, also promote tumors
induced by a BHC and 3 BHC.
Kimbrough, R.D., and Linder, R.E., "Induction of
Adenofibrosis and Hepatomas of the Liver in BALB/cj
Mice by Polychlorinated Biphenyls (Aroclor 1254)",
J. Natl. Cancer Inst., _53, 547 (1974).
Two groups of 50 BALB/cj inbred male mice were fed
300 ppm of Aroclor 1254 in the diet for 11 and 6 months.
The six-months group was given a recovery period of
5 months. The results are presented below:
Hepatoma
0
0
9
1
Dietary
Level (ppm)
0
0
300
300
Exposure
Time (Mo.)
0
0
11
6
Total
Survivors
34
24
22
24
F - 17
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In addition, all 22 mice in the group receiving
Aroclor 1254 demonstrated adenofihrosis which was
not observed in any other group.
5. Makiura, S., et al, "Inhibitory Effect of Poly-
chlorinated Biphenyls on Liver Tumorigenesis in
Rats Treated with 3'-Methyl-4-Dimethylaminoazo-
benzene, N-2-Fluorenylacetamide, and Diethyl-
nitrosamine", J. Natl. Cancer Inst., 53_, 1253
(1974) .
Ihe effect of PCBs (Kanechlor 500) on liver carcino-
genesis induced by 3-methyl-4 diraethylaminoazobenzene
(3' Me-DAB), N-2-fluorenylacetaitu.de (2-EAA) and/or
diethylnitrosamine (DEN) was studied in male Sprague-
Dawley rats. Duration of exposures were 20 weeks.
Liver tumors developed with the three known liver
carcinogens, i.e., 3' Me-DAB, 2 FAA, and DEN. No
tumors developed in the animals fed PCBs alone and
when fed with the above mentioned carcinogens a marked
reduction in tumor incidence was observed. The lack
of tumors in the PCBs fed rats may have been the result
of low dose (500 ppm) and/or the short period of ad-
ministration since these same authors had induced
tumors in rats treated with Kanechlor 500 at 1000 ppm
for 72 weeks. Histopathology findings of the livers
were similar as previously reported; i.e., fatty
changes and cell hypertrophy.
6. Kimbrough, R.D.; Squire, R.A.; Linder, R.E.; Strandberg,
J.D.; Montali, R.J. and Burse, V.W., "Induction of
(R)
Liver Tumors in Rats by Polychlorinated Biphenyl Aroclor
1260", J. Natl. Cancer Inst. (in press, 1975).
F - 18
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Two hundred Sherman Strain female rats were fed 100
ppm of polychlorinated biphenyl (Aroclor 1260) for
approximately 21 months, and 200 female rats were
kept as controls. The rats were sacrificed when 23
months old. Twenty-six of 184 surviving experimental
rats and 1 of 173 surviving control rats examined had
hepatocellular carcinomas. None of the controls, but
146 of the 184 experimental rats, had neoplastic
nodules in their liver. Areas of hepatocellular
alteration were noted in 28 of the 173 controls and
182 of the 184 experimental rats. It was concluded
that Aroclor 1260 had a hepatocarcinogenic effect in
female Sherman Strain rats. The incidence of tumors
in other organs did not differ appreciably between the
experimental and control groups.
1.2.5 Bryan-Mantel and One Hit Model Calculations of Animal Data
for Extrapolation to Humans
As indicated previously, statistical handling of experimental
data helps resolve questions of experimental design and the problems of threshold
in setting safe doses. We have applied the Bryan-Mantel and One Hit Model calculatioi
to two studies. The results of these analyses are presented in Tables I and II.
Therefore, using the recommendations set forth previously, we
conclude that the use of the Bryan-Mantel Probit Model should be used to calculate
the "safe" level of PCBs using a theoretical maximum acceptable lifetime risk of
1/10 of development of hepatomas (neoplastic nodules). This dose is 167 ppt at the
99-percent confidence limits if the latest data in rats (Kimbrough 1975) is used.
In the case of development of hepatocarcinomas, the level would be 11,887 ppt.
The rather low "safe" dose relative to the hepatomas reflects
that the dosage level used in the experiment (i.e., 100 ppm) was too high for that
response (146 hepatomas in 184 rats). These neoplasms are mostly benign tumors
F - 19
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Table I
Analysis of Carcinogenic Risk to Humans from Ingested
PCBs Based on Kinnbrough 1975 Study (Rats)
Intake Level in ppt for Specified
Analytical
Method
Bryan-Mantel
Bryan-Mantel
One Hit
One Hit
Confidence
Limits_ (%)
95
99
95
99
Analytical
Method
Bryan-Mantel
Bryan-Mantel
One Hit
One Hit
Confidence
Limits (%)
95
99
95
99
Levels
1/10 8*
1963
1645
4
4
Intake
Levels
1/10 8
27
23
0
0
Intake
Levels
1/10 8
0
0
0
0
of Risk
1/10 7*
5080
4257
for Hepatocarcinomas
1/10 6*
14,187
111,8871
45 447
39 391
Level for ppt for
of Risk
1/10 7
1/10 5*
43,640
| 36,566
4,472
3,906
Specified
for Neoplastic Nodules
1/10 6
70 197
60 1 167|
2 21
2 18
Level for ppt for
of Risk
1/10 7
1
1
0
0
for Foci
Viol
3
2
0
0
1/10 5
605
512
205
180
Specified
1/lQ5
10
6
3
1
*Risk level of one tumor per 108,107,106, or 105 population
F - 20
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Table II
Analysis of Carcinogenic Risk to Humans from Ingested
PCBs based on Kimbrough-1974 Study (Mice)
Intake Level in ppt
for Specified Level of Risk
for Hepatoma (Neoplastic Nodules)
Analytical Method
Bryan-Mantel
One Hit
Confidence Limits (%) 1/10
95
99
95
99
1/108*
451
297
2
2
7*
1/10
1167
768
21
16
1/106*
3258
1 2145 1
214
160
5*
1/10
10022
6597
2140
1596
*Risk level of one tumor per 10 , 10 , 10 , or 10 population.
F - 21
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occurring late in life. There is little time left for them to become malignant
in the remaining life-time of the rat. Until further data become available or
other means are used to handle existing data, one should assume the "safe" dose
in lifetime human diet to be between 0.2 ppb and 12 ppb.
It is interesting to note that if the simian reproduction data
is used and the classical 1/100 safety factor is applied to the lowest dose
studied (2.5 ppm), a "safe" dose of 25 ppb is obtained. This dose (2.5 ppm), how-
ever, appears to be a minimal effective dose, whereas normally the hiahest no-
effect level is used. Use of minimum effect levels and even other safety factors
have been used; e.g., 1/10 to 1/5000. These would result in dosage levels ranging
from 250 ppb to as low as 0.5 ppb.
These calculations must be considered preliminary since time
has not permitted consideration of other factors, such as:
1) Body surface area instead of 'body weight in determining
daily intake
2) Comparison with most likely human daily intake
3) Further calculations of existing data
4) Combination of all existing animal data
5) Consideration of metabolism, storage and excretion data
among animals species as compared to man
1.3 Observations in Humans
In addition to data provided by continuing studies of the various effects
of PCBs on laboratory animals, some information is available on the subacute or
chronic effects of PCBs on humans.
Human intoxication with Kanechlor 400, a PCB manufactured in Japan
(48-percent chlorine) was observed after a heat exchanger leaked fluid into rice
oil which was then consumed by Japanese families in 1968. Approximately 1,000
persons were affected, and typical clinical findings included:
F - 22
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1. Increased eye discharge
2. Acne-like eruptions
3. Dark brown pigmentation of nails
4. Pigmentation of skin
5. Transient visual disturbance
6. Feeling of weakness
7. Numbness in liitibs
8. Headache
9. Weight loss
10. Vomiting
11. Diarrhea
12. Fetal toxicity
Items 5 through 8 represent symptoms of damage to the nervous system
seen in "Yusho" patients. PCBs are known to enter the brain, but they do not
have a predominant central neurotoxic effect like the related hexachlorophene.
Laboratory findings in the severe cases included:
1. Red blood cells and hemoglobin decreased; leukocytes increased
2. Total serum lipids, triglycerides, alpha 2-globulins increased
3. Slight increase in alkaline phosphatase
4. Liver biopsy-reduction of rough endoplasmic reticulum; hypertrophy
of smooth endoplasmic reticulum; giant mitochondria were fre-
quently encountered
When 159 "Yusho" patients were examined in 1969 and 1970, it was found
that 50 percent showed no clinical improvement and 10 percent were worse, another
indication of the persistence of PCBs in the human body. The chemical was found
to be stored primarily in the adipose tissue but also passed into the placenta and
fetus.
A very early and common symptom in these patients was chloracne.
Chloracne is an occupational skin disease caused by many chemicals. Chloracne
resembles adolescent acne in some ways, but is generally more severe. Its symptoms
consist of comedones with or without cysts and pustules. The openings of the hair
F - 23
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fallicles are filled with oil and protein material. Darkening of the skin and
secondary inflammation nay also occur. During the 1930s and 1940s several large
outbreaks occurred in workers engaged in the manufacture of PCBs and closely
related chemicals.
The disease can be produced by both direct skin exposure and by oral
intake of PCBs. The ability of oral consumption of PCBs to cause persistent
chloracne was convincingly demonstrated in the "Yusho" incident, where chloracne
was still present in several people three years after oral consumption of PCBs
had ceased.
The same study showed no significant difference among sexes, but a
significant difference in clinical severity by age was observed, with the 13- to
29-year-old group being the most sensitive. Of the 11 babies born to affected
mothers, 2 were stillborn, 9 had dark-brown stained skin, and increased eye dis-
charge was noticeable in most. Growth rates of affected children, as measured by
both height and weight gains, were monitored and compared with unaffected class-
mates; a significant decrease in growth rate was detected in the males who were
poisoned, but no definitive change was observed in the females.
Rice oil exposure levels were calculated at approximately 15,000 mg/day
(average); the oil itself was reported to be contaminated at about 2,000 ppm
Kanechlor 400 (derived from the known organic chlorine content of rice oil in
relation to the known organic chlorine content of the PCB). The average total dose
of PCBs causing an effect in these victims was reported as 2,000 mg. The lowest
PCB level that produced human effects (50 kg man) was 500 mg consumed over a period
of 50 days at a rate of approximately 200 ug/kg/day. The effect level was based,
however, on overt symptoms, rather than on sensitive biochemical indicators that
might have demonstrated effects at even lower levels. Since PCBs probably have a
long biological half-life in humans, a toxicological analysis of the human data
must be based on the assumption that ingested PCBs would continue to accumulate in
tissues for a long period of time.
The apparent human health threat from chronic ingestion of PCBs prompted
the U.S. Food and Drug Administration to issue proposed limitations on the levels
F - 24
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of PCBs in foods, animal feeds, and food packaging materials. On July 6, 1973,
final regulations were promulgated that established temporary tolerances for
PCB residues arising from unavoidable contamination. These tolerances are:
1. 2.5 ppm in milk (fat basis)
2. 2.5 ppm in manufactured dairy products (fat basis)
3. 5 ppm in poultry (fat basis)
4. 0.5 ppm in eggs
5. 0.2 ppm in finished animal feed for food-producing animals
(except the following finished animal feeds: feed concentrates,
feed supplements, and feed premises)
6. 2 ppm in animal feed components of animal origin, including
fishmeal and other by-products of marine origin and in fish
animal feed concentrates, supplements, and premixes intended
for food-producing animals
7. 5 ppm in edible portions of fish and shellfish (the edible
portion of fish excludes head, scales, viscera, and inedible
bones)
8. 0.2 ppm in infant and junior foods
9. 10 ppm in paper food-packaging material intended for or used
with human food, finished animal feed and any components in-
tended for animal feeds (the tolerance does not apply to paper
food-packaging material separated from the food by a barrier
impermeable to migration of PCBs)
1.4 Conclusions
PCBs localize in certain tissues and do not break down easily in the
body. This persistence leads to cumulative toxicity. Early toxicological evidence
concerning the chronic adverse health effects of PCBs from experimental animals
such as mice and rats and from observational data in humans has been more recently
F - 25
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supplemented by additional experimental findings in monkeys. A close correlation
exists between the symptoms noted in humans and those noted in the monkeys,
suggesting that the dose response relationships and metabolic and excretion pheno-
mena of PCBs are similar in both humans and monkeys. According to some pathologists,
PCB exposure can cause cancerous liver lesions.
Evidence from relatively short-term exposure (several months) and
chronic exposure in animals or humans demonstrates that PCBs are a significant
health hazard.
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EVALUATION OF RISK FOR POTENTIAL SUBSTITUTES FOR PCBs
2.0 INTRODUCTION
Although unattainable, absolute safety (i.e., absolute control) is the goal
society would like to achieve with regard to all chemicals introduced by industry.
Safety as practiced, however, always entails some degree of risk. But experience
has shown that maximization of chemical, physical, and toxicological information
will minimize risk. For example, if a given compound is known to end up in man's
food supply, information on its chemistry and potential chronic toxicity would be
essential to minimizing the public health hazard.
The experience with PCBs illustrates the enormous range of complexity of risk
evaluation that many new compounds may require for maximum public safety. We
believe no one could have foreseen the present situation with PCBs. Thus we
strongly feel all substances should not be subjected to a single rigid routine of
study, as such action would be self defeating.
Instead, we propose that an orderly step-wise approach be made. Information
gathered on specific chemicals should show the direction for the acquisition of
additional information. The continuous use and especially the increasing use of
new chemicals should be paralleled by additional testing of the chemicals. Such
a hierarchy or sequential testing will: (1) result in avoidance of unnecessary
test procedures and (2) answer those questions which will in the long run reveal
the most productive information.
2.1 Estimation of Dose to the Target System
Mass production of chemicals invariably results in some degree of
environmental contamination, but the route by which a given contaminant affects
humans varies according to the type of compound. Vinyl chloride, for instance,
presents a hazard almost entirely on the occupational level - that is, among
workers dealing with vinyl chloride. For PCBs, on the other hand, exposure through
direct contact is not the issue; bioaccumulation through the food chain is the
exposure route of interest.
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The pattern of use is one of the most significant factors in deter-
mining the exposure of the target system. The use of PCBs in carbonless paper
prior to the voluntary ban on this use in 1971 has proven to be an excellent
example of the devious routes by which pollutants find their way into our food —
carbonless paper is recycled to paperboard for food packaging, and, in addition
to PCS release to the waterways during the recycling process, the paperboard itself
leaches PCBs to food it contains.
The method of disposal of waste also presents problems, especially with
such highly stable compounds as PCBs. Ease of disposability and rapid decomposition
to inert compounds after disposal are characteristics which are hiahlv desirable in
substitutes for PCBs.
For some PCB substitutes an elaborate examination of their movement
through the environment, their transformation by chemical, physical or biological
interactions and the dissemination and transport of the resultant compounds may
be essential.
The nature of injury must be considered. A reversible functional effect,
though undesirable, would be of vastly less consequence than irreversible and
fatal effects. Mutagenesis and teratogenesis are more subtle forms of injury, but
the testing methods for these grave threats generally are elaborate and involved.
This field, however, is advancing rapidly.
With respect to wildlife, considerations are substantially different
than with man. Because of the impossibility of pretesting all species with all new
chemicals, concern must of necessity be on the endangerment of a species or of a
local animal population. This type of information frequently can only be obtained
by constant surveillance of the environment within which a compound is released.
2.2 Nature of Tests Needed to Evaluate Human Health Effects
The major determinants of the effects of chemicals upon the health and
well-being of the individual and society are:
1. The nature of the chemical per se_
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2. The duration of exposure
3. The quantity of the chemical
If a relatively large amount of a toxic chemical acts for a short
period of time, the effects are acute, while relatively small amounts acting over
long periods tend to produce chronic effects. Other more subtle effects have
been noted, and cancer, modification of behavior, genetic effects, potentiation
of the toxicity of other environmental compounds may also have to be investigated.
Clearly there is no one protocol by which to evaluate toxicity of every
chemical. The following protocols are presented as guidelines only.
2.3 Physical and Chemical Properties
Basic information on physical and chemical properties are, of course,
essential. These data are needed not only for analysis and monitoring, but to
assess stability and determine whether and where a chemical is likely to be found
in the environment. The following data can be easily gathered in a laboratory:
1. Chemical composition
2. Common name, if established
3. Chemical name (Chemical Abstracts, Wiswesser nomenclature)
4. Trade name
5. Structural formula
6. Melting point
7. Boiling point
8. Vapor pressure
9. Density or specific gravity
10. Solubility in water and in selected organic solvents and oils
11. Dissociation constants (pKa or pKb)
12. Physical state
13. Color
14. Odor
15. pH
16. Flashpoint
17. Viscosity
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Reactions and other characteristics of a chemical in relation to other
compounds such as, water, air, and soil should include the following:
1. Oxidizing properties
2. Reducing properties
3. Corrosive hazard
4. Explosive characteristics
5. Hydrolysis rate
6. Photochemistry
2.3.1 Structure and Reactions
Elemental composition, structure, and formula weight may suffice
to suggest various reaction a compound is capable of, but the chemistry of new
compounds may be highly specialized, and predictive characteristics may not be
apparent. In addition to the oxidative, reductive and hydrolysis reactions,
reactions of biological importance should also be considered; for example,
alkylation, dealkylation, esterification, isomerization, and conjugation with
animal and plant constituents may aid in the choice of future testing procedures.
Rates and degree of completion of reactions also are useful; for example, the rate
of dehydrohalogenation of organochlorine compounds at high pH could provide leads
to relative persistence.
2.3.2 Physical Properties
Knowledge of physical properties assists not only in determina-
tion of purity, but more importantly, aids in assessment of the potential behavior
in and flow through the environment. Physical properties are also useful to the
toxicologist in the design of his studies.
2.3.3 Impurities
Impurities such as residues of reactants, residual solvent and
congeners, and the products of side reactions must be identified. Many final
conmercial products are deliberate mixtures. The toxicologist must recognize the
problems of impurities and mixtures. The recent experience of 2,4,5T having dioxin
contamination is an example. This impurity later was shown to have an lAr for
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guinea pigs of 1 yg/Kg. Chlorobenzofuran appears to be not only a likely impurity
of the parent PCBs, but may also be produced in the intended use of the PCBs;
indeed it may even be a metabolic transformation product.
2.4 Information on Manufacturing Process and Possible Losses
The following data on manufacture will be useful in the assessment of
PCB substitutes:
1. Description of the basic manufacturing process
2. Purity of starting and intermediate materials
3. Description of quality controls
4. Composition of the technical product including the names and
amounts of impurities
5. Annual production reports
6. Present and anticipated uses
7. Means of transportation to site of use
8. Disposal of waste of production
9. Disposal of "spent" material that may contain the chemical
10. Accidental losses likely to occur
2.4.1 Production, Use, Disposal
Knowledge of the production, use and disposal of a chemical will
be extremely helpful, along with physical and chemical properties, to estimate
exposure levels to specific target systems. Itiese estimates then can be used to
identify the control systems that might be instituted to minimize release to the
environment. In general, releases associated with production are amenable to
controls on manufacturers; releases associated with use are amenable controls on
users. Voluntary control over releases during use (equivalent to the voluntary
controls exercised by Monsanto with regard to production) warrant further investi-
gation, because the use of a chemical is intimately related to its potential re-
lease to the environment. Releases associated with disposal are also related to
production and use, but are most easily controlled at the municipal level.
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2.4.2 Production Specifics
Production is the first level at which a chemical is likely to
be introduced to the environment (i.e., through emissions); it is also at this
stage that human toxicological data may be first obtained, through occupational
exposure. Records of health and exposure levels of employees as now required by
the Occupational Health and Safety Administration will be of inestimable value
in assessing health effects; the discovery of hemangiosarcoma in workers exposed
to vinyl chloride is an example.
Data on production and production losses must be obtained from
manufacturers. Inventory statistics and data on methods of transport to major
clients will be essential in quantifying losses. All data should be expressed on
the final product, i.e., commercial grade, since impurities may prove more harmful
than the product itself. Data on the losses from production and transport pro-
cesses are of critical importance. Much of these data are company confidential and
allowances will be necessary to protect confidentiality.
2.4.3 Uses
»
By far the most important information needed to estimate the
exposure of a target population is a knowledge of the uses of a chemical. The
first step in understanding how chemicals get to the environment would be to
classify the uses into two categories: (1) contained uses, and (2) dispersive uses.
In general those uses designated as contained will not introduce
large quantities of chemicals to the environment. However, experience with PCBs
has shown that accidents, when they occur, frequently result in massive spills.
Information on possible methods and amounts of release during normal contained
usage should be carefully considered. The ultimate air route of dispersal of PCBs
was never considered a serious threat, though it now appears this may be the major
route of dispersal.
The use of consumer products containing toxic materials can result
in significant direct exposure as well as affect the disposal pattern of these
rraterials.
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2.4.4 Disposal
The disposal of chemicals in contained uses is, of course, a
major concern, especially with persistent materials such as PCBs. Labelling and
refund incentives may be necessary in order to get "spent" materials into the
hands of persons knowledgeable in proper disposal techniques. The flow of dis-
carded consumer products, however, presents a much more serious threat. Lack of
ability to control this type disposal is obvious.
For products having a short life, disposal rates are approximately
equal to production rates. For products with a longer life and rapidly growing
consumption rate, the rate of disposal will be smaller than the rate of production
and may be estimated from the service life of the product and from production
records.
2.5 Environmental Rate - Chemodynamics, Environmental Alteration, and
Bioaccumulation
2.5.1 Outline
The following outline lists the type of information needed to
investigate adequately the toxicological consequence of introduction of a new
chemical such as a PCB substitute. It is not meant to be conclusive but is only
intended as a guideline. These data will assist the toxicologist in relating the
adverse effect levels in animals to appropriate exposure levels for humans.
I. Movement and fate in water
A) Dissipation rate in distilled water
1. hydrolysis rate at acid, basic, and neutral pH
2. photodegradation
B) Degradation in water containing suspended solids
C) Degradation in bottom sediments
D) Rate and extent of movement in flowing water — chemical
analysis of water downstream
E) Bioaccumulation in aquatic microorganisms
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II. Movement and fate in soil
A) Soil metabolism studies — aerobic and anaerobic
B) Soil persistence studies
C) Leaching studies
III. Movement into and fate in air
A) Volatilization from water, soil and normal use
B) Photodegradation
IV. Fish uptake — in flowing water until plateau is
reached and clearing in clean water
V. Biodegradability under sewage treatment conditions
2.5.2 Behavior in Aquatic Environment
The major factors contributing to the partition of a chemical
into the aquatic environment are its solubility and latent heat of solution. Be-
cause so many organic compounds are hydrophobic, exact solubilities are difficult
to obtain. Many of these compounds tend to accumulate at the air/water interface
and to form clusters of varying particle size. Temperature, pH, salt content, and
other variables affect solubility.
Microbial, photochemical and chemical transformations in aquatic
systems play an important role in the ultimate fate of chemicals. Bioaccumulation
occurs through:
1.) Direct, active ("intended") transport into an organism's
system
2.) Active transport, where the compound is mistaken for
one with similar properties (e.g., arsenic being taken
up in place of phosphorus)
3.) Passive complex formation, with ligands in the organism
4.) Solubility equilibrium between fat (in the organism)
and water
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II. Movement and fate in soil
A) Soil metabolism studies — aerobic and anaerobic
B) Soil persistence studies
C) Leaching studies
III. Movement into and fate in air
A) Volatilization from water, soil and normal use
B) Photodegradation
IV. Fish uptake — in flowing water until plateau is
reached and clearing in clean water
V. Biodegradability under sewage treatment conditions
2.5.2 Behavior in Aquatic Environment
The major factors contributing to the partition of a chemical
into the aquatic environment are its solubility and latent heat of solution. Be-
cause so many organic compounds are hydrophobic, exact solubilities are difficult
to obtain. Many of these compounds tend to accumulate at the air/water interface
and to form clusters of varying particle size. Temperature, pH, salt content, and
other variables affect solubility.
Microbial, photochemical and chemical transformations in aquatic
systems play an important role in the ultimate fate of chemicals. Bioaccumulation
occurs through:
1.) Direct, active ("intended") transport into an organism's
system
2.) Active transport, where the compound is mistaken for
one with similar properties (e.g., arsenic being taken
up in place of phosphorus)
3.) Passive complex formation, with ligands in the organism
4.) Solubility equilibrium between fat (in the organism)
and water
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