EPA 560/6-77-034
E5
INPUT/OUTPUT STUDIES
TASK V
BENZENE CONSUMPTION
AS A SOLVENT
OCTOBER J97S
^
T • -*
U.S. ENVIRONmENTflL PROTECTION AGENCY
OFFICE OF TOXIC SUBSTANCES
WASHINGTON, D.C. 2O46O
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EPA-560/6-77-034 AAI 2378/2379-105-FR-5
Market Input/Output Studies
Task V
Benzene Consumption as a Solvent
M. Lynne Neufeld
Marcus Sittenfield
Rowland Henry
Susan Hunsickef
October, 1978
Final Report
Contract No. 68-01-1996
Project Officers
Tom Kopp
Vincent DeCarlo, Ph.D.
Prepared for:
Office of Toxic Substances
U.S. Environmental Protection Agency
, . Washington, B.C. 20460
Document is available to the public through the
National Technical Information Service, Springfield,
Virginia 22151
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NOTICE
This report has been reviewed by the Office of Toxic Substances, Environ-
mental Protection Agency, and approved for publication. Approval does not
signify that the contents necessarily reflect the views and policies of
the Environmental Protection Agency. Mention of tradenames or commercial
products is for purposes of clarity only and does not constitute endorse-
ment or recommendation for use.
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FOREWORD
This study was conducted to determine the current status of the indus-
trial and consumer consumption of benzene as a solvent, and to identify where
possible any impact on its use as a solvent due to the OSHA Emergency Benzene
Standards (42 FR 27452, May 27, 1977).
Approach to the Study
Since the consumption patterns for benzene as a solvent fall into two
major areas (as an adjunct to chemical manufacturing processes and in the formu-
lation of industrial and consumer products), it was necessary first to identify
those companies which manufacture chemicals utilizing processes where benzene
could be a solvent (esterification, azeotropic dehydration, extraction,
recrystallization and reaction solvent uses), and manufacturing companies in
the following areas: paints, coatings and paint removers, and solvent-type
rubber-based adhesives.
Altogether 405 companies were identified and interviewed to determine
the status of their use of benzene. They were identified through the use of
appropriate trade and manufacturing directories and from our personal knowledge
of the chemical manufacturing industry. A list of the companies contacted is
presented in Appendix II.
In addition, a thorough search of the published literature was con-
ducted to uncover any relevant consumption data.
Organization of the Study
The study is organized into five sections. Section I presents a
general overview of the technical and commercial history for the manufacture
of benzene. Section II discusses the marketing and distribution patterns of
benzene into the miscellaneous or small volume use areas which constitute the
basis of its consumption as a solvent. Section III examines in detail the con-
sumption processes for the two major areas of benzene use as a solvent discussed
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above, presenting, where the information was available, patterns before and
after the OSHA regulations. Section IV presents feasible alternatives to the
use of benzene as a solvent, and Section V summarizes the losses of benzene
to the environment with an estimation of their geographic distribution, as a
result of the processes described in Section III.
Acknowledgements
This report was prepared by the staff of AUERBACH Associates, Inc. (AAI),
Philadelphia, PA and their subcontractor, Marcus Sittenfield & Associates.
Mr. Tom Kopp and Dr. Vincent DeCarlo, Environmental Protection Agency, Office of
Toxic Substances, served as Project Officers. Technical guidance was also pro-
vided by Mr. Richard Johnson of the Office of Air Quality, Planning and Standards,
Research Triangle Park, NC.
AAI is indebted to the 405 companies who contributed data and expert
opinion concerning conclusions drawn from the data. AAI and Marcus Sittenfield &
Associates, however, assume full responsibility for any errors or omissions.
The patience and diligence of Ms. Michele Fecca in typing drafts and
numerous revisions is also gratefully acknowledged.
ii
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TABLE OF CONTENTS
PARAGRAPH TITUE PAGE
SECTION I. STATUS AND OUTLOOK SUMMARY
1.1 OVERVIEW OF THE TECHNICAL HISTORY OF BENZENE 2
1.2 OVERVIEW OF THE COMMERCIAL HISTORY OF BENZENE 3
SECTION II. GENERAL MARKETING AND
DISTRIBUTION PATTERNS
2.1 PRODUCERS 15
2.2 LARGE BULK DISTRIBUTORS •. 16
2.3 FORMULATORS AND BLENDERS 18
2.4 SMALL DISTRIBUTORS 18
2.5 TRANSPORTATION 20
SECTION III. CONSUMPTION PROCESS STUDY
3.1 ADJUNCT IN CHEMICAL PROCESSES 26
3.1.1 General Organic Synthesis 29
3.1.1.1 Process Description 29
3.1.1.2 Process Consumption 31
3.1.1.3 Environmental Losses 36
3.1.2 Pharmaceutical Industry 37
3.1.2.1 Process Description 39
3.1.2.2 Process Consumption 39
3.1.2.3 Environmental Losses 42
3.2 SMALL VOLUME SPECIALTY CHEMICALS 45
3.2.1 Aluminum Alkyls 45
3.2.1.1 General Description of the Industry 45
3.2.1.2 Losses and Environmental Management 47
3.2.1.3 Alternate Solvents 47
3.2.2 Ethyl Cellulose Resins 47
3.2.3 Alcohols 48
iii
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TABLE OF CONTENTS (CONTINUED)
PARAGRAPH TITUE PAGE
3.2.3.1 Denatured Ethyl Alcohol .48
3.2.3.2 Anhydrous Ethyl Alcohol ..... 53
3.2.3.3 Other Alcohols 55
3.2.4 Bisphenol-A 57
3.3 FORMULATED INDUSTRIAL AND CONSUMER PRODUCTS 58
3.4 FORMULATED PRODUCTS: ADHESIVES 59
3.4.1 General Consumption Patterns 65
3.4.2 Solvent Type Rubber-Based Adhesives 69
3.4.2.1 Tires and Tubes 69
3.4.2.2 Tire Retreading 71
3.4.2.3 Industrial Rubber Products 72
3.4.2.4 Rubber Reclaiming 72
3.4.2.5 Tire and Tube Repair or Patch Kits 72
3.4.2.6 Miscellaneous Uses 73
3.5 FORMULATED PRODUCTS: PAINTS AND ALLIED PRODUCTS 75
3.5.1 Paints and Coatings 75
3.5.2 Paint Removers 76
3.6 SUMMARY 80
SECTION IV. USE ALTERNATE ANALYSIS
4.1 ALTERNATE SOLVENTS IN CHEMICAL MANUFACTURING PROCESSES. ... 83
4.2 ALTERNATE SOLVENTS IN SPECIALTY CHEMICAL MANUFACTURE 84
4.2.1 Aluminum Alkyls 84
4.2.2 Ethyl Cellulose Resins 84
4.2.3 Alcohols 84
4.2.4 Bisphenol-A 85
4.3 ALTERNATE SOLVENTS FOR RUBBER-BASED ADHESIVES 85
4.4 ALTERNATE SOLVENTS FOR PAINT AND ALLIED PRODUCTS 86
4.5 ALTERNATE PROCESSES AND END PRODUCTS 86
iv
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TABLE OF CONTENTS (CONTINUED)
PARAGRAPH TITUE PAGE
4.6 ENVIRONMENTAL MANAGEMENT OF ALTERNATE SOLVENTS 87
SECTION V. SUMMARY OF BENZENE LOSSES
5.1 ENVIRONMENTAL LOSSES 92
5.2 GEOGRAPHIC DISTRIBUTION 93
5.3 TRENDS 94
REFERENCES 96
APPENDIX I. NOTES ON CALCULATIONS FOR TABLE 1-4.1 99
APPENDIX II. LIST OF COMPANIES CONTACTED 101
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LIST OF TABLES
TABLE TITLE PAGE
1-1 Benzene Supply Sources 3
1-2 U.S. Production of Benzene '. 3
1-3 Annual Capacity of Benzene Producers 5
1-4 Estimated Consumption of Benzene as a Chemical
Intermediate 8
1-5 Conversion "Factors.for Benzene Consumption 9
1-6 Benzene Consumption for Major Chemical Derivatives,. 1977 . . 9
1-7 Benzene Inventory.Data 10
1-8 Supply/Demand Summary of the Benzene Market 11
2-1 Benzene Sales Volumes of Large Distributors to the
Miscellaneous Use Market 17
2-2 Benzene Consumption of Solvent Blenders 19
2-3 Benzene Sales Volumes of Small Distributors 21
3-1 Benzene Consumption in General Organic Synthesis 34
3-2 Estimated Benzene Solvent Loss to Environment From Chemical
Manufacture 37
3-3 Benzene Consumption in Pharmaceutical Manufacture 41
3-4 Estimated Benzene Solvent Loss to Environment From
Pharmaceutical Manufacture 44
3-5 Domestic Producers of Aluminum Alkyls 45
3-6 Consumption of Solvents as Packaging Blend for Aluminum
Alkyls 46
3-7 Annual Domestic Production of Ethanol, 1976 49
3-8 Denaturant Formulae and Authorized Uses as a Solvent .... 50
VI
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LIST OF TABLES
TABLE TITLE PAGE
3-9 Volume of Ethanol Denatured with Benzene and Equivalent
Benzene Consumed 51
3-10 Benzene Consumption in the Ethyl Alcohol Industry 52
3-11 Azeotropic Data for Ethyl Alcohol 53
3-12 Producers of Anhydrous Ethyl Alcohol 54
3-13 Manufacturers of Anhydrous Isopropyl Alcohol 55
3-14 Consumption of Benzene as an Azeotrope for Other Anhydrous
Alcohols " 56
3-15 Manufacturers of Bisphenol-A 57
3-16 Basic Types of Adhesives and Applications 60
3-17 Classification of Adhesives Based on Origin of the Principal
Components 64
3-18 Classification of Adhesives by Physical Type .' . 59
3-19 Principal Polymers for Water and Solvent Based Adhesives . . 66
3-20 End Uses and Adhesive Components 65
3-21 Estimated Share of Household Adhesive Market 68
3-22 End Use Consumption of Rubber-Based Adhesives 69
3-23 Calculated Solvent Consumption for Retreading, 1977 71
3-24 Major Tire Repair Kit Manufacturers 72
3-25 Estimated Atmospheric Benzene Losses From Paint
Removers, 1976 79
3-26 Summary of Benzene Solvent Consumption 81
4-1 Alternate Solvents for Benzene 88
5-1 Consumption Versus Environmental Loss for Benzene Solvent
Uses 91
vii
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LIST OF ILLUSTRATIONS
FIGURE TITLE PAGE
1-1 Input/Output Summary of Benzene Consumption, 1977 .... 12
3-1 Miscellaneous Benzene Uses, 1976 27
3-2 Typical Azeotropic Distillation Processes 30
3-3 Typical Extraction Process and Recrystallization
Purification Process 32
5-1 Geographic Distribution of Solvent Benzene
Consumption by Region, 1976 95
viii
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SECTION I. STATUS AND OUTLOOK SUMMARY
Benzene is a major raw material for the chemical industry. Almost all
the benzene produced is converted into other chemical products. The small
quantity remaining goes into inventory, export, or various miscellaneous commer-
cial and industrial solvent applications.
With the growing concern over the health and environmental hazards of
benzene and the increasing regulation of the amount permitted in the workplace,
most small consumer-oriented uses of benzene, as a solvent in such products as
paint removers, tire patch kits and rubber adhesives, have been eliminated.
Until the late 1950's, benzene was obtained chiefly as a by-product of
coke manufacture. Petroleum-derived benzene entered the marketplace in the
period 1940-1950. Since then, petroleum-derived benzene production has grown
and today provides more than 90% of all benzene produced in the United States.
Since 1967, benzene production has shown an average annual growth
rate of more than 5%. Annual changes in benzene production have varied from
a decline of 31% between 1974 and 1975 to an increase of 39% between 1975 and 1976.
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Benzene production appears to be sensitive to both the economic cycle
and to the increasing demand for aromatics in unleaded gasoline. It is expected
that the supply-demand situation for benzene will continue to follow past patterns.
1.1 OVERVIEW OF THE TECHNICAL HISTORY OF BENZENE
Originally, benzene was obtained only as a by-product of coke manu-
facture. With the rapid increase in demand for aromatics during World War II,
petroleum refiners developed methods for the recovery of toluene and xylene from
petroleum. As demand for benzene grew in the late 1940's, these processes were
easily adapted for benzene production. 1950 was the first year that measurable
quantities of petroleum-based benzene were produced. Within ten years, more
benzene was being produced from petroleum than from coal. Today more than 90%
of benzene production is petroleum-based (see Table 1-2).
Coke-oven benzene is isolated by fractional distillation of light
oil recovered from coal gas derived from coking of coal. A small amount of
light oil occurs as a fraction of by-product coal tar. About two gallons of
benzene are recovered per ton of coal (Lowenheim and Moran, 1975).
There are three major petroleum sources of benzene: the catalytic
reformate from refinery streams; pyrolysis gasoline, a by-product of ethylene
manufacture; and hydrodealkylation of toluene (Fick, 1976). Nearly half of
the supply of benzene is from refinery reformate. By 1985, this is expected
to slip to only 38% of supply, although production from this source should
exceed one billion pounds. Pyrolysis gasoline as a benzene source is forecast
to account for a 31% share of production in 1985, spurred by projected increases
in ethylene capacity (Fick, 1976) for the manufacture of polyethylene. Produc-
tion of benzene from toluene depends on the markets for and relative prices of both
chemicals. Hydrodealkylation is an expensive process, and is only profitable
when there is a large price spread between toluene and benzene. The need for
high octane unleaded gasoline could spur demand for toluene for this use, making
it less available for conversion to benzene.
Table 1-1 shows the distribution of benzene supply sources for 1976,
together with projections for 1985.
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TABLE 1-1. BENZENE SUPPLY SOURCES
(Fick, 1976)
1976*
1985
Refinery Reformate
Pyrolysis Gasoline
Toluene Hydrodealkylation
Coal Processes
Imports
Total
million
gallons
710
155
450
100
75
1490
48
10
30
7
_5
100
million
gallons %
1070
880
550
200
150
38
31
19
7
5
2850
100
* 1976 figures are estimates made during the first half of 1976, and as such
will not correspond to official U.S. International Trade Commission data cited
elsewhere in this report.
1.2
OVERVIEW OF THE COMMERCIAL HISTORY OF BENZENE
Benzene production, broken down by source, is shown for the last fien
years in Table 1-2.
TABLE 1-2. U.S. PRODUCTION OF BENZENE (Millions of Gallons)
(U.S. International Trade Commission, 1975-1978;
U.S. Tariff Commission 1970-1974)
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977(p)
From
Coke Oven
Operations
92.6
,7
,5
.1
101.
93.
72.
79.8
85.9
82.1
65.0
60.4
From
Petroleum
907.5
1083.6
1040.0
1003.8
1172.6
1367.4
1406.1
958.9
1364.8
.1
.3
Total
1000.
1185.
1133.5
1075.9
1252.4
1453.3
1488.2
1023.9
1425.2
1535.4
Change
18.5
-4.4
-5.1
16.4
16.0
2.
-31.
39.
.4
,2
,2
7.7
P = Preliminary
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Benzene production has grown at an average rate of more than 5% per
year since 1967. The most extreme annual changes occurred in the period
1974-1976. Production plummeted 31% in 1975, to the lowest level since 1968,
and then rebounded in 1976, increasing 39% over the low of the previous year.
This corresponds to the general economic recession in 1974 and 1975.
There are 41 producers of benzene, operating 57 plants. Estimated
total capacity is 2,003 million gallons per year. Table 1-3 lists the producers
with capacities by plant.
Benzene is the basic chemical building block for the aromatic chemical
industry. Over 97% of the benzene produced in 1977 was converted into other .
chemical products. Estimated benzene consumption as a chemical intermediate
has been calculated from published production statistics where available, or
from the best available information from private sources. These estimates
are presented in Table 1-4. In several cases, figures for derivative production
were adjusted to account for non-benzene based sources.
The best available conversion factors were used to obtain benzene
consumption from the production statistics for each derivative. They appear
in Table 1-5. The conversion factors were assumed to be constant over the
period studied (1971-1977). A density factor of 7.365 Ibs./gal. of benzene was
used to change pounds into gallons.
Calculations of benzene consumption are subject to much uncertainty.
Inaccurate or incomplete reporting of production data to government and trade
organizations is one source of error. Another is the selection of conversion
factors, which may vary widely, as illustrated by the inclusion of factors
from two different sources in Table 1-5. A small change in the conversion factor
could have a large effect on the computed benzene consumption figure.
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TABLE 1-3. ANNUAL CAPACITY OF BENZENE PRODUCERS
(Gunn and Ring, 19.77; Private Industry Contacts, 1978).
Company
Amerada Hess Corp.
Hess Oil Virgin Islands Corp.
American Petrofina Inc.
American Petrofina Co. of Texas
American Petrofina of Texas/Union
Oil Co. of California
(joint venture)
Cosden Oil and Chemical Co.
Armco Steel Corp.
Ashland Oil, Inc.
Atlantic Richfield Co.
Arco Chemical Co.
Bethlehem Steel Corp.
CF&I Steel Corp.
The Charter Co.
Charter Oil Co., subsidiary
Charter Chemicals -
Charter International Oil Co.
Cities Service Co.
Coastal States Corp.
Commonwealth Oil Refining Co., Inc.
Commonwealth Petrochemicals, Inc.
Crown Central Petroleum
The Dow Chemical Company
Exxon Corporation
Exxon Chemical Co., div.
Getty Oil Company
Plant Location
St. Croix, VI
Port Arthur, TX
Beaumont, TX
Big Spring, TX
Middletown, OH
Ashland, KY
North Tonawanda, NY
Channelview, TX
Houston, TX
Wilmington, CA
Bethlehem, PA
Sparrows Point, MD
Pueblo, CO
Houston, TX
Lake Charles, LA
Corpus Christi, TX
Penuelas, PR
Pasadena, TX
Bay City, MI
Freeport, TX
Baton Rouge, LA
Baytown, TX
El Dorado, KS
Capacity (MM gal.)
65
20
22
58
3
64
23
32
42
12
4
15
3
5
25
70
185
23
30
50
70
60
13
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TABLE 1-3. ANNUAL CAPACITY OF BENZENE PRODUCERS (cont'd)
Company
Gulf Oil Corp-
Gulf Oil Chemicals Co., Div.
Independent Refining Corp. •
Kerr-McGee Corp.
Southwestern Refining Co., Inc.
The LTV Corp.
Jones & Laughlin Industries, Inc.
Lone Star Steel Corp.
Subs, of Northwest Industries, Inc.
Marathon Oil Company
Mead Corporation
Mobil Corporation
Mobil Chemical Co.
Monsanto Company
Monsanto Chemical Intermediate Co.
Pennzoil Co.
Atlas Processing Co.
Phillips Petroleum Co.
Phillips Chemical Co.
Phillips Puerto Rico Core, Inc.
Quintana-Howe11
(joint venture of Quintana Refinery
Co. and the Howell Corp.)
Shell Oil Co.
Shell Chemical Co.
Standard Oil Co. of California
Chevron Chemical Co.
Plant Location
Alliance, LA
Philadelphia, PA
Port Arthur, TX
Winnie, TX
Corpus Christi, TX
Aliquippa, PA
Lone Star, TX
Texas City, TX
Chattanooga, TN
Woodward, AL
Beaumont, TX
Alvin (Chocolate Bayou) /
Texas City, TX
Shreveport, LA
Sweeny, TX
Guayama, PR
Corpus Christi, TX
Deer Park, TX
Odessa, TX
Wood River, IL
El Segundo, CA
Capacity (MM gal.)
67
37
40
3
16
10
1.4
0.2
1.4
60
85
15
10
110
90
12
45
23
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TABLE 1-3. ANNUAL CAPACITY OF BENZENE PRODUCERS (cont'd)
Company
Standard Oil Co. of Indiana
Amoco Oil Co.
The Standard Oil Co. (Ohio)
BP Oil Inc.
Sun Company Inc.
Sun Oil Company of Pennsylvania
Sun Petroleum Products Co.
Tenneco Inc.
Tenneco Oil Co.
Texaco Inc.
Union Carbide Corp.
Chemicals and Plastics Div.
Union Oil Co. of California
Union Pacific Corp
Champlin Petroleum Co., subs.
United States Steel Corp.
USS Chemicals
Total
Plant Location
Texas City, TX
Marcus Hook, PA
Corpus Christi, TX
Marcus Hook, PA
Toledo, OH
Tulsa, OK
Chalmette, LA
Port Arthur, TX
Westville, NJ
Taft, LA
Lemont, IL
Corpus Christi, TX
Clairton, PA
Geneva, U7
Capacity (MM gal.)
85
38
29
49
24
10
45
35
70
17
10
45
4
2003
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TABLE 1-4. ESTIMATED CONSUMPTION OF BENZENE AS A CHEMICAL INTERMEDIATE (1.000 Gallons)*
(AAI, 1977, 1978)
Ethylbenzene
Cume no
Cyclohexane
Aniline
ChlorobenzenCj Mono-
Chlorobenzene, Di-
Alkylbenzene> Linear
Alkylbenzene, Branched
Maleic Anhydride
Phenol (from Benzene Sulfonlc Acid)
Anthraqulnone
Resorclnol
Blphenyl
Nitrobenzene (not for Aniline)
!
;llydroqulnone
Total Consumption as Intermediate
1971
535,686
200 ,-872
162,082
44,723
45,527
10,443
29,875
11,304
38,817
14,802
9,473
3,026
2,854
1,543
303
1,131,330
1972
688,125
214,818
239,436
50,080
44,925
11,760
28,459
10, 768
46,578
16,357
10,257
3,523
3,321
1,946
352
1,370,705
1973
692,310
249,712
221,122
55,924
44,254
10,841
27,060
10,238
47,830
15,259
10,088
4,090
3,853
1,090
409
1,394,080
1974
689,931
272,218
244,969
67,354
42,217
10,406
28,938
10,947
49,188
14,287
10,084
4,196
3,948
1,788
420
1,450,891
1975
534,687
187,626
180,603
49,727
34,072
8,455
26,897
10,177
34,799
13,339
7,901
2,880
2,716
1,462
288
1,095,629
1976
720,605
254,436
227,787
66,450
36,638
9,031
28,713
10,862
41,531
16,293
10,048
4,073
2,716
2,716
407
1,432,306
1977
780,685
247,320
233,508
71,374
36,741
9,056
28,520
11,123
36,343
16,483
10,048
4,073
2,783
2,716
407
1,491,180
I
00
* See Appendix I, Notes on Calculations
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TABLE 1-5. CONVERSION FACTORS* FOR BENZENE CONSUMPTION
(Gunn and Ring, 1977; Lowenheim and Moran, 1975)
Derivative Factor
Ethylbenzene
Cumene
Cyclohexane
Aniline
Monochlorobenzene
Dichlorobenzenes
Linear Alkylbenzene
Branched Alkylbenzene
Maleic Anhydride
Phenol (from Benzene
Sulfonic Acid)
Nitrobenzene
0.76 (0.74)**
0.69 (0.80)
0.93 (0.94)
0.90
0.82 (0.95)
0.62
0.40 (0.49)
0.40
1.25 (1.34)
(1.00)
(0.65)
* Pounds of benzene per pound of derivative
** Figures in parentheses ( ) are from Lowenheim and Moran; all others are from
Gunn and Ring.
Seven major benzene derivatives accounted for 97.5% of benzene
consumption in 1977, and have consumed more than 97% of the benzene produced
since at least 1971. They are listed in Table 1-6.
TABLE 1-6. BENZENE CONSUMPTION FOR MAJOR CHEMICAL DERIVATIVES, 1977
(AAI, 1978, based on Table 1-4)
% of Total Consumption
Ethylbenzene 52.4%
Cumene 16.6
Cyclohexane 15.6
Aniline 4-8
Chlorobenzenes 3.1
Alkylbenzenes 2.6
Maleic Anhydride 2.4
97.5%
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.The remaining benzene is consuued by the manufacture of smaller-
volume derivatives (see lower part of Table 1-4), miscellaneous uses, changes in
inventory, and net exports. The miscellaneous uses of benzene, which take up a very
small portion of the total consumption, include the synthesis of a wide variety
of speciality chemicals^ use-as an adjunct in the manufacture of chemicals,
petrochemicals and polymers, and as a solvent in formulated products.
Inventory data, obtained from the National Petroleum Refiners
Association (NPRA), are incomplete. Where available, they represent only the
amount reported by those benzene manufacturers and major benzene consumers who
submit data to the NPRA. For example, the 1976 inventory contained data from
one company that did not report in 1975. This omission is estimated to amount
to as much as 50 million gallons. The data also do not include benzene held
in storage by brokers, resellers, or smaller benzene consumers. Inventory data
for five years are shown in Table 1-7.
TABLE 1-7. BENZENE INVENTORY DATA
(National Petroleum Refiners Association, 1977, 1978)
Benzene in Inventory Change in Inventory
as of Dec. 31 (gal.) Compared to Previous Year (gal.")
1977 192,943,000 -17,003,000
1976 209,946,000 92,247,000
1975 117,699,000 -55,000,000
19?4 172,699,000 86,145,000
1973 86,554,000
An overall supply/demand summary of the benzene market based on Table
1-4, published information, and industry sources is presented in Table 1-8,
and illustrated for 1977 in Figure 1-1. The table shows an approximate material
balance for benzene and is not intended to provide a concrete numerical assess-
ment of benzene availability and demand. The next to last row of the table,
the difference between total available benzene and total consumption, is subject
' -10-
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TABLE 1-8. SUPPLY/DEMAND SUMMARY OF THE BENZENE MARKET (1,000 Gallons)
(AAI, 1978)c
Total Benzene Production
Imports
Tofal Benzene Available
Consumption (Table 1-4)
Exports
Total Benzene Consumption
Difference: Available -Consumed
Inventory Change
1971
1,075,900
76,687
1,152,587
1,131,330
42,589
1,173,919
-21,332
1972
1,252,400
95,965
1,348,365
1,370,705
29,002
1,399,707
-51,342
1973
1,453,300
51,867
1,505,167
1,394,080
29,610
1,423,690
81,477
1974
1,488,200
102,258
1,590,458
1,450,891
23,453
1,474,344
116,114
86,145
1975
1,023,900
70,320
1,094,220
1,095,629
18,300
1,113,929
-19,709
-55,000
1976
1,425,200
52,523
1,477,723
1,432,306
28,917
1,461,223
16,500
92,247
1977
1,535,400
61,346
1,596,746
1,491,180
26,834
1,518,014
78,732
-17,003
V
Sources: Production data. Table 1-2; Import and Export statistics, Bureau of Census, U.S. Dept. of Commerce,
1972-1978; Consumption figures, Table 1-4; Inventory, Table 1-7.
-------
PRODUCTION
1,535.4 MM gal.
IMPORTS
61.3 MM gal.
BENZENE
26.8 MM gal.
EXPORTS
CONVERSION TO CHEMICALS
LISTED IN TABLE
1,491.2 MM gal.
MISCELLANEOUS CHEMICAL
CONVERSION, SOLVENT USES
& INVENTORY CHANGES
78.7 MM gal.
Figure 1-1. Input/Output Summary of Benzene Consumption, 1977
-12-
-------
to uncertainty, due to the reporting and calculation errors in the figures
which make it up (see earlier discussion of inventory data and conversion fac-
tors) .
There is considerable variation in the material balance difference
from year to year. Inclusion of annual inventory changes in the table does
little to minimize this variation. As noted earlier, the calculation errors
in determining benzene consumption and reporting errors of production are large
enough to account for the entire difference between benzene availability and
consumption (see final rows of Table 1-8).
The small volume of benzene consumed in the miscellaneous market is
included in these difference figures. The miscellaneous market includes a
range of consumer and industrial applications, such as:
(1) Conversion to small volume specialty organic chemicals
(2) Use as an adjunct in 'chemical manufacturing processes; e.g., as an
aseotropic agent or extraction solvent
(3) Use as a denaturant for ethyl alcohol
(4) Use as a solvent in the formulation of consumer products, such
as paint removers and rubber-based adhesives.
According to industry sources, the amount of benzene that enters this
market is extremely small, probably on the order of three to five million gallons
or less per year.
Benzene use as a solvent in consumer products such as paint removers and
strippers, tire patch and retread adhesives, and rubber cements is reported to
have dropped to near zero as a result of the Occupational Safety and Health
Administration's emergency temporary benzene standard of May, 1977 (OSHA, 1977),
which reduced the allowable concentrations of benzene in the workplace. This
action also caused major benzene sellers and resellers to withdraw from the drum and
small volume sales market. In addition, the Consumer Product Safety Commission
has recently (May 19, 1978) issued a ban on the use of benzene in consumer products
(Federal Register, 1978). This could lead to the total elimination of benzene
-13-
-------
from the formulations of consumer goods. The majority of consumer products
have already been reformulated to eliminate benzene. In those cases where
benzene is present, it is as an accidental contaminant in alternative solvents.
Benzene does find some use as a denaturant of alcohol. Currently, however, its
most widespread miscellaneous use occurs in chemical manufacture, where it is
used both as a chemical intermediate for specialty chemicals and an adjunct.
Benzene is sold through manufacturers, distributors and resellers.
Large bulk sales are handled by producers and distributors having appropriate
terminals from which it is moved by pipeline, barge, railroad tank car or •
tank truck. Smaller sales, in tank wagon or drum quantities, are made by dis-
tributors and resellers.
As a result of the OSHA ruling, many of the larger benzene distribu-
tors and resellers have discontinued small volume drum sales. Nearly all of
the smaller solvent dealers have stopped handling benzene. A few "can get"
benzene, but will not store, handle or drum it themselves.
-14-
-------
SECTION II. GENERAL MARKETING AND
DISTRIBUTION PATTERNS
The sales and distribution patterns for the miscellaneous markets of
benzene have been affected by the OSHA temporary standard, resulting in a strong
trend away from small volume benzene handling (drums and spot sales in bulk) among
suppliers. Benzene manufacturers and large bulk solvent distributors are dis-
continuing all but large volume bulk sales, which are generally to chemical manu-
facturers for intermediate use. Smaller distributors and solvent blenders are
eliminating benzene sales which require storage and repackaging. Many have
discontinued all sales of benzene. Some customers who still want benzene for
their processes have reported difficulties in obtaining the small quantities they
require.
2.1 PRODUCERS
The producers of benzene, which include steel (coke) manufacturers and
petroleum refiners, are geared to high volume bulk sales and distribution. These
companies report sales in tankcar, barge and pipeline quantities to "major
consumers", who are generally either large regional distributors or chemical
companies who use the benzene as a chemical intermediate in the production of
-15-
-------
derivatives such as styrene. None of the suppliers in this group deal in
quantities smaller than carloads or truckloads. However, some of the companies
that produce benzene are equipped to deal in the occasional tankcar and tankwagon
volumes required by small users.
Since these large producers sell the bulk of their benzene directly
to chemical manufacturers or regional distributors they make little direct
contribution to the small volume miscellaneous use market.
2.2 LARGE BULK DISTRIBUTORS
Some benzene enters the miscellaneous use market from large bulk
distributors, many of whom have shipping terminals and offices nationwide. They
sell benzene directly in tankcar and tankwagon quantities, as well as in larger
quantities (via barge and pipe line) to major consumers, and to distributors.
The companies in this group handle large volumes of benzene and
other solvents, both in bulk and in small lots. In recent years, and especially
since the May, 1977 OSHA ruling, these companies have been moving away from
small volume (drum) benzene sales. Two of the national distributors contacted
have discontinued handling benzene in their terminals.
Table 2-1 presents a representative view of the consumption patterns
of benzene based on interviews with 13 major distributors. For several
of these companies the distinction between "producer" and "large distributor"
is difficult to make. This table does not attempt to account for all benzene
entering the miscellaneous use market; however, the drop to approximately
25% of the sales volume prior to 1977 agrees with the general trend as reported
elsewhere in this study.
Current benzene distribution can be characterized as follows. The
large producers pipeline or barge benzene in bulk to large chemical consumers
or to major distributors, who have strategically located bulk terminals. From
the major distributors it would be shipped in bulk (tankwagon or tankcars) to
regional distributors or local solvent resellers and formulators, or directly
to regional end users. The large producers and distributors have discontinued all
-16-
-------
TABLE 2-1. BENZENE SALES VOLUMES OF LARGE DISTRIBUTORS
TO THE MISCELLANEOUS USE MARKET
Company
A
B
C
D
E
F
6
H
I
J
K
L
M
Estimated
Total
Annual Volume
Sold Pre-OSHA (1976)
(gallons)
100,000-125,000
minimal tank wagon
sales
direct bulk sales only
50,000 tank wagon
lots to local
distributors
direct bulk sales only
bulk sales '
shipload sales only
200,000 (90% of small
sales to paint
industry)
800,000
100,000
1,000,000
not available
200,000
2,450,000
Annual Volume
Sold Post-OSHA (1977)
(gallons)
100,000-125,000
bulk sales only
200,000
direct bulk sales only
bulk sales only
direct, bulk sales only
bulk sales
shipload sales only
140,000 (Al. Alkyls)
10,000 (Misc. uses)
discontinued sales to
small consumers
discontinued handling
benzene at all 30
locations
bulk sales only
290,000
not available
740,000
Customer type /Comments
1-2,000 gallons in drums
but do not drum them-
selves
aluminum alkyls (170,000)
a national solvent
distributor
chemical intermediate
reseller
chemical intermediate
aluminum alkyls; ceased
drumming operations
alkyls and tetraethyllead;
25,000 purchased for
drumming
paint remover (discontinued
1978); insecticide manu-
facturer; tire patch kits
-17-
-------
drumming facilities, and many regional bulk terminals have been eliminated.
A few of the large producers are continuing to make "spot" or non-contract
bulk sales of benzene.
2.3 FORMULATORS AND BLENDERS
In the past, benzene has been sold as a component of solvent and paint
stripper blends. All of the eight formulators contacted reported no longer
using benzene in their blends. Benzene use was halted as much as four to six
years ago in some cases, while in others, use was discontinued as recently as
the May, 1977 OSHA ruling. Chlorinated solvents and other solvents considered
less hazardous than benzene have been substituted in the solvent blends. Benzene
consumption in solvent blends is given in Table 2-2 for those companies
providing data. Section 3.5 contains a complete discussion of benzene use
in the paints and coatings industry.
According to one company's spokesman, the OSHA regulations have
increased costs to the company in areas such as the handling and drumming of
benzene, equipment, and insurance. Small companies are hit harder by the
standard than are larger ones. The spokesman stated that his company may
cease handling benzene regardless of customer demand.
2.4 SMALL DISTRIBUTORS
The majority of the benzene that enters the small volume market
is handled by regional or local solvent distributors and resellers. Sales
have been in drum lots, with individual companies generally selling a few
thousand gallons a year each, although several reported annual turnovers of
10-15,000 gallons or more. Of the 54 small solvent distributors contacted, over
half (29) said they had never carried benzene, had discontinued handling it
more than four years ago, or simply that they did not now sell benzene. Another
17 discontinued handling benzene within the past 18 months. A few of these
said they could get benzene, although it was not an active item. Only
eight companies were identified as currently selling benzene.
-18-
-------
TABLE 2-2. BENZENE CONSUMPTION OF SOLVENT BLENDERS
Company
A
B
C
D
E
Total
Annual Volume Used
in Solvent Blends -
Pre-OSHA (1976)
(gallons)
10,000
15-20,000
5,000
8-10,000
<5,000
43,000-50,000
Annual Volume Used
in Solvent Blends -
Post-OSHA (1977)
(gallons)
Nil
Nil
Nil
Nil
Nil
0
>
i
Customer Type /Comments
Formulated paint stripper,
was 20% benzene. Benzene
eliminated several years ago.
Formulated paint stripper
Formulated paint stripper
Sales to paint companies for
formulation into strippers and
thinners
Drum sales to paint companies
VO
I
-------
Table 2-3 summarizes benzene sales before and after the May, 1977
OSHA ruling for those small distributors who supplied sales information.
Among small volume distributors, there has been a strong movement
away from benzene sales. The hazards of handling benzene and the expense of
compliance with the OSHA standard and other local pollution and health regula-
tions, combined with the sharp decline in demand for the solvent, have caused
many companies to discontinue small sales of benzene.
2.5 TRANSPORTATION
The OSHA benzene standard will have an effect not only on the pro-
cessing, handling and distribution of benzene, but on its transportation as
well. An estimated 500-600 workers are involved in benzene transport by barge,
railcar and truck. To meet the standard, improvements and changes in equipment
and procedures may be necessary (Chemical Week, 1977). Another consideration
in the movement of benzene is the growing concern over the safe transport of
hazardous chemicals. Insurance problems, regulatory action and need for
equipment modifications may all have an effect on the transportation of benzene.
Most miscellaneous market shipments of benzene are in tank trucks,
compartmentalized trucks and drums. Several trucking companies were contacted
concerning their transporting of benzene. Only one trucker reported refusing
to haul benzene, as a result of the OSHA ruling. They had worked together with
a major oil company trying to meet the standards. When they found they could
not, they discontinued handling benzene, rather than invest in closed loading
systems and equipment.
-20-
-------
TABLE 2-3. BENZENE SALES VOLUMES OF SMALL DISTRIBUTORS
Company
A
B
C
D
E
F
G
H
Annual Volume
Sold - Pre-OSHA
(1976) (gallons)
<4,000
6,400
20,000
27,500
(1973)
13-14,000
13-20,000
x**
X
Annual Volume
Sold - Post-OSHA
(1977) (gallons)
Nil
60 gal sold, last
9 months of 1977
10,000 gal/yr. to
one customer
6,600
(13-14,000)*
(13-20,000)
will sell in tank cars
occasional partial tank
wagon (500 gallons)
Customer Type/Comments
Paint remover, adhesives
Most sold in drums, but some in
blends; company discouraging benzene
sales
Will still drum, but not store benzene
Pints and gallons for lab use, paint
and adhesives industries
For use as extraction solvent, chemical
intermediate (specialty)
Adhesives, fine chemicals
Will not sell drums. Use: industrial
and specialty coatings
Alcohol denaturant, paints and coatings
Do their own drumming
Sales have dropped since OSHA ruling
* Pre-OSHA volume inserted in parentheses for companies not reporting current volumes, but considered to be still
handling benzene.
** X = no volume reported
-------
TABLE 2-3. BENZENE SALES VOLUMES OF SMALL DISTRIBUTORS (continued)
Company
I
J
K
L
M
N
0
Total
Annual Volume
Sold - Pre-OSHA
(1976) (gallons)
6,000
1 tank car load,
in drums
X
<3,000
2,500
7-10,000
mid-1976-mid-1977
12,000
120,400-131,400
Annua 1 Vo 1 ume
Sold - Post-OSHA
(1977) (gallons)
(6,000)
(1 tank car load)
about 1 drum in the
past 18 months
Nil
Nil
Nil
Nil
55,215-63,215
Customer Type /Comments
Paint remover (industrial) sold in
drums
Sales low since shortage of 1973
Said they can get benzene if required
Sales were in drums for paint remover
and rubber cement
Sales were for paint removers ; will no
longer drum benzene
Sales were for adhesives and paint removers
Will sell bulk quantities , but will not
store or handle; none in drums
Furniture strippers ; sold in drums
-------
Another company has felt no effects from the OSHA regulation. Their
transport of benzene has always been erratic, fluctuating with the supply of
rail tankcars. Because of this, they have no real way of knowing how the benzene
market is faring under OSHA. The spokesman added that if the permanent standard
goes into effect, everyone would have to convert to closed loading systems. So
far, however, his company has not invested in any such equipment.
A third trucker has experienced no drop in benzene hauls in the
Northeast since the OSHA emergency standard, and is running at about the same
level of activity as last year. The spokesman for another trucking company
estimated that the benzene standard has cost his trucking firm between $100,000
and $150,000. This includes the costs of monitoring, safety instruction and
dedicated tank trailers where required.
The OSHA regulation will lead to increased costs for the transportation
of benzene, brought about by equipment modifications, insurance and safety
surveillance needed to meet the standard.
-23-
-------
SECTION III. CONSUMPTION PROCESS STUDY
The consumption patterns for benzene's solvent and miscellaneous
uses are reviewed in Section I. Benzene's.basic use in the chemical industry
is as an intermediate in the manufacture of a wide variety of chemicals (see
Table 1-4) , which consumes over 98% of the benzene produced. The balance is
distributed between inventory, specialty chemical manufacture and a number of
miscellaneous solvent uses.
The environmental exposure to benzene occurs in several ways:
(1) Fugitive escape during production and transportation
(2) Fugitive escape during the chemical conversion of benzene to
other chemicals
(3) As a component of gasoline
(4) As a solvent in consumer and industrial products or fugitive
escape during its use as an adjunct in chemical processes where
it does not enter into a chemical reaction
There have been a number of studies on benzene production processes
and its consumption in the production of other chemicals. Studies on its use
-24-
-------
in gasoline have also been made. Because of the fragmented nature of the
solvent applications of benzene, these uses have often been considered to
be a part of the "other uses" in input-output balances previously made.
Neither the exact amount of benzene that is used as a solvent nor a detailed
breakdown of its uses and losses has been- known with any degree of accuracy-
This section addresses itself to a study of the quantity and .
uses of benzene as a solvent. There are two principal areas in which benzene
is used exclusively as a solvent'.
(1) As an adjunct in chemical manufacturing processes
(2) For the formulation of industrial and consumer products
The results of this study indicate that the benzene demand for use
as a solvent does not exceed five million gallons. Although this is a small
volume compared to the availability of benzene (less than 0.5%), it represents
a significant potential loss of a hazardous chemical to the environment.
This study, therefore, was undertaken to assess the potential hazard to health
and environment resulting from this use of benzene.
The solvent uses of benzene by industry are numerous. The quantity
consumed by any one processor varies from as little as 200 gallons per year
to as much as 500,000 gallons per year. Because the quantity per user is
small, it was necessary to interview a very large number of companies who might
be solvent users to ascertain:
(1) Their present and past benzene consumption
(2) The influence of the OSHA Emergency Benzene Standard on
benzene consumption
(3) Alternate solvents
(.4). Methods of control and disposal of benzene emissions and
wastes
(5) Where possible, the actual environmental losses.
-25-
-------
Figure 3-1 illustrates the miscellaneous uses of benzene as a solvent that
have been considered in the preparation of this study.
3.1 ADJUNCT IN CHEMICAL PROCESSES
A wide variety of solvents is used in chemical -manufacture and chemical
processing for the following operations:
(1) As an azeotroping agent for water removal (dehydration)
(2) As a reaction solvent or reaction medium
(3) As an extracting agent to separate product from the reaction
mass
(4) As a recrystallizing agent to remove impurities from the
product.
These operations are widespread in the chemical industry, and are
used in the following sectors:
(1) Pharmaceuticals
(2) Fine Chemical Manufacture
(3) Flavors and Fragrances
(4) Botanicals
(5) Pesticides
(6) Synthesis of Esters
(7) Anhydrous Alcohols (ethyl and propyl)
Each of these sectors covers a multitude of chemicals. Considerable pro-
prietary information would have to be obtained if process solvent uses were
to be correlated with the manufacture of an individual chemical. Specific
chemicals for which sufficient data could be obtained are discussed in separate
parts of this section. These include:
(1) Aluminum alkyls
(2) Ethyl cellulose
(3) Alcohol manufacture, including denaturing of ethyl alcohol
(4) Bisphenol-A
Benzene has a long history of use as a solvent in chemical manu-
facture because of its relatively high volatility (low boiling point), strong
solvent properties for many organic materials, and insolubility in water.
-26-
-------
I
to
Miscellaneous
Benzene Use
Small Volume
Specialty Chemicals
.7>- Solvent Uses
Aluminum A IkyIs
.denatured
Alcohols
inhydrous
Bisplieno]-A
Ethyl Cellulose
Resins
Adjunct in chemical
_\ manufacture
Solvent-Based
Rubber Adheslves*
Paint Removers*
Reaction
Solvents
A/.cotrop J c
Distillation
Extraction
_^_^r Recrystal.lizat.l.on
Figure 3-1. Miscellaneous Benzene Uses, 1976
* As of 1977, benzene has been substantially eliminated from these products.
-------
In addition, benzene has sold at a lower price than other comparable solvents
and has been readily available.
Benzene consumption as a solvent for chemical manufacture has been
decreasing over the years primarily because of its toxicity and increases in
price which have eroded any cost advantage that it may have had over other
solvents. This trend has accelerated following the promulgation by OSHA in
May, 1977 (OSHA, 1977) of a regulation restricting the use of benzene in the
workplace.
The Standard Industrial Classification (SIC) classifies the chemical
industry as follows:
281: Industrial Inorganic Chemicals
282: Plastic'Materials and Synthetics
283: Drugs
284: Soaps, Cleaners and Toilet Goods
285: Paints and Allied Products
286: Industrial Organic Chemicals
287: Agricultural Chemicals
289: Miscellaneous Chemical Products
In this section, the potential for benzene use as a solvent in the manufacture
of chemicals will be studied for the following classes:
282: Plastic Materials and Synthetics
283: Drugs
286: Industrial Organic Chemicals
289: Miscellaneous Chemical Products
Section 285, Paints and Allied Products will be reviewed in Section 3.3.3. A
.review of the processes used in the manufacture of products covered by
industrial classifications 281, 284 and 287 indicated that benzene solvents
are not used as an adjunct in their manufacturing processes.
-28-
-------
3.1.1 General Organic Synthesis
Benzene is one of many solvents used as an adjunct to the manufacture
of a large number of organic chemicals. The industrial classifications which
encompass the bulk of these applications are:
2869: Industrial Organic Chemicals, N.E.C.
282 : Plastic Materials and Synthetics
283 : Drugs
A discussion of the use of benzene in the manufacture of pharmaceutical
chemicals (SIC 283) will be found in Section 3.1.2.
Solvents are used in the polymerization of certain polymers
and synthetic rubbers (SIC 282). In these processes benzene finds limited
use both as a catalyst carrier and reaction solvent. This application will
be discussed in Section 3.2.1.
3.1.1.1 Process Description
Process operations in which benzene is used as a solvent vary widely
with the chemical manufactured. In a typical azeotropic dehydration process
in which water is removed (e.g., esterification reactions or production of
anhydrous ethanol), the benzene is added to the reactants in a distillation
apparatus, and heat is applied to boil the water-benzene azeotrope. The resulting
vapors are condensed, the condensate flows to a decanter where benzene
is removed as a top layer and returned to the distillation unit;.the:water
saturated with benzene is removed for disposal.
When all the water is removed from the reaction mixture, the benzene
is distilled and recovered for reuse. Process flow diagrams for typical
azeotropic distillation processes are shown in Figure 3-2.
Extraction processes requiring the use of solvents as an adjunct to
chemicals manufacture are common to chemical operations. They find application
in the purification of chemicals and recovery of intermediate or end products
from a reaction mass.
-29-
-------
o
I
Benzene-l/ater
Azeotrope Vapors
Reactants
Benzene
Makeup Benzene
•*
Water-Ethanol
Feed
Waste Water
Recovered
Benzene
Hxh
Waste
Water
Anhydrous Ethanol
Batch Esterification Process or
Reaction in Presence of Solvent
Continuous Azeotropic Ethanol
Dehydration Process
Figure 3-2. Typical Azeotropic Distillation Processes
-------
In extraction processes, benzene is mixed with the reaction mass
which contains the desired component dissolved in a liquid immiscible with
benzene. The benzene extracts (dissolves preferentially) the desired chemical.
The resulting solution is separated "by decantation followed by distillation
where the benzene is vaporized and recovered, leaving the desired component
as a residue. Alternately, the" benzene extract may be fed to a reactor
for further reaction. The benzene solvent is recovered by distillation.
In purification operations, the benzene may be used to recrystal-
lize a material, leaving the impurity in solution from which the benzene
is then recovered by distillation.
Process flow diagrams for typical batch extraction and recrystal-
lization (purification) processes are shown in Figure 3-3.
3.1.1.2 Process Consumption
According to the Census of Manufactures for 1972, there were 514
establishments (sites) which reported the manufacture of chemicals under SIC
2869. Of these, 295 had 20 or more employees. Since chemical companies may
manufacture industrial organic chemicals at more than one site, the number of
establishments may not be equated to the number of companies. We have assumed
that companies employing more than 20 people are the only ones that could
manufacture chemicals at more than one site. On this basis, it is estimated
that there are about 367 companies* which manufacture products under SIC 2869.
For this portion of the study, 142 companies who synthesize organic
compounds were interviewed. Thirty-six companies (25%) representing about 41
establishments, reported that they used or were using benzene as a solvent
material within the past five years; the remaining 106 companies used alternate
* It is assumed that the average number of sites per company with over 20
employees is two; the 295 "large" sites therefore represent 148 companies.
Each of the smaller employment sites represents one company for a total of
514 - 295 = 219 companies; 219 + 148 = 367 potential companies who manufacture
under SIC 2869.
-31-
-------
Reaction Mass
Benzene
i
OJ
N>
I
Steam
Extrac
Reacto
I
X
f*
Soli
ai
Recrysl
Ve:
O
-s.
tion
d
allizat
sel
o
*
Dn
M ^.
Coolant
Out
HXI-
•w-
Recovered
Benzene
Coolant
In
Centrifuge
Solvent to
Recovery
Aqueous layer
Recovered
Product to
Drying
Product
Extraction Processes
Recrystallization Purification
Figure 3-3. Typical Extraction Process and
Recrystallization Purification Process
-------
solvents or no solvents in their operations. Only two of the thirty-six
companies reported they had discontinued benzene use prior to 1976. Fifteen
of the thirty-six user companies reported they were no longer using benzene
as a solvent in their operations as of May 1978 one company eliminated its
use at one of its process sites, while one other reduced its consumption. The
companies which eliminated benzene in their process are now using alternate
materials.
Benzene consumption by company varies from 570,000 gallons to as
little as 300 gallons. Site consumption is considerably less since the large
benzene solvent users have more than one manufacturing site.
Total annual consumption in 1976 by those companies contacted who
reported use of benzene as a solvent ranged between 1.098 and 1.198 million
gallons. This data is summarized in Table 3-1. In 1978, following the
issuance of OSHA's benzene regulations, the annual consumption is expected to
decline to between 813,800 and 885,750 gallons.
The average benzene consumption per company, based on the 142
companies contacted, was 8,000 gallons annually in 1976 and about 6,000 gallons
in 1978. On the assumption that there are 367 companies (see footnote on
previous page) which could have processes requiring a solvent as an adjunct,
then the benzene solvent consumption in the U.S. for chemical processing
is estimated to be 2,962,000 gallons in 1976, and projected to be 2,214,000
in 1978.
Company spokesmen stated that the trend in the chemical industry is
to look for alternate solvents, and that the figure of 2.2 million gallons
projected consumption in 1978 is expected to decline rapidly during the next
three to five years. The decline is attributable to the emphasis on the
toxicity of benzene and the limitations on the quantity to be permitted in the
workplace by OSHA.
The consumption of benzene for solvent purposes represents make-up for
system losses. Many of the companies interviewed reported that emission control
systems were being used to reduce benzene and other chemical emission to the
environment. The estimated amount of benzene consumed given in the preceeding
paragraphs must not be equated to the quantity lost to the environment.
-33-
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TABLE 3-1i BENZENE CONSUMPTION IN GENERAL
ORGANIC SYNTHESIS (gallons/year)
Company
A
B
C
D
E
F
G
H
I
J
K
L
M
N
0
P
Discontinued Use
Prior to 1976
1976
572,000
50 to
100,000
150,000
75,000
75 to
100,000
20,000
20,000
20 to
30,000
10,000
11,000
5,000
5 to
10,000
5 to
8,000
6,600
6,800 to
13,700
5,000
1978
429,000
50 to
100,000
150,000
75,000
0
20,000
20,000
20 to
30,000
0
1,000
5,000
5 to
10,000
0
0
6,800 to
13,700
0
Application
Azeo tropic dehydration
Azeotropic agent
Reaction solverit
Reaction solvent
Azeotropic agent
Azeotropic agent
Esterification
Reaction solvent
Polymerization
Purification extraction
Reaction solvent
Azeotropic distillation
Reaction solvent
Azeotropic distillation
Esterification
Reaction solvent
Azeotropic dehydration
Solvent recovery and
Resale
Azeotropic distillation
Esterification
Azeotropic dehydration
Reaction solvent
Reaction solvent
Azeotropic distillation
-34-
-------
TABLE 3-1. BENZENE CONSUMPTION IN GENERAL
ORGANIC SYNTHESIS (gallons/year) (continued)
Company
Q
R
S
T
Other
Total
i
Discontinued Use
Prior to 1976
8 to 9,000
1976
2,500
2,000
2,000
1,300
54,300
1,098,500
to
1,198,400
1978
2,500
0
2 , 000
0
27,500
813,800 to
855,750
i
Application
Azeo tropic agent
Ester if ication
Reaction solvent
Purification, extraction
Purification, extraction
-35-
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3.1.1.3 Environmental Losses
Losses from solvent use of benzene in chemical processes may occur as
a result of air emissions, waste water discharges or by disposal of solid wastes,
Air emission losses are directly attributable to:
(1) Inefficient condensation of vapors in distillation processes
(2) Vaporization of benzene leakage from pumps and agitators,
and from valves, flanges, etc.
(3) Drying of solids
(4) Venting of storage and process tanks.
Liquid losses result from:
(1) Solubility in water removed as an azeotrope with benzene
(2) Contaminated liquid waste products obtained from distillation,
or extraction.
Solid losses result from:
(1) Residue in filter cakes
(2) Residue in extracted solids (e.g., botanicals).
The quantity lost from process operations varies from 1% of the total volume of
solvent circulated through the system to 100% in those instances where benzene
cannot be separated readily from waste materials, or the volume of benzene is
too small for economic recovery.
None of the reporting companies were able to provide data on the
amount of benzene actually lost via any specific route (air, liquid or solid).
This was due to the relatively small volume of benzene lost from a specific
process. For example, a loss of 10,000 gallons per year is equal to about
0.023 gallons/minute or 0.151 pounds/minute. If this quantity were vaporized,
this would be equivalent to 1.0 cubic ft. per minute. For most operations,
losses are probably divided equally between vapor emissions (to the atmosphere)
and waste water losses.
-36-
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The amount of benzene lost to the environment was determined from a
review of the emission control information reported by the companies interviewed.
The controls used included incineration of collected vent gases, incineration
of liquid wastes, biological treatment of water effluents and approved solid
waste disposal methods.
Table 3-2 presents our best estimate of the probable net loss to the
environment of benzene when used as a solvent adjunct to the manufacture of
chemicals. Extrapolation to the total environmental loss for the General Organic
Synthesis industry was made by direct proportion, based on analysis of the data
obtained from the companies interviewed and the total number of companies in
this group (see footnote, page 31).
TABLE 3-2. ESTIMATED BENZENE SOLVENT LOSS TO ENVIRONMENT
FROM CHEMICAL MANUFACTURE (1.000 gallons)
For Companies Directly Contacted
Total Consumption
Estimated quantity destroyed in
pollution control systems
Net loss to environment
Extrapolation for Total General
Organic Synthesis
Total extrapolated consumption
Estimated quantity destroyed in
pollution control systems
Net estimated loss to environment
1976
1,098 to 1,198
842- to 927
262 to 277
2,962
2,271
691
1978 (projected)
814 to 886
704 to 764
110 to 122
2,214
1,915
309
3.1.2. Pharmaceutical Industry
The pharmaceutical industry, as defined in the SIC 283, is composed of
companies whose operations range from reselling formulated Pharmaceuticals
manufactured by other firms under private labels, to companies who synthesize,
formulate and market their own pharmaceutical products.
-37-
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Except for certain large volume chemicals such as aspirin, citric
acid, and various fermentation products, most pharmaceutical synthesis is done
in small (100 or 200 gallon capacity) batch-type reactors. Consequently,
chemical production volumes are small, and solvent usage and accompanying losses
would be correspondingly low.
According to the Statistical Abstract of the United States (1976),
there were approximately 1,000 establishments classed as drug (pharmaceutical)
companies (SIC 283) in 1972. Of these about 680 are classed in the subgroup
2834, Pharmaceutical Preparations, leaving approximately 400 establishments in
subgroups 2831, Biological Products, and 2833, Medicinal Chemicals and Botanical
Products.
The Census of Manufactures (1967) reported a total of 1,129 establish-
ments in SIC 283. Of these, 125 or 11% were in SIC 2831 and about the same
percentage in SIC 2833. It is within the SIC subgroups 2831 and, in particular,
2833 that are found companies with synthesis facilities "primarily engaged in
(1) manufacturing bulk organic and inorganic medicinal chemicals and their
derivatives; and (2) processing (grading, grinding and milling) bulk botanical
drugs and herbs."
According to a 1970 compilation of 25,000 Leading U.S. Corporations
(Newsfront, 1970), 90 companies that have sales ranging from one million dollars
to over one billion dollars are listed in SIC 283. It is difficult to identify
from published industry statistics those pharmaceutical companies which could
have synthesis facilities (SIC 2831 and 2833) and those which are only formula-
tors and processors of pharmaceutical preparations (SIC 2834). Many manufac-
turing pharmaceutical companies have been merged into larger firms with the
result that for any given company, there may be one location at which chemical syn-
thesis is performed and many locations at which formulation and packaging is done.
-38-
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Several companies listed, e.g. American Cyanamid and Witco Chemical, are
normally considered to be organic chemical manufacturers rather than pharmaceutical
companies. The contribution of chemical synthesis to sales of most pharma-
ceutical companies is usually a small proportion of their business.
3.1.2.1 Process Descriptions
Pharmaceutical chemical manufacturing processes are identical with
those used to synthesize general organic chemicals. The basic difference lies
in the smaller equipment size and the relatively large number of steps required
to produce a pure pharmaceutical chemical.
According to industry sources, processes which use solvents as an
adjunct to pharmaceutical manufactuirng are almost identical to those required
in general organic chemical manufacture as described in Section 3.1.1.1. These
include:
Azeotropic distillation
Azeotropic dehydration
Extraction
Purification and recrystallization
Reaction solvent.
3.1.2.2 Process Consumption
For this section of the study, a list of 46 companies which could
have facilities for chemical synthesis or botanical extraction was developed.
From this list, twenty-eight companies or subsidiaries were contacted. Of
these, ten companies reported some consumption of benzene as a solvent prior
to May, 1977. Subsequent to this date , six companies substituted alternate
solvents for benzene.
-39-
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Prior to May 1977, the ten user companies (Table 3-3) reported
benzene consumption in the range of 562,000 to 542,000 gallons per year.
Current (May, 1978) consumption has dropped to the range of 213,200 to 214,200
gallons per year.
Companies such as Abbott, Merck, and Pfizer synthesize large quantities
of organic and pharmaceutical chemicals for both merchant sale and captive
use. In many respects the operation of this type of company is closer to. that of
organic synthesis manufacturers than pharmaceutical manufacturers. Generally,
benzene solvent consumption by companies in this group is over 20,000 gallons
each per year.
Typical pharmaceutical companies, such as Wyeth, Smithkline, Parke
Davis, and Schering Corp., manufacture pharmaceutical chemicals on a smaller
scale for captive use.
Because of the wide variation in benzene solvent uses between
companies who manufacture Pharmaceuticals and fine chemicals and those who
manufacture only Pharmaceuticals, an extrapolation of the data in Table 3-3
to the industry would have little validity. A more realistic approach to
developing an average benzene consumption for the industry is to eliminate
the few high volume consumers (over 20,000 gallons) and average the use by the
remaining companies contacted. On this basis, the average benzene solvent use
by any one pharmaceutical manufacturing company is calculated to be 2,370
gallons per year.* Extrapolating this figure, it is calculated that the probable
consumption of benzene solvent by the entire pharmaceutical industry prior to
May, 1977 was on the order of 40,000 gallons per year, exclusive of the 550,000
to 630,000 gallons per year reported by the five large users (i.e., over 20,000
gallons per company).
* (Total to be excluded = 550,000 gallons, leaving 11,850 gallons to be
averaged among five companies)
-40-
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TABLE 3-3. BENZENE CONSUMPTION IN PHARMACEUTICAL MANUFACTURE
(Gallons per year)
Company
A
6
C
D
E
F
G
H
I
J
Total
Consumption
Pre-OSHA
1976
60-70,000
20-40,000
2,000
250 - 300,000
(multiple sites)
1,000
20,000
200,000
550
300
8,000
561,850 to
641,850
Post-OSHA
1978 (projected)
4-5,000
1,000
200
200,000
0
0
0
0
0
8,000
213,200 to
214,200
Uses
Dehydration, azeo tropes,
crystallization
Reaction solvent in
esterification
(azeotropic solvent)
Product crystallization
(purification and
reaction solvent)
Reaction solvent, azeo-
tropic dehydration,
product crystallization
Azeotropic dehydration
Extraction of botanicals
plus reaction solvent
Reaction solvent, azeo-
tropic dehydration
Not -reported
Not reported
Reaction solvent, azeo-
tropic dehydration
-41-
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Table 3-3 shows that current (May, 1978) benzene consumption as a
solvent by the pharmaceutical companies interviewed is between 213,200 and
214,200 gallons per year. It is to be noted that all but one of the large
users of benzene as a solvent have substituted other chemicals. Following the
method of extrapolation discussed in the previous paragraph, the probable con-
sumption of benzene in 1978 by the small users contacted, i.e., 13,200 gallons*,
can be extrapolated to a total of 22,000-23,000 gallons annually for typical
pharmaceutical companies. The total probable consumption for 1978 will be about
222,000 gallons.
3.1.2.3 Environmental Losses
Processes used in the manufacture of pharmaceutical chemicals are
quite similar to those used in the manufacture of organic chemicals described
in Section 3.1.1.3. Environmental losses from pharmaceutical manufacture are
due to essentially the same sources described previously:
(1) Vent losses from distillation operations
(2) Venting of storage and process tanks
(3) Vaporization of leaks from mechanical equipment
(4) Drying of solids
(5) Water wastes from distillation operations
(6) Contaminated liquid wastes from distillation, recrystallization
or extraction
(7) Residues in filter solids or extracted solids
There are no data which relate solvent losses in this industry as a
percent of the volume in process. Since the quantities used are relatively small,
there is a general consensus that percentage losses tend to be high, i.e. over
10%. Where in-process quantities are small, solvent recovery is usually not
economic, nor is the installation of emission or waste liquid control systems.
In such instances, contaminated solvents may be drummed for disposal by waste
disposal companies.
* Total to be excluded = 200,000 gallons, leaving 13,200 gallons to be averaged
among the four companies
-42-
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As is the case for general organic synthesis, the consumption
of benzene solvent usually does not represent loss to the environment. The
loss to the environment is the difference between the total loss from the process
and the amount that is destroyed through the use of pollution control methods.
A review of the industry responses to our questions on environmental
loss and environmental controls showed that very little control is exercised
over air emissions, except for improvement in condensing efficiency.
Liquid waste effluent control generally consists of subjecting the
contaminated waste water to at least a primary treatment. Other contaminated
liquids (organics), which cannot be recovered by distillation are incinerated or,
more often, sent to a commercial disposal company. There is no consensus as to
the percent of benzene consumed by the pharmaceutical industry (i.e., process
loss) as solvent make-up and lost to the environment, versus that which is
destroyed.
One company noted that about 10% of the amount consumed was lost to
the atmosphere. The balance were liquid losses. Of the liquid losses, about
22% was incinerated, another 22% was treated in secondary waste treatment
systems, and the balance was sent as a dilute water solution to a municipal
treatment system from which most of the contained benzene leaves without change.
In other words, over 50% of the liquid losses could enter the environment as a
component of waste water.
Most companies, including the one just discussed, believe that probably
70% of all benzene-containing liquid effluents are treated in such a way as
to prevent their entering the environment, and within a few years, perhaps close
to 90% will be treated.
On the basis that atmospheric loss represents 10 to 20% of the total
consumed, and that 20 to 25% enters the water environment via waste water,
it is concluded that between 30 and 40% of the benzene consumed as a solvent
(make-up loss) by the pharmaceutical industry could enter the environment.
Table 3-4 gives a calculated estimate of the amount of benzene lost
to the environment by the pharmaceutical industry, based on the previously
estimated 30% environmental loss of the benzene consumed for process make-up.
-43-
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TABLE 3-4. ESTIMATED BENZENE SOLVENT LOSS TO ENVIRONMENT
FROM PHARMACEUTICAL MANUFACTURE (1,000 gallons)
Reporting Companies
1976-77
1977-78
Total Consumption
Estimated quantity
destroyed in pollution
control systems
Net Loss to Environment
Total Pharmaceutical Industry
561.85 to 641.85
393.3 to 449.3
169.55 to 192.55
213.2 to 214.2
149.2
63.96
Total Estimated Consumption
Estimated quantity
destroyed in pollution
control systems
Net Loss to Environment
601.85 to 681.85
421.29 to 477.29
180.56 to 205.56
222.00
155.4
66.6
-44-
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3.2 SMALL VOLUME SPECIALTY CHEMICALS
This section discusses a group of specialty chemicals whose production
volume, although small, is sufficiently large to permit individual analyses of
solvent uses of benzene. These chemicals were selected as potential users of
benzene as a process solvent based on literature and industry references. The
chemicals selected include aluminum alkyls, ethyl cellulose resins, alcohols,
arid bisphenol-A.
3.2.1 Aluminum Alkyls
Aluminum alkyls have been in commercial production in the United States
since 1959. Although there are approximately 30 aluminum alkyls available
in developmental and commercial quantities, the chief commercial products are
triethylaluminum, trimethylaluminum and triisobutylaluminura.
3.2.1.1 General Description of the Industry
There are four domestic producers of aluminum alkyls, as shown in
Table 3-5, but only Texas Alkyls (a division of Stauffer Chemical Co.) and Ethyl
Corporation make merchant sales; the other two companies make these compounds
for captive use. The producers of aluminum alkyls are large companies with a
wide organic product range. There is also one small company that produces research
and experimental quantities of aluminum alkyls.
TABLE 3-5. DOMESTIC PRODUCERS OF ALUMINUM ALKYLS
(AAI, 1978)
Company Market
Ethyl Corp. captive/merchant
Texas Alkyls " merchant
Hercules captive
Conoco captive
-45-
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Aluminum alkyls are used as catalysts in Ziegler-type reactions to produce
high density polyolefins such as polyethylene, polypropylene, 1,4-polybutadiene
and in the Alfol process for manufacturing long-chain alphar-alcohols.
Domestic production (based on reports from the four producers) is
estimated at about .157 million pounds annually.
Aluminum alkyls are shipped as the pure compound or dissolved in a
suitable solvent„ Solvent solutions are often requested by the consumers because:
(1) aluminum alkyls are pyrophoric compounds which react violently when exposed
to oxygen (the solvents help shield them from contact with oxygen) (2) the solvent
is used by the consumer in his process as the reaction medium.
The hydrocarbon solvents most used as packaging mediums and their approx-
imate consumption are shown in Table 3-6.
The choice of solvent is usually determined by the purchaser's process
requirements, i,e., the packaging diluent is the same as the solvent used in the
reaction and frequently supplies up to 100% of the process "make-up" solvent.
Industry sources stated that the benzene-aluminum alkyl blend all goes to
one consumer who uses it as a catalyst to produce a synthetic rubber.
TABLE 3-6. CONSUMPTION OF SOLVENTS AS PACKAGING BLEND
FOR ALUMINUM ALKYLS OT.QTAL U.S. & CANADIAN MARKET)
(AAI and Industry Estimates, 1978)
Solvent MM Ibs./yr
Hexane 5.0
Xylene 1.2
Benzene 2.3
Heptane 0.5
Toluene 1.8
Isopars (n-octane) 0.3 - 0.5
Cyclohexane *
Just entering the market as a replacement for benzene.
-46-
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An estimated 2.3 million pounds of benzene (312,000 gallons) are shipped annually
as an 80-85 wt.% blend of benzene with aluminum alkyl (15 to 20 wt.7.). The
benzene value of this blend is approximately $235,000,
3.2.1.2 Losses and Environmental Management
In the process of blending aluminum alkyls with solvent (benzene),
approximately 2.4% of the benzene (about 55,000 Ibs.) is lost as liquid waste and
disposed of by incineration. About 0.170 (or 2,000 Ibs.) of the solvent is
lost to the atmosphere. Atmospheric losses are minimized by handling benzene in
closed, nitrogen blanketed tanks and interconnected vent piping systems. Transfer
lines are blown free of liquid before they are opened.
The user of the benzene/aluminum alkyl blend purchases an additional
300,000 gal/year (or 2.2 million Ibs.) Of benzene'in tank-wagons to further dilute
the catalyst, and for use as a make-up solvent for the polymerization reaction.
The approximately 4.5 million Ibs. of benzene consumed in this process is vented
to the atmosphere in the drying of the polymer crumb. The vented benzene has
an estimated value of $458,186.
3.2.1.3 Alternate Solvents
Alternate solvents that are currently used as a protective diluent
include cyclohexane, toluene or heptane. The current user of aluminum alkyLs
dissolved in benzene is phasing in cyclohexane as a substitute, as a result of the
impending OSHA regulations for benzene.
3.2.2 Ethyl Cellulose Resins
Ethyl cellulose resins are produced domestically by Dow Chemical Co. and
Hercules Corp. These resins, which are soluble in alcohol and aromatic hydro-
carbons, are tough, flexible and alkali resistant, and are used in a variety of
lacquer coating applications.
One company uses toluene as the process solvent, consuming about 30,000
gallons/year. Until about one and a half years ago, they had used benzene, but
switched to toluene due to increasing concern over health and environmental hazards.
The other company uses ethanol and diethyl ether as solvents, and has never used
aromatic solvents.
-47-
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Both companies recover and recycle the solvents. Reaction vessels are
vented through cooling systems to condense any organics.
3o203 Alcohols
Benzene has two main uses in the manufacture of aliphatic alcohols. It
is an approved denaturant for ethyl alcohol, under regulations of the Department
of the Treasury, Bureau of Alcohol, Tobacco and Firearms (Code of Federal
Regulations, 1977). It is also used as an azeotropic agent in the dehydration
of 95% ethanol and 91% isopropanol to produce anhydrous alcohols. Higher alcohols
(C-4 and above) do not require the use of azeotroping agents for dehydration since
they are immiscible with water.
Various government agencies report statistics on domestic production
and consumption of ethanol (U.S. Department of the Treasury, 1976; U.S.
International Trade Commission, 1977), but do not break out figures for anhydrous
alcohol. Table 3-7 shows relevant data for ethanol for 1976, based on government
statistics as reported by industry, and on estimates made by two major producers
of anhydrous and denatured alcohol. From this it can be seen that about one-third
of the annual ethanol production of approximately 300 million gallons is converted
to the anhydrous form, using various azeotroping solvents. It should be noted that
all data have been converted from pounds and proof gallons to U.S. or "wine"
gallons.* The variation in figures is due to the fact that the Bureau of
Alcohol, Tobacco and Firearms reports on a fiscal yearly basis,
3.2.3.1 Denatured Ethyl Alcohol
There are three approved formulae for denatured alcohol using benzene
(Code of Federal Regulations,. 1977). The formulae and their fi-nd uses are given in Table
3-8. There is presently no alcohol denatured according to Formula 2-C. Production
volumes of benzene-denatured alcohol and the equivalent benzene used for 1976
are shown in Table 3-9,
wine gallon = 1 U.S. gallon
-48-
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TABLE 3-7. ANNUAL DOMESTIC PRODUCTION OF ETHANOL. 1976
(millions of gallons)
Anhydrous
Denatured (all formulae)
Synthetic ethanol,
total (190+ proof)
Ethanol from
fermentation
Denatured with benzene
Total (anhydrous plus
natural and synthetic
190+ proof ethanol)
Impor ts
Company A
(estimate)
110
200
310
Company B
(estimate)
105
210
Bureau of Alcohol,
Tobacco & Firearms
2201
189-1993
78-813
25
280
A
Q
USITC
2252
(78-81)3
305
''U.S. Department of the Treasury, Bureau of Alcohol, Tobacco and
Firearms (1976), Summary Statistics, 34.
2U.S. International Trade Commission (1977), "Synthetic Organic
Chemicals: United States Production and Sales, 1976," U.S. International
Trade Commission Pub. 833, Government Printing Office, Washington,..D.C.
3U,S. Department of the Treasury, Bureau of Alcohol (1976), Summary
Statistics, p. 22.
4U,S. Department of the Treasury, Bureau of Alcohol (1976), Summary^
Statistics, p. 23.
-49-
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TABLE 3-8. DENATURANT FORMULAE AND AUTHORIZED USES AS A SOLVENT
(Code of Federal Regulations, 1977)
Formula 2-B
(0.5 gal benzene/100 gal
alcohol)
. Formula 2-C
(0.5 gal benzene/100 gal alcohol
plus 33 Ibs. metallic sodium)
Formula 12-A
(5 gal benzene/100 gal
alcohol)
Cellulose plastics.
Non-cellulose plastics,
including resins.
Photographic film and
emulsions.
Transparent sheeting.
Explosives.
Cellulose compounds
(dehydration).
Sodium hydrosulfite
(dehydration).
Other dehydration
products.
Petroleum products.
Processing pectin.
Processing other food
products.
Processing crude drugs.
Processing glandular
products, vitamins,
hormones and yeasts.
Processing antibiotics
and vaccines.
Processing medicinal
chemicals, including
alkaloids.
Miscellaneous drug
processing (includ-
ing manufacture of
pills).
Processing dyes and
intermediates.
Processing perfume
materials and
fixatives.
Processing photo-
graphic chemicals.
Processing other
chemicals.
Processing mis-
cellaneous
products.
Processing medicinal chemicals
(including alkaloids)..
Processing other chemicals.
Processing miscellaneous
products.
Cellulose plastics.
Non-cellulose plastics,
-including resins.
Adhesives and binders.
Processing glandular
products, vitamins,
hormones and yeasts.
Processing antibiotics
and vaccines.
Processing medicinal
chemicals (including
alkaloids).
Processing blood and
blood products.
Processing dyes and
intermediates.
Processing perfume
materials and
fixatives.
Processing rosin.
Processing other
chemicals.
Processing miscellaneou:
products.
Sterilizing and
preserving solutions.
-50-
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TABLE 3-9. VOLUME OF ETHANOL DENATURED WITH BENZENE AND
EQUIVALENT BENZENE CONSUMED •
(U.S. Dept. of Treasury, 1976)
FORMULA
2-B
12-A
Total
ALCOHOL (GALLONS)
24,896,888
94,940
24,991,828
EQUIVALENT BENZENE
CONSUMED (GALLONS)
124,500
4,750
129,250
It can be seen from Department of the Treasury figures that
approximately 129,000 gallons of benzene valued at about $100,000 were consumed
in 1976 in the denaturing of alcohol. This is in rough agreement with the
figures reported by individual companies for pre-OSHA regulation use (i.e.,
prior to the OSHA Emergency Benzene Standard of May 27, 1977) in Table 3-10,
column one. Of the eight alcohol producers who had denatured alcohol with
benzene, only one was still using benzene, and total usage as a denaturant had
dropped to about 2,000 gallons or less per year. That company anticipates its
few remaining customers who use benzene as a denaturant will likely accept a
substitute within the next year. The existing customer's end use of the alcohol
is at a dilution such that the presence of the original denaturing benzene is in
the part per million range, and thus for him, not a health concern. However,
the one remaining company who plans to fill customer orders for benzene-denatured
alcohol purchases it for this purpose in drums. It is increasingly difficult to
find solvent distributors willing to drum benzene (see Section II) and this
may be the determining factor in eliminating benzene as an alcohol denaturant.
Benzene loss to the atmosphere occurs when the drums are opened, and
during the blending process. This is done either in the open, or with ventilation
to the atmosphere. None of the former users reported any environmental controls
-51-
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TABLE 3-10. BENZENE CONSUMPTION IN THE ETHYL ALCOHOL INDUSTRY
A
B
C
D
E
F
G
H
I
J
K
L
M
TOTAL
Denatured, gallons
pre-OSHA
10-12,000
4,000
*
*
200
100
*
100
*
3-5,000
100,000
5-10,000
1,300-2,000
124-127,000
post-OSHA
-
2,000
-
-
-
-
-
-
-
-
-
-
2,000
Anhydrous, gallons
pre-OSHA
8-10,000
30-35,000
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
*
20,000
YES
*
58-65,000**
post-OSHA
-
30-35,000
N.A;
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
-
20,000
-
-
50-55,000
Total, gallons
pre-OSHA
20,000
34-39,000
-
200
100
-
100
-
3-5,000
120,000
approx.
200,000
post-OSHA
-
32-37,000
-
-
-
-
'-
-
-
20,000
approx.
55,000
*Benzene never used in the process, or not used within the last several years.
**Total estimate low since Company L would not supply actual figures.
Those companies for which data is not applicable never produced anhydrous
alcohol.
-52-
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for their denaturing operations. Losses to the atmosphere were estimated at
no more than 0.0025% (Sittenfield, 1978), or about 320 gallons of benzene in 1976.
Minimal losses of benzene in water, disposed to chemical sewers, were also reported.
The chief alternate solvent being used as a denaturant is toluene. The
Bureau of Alcohol, Tobacco and Firearms (U.S0 Department of Treasury, 1978)
recently issued guidelines concerning authorized use of toluene and rubber
hydrocarbon solvent in lieu of benzene. Alcohol denaturers have reported the use
of methyl isobutylketone, methanol, gasoline and ethyl acetate as substitutes.
In summary, the pending OSHA standards concerning exposure to benzene
in the workplace have had the effect of reducing benzene consumption from about
129,000 gallon/year to less than 2,000 gallon/year, and it is expected to drop to
zero once the standard is upheld.
3.2.3.2 Anhydrous Ethyl Alcohol
Benzene has been the chief solvent used in the azeotropic distillation
of 95% ethanol to make absolute or anhydrous ethanol. It forms a ternary
azeotrope, which carries over the water, leaving behind anhydrous alcohol. The
proportions of the three components in the distillate, which boils at 64.6°, are
shown in Table 3-11.
TABLE 3-11. AZEOTROPIC DATA FOR ETHYL ALCOHOL
(Advances in Chemistry Series 116, 1973)
A-Component
Water
Water
Water
Water
Water
B-Component
Ethyl Alcohol
Ethyl Alcohol
Ethyl Alcohol
Ethyl Alcohol
Ethyl Alcohol
C-Component
Benzene
Cyclohexane
Isopropyl
Ether
Toluene
Heptane
B.P.
°C
64.9
62.6
61.0
74.4
68.8
WT.
%A
7.4
4.8
4.0
12
6.1
WT.
%B
18.5
19.7
6.5
37
33.0
WT.
%C
74.1
75.5
89.5
51
60.9
-53-
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This table also shows the proportions of water carried over using other
solvents as azeotroping agents0 It can be seen that benzene offers many
advantages in terms of boiling point, proportion of water, benzene and ethanol.
The companies which currently produce anhydrous ethyl alcohol are
listed in Table 3-12. While all of these companies used benzene as the
azeotrope prior to May 1977, only two are continuing to do so. The total
quantity of benzene currently used as an azeotrope for anhydrous alcohol is
about 50,000 gallon/year, for a value of about $38,000 (see Table 3-10).
TABLE 3-12. PRODUCERS OF ANHYDROUS ETHYL ALCOHOL
(Chemical Week Buyers' Guide, 1977)
IMC Chemical Group, Inc.
Publicker Industries, Inc.
Shell Chemical Co.
Union Carbide Corp.
Companies were generally reluctant to discuss losses. They all operate
closed systems, but report pumps, valves, and equipment vents as possible sources of
loss to the air. Some liquid loss occurs in the water distilled over, and in side
streams containing process impurities. The current overall loss of benzene due
to anhydrous alcohol production (equivalent to the make-up purchases) is 50,000
gallon/year or about 200 gallons/day of plant operation.
All companies planning to continue using benzene are aware of the
hazards, and anticipate using more stringent controls. These will include
flushing hoses before breaking connections when charging benzene, condensers or
absorbers on vents, and incineration of liquid wastes rather than chemical
sewer disposal.
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There are alternate processes for the production of anhydrous ethanol
such as countercurrent extraction with a third component, for example, glycerine
or ethylene glycol. The added component depresses the vapor pressure of water
allowing anhydrous alcohol to be distilled from the top of the extraction column
(Lowenheim and Moran, 1976). Industry sources also report the development of a
new direct hydration process for making anhydrous ethanol. At least one major
company is considering this as an alternate process to benzene extraction.
Some of the companies contacted feel that for their process, there can
be no substitute solvent. Those companies that have changed solvents are using
cyclohexane. One indicated that they anticipated some process adjustments due
to the changeover.
3.2.3.3 Other Alcohols
There are currently four companies that produce anhydrous isopropanol,
as listed in Table 3-13.
TABLE 3-13. MANUFACTURERS OF ANHYDROUS ISOPROPYL ALCOHOL
(Lowenheim and Moran, 1975; Industry Sources, 1978)
Company Plant Site
Atlantic Richfield Co. Channelview, TX
Exxon Chemical Co. Baton Rouge, LA
Shell Chemical Co. Deer Park, TX
Dbminguez, CA
Union Carbide Corp. Texas City, TX
Whiting, IN
Of these four companies, only two companies had used benzene for
the dehydration of isopropanol. One had ceased using it in July, 1977, due to
the OSHA Emergency Benzene Standard. Up to this point, they had consumed about
215,000 gallons annually, of which approximately 20,000 gallons was vented to
the atmosphere from process losses, and about 196,000 gallons was lost with a
side stream purge and incinerated.
-55-
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The second company was still using benzene (as of the writing of this
report) with an annual consumption (and loss) of about 40,000 gallons. This.represents
about 0.09% of the volume in process. However, they are trying to substitute
cyclohexane in their process. Again, assuming about 90% loss through liquid slop
which is incinerated or sent to refining operations, and a 10% loss to the atmosphere,
.there are about 36,000 gallons of benzene lost in the liquid stream and about 4,000
gallons vented to the atmosphere. Thus, current annual consumption of benzene in
anhydrous isopropanol production is about 255,000 gallons for a value of approx-
imately $191,000. These results are summarized in Table 3-14,
Benzene is used as an azeotrope in the production of one other
anhydrous alcohol, propargyl alcohol, which is used mainly as a corrosion
inhibitor in the oil industry. Only one company was found to use benzene for
this purpose, consuming about 10,000 gallons/year.
The data for benzene consumption for isopropyl and propargyl alcohols
are summarized in Table 3-14, which clearly shows the downward trend in benzene
use since the proposed OSHA Standard. The benzene usage should be reduced by
an additional 40,000 gallons/year when the second isopropyl manufacturer converts
to an alternate solvent. Chief alternate solvents are isopropyl ether and
cyclohexane.
TABLE 3-14. CONSUMPTION OF BENZENE AS AN AZEOTROPE FOR
OTHER ANHYDROUS ALCOHOLS (gallons/year)
Alcohol
Isopropyl
Isopropyl
Propargyl
TOTAL
Benzene
Consumed
Pre-
OSHA
215,000
40,000
10,000
265,000
Post-
OSHA
Nil
40,000
10,000
50,000
Estimated
Liquid Losses*
Pre-
OSHA
196,000
36,000
9,000
241,000
Post-
OSHA
Nil
36,000
9,000
45,000
Estimated
Atmospheric Losses
Pre-
OSHA
20,000
4,000
1,000
25,000
Post-
OSHA
Nil
4,000
1,000
5,000
* Incinerated or fuel blended
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3.2.4 Bisphenol-A
Bisphenol-A is made by reacting phenol with acetone in the presence
of an acid catalyst. The four manufacturers are listed in Table 3-15.
TABLE 3-15. MANUFACTURERS OF BISPHENOL-A
(Chemical Marketing Reporter, 1977)
Company Plant Site
Dow Chemical U.S.A Freeport, TX
General Electric Co. Mount Vernon, IN
Shell Chemical Co. Houston, TX
Union Carbide Corp.* Penuelas, PR
* Ceased production at Marietta, OH plant
The basic process produces crystalline Bisphenol-A in a slurry with phenol.
The major producers have made various refinements on the synthesis and purification
process, whereby the water and phenol are removed in order to meet the demand
for higher quality for use in polycarbonate resins. Polycarbonates now occupy
40% of the Bisphenol-A market, and epoxy resins 47%. Total consumption of
Bisphenol-A in 1977 was 460 million pounds (Chemical Marketing Reporter, 1977).
Only one producer has ever used benzene in the extraction process,
and they ceased doing so in mid-1976. The substitution of an alternate solvent
was the result of an internal process change, and not due to pending OSHA
regulations. In 1975, the last full year of benzene use, 20 million pounds or
2.99 million gallons of benzene were consumed. This company has substituted
methylene chloride as the solvent.
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3.3 FORMULATED INDUSTRIAL AND CONSUMER PRODUCTS
Solvents are used in the manufacture of many formulated products.
Among the products which may require solvents are:
Adhesives and rubber based cements
Paints, coatings and allied products
Dry cleaning agents
Degreasing agents
Furniture and floor polishes
Printing inks
There are many different solvents used to formulate industrial and
consumer products. The more common ones include:
Aliphatic
Hexane
Heptane
Mineral spirits
Aromatic
Benzene
Toluene
Xylene
Ke tones
Chlorinated solvents
Alcohols
Historically, benzene as an active solvent has been associated with
the formulation of adhesives and rubber based cements, tire repair kits, tire
manufacture, paints and allied products, and gravure printing inks. The use of
benzene in gravure printing ink manufacture or in gravure printing processes
has been eliminated (U.S. Department of Labor, OSHA, 1977; Industry Sources,
1977). Consequently, no detailed investigation of this former use was made
for this study.
The next two sections (3.4 and 3.5) will be devoted to a review of
potential uses of benzene as a solvent in the formulation of adhesives and rubber-
based cements, tire repair kits, tire manufacture and paints and allied products.
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3.4 FORMULATED PRODUCTS; ADHESIVES
The adhesives industry as a whole is dominated by companies with
fewer than 20 employees. According to the 1972 Census of Manufactures the total
number of establishments in SIC 2891 was 463. Those with 75% or more product
specialization accounted for 422 establishments. Of these 187 or 39% had 20
or more employees. The specific segment of interest, SIC 28914, Synthetic
Resins and Rubber Adhesives, had 252 establishments, 171 of which had 75%
or more product specialization.
The adhesives industry produces a wide diversity of products based
on the type of adhesive substance used. The types of adhesives, the form in
which they are used, the method of use and applications are given in Table
3-16 . Table 3-17 classifies adhesives based on the origin of the principal
components, and Table 3-18 classifies adhesive systems.
TABLE 3-18. CLASSIFICATION OF ADHESIVES BY PHYSICAL TYPE
(M. Sittenfield & Associates, 1978)
Solvent Responsive
aqueous solution
solvent solution
emulsion type
remoistenable
Chemically Reactive (Thermo-setting)
Pressure Sensitive*
Hot Melt
* Pressure sensitive adhesives are applied to a backing from a
solvent solution.
Solvents used to formulate solvent type adhesives can include benzene,
toluene, xylene, hexane, heptane, mineral spirits, ketones, and alcohols.
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TABLE 3-16. BASIC TYPES OF ADHESIVES AND APPLICATIONS
Main Ingredient
Acrylics
Allyls
(Unsaturated
Polyesters)
Cellulose Derivatives
(A) Acetate
(B) Acetate-Butyrate
(C) Caprate
1 (D) Nitrate
O
1
Chlorinated Polyethers
Coumarone-Indenes,
Petroleum Resins and
Poly terpenes
Cyanoacryl.ite
(A) Epoxy
(B) Epoxy-
Phenolic
(C) Epoxy-
Resorclnol
(D) Epoxy-
Polyamlde
Physical
Characteristics
Tlierraoplastic
Therraosettlng
Thermoplastic
Thermoplastic
Thermoplastic
Thermoplastic
Thermoplastic
Thermoplastic
Cold Setting
Thermosetting
Thermosettlng
Thermosett Ing
Thermosettlng
CM. Sittenfield & Associates, 1978)
Form Used Method of Use
Solution, Emulsion, Polymer- Cured by heat, U.V.
Mon. Mlxt. Radiation, Catalysts
Alone Heat cured with
Benzoyl Peroxide
Catalyst
Solution With Plasticizers Solvent Evaporation
Solution with Plasticizers Solvent Evaporation
Solution with Plasticizers Solvent Evaporation
Solution with Plasticizers Solvent Evaporation
Alone Heat Seal
Alone or in Solution with Solvent Evaporation
Aromatic Solvent or pressure sensitive
applications
Alone Polymerizes at R.T.
Alone (Catalyst added Heat cured with
just prior to use) Anhydride or Amine
Catalyst
High temp, cured
High Temp, cured
Heat cured
Maximum
Useful
Temp. "C Bonding Applications
50 Pressure Sensitive Tapes,
(VAC copolymers) paper &
packaging, acrylic plastics,
glass, metals, .leather, and
textiles
Optical Cement
CaSO Household Cements, balsa
wood (model aircraft),
cellulose acetate plastics,
Photographic film
>30 Balsa wood (Model aircraft),
Cellulose Acetate Plastics,
Photographic film
7u . O|>LJ.i'.al Cement
Depends Household cement for gla.is,
on comp- leather fabrics, paper,
position metals, wood, plastics
. 125° Plastics (e.g. Polyvtnyl
chloride), hot water equip-
ment, valves, etc.
Modifier for Polystyrene,
rubber adheslves, rubber,
pressure sensitive tapes
80-100 Wood, glass, metals, rubbers,
plastics, cork felt, leather
95 Structural adehsives for
metals, plass, ceramics,
. wood, rubbers, plastics
>260 High temp. Structural
applications - missiles,
jets, etc.
>260 High Temp, structural
applications - missiles,
jets, etc.
90 Metals, glass, ceramics,
rubbers, wood, leather,
plastics
Furanes
Thermosetting
Alone
l.ow Temp, cured
using acid catalyst
1.50
Modify other resins,
chemically resistant
cements, phenolic laminates,
Cap filling
-------
Hain Ingredient
TABLE 3-16. BASIC TYPES OF ADHESIVES AND APPLICATIONS (continued)
Maximum
Physical Useful
Charactcristic.s Form Used Method of Use Temp. *C
Bonding Applicatlo11
(Socyanates
Polyurethanes)
Melamlne-Formaldehyde
Nylon
(Polyamlde)
Pelmolic
(A) Phenol-
Formaldehyde
(B) Phenolic-Epoxy
(C) Phenolic-
Neoprene
(D) Phenolic-
Nitrile
(E) Phenolic-
Polyamlde
(F) Phenolic-Vinyl
(e.g. polyvinyl
Butyral)
(G) Phenolic-
Resorclnol.
Polyesters (Alkyds)
arid unsatitrated
Polyesters
Tliermosettlng
Thermosetting
Tliermoplastic
Tliermosetting
Thermosetting
Thermosetting
Therinosetting
Thermosetting
Tliermosetting
and thermoplastic
mixture
Tliermoscttinp,
Thcrmonctting and
Tliermoplastic
In Solution
Solution or Paste
Alone or in Solution
Alone in film, liquid or
powder form
Alone
Alone in film, liquid
Alone
Phenolic resins and poly-
amide film applied separately
Apply liquid phenolic,
then dust polyvinyl
formal powder
Alone as liquid
Alone
Heat cured
Heat cured with
catalyst
Heat seal or solvent
evaporation
Cured by heat and
pressure
High temp. cured
Heat cured
Heat cured under
pressure
Heat and pressure
cured
Heat cured under
pressure
Cold setting or hot
pressed
Cured by heat or
catalyst
90
Low
100
>260
93
150-270
>150
85
180
150
Metals, rubbers, glass
plastics, fabrics, leather,
modifier and curing apent
for rubber-based adhesives
Plywood, furniture, modifier
urea adhesives
Epoxy modifier, paper, metal
foil, leather plastics,
cellophane, packaging
labelJng
Plywood, reinforced plastic
laminates (Phenollcs, ureas,
melamines), metal to wood
High temp, structural
applications - missiles,
jets, etc.
Metals, rubbers, many
plastics, wood, glass
ceramics - may be modified
by isocyanates
Structural metals, brake
shoes, linings, rubbers,
plastics, wood, glass,
ceramics
Metals for high temperature
applications - e.g. aircraft
structures
Structural metals, cyclized
rubber, metals, and plastics,
gap filling, metal to wood,
(Phenol used to lower cost
of resorcinol adhesive)
Modifications of pheno.Ucs,
wood, plastics, gap filling
metal to wood, (Phenol used
to lower cost of resorclno]
adhesive)
Fiberglass laminates optical
cements, modifiers for
isocyanates
Protein
(A) Animal & Fish
(B) Casein
Hot water Solution
Water Solution
Solvent Responsive
Cold Press
60
60
Bookhlnding, ahraslvcs, wood,
leather, cloth.
Wood, Paper coating,
construction, packaging,
leather, cloth
-------
TABLE 3-16. BASIC TYPES OF ADHESIVES AND APPLICATIONS (continued)
Physical
Characteristics
Form Used
Method of Use
Maximum
Useful
Temp. °C
Bond Application
ON
K)
I
(C) Soy Bean
(D) X.ein
Resorcinol
(A) Resorctnol-
Kormaldehyde
(n) Resorcinol-
PhcnolLc
Rubber
(A) Natural
Thermosetting
Water Solution
Alone
Alone as liquid
Thermcao.ttiiif.
Thermoplastic &
Thermosetting
Alone ar. liquid
Solvent Responsive
Used in Hot Melt
Formulation
Cold setting or
hot pressed
Cold netting or
Hot pressed
60
180
180
Solution or Latex
Set by solvent
Evaporation and/or
vulcanization
Unvulo.
65°
Vulcanized
95°
(B) Synthetic
(e.g. Neoprene,
SDR)
(C) Reclaimed
(Natural &
Synthetic)
Silicate
Thermosetting
Solution or Latex
Solution or Emulsion
Aqueous Solution
90-150
Sllicones
Thermosetting
Solution
Sets by loss of
water
Room temperature
and liunt cure
>250
Luw-Gradn plywood, paper
lamiii.Ttlon, wallpaper
coating
Wood, paper, cloth and
glass
Structural applications
(boats, roof trusses
laminated timber)
modification of pheiiollcs,
wood, plastics, gap fllinft
metal to wood
Wood; plastics, gap
filling, metal to wood
(phenol used to lower
cost of resorclnol
adhesive)
Pressure sensitive
applications, bootwear,
leather, rubber, paper,
felt, textiles, metal foil
to paper or wood, sponge
rubber, also a modifier
for phenoltcs and epoxies
in structural, automotive
and aircraft use.
Non-Structural
applications, e.g. paper,
cloth and rubber
Corrugated paperboard,
glass, stone paper to
aluminum foil, low
grade plywood, heat
insulating products
(asbestos, mica, etc.)
Pressure sensitive
tapps, Insulating tapes,
si II cone rubber, high
temp, structural adhesives,
(e.g. blended with
epoxies)
-------
TABLE 3-16. BASIC TYPES OF ADHESIVES AND APPLICATIONS (continued)
Main Ingredient
Physical
Characteristics
Form Used
Method of Use
Maximum
Useful.
Temp. "C
_Bond Apj> Li.ca i:ions
Starch & Uextrlns
Styrene (Butadiene
Copolymet-ORS)
Thennosettlng
Thennosetting
Aqueous Solution
Solution
Water Responsive
Solvent Evaporation
CA. 100 Packaging, paper
converting, labeling
70-95 General Purpose
(sen synthetic rulihi-rs)
Urea-Forma ideliyde
Therraosetting
Syrup or Powder
Hot and cold setting
60
OJ
I
Vinyls
(A) Polyvinyl Acetals Thermoplastic
(B) Polyvinyl Acetate Thermoplastic
(C) Polyvinyl Alcohol Thermoplastic
(D) Polyvinyl Chloride Thermoplastic
Waxes
Thermoplastic
Solution
Water emulsions, solvent
solutions," hot melts,
powder
Water Solution
Solution in chlorinated
solvent
Alone
Evaporation or
solvent
Cold setting
Evaporation of Water
Evaporation of solvent
Hot Melt
50
65
Low
Furniture, plywood,
corrugated fiberboard,
some plastics (plienolics,
nruas, nie.lamines)
Phenolic modifier in
structural, metals, safety
glass
Food packaging, wood, papoi;
paper, leather, cloth,
metals, glass, ceramics,
many plastics, bookbinding
Food Packaging
Used as copolymer with PVAc
for bonding vinyl plastics
to metals and glass; also
used with synthetic rubber
Compounded with elasto-
merics for added flexi-
bility, temporary bonds
for metals, glass, labels,
packaging
-------
TABLE 3-17. CLASSIFICATION OF ADHESIVES BASED ON ORIGIN
OF THE PRINCIPAL COMPONENTS
(M. Sittenfield & Associates, 1978)
Component Origin
Natural Adhesives
Animal
Vegetable
Natural Resins
Inorganic
Elastomeric
Elastomeric
Thermoplastic Resins
Thermosetting Resins
Animal hide or bones; fish; casein
(derived from milk); blood albumin
Starch and dextrin; soybean
Bitumens (including asphalts);
coumarone-indene; petroleum resins;
polyterpenes; shellac; resins; gum
arabic
Silicates; ceramic compositions
Natural rubber (and its derivatives);
chlorinated rubber, cyclized rubber;
rubber hydrochloride
Synthetic Adhesives
Synthetic rubbers (neoprene, nitrile,
polysulfide, SBR, silicone); reclaimed
rubbers
Vinyls; cellulosics, acrylics;
cyanoacrylates; polyamides, poly-
isobutylenes; hydrocarbon resins;
polystyrenes
Phenolics; ureas and melamines;
epoxides; furanes; resorcinols;
polyesters (alkyds); polyurethanes;
silicones
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Table 3-19 lists the principal polymers used in the formulation of water
and solvent based adhesives.
The information summarized in these tables shows the relation of the
rubber-based adhesives to the adhesives industry in general, and also shows
other segments of the adhesives industry in which solvents are used.
Interviews with adhesive manufacturers indicate that there are no
uses of benzene as an active solvent in non-rubber based adhesive formulations.
One small company reported that it does use benzene in small quantities (300 to
600 gallons per year) in formulating some epoxy cements. However, this use
is atypical for the industry.
3.4.1
General Consumption Patterns
The major end use industries for adhesives in terms of weight and
the major adhesive components used are given in Table 3-20.
TABLE 3-20. END USES AND ADHESIVE COMPONENTS
(Marcus Sittenfield & Associates, 1978)
End Use
Estimated % of Total
Adhesives Manufactured
Major
Adhesive Components
Paper & Packaging
Wood Products
Structural & Metal
Miscellaneous
Industrial Specialties
Household
32
25
33
8
0.6
Starch, vinyls, silicates,
animal, protein, acrylic
urea, phenolic, protein
phenolic, elastomeric,
vinyl, epoxy
elastomeric, vinyl, acrylic
vinyl, elastomeric,
cellulosic, epoxy, animal
A review of the types of adhesives used in each of these industries shows that
solvent based adhesives find three applications: structure and metal,
miscellaneous industrial specialties, and household uses.
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TABLE 3-19. PRINCIPAL POLYMERS FOR WATER AND SOLVENT BASED ADHESIVES
WATER SOLUTION BASED
Starch & Dextrin
Gums
Glue
Albumin
Sodium Silicate
Casein
Sodium Carboxymethylcellulose
Lignin
Polyvinyl Alcohol
Methyl Vinyl Ether - Maleic Anhydride
Copolymer
Polyvinyl Pyrollidone (PVP)
WATER (LATEX) OR SOLVENT BASED
Rubber (natural and synthetic)
PVAc and copolymers
Polyvinyl chloride and copolymers
Polyvinyl ethers
Polyvinylidene chloride &
copolymers
Polyacrylates and polymetha-
crylates
Polyamides
Asphalt
Urea-formaldehyde
Phenol-formaldehyde
Resorcinol formaldehyde
Rosin esters
SOLVENT BASED
Nitrocellulose
Cellulose acetate
butyrate
Cyclized rubber
Polyisobutylene
Polyurethane
-------
Areas of application in the structural and metals market encompasses
the entire range of mechanical industries, including construction of automobiles,
aircraft, machinery, steel structures, tanks, railroad equipment, ships,
electrical equipment, tools, etc. These end uses can be classified according to
their degree of importance as follows: building materials, automotive, tire
cord, aircraft and missiles and other metals. The current market for adhesives
in these applications is estimated* to be of the order of $500 million per year.
Solvent-based adhesives find limited use in these applications. They are
generally required for such uses as joining plastic or plastic coated metals,
plastic pipe and other plastic building materials. Benzene is not used to
formulate the solvent-based adhesives used for structural and metal applications.
Most of the adhesives used in the automotive and the tire tread industries are
solvent formulated rubber adhesives and will be discussed in Section 3.4.2.1.
The category of miscellaneous industrial specialties includes a multitude
of adhesive applications, the most important of which are pressure sensitive
products, non-woven fabrics, shoes, and coated and bonded abrasives.
Pressure sensitive adhesives are manufactured by applying the
adhesive to the backing by solvent coating, calendering or aerosol spraying.
The solvent is removed (and recovered) during the manufacture of the pressure
sensitive material. None of the solvent reaches the consumer. The adhesives
used in pressure sensitive formulations comprise styrene-butadiene rubber,
nitrile, and other rubber types. Acrylics, silicones and similar materials are
also used. Benzene is not a component of the solvent blends used in the
manufacture of pressure sensitive tapes. However, it may be an accidential
contaminant of some of the solvents used, such as toluene, hexane, or mineral
spirits. Pressure sensitive products represent the largest market share of the
miscellaneous products market.
Adhesives for the non-woven fabric market are either hot-melt or
water based latex adhesives. Solvent formulated adhesives are not used.
* Industry sources
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Elastomeric rubber-based and polyurethane adhesives are those most
commonly used in shoe and footwear production. Industry information indicates
that over 90% of the elastomeric materials are used as solvent cements, the re-
mainder in latex form. This market will be discussed further in Section 3.4.2.
No solvent-based adhesives are used in the manufacture of coated and
bonded abrasives.
Household adhesives form a relatively small market, accounting for
less than 1% of the total adhesives sold and produced in the United States.
The estimated share of the household market held by each of the adhesive types is
given in Table 3-21. The rubber "contact cements", the cellulosics and other
plastic cements formulated with solvents share an equal part of the household
adhesive market, which is dominated by the polyvinyl acetate water emulsion
adhesives. None of the solvents used for the cellulosics or other plastic
cements use benzene as a component of the blend.
TABLE 3-21. ESTIMATED SHARE OF HOUSEHOLD ADHESIVE MARKET
(M. Sittenfield & Associates, 1978)
Polyvinyl Acetate 49.0%
Rubber "contact cements" 14.5
Cellulosics and other plastics 14.5
Animal and fish 9.1
Epoxy 3.6
All others 9.0
Rubber "contact cements" and other elastomeric adhesives will be
discussed in greater detail in Section 3.4.2.
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3.4.2 Solvent Type Rubber-Based Adhesives
Solvents are used in the manufacture of most rubber-based adhesives
and as an adjunct in the manufacture of rubber products in order to promote
bonding. Rubber-based adhesives are used chiefly for industrial applications,
with no more than six percent of the total manufactured used in the home or
office. The estimated percent consumption of rubber adhesives by end use is
shown for 1978 in Table 3-22.
TABLE 3-22. END USE CONSUMPTION OF RUBBER-BASED ADHESIVES
(M. Sittenfield & Associates, 1978)
Rubber Industry
Tires 57.6%
Industrial rubber products 0 %
Reclaimed rubber 0 %
Tire and tube repair patch kits 2.0%
Automotive 20.5%
Shoe manufacture and repair 16.4%
Household 3.5%
3.4.2.1 Tires and Tubes
Elastomeric solvent-based adhesives and solvents are .used in the
manufacture of tires to cement the plies during the build-up of the tire prior
to molding and vulcanizing. Solvents are also used directly to "freshen"
the rubber when it is dry and has lost its tackiness.
Modern tire manufacturing techniques do not require cement or solvent
tackifers. This is a result of changes in rubber formulations that provide the
rubber with sufficient tack so that adhesives do not have to be used in order
that the plies bond together during the build-up process. When additional
tack is required, some of the manufacturers contacted indicated they used
phenolic resins or water-based rubber cements.
Another change which is reducing the use of elastomeric solvent-
type adhesives and solvents by the tire industry is the increasing popularity
-69-
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of radial tires, whose manufacture requires little if any rubber cement.
The amount of rubber cement used in the manufacture of tires is
estimated* to be of the order of 140 million pounds for 1977. On the basis
that solvents represent about 80% by weight of rubber cements, the solvent
consumption in this application is about 15 million gallons. As noted, solvents
are also used occasionally during the manufacturing to rewet or tackify rubber
plies that have lost tack. The volume required for this use is estimated not to
exceed 20% of the quantity used in the adhesives, or about 3 million gallons.
Based on interviews with six of the major tire manufacturers, the
total solvent use for this industry in 1977 was estimated to be between 20
and 25 million gallons.
Solvents used to formulate rubber adhesives are known variously
as "Rubber Maker's Naphtha" or "Rubber Solvent". They are special fractions of
aliphatic hydrocarbons ranging from hexane to octane. Since the issuance of the
proposed OSHA benzene regulations, the tire manufacturers are requiring that their
suppliers provide the solvents with a maximum benzene content of 0.5%.
There is considerable doubt on the part of producers that the benzene
content can be reduced below the 0.5% level without the expenditure of
significant sums by refiners, and a consequent substantial price rise which
could'prove prohibitive to many manufacturers whose products require solvents.
All the solvent used in tire manufacturing industry applications
is vaporized and lost into the atmosphere. The probable benzene loss, at
0.5% concentration in the solvents used, is calculated to be between 100,000
and 125,000 gallons annually. This volume is dispersed from over 200
establishments (Census of Manufacturers, 1972) scattered throughout the United
States. The volume of benzene lost per year per establishment is calculated
to be between 500 and 625 gallons.
*Industry estimates and Marcus Sittenfield & Associates calculations.
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3-4.2.2 Tire Retreading
Rubber adhesives and solvents are used in the manufacture of
retread tires to develop tack in the old rubber and allow new tread stock
to adhere to the tire carcass prior, to revulcanization. According to an
industry spokesman, about six grams of solvent are used per kilogram of new
rubber, (about 0.1 ounces (wt.) per pound).. The average amount of rubber used is
10 pounds per passenger tire and 35 pounds per truck tire.
Trade sources (Modern Tire Dealer, 1978) indicate about 13 million truck
tires, 32 million passenger tires, and 14.5 million snow tires were retreaded
in 1977. The calculated solvent consumption in tire retreading is shown in
Table 3-23.
TABLE 3-23. CALCULATED SOLVENT CONSUMPTION FOR RETREADING, 1977
Tire type
Passenger-replacement
-snow
Truck-replacement
Total
Millions
of Tires
32
14.5
13
Solvent
used, .MM .Ibs.
4.23
1.92
6.01
12.16
MM. gals.
0.55
0.25
0.78
1.58
All of this solvent is lost to the atmosphere during retread processes.
The solvents used in tire retreading are petroleum naphthas; no benzene
is used in the solvent formulation except as an accidental contaminant of
the naphthas. As with the tire manufacture industry, the solvent is being
purchased based on supplier's ability to reduce the benzene content to or
below 0.5%.
On this basis, the potential benzene loss in the U.S. from tire
retread operations is calculated to be 7,500 gallons per year at dispersed
locations.
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3.4.2.3 Industrial Rubber Products
Industrial rubber products cover a wide range of articles manufactured
by molding or laminating processes. These include hoses, seals, belts,
rolls, life rafts, and industrial tires. None of the companies contacted
used solvents in the manufacture of this class of products. No benzene is
used, or has been used, in manufacturing processes for this segment of the
rubber industry.
3.4.2.4 Rubber Reclaiming
Scrap rubber and scrap tires are reclaimed by the use of one of two
processes. One employs mechanical grinding methods; the other is treatment
with sodium hydroxide. Neither process uses a solvent. Large quantities of
reclaimed rubber are used in the manufacture of rubber cements, chiefly
because it is cheaper than virgin synthetic or natural rubber.
Some petroleum (naphtha) solvents may be used for cleaning process
equipment. However, none of the companies contacted reported the use of
benzene.
3.4.2.5 Tire and Tube Repair or Patch Kits
Tire repair kits are largely sold to tire repair shops, garages and
service stations. They are also used to a limited extent by consumers to
repair bicycle and automobile tires. There are no published statistics
available to indicate the size of the industry or categorize the type of
businesses^ However, according to industry sources, there are about 40
manufacturers, and five who share the bulk of the business. They are shown
in Table 3-24.
TABLE 3-24. MAJOR TIRE REPAIR KIT MANUFACTURERS
no. of employees
Egan Manufacturing Co. *
Patch Rubber 20-49
Technical Rubber Co. 100-499
Kex Rubber Co. 50-99
Better Monkey Grip Co. 100-499
*Not available.
-72-
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Benzene is no longer used by the industry in the solvent adhesive
package that is included in the tire repair kit. Only one company stopped
using it as a direct result of the proposed OSHA regulations. Most companies
had switched solvents earlier because of benzene's known toxicity. The
alternate solvents reported used are petroleum naphthas and aromatics such
as toluene, which contain less than 1% benzene. The total volume of solvent
used in tire repair kits was estimated by one company to be of the order of
100,000 gallons per year.
^.
Environmental losses of solvents used in tire repair kits are
substantially 100% to the atmosphere. Considering a maximum content of
1% benzene (as an accidental contaminant), the probable maximum exposure of
the environment to benzene from this source is 1,000 gallons per year. This
volume is lost in very small quantities at multiple sites.
3.4.2.6 Miscellaneous Uses
Elastomeric adhesives find use in many phases of shoe and footwear
production either as a structural (permanent) or non-structural '(temporary
holding) adhesive. The major operations requiring adhesives are:
(1) Making the shoe upper
(2) Lasting
(3) Sole assembly
(4) Shoe repair
Latex and solvent based elastomers are the adhesives most commonly
used in shoe production and shoe repair. Polyurethane and hot melt adhesives
are now making inroads into the elastomer market. This is due to a changeover
from stitching to bonding of insoles and outsoles, and to increased production
line speeds and automation.
Industry reports indicate that adhesive consumption by the shoe manu-
facturing and repair industry is of the order of 7 million pounds of solids.
It has been estimated that 38% of this quantity are rubber and neoprene based
adhesives, 43% polyurethane and 19% hot melts.
-73-
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Over 90% of the elastomeric (rubber, neoprene and polyurethane) materials used
are solvent based, the balance are in latex form.
The calculated volume of solvent used in this industry, based on
the previously noted percentages, is about 15 million pounds or 2.2 million
gallons.
The solvents used in rubber-based cements are usually blends of
toluene, toluene-xylene, naphtha, acetone and methyl ethyl ketone. No benzene
is used in the solvent formulations. Accidental benzene contamination of these
solvents may occur as a result of the petroleum refining process. This con-
tamination is currently being limited to 0.5% to meet the requirements of the
proposed OSHA regulations.
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3.5 FORMULATED PRODUCTS; PAINTS AND ALLIED PRODUCTS
Paints, paint thinners, and paint removers all use solvents. The
solvents used in this industry include petroleum distillates, aromatic chemicals,
ketones, chlorinated chemicals and alcohols. "Rule 66" in Los Angeles
County* and "Regulation 5"** in the San Francisco area are partially responsible
for the elimination of benzene and other photo-oxidizable hydrocarbons from
paint formulations. OSHA regulations on permissible solvent concentrations
in the workplace together with the California air quality regulations have
resulted in the greater use of water based paints which are now used both for
interior and exterior applications. Electrostatic coating and other technologies
are being used in many industrial applications to eliminate the presence of
solvents.
Paint thinners are formulated from turpentine or petroleum naphthas.
Benzene is not and has not been an ingredient of this group of products.
3.5.1 Paints and Coatings
Benzene's solvent powers and high volatility made it a desirable
component in solvent blends for the manufacture and formulation of nitrocellulose
lacquers, cellulose esters, airplane dopes, varnishes and stains. According to
benzene manufacturers, and distributors and paint manufacturers*, there has
been a move away from benzene in these areas for the past 10 years. It is
reported that benzene has been eliminated from the solvent blends used in
paint formulations because of known toxic and flammable properties. The
paint industry spokesmen also noted that there is a trend away from solvent
based paints and coatings toward the use of water-based emulsion type paints.
It is estimated that by 1981 only 22% of all paint sales will contain an
organic solvent (Chemical Week, 1976).
*South Coast Air Quality Management District Regulation 442: Usage of
Solvents, Reg. 443: Labelling of Solvents.
**Air Pollution Episode Plan, adopted March 21, 1974, revised July 16, 1975.
+Shell, Exxon, Texaco, Gulf Oil, Charter Oil, AMSCO, Glidden, du Pont,
Sherwin-Williams.
-75-
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3.5.2 Paint Removers
Until 1977, the largest solvent use of benzene by the paint and
allied products industry had been as a component of low-cost paint removers and
strippers. According to industry sources, perhaps one out of 10 paint remover
formulations used benzene to the extent of 25 to 50 volume percent of the
total solvent. These were usually the low cost brands produced either under
the manufacturer's label or packaged as a "private label" brand for sale by
paint manufacturers or various store chains.
Benzene-containing paint remover formulations were being produced
until the early part of 1977. Since then, the companies contacted stated
they have removed benzene as a direct component of their formulation. However,
it is possible that some of the older products which contain benzene are
still on the shelves of some stores.
Specific data on the amount of benzene that may have been used by
companies formulating paint removers in recent years is difficult to obtain
because of the reluctance of companies to reveal figures they consider
confidential. Industry sources, including benzene manufacturers and distributors,
estimated that between 300,000 and 400,000 gallons of benzene may have been
used in these products in 1976.
The 1972 Census of Manufactures (U.S. Department of Commerce,
Bureau of Census, 1976) reported the quantity of shipments of paint and varnish
removers was 12.6 million gallons. Industry spokesmen believe that the total
volume of these products has not changed appreciably since then. Industry
sources estimate that a maximum one out of ten, or 10% of all paint and
varnish remover products produced prior to 1977 contained benzene, with an
average benzene content of between 20 and 50%. The maximum 1976 consumption of
benzene in paint removers is calculated to be in the range of 300,000 to 600,000
gallons excluding the benzene content resulting from its accidental presence
in other solvents. This confirms the industry reported information.
-76-
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The major companies in the paint remover field report that they
have discontinued the manufacture and sale of benzene-containing products as
of 1977, probably about the time of the issuance of the regulatory notice by
OSHA (Federal Register, 1977). However, one distributor-reseller reported that
he had sold a small volume (less than 5,000 gallons) of benzene to a small
company manufacturing a furniture refinisher for commercial use (not consumer sales)
The paint and varnish removers on the market today are blends of
materials such as acetone, methanol, toluene, xylene, methylene chloride and
naphtha-type hydrocarbons. Of these, toluene and the naphthas could be
contaminated with a maximum of 1% benzene.
The "Briefing Package and Related Documents Regarding Benzene"
(U.S. Consumer Product Safety Commission, 1977) contained letters from the
following paint remover manufacturers:
MANUFACTURER
United Gilsonite Laboratories
Savogran Company
Cook Paint and Varnish Co.
Elliott Paint and Varnish Remover
Reliable Paste and Chemical Co.
PRODUCTS
Raizoff Paint and Varnish Remover
Kutzit Paint and Varnish Removers
Kut-All Paint and Varnish Remover
Penetrating Oil Stain
Stay Wet Liquid Remover
Comet Liquid Remover
Antique Refinishers Remover
Stay Put Heavy Bodied Remover
Dox Liquid Brush Cleaner
They stated that none of their products currently contain benzene. Either they
have removed the specific formulation from their product list or have reformulated
the product eliminating benzene as a component.
The large paint companies such as Glidden, Sherwin-Williams and
duPont all reported (1977) that they do not use benzene as a solvent
in the formulation of any of their products nor do they buy solvent blends
where benzene concentration is more than 3%, preferably less than 1%.
(These specification limits have been reduced to conform to the OSHA proposed
regulations of 1978).
-77-
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A major paint manufacturer stated that as of May 1977, the only
paint remover product they had produced that contained benzene had been formulated.
No product currently manufactured contains benzene according to the spokesman. A
spokesman for another company reported that benzene had been eliminated from
their products.
A spokesman for another coatings manufacturer reported that his
company has not used benzene as a solvent or as a component or any of their
industrial paints, coatings and related products for a number of years. He
stated that the coating and paint industry has recognized benzene to be a
major health hazard and voluntarily removed it from their products.
The distributors and resellers of solvents and solvent blends
confirmed the statements of the paint remover fortnulators that benzene is no
longer being bought for this use.
One formulator who sells solvent blends for many purposes
stated that until 1977, they sold a solvent blend containing benzene to
companies making paint removers. As of the middle of 1977, they reformulated
their blend eliminating benzene.
The Houston district branch of one of the largest national dis-
tributor companies sold an average of 60,000 to 70,000 gallons of benzene per
year. About one quarter (15,000 to 17,000 gallons) of this went for chemical
intermediate use. About one half (30,000 to 35,000 gallons) was sold to
companies formulating paint removers. The balance (15,000 to 17,000 gallons)
was sold for miscellaneous industrial solvent uses. A representative of this
company stated they no longer sell benzene to any of these markets.
Another benzene distributor in the southwest market area reported
that at one time they formulated about 50,000 gallons/year of paint stripper
blends containing 20% benzene. Several years ago this product was reformulated
to eliminate benzene.
-78-
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The Texas Air Control Board (1977) provided AAI with the opportunity
to review non-confidential data obtained from all paint, rubber and chemical
companies in Texas that had shown hydrocarbon emissions in a state wide
monitoring effort. Some of the data was obtained in 1972, updated in 1973 to
include only companies whose total of all types of chemical emission exceeded
50 tons per year and further revised in 1975 to include selected companies with
large air emissions. None of the companies which replied to the questionnaire
sent by the Texas Air Control Board reported the use of benzene.
The solvents used to formulate paint removers and strippers are
vaporized into the atmosphere during use.
The estimated benzene emission to the atmosphere for 1976 is
calculated in Table 3-25.
TABLE 3-25. ESTIMATED ATMOSPHERIC BENZENE LOSSES FROM PAINT REMOVERS. 1976
(M. Sittenfield & Associates, 1978)
Benzene containing formulations 300,000 to 600,000
Accidental contamination* 190,000
Total Loss 490,000 to 790,000
Present benzene losses (1978) to the atmosphere due to the contamination
of petroleum hydrocarbon solvents will not exceed 30,000 gallons, based on a
maximum content of 0.5% benzene in the solvent.
* 12,600,000 gallons x 50% hydrocarbon content x 3% benzene = 190,000 gallons
-79-
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3.6 SUMMARY
Benzene consumption as a solvent has been approximately halved in the
two year period from 1976 to 1978. It has been eliminated altogether from the
formulated industrial and consumer products (where there was almost 100% loss
to the environment). As shown in Table 3-26, consumption has dropped from about
4.8 million gallons in 1976 to an estimated 2.8 million in 1978.
The OSHA Emergency Benzene Standard of May, 1977 is the major factor
contributing to the decline in benzene consumption, although some companies
reported moving to alternate solvents prior to the OSHA action, based on the
known toxicity of benzene and its large increase in price, relative to other
solvents.
The trend is definitely towards eliminating benzene solvent consumption
wherever feasible. The smaller volume users, for example, those in the pharma-
ceutical industry, are more inclined to eliminate benzene since they have no uses
for it other than as a solvent, and because they are having increasing difficulty
in obtaining benzene in small quantities. This is borne out in Tables 3-1 and
3-3, which show the greatest drop in use in this area.
Those who consume benzene as an adjunct in general organic syntheses
frequently use benzene in their plants as a chemical intermediate, and are
thus more likely to have well developed workplace and pollution control systems,
and less need to look to alternate solvents.
-80-
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TABLE 3-26. SUMMARY OF BENZENE SOLVENT CONSUMPTION
/ o do
' 0 fl.c
Consumption Area
General Organic Synthesis
Pharmaceutical Synthesis
Small Volume Chemicals
Aluminum Alky Is
Alcohols
Bisphenol-A
Ethylcellulose
Formulated Industrial &
Consumer Products
Adhesives
Rubber-based adhesives
Tire manufacture
Tire retreading
Industrial rubber products
Tire patch repair kits
Miscellaneous
Automotive
Shoe
Paints and Allied Products
Paints & coatings
Removers
TOTAL
Estimated Consumption
1976
2,962
650
312
465
0
0
0
0
0
0
0
100
0
0
0
300 to
500
4,789 to
4,989
1978
2,214
220
312
100
0
0
0
0
0
0
0
0
0
0
0
2,846
-81-
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SECTION IV. USE ALTERNATE ANALYSIS
Benzene has strong solvent properties for many organic chemicals.
Its availability and, until recent years, its relative low cost, has made
it the solvent of choice for many uses. However, because of its recognized
toxicity, and the promulgation of regulations by OSHA, work has been done to
find substitutes that are less hazardous.
The major emphasis in developing alternate solvents has been for
formulated products that are used by the general public or by small companies
who would find the cost to meet in-plant safety measures excessive.
The chemical and related process industry is a major user of benzene
as a solvent adjunct in chemical manufacturing. Benzene has been selected
for this use because of its excellent solvent power when compared to other
solvents, its boiling point, and its azeotroping characteristics.
Use of alternate materials in these industrial areas is often not
a case of simple substitution, for technical or economic reasons. Use
of an alternate material can sometimes not be made without causing process
adjustments and/or increases in production cost.
-82-
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4.1 ALTERNATE SOLVENTS IN CHEMICAL MANUFACTURING PROCESSES
Solvents are used as adjuncts in the manufacture of a large number
of chemicals. For a given application, there are many potential alternate
solvents.
However, in making substitutions, choices are influenced by the pro-
ducts, the impurities and the other system components, and each process and its
requirements must be evaluated separately.
The main processes which may require a solvent adjunct are:
• Reaction solvents
• Azeotropic dehydration and distillation
• Extraction
• Recrystallization and purification
Where benzene is used as the solvent medium for a reaction, it may
also be one of the reactants, as in its use in the Friedel-Crafts reaction.
In polymerization reactions, for example, in the production of synthetic
rubber, it may be used as a reaction solvent. Cyclohexane, toluene and xylene
are the chief alternates to benzene in this application. For example, cyclohexane
is being phased in as a substitute for benzene in one manufacturer's polymeri-
zation process for synthetic rubber. In many instances, substitutions may re-
quire process changes or adjustments.
Azeotropic dehydration/distillation is the major operation to use
benzene in the manufacture of chemicals, and to be adaptable to the use of
alternate solvents. Our current review of the industry has shown the following
solvents to be the main choices for substitution: toluene, xylene, cyclohexane,
and some esters, such as ethyl acetate. It is necessary that the alternative
solvent be compatible with the system and not react with the components which
are to be separated. The substitution of the solvents listed above often re-
quires no major process change, only adjustments in temperature and flow rates.
There is very little use of heptane and hexane as alternates to benzene as
azeotroping agents.
-83-
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Alternate solvents for extraction processes are selected on the basis
of the product, the impurities, and their relative solubilities. Again,
toluene, xylene and cyclohexane are used as alternates to benzene, as well as
some aliphatics such as hexane.
Recrystallization and purification processes allow more freedom in
the choice of alternates. Again, the properties of the product and its
impurities are the chief considerations. Cyclohexane, cyclohexanone, toluene,
xylene, ketones and naphthas may replace benzene for this use.
4.2 ALTERNATE SOLVENTS IN SPECIALTY CHEMICAL MANUFACTURE
For this area of chemical manufacture, the alternate solvents are
more dependent on the end use of the product than in the case of general
organic syntheses. Alternate solvents for each chemical will be reviewed
separately, since they are used differently in each process.
4.2.1 Aluminum Alkyls
There are seven hydrocarbon solvents currently being used as alternates
for benzene as packaging blend for aluminum alkyls. All serve to render the
catalysts non-pyrophoric, and include hexane, xylene, heptane, toluene,
isopars and cyclohexane. With the substitution of cyclohexane in the one
remaining process which currently uses benzene as a solvent for a synthetic
rubber polymerization reaction, benzene will no longer be used in the aluminum
alkyl industry as a packaging medium.
4.2.2 Ethyl Cellulose Resins
Benzene was phased out as the process solvent for this application in
1976. Alternate solvents include toluene, ethanol and diethyl ether.
4.2.3 Alcohols
Solvents have two different uses in alcohol processing, one as a
denaturant, and one as a dehydration agent. Once the pending OSHA standard is
-84-
-------
upheld, it is predicted that alternate solvents will have replaced benzene as
a denaturant (1978 consumption is estimated at 2,000 gallons). Alternate
denaturants depend on the end use, for example, industrial, pharmaceutical,
the vinegar industry, and include toluene, methyl isobutylketone, methanol,
gasoline, rubber hydrocarbon solvent, and ethyl acetate.
The use of benzene to dehydrate ethanol to the anhydrous finds
limited alternate solvent choices due to the proportions of the azeotropic
mixture formed. The companies that have changed solvents are using cyclohexane.
Alternate solvents for the dehydration of other alcohols (isopropyl
and propargyl) are cyclohexane and isopropyl ether. Two anhydrous
isopropanol producers have substituted alternates, and a third plans to do so.
4.2.4 Bisphenol-A
The use of benzene as an extractant for Bisphenol-A ceased in 1976.
The substituted solvent was methylene chloride.
4.3 ALTERNATE SOLVENTS FOR RUBBER-BASED ADHESIVES
Elastomeric adhesives, both natural and synthetic, are soluble in
a number of hydrocarbon solvents, and for most applications (see Section
3.4.2) adequate alternates have been found. These are discussed individually
in this section.
In the tire manufacturing and retreading industries, special
fractions of aliphatic hydrocarbons ranging from hexane to octane, and known
as "Rubber Makers' Naphtha" or "Rubber Solvent" have been substituted for
benzene. In some tackifier applications, phenolic resins or water-based rubber
cements have been substituted, eliminating solvent use altogether. Petroleum
naphthas, and aromatics such as toluene, have been substituted in the solvent
adhesive package in tire and tube repair kits.
-85-
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Industrial rubber products and rubber reclaiming operations do
not use solvents of any kind.
Benzene is no longer used as a solvent in the elastomeric adhesives
used in the footwear industry. Petroleum naphthas, toluene and xylene are
the substituted solvents, or alternate adhesives such as hot melt adhesives
or, in special instances, latex based adhesives are used.
Rubber-based "household cements" no longer contain benzene, with
blends of toluene and naphtha being the main substitute.
4.4 ALTERNATE SOLVENTS FOR PAINT AND ALLIED PRODUCTS
Benzene has not been a component of paints for the last several
years. Aromatics such as toluene and xylene, and petroleum distillate
fractions have been the alternate solvents. In addition, there has been a
significant shift in the market from solvent-based to water-based paints.
Paint and varnish removers are now blends of such materials as
acetone, methanol, toluene, xylene, methylene chloride and naphthas.
4.5 ALTERNATE PROCESSES AND END PRODUCTS
Benzene as an adjunct to manufacture is used for its physical, rather
than chemical reactant properties. The process technologies used in connection
with benzene's employment as an adjunct comprise distillation, extraction, and
crystallization, all based on the physical action of a solvent. Although
the process technology is independent of the solvents employed, the reactants,
and the impurities influence the choice of adjunct solvent. Process
economics and equipment design may be adversely affected by the use of alternate
solvents. Some adjustments in the process, such as temperature or flow rate
are frequently required.
Processes for preparing.a formulated product such as paint removers,
adhesives and similar products are physical in nature. No chemical change occurs
which would alter the character of the raw materials. Hence, the technology used
to prepare these products is independent of the materials used in their form-
ulation. The use of alternate chemical solvents in the preparation of the end
product does affect selling price, and could change the effectiveness of the
product.
-86-
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The elimination of benzene as a solvent material in the paint and
allied products field, the adhesive industry, and the rubber tire retread
industry has not changed the overall effectiveness of the reformulated products.*
However, price increases have resulted in several cases.
Table 4-1 summarizes alternate solvents currently replacing benzene
for the consumption areas investigated in this report.
4.6 ENVIRONMENTAL MANAGEMENT OF ALTERNATE SOLVENTS
The environmental management for processes and methods which use
benzene as a solvent does not change with the use of alternate solvents. The
same precautions and methods of environmental control should be employed regard-
less of the solvent.
Proper maintenance of equipment, such as seals on pumps and agitators,
is required to minimize losses. Spills and leakage on the floor or ground
should be cleaned promptly either by flushing with water to a suitable liquid
waste disposal system or adsorbed on material such as adsorbent clay for ultimate
disposal.
Storage and process vessels should use control systems to minimize
or eliminate air emissions. 'These systems may include vapor return between
vessels, refrigeration to eliminate or reduce solvent vapors in vent gasses, or
incineration. Liquid and solid residues containing solvent that cannot be
recovered economically may be incinerated or buried in suitable landfills.
Solvent contaminated air exhausted from the work place should be passed through
a suitable gas adsorption system before being permitted to enter the atmosphere.
Again, the size of the establishment and type of process have a
bearing on the economic resources which can be committed to pollution control.
Adjunct chemical uses usually occur as part of large chemical operations, with
well-developed environmental management programs. Pollution control for use
of solvents in formulated products is less thorough and consistent, with most
losses being vented to the atmosphere. Recovery here is more difficult tech-
nically, and less economic based on the volume lost compared to the volume
consumed.
* Discussions with industry spokesmen.
-87-
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TABLE 4-1. ALTERNATE SOLVENTS FOR BENZENE
V
N, Alternate
Application N.
Chemical Adjunct
Reaction Solvent
Azcotrope
Extractant
Re crystallization
Aluminum Alkyls
Ethyl Cellulose
Resins
Ethanol, Denatured
Ethanol, Anhydrous
Other alcohols
Bisphenol-A
Snlvent-type
Rubber-based
Adhesives
Paints
Paint thinners
Paint removers
Cyclohexane
X
X
X
X
X
X
X
Toluene
X
X
X
X
X
X
X
X
X
X
01
c
1)
£
X
X
X
X
X
X
X
0)
a
lO
u
a.
£
X
Hexane
X
X
Cyclohexanone
X
Other
Ketones
X
X
X
01
u
a
u
0)
u
<
^
>,
'u
Ul
X
X
Naphthas
X
X
X
Methylene
Chloride
X
X
Die thy 1
Ether
X
1
Ethanol j
X
Methanol !
X
X
Rubber Hydrocarbon
Solvent
X
Other
Isopars
Gasoline
Isopropyl ether
Hexane-octane blends;
phenolic resins
latex cements
Petroleum distillates
Turpentine
i
1
-88-
-------
In terms of alternates for benzene, it can be seen from Table 4-1
that toluene is one of the most frequently used substitutes, particularly in
high volume consumption areas such as chemical adjunct processes. There are
various state and local regulations concerning the emission of photochemically
reactive chemicals, such as Rule 66 in Los Angeles County and Regulation 5 in
the San Francisco area. The State of Connecticut limits toluene emissions to
25 pounds per day. For formulators, the cost of reducing emissions to this
level may be prohibitive. Thus, many industries may have to find substitutes
for toluene, should this action be indicative of a trend.
-89-
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SECTION V. SUMMARY OF BENZENE LOSSES
The consumption patterns of benzene as a solvent were discussed in Section
3 and are summarized in Section 3.6. In the context of this study, benzene
consumption as a solvent represents losses resulting from its use as a process
adjunct or as a component of a formulated product. The percentage losses are
dependent on its application.
When the solvent is a component of a formulated product, the loss can
be 100 percent during its ultimate use. When the solvent is used as an adjunct
in a chemical process or in the manufacture of a formulated product, losses are
estimated to be in the range of 1 to 10% of the volume in process, and are a
result of:
(1) Fugitive losses from process equipment, storage and handling
facilities and leakage from flanges, pumps, valves, etc.
(2) The solvent being a component of process waste streams.
The total volume of benzene circulated in those chemical processes
which use benzene as a solvent adjunct can be calculated at any given time from
overall consumption data. According to Table 5-1 approximately 4.8 million
-90-
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TABLE 5-1. CONSUMPTION VERSUS ENVIRONMENTAL LOSS
FOR BENZENE SOLVENT USES (1,000 gallons)
Consumption Area
General Organic Synthesis
Pharmaceutical Synthesis
Small Volume Chemicals
Aluminum Alky Is
Alcohols
Bisphenol-A*
Ethyl Cellulose
Formulated Industrial &
Consumer Products
Adhesives
Rubber based adhesives
Tire manufacture
Tire retreading
Industrial rubber
products
Tire patch repair kit
Miscellaneous
Automotive
Shoe
Paints and Allied Products
Paints and & Coatings
Removers
Total
Estimated
Consumption
1976
2,962
650
312
465
0
0
0
0
0
0
0
100
0
0
0
300 to
500
4,789 to
4,989
1978
2,214
220
312
100
0
0
0
0
0
0
0
0
0
0
0
Estimated
Environmental Loss
1976
691
200
312
225
100
-
300 to
500
1,828 to
2,028
1978
309
66
312
55
0
150**
892
* Use in 1975 was 2,990,000 gallons
** Estimated amount in product made prior to May, 1977 and sold in 1978
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gallons of benzene were "lost" in 1976, exclusive of the amount used in
formulated products. This is equivalent to a nationwide consumption (or loss)
of approximately 12,000 gallons per day. Assuming an average loss of 5%, the
in-process volume can be estimated to be 240,000 gallons, exclusive of storage.
Overall losses of benzene resulting from its solvent applications
are not equatable with environmental losses. These will be discussed in
Section 5.1.
5.1 ENVIRONMENTAL LOSSES
Environmental losses to air, waste water systems and the soil occur
as a result of the various solvent uses of benzene.
Air emissions result from:
(1) Evaporation of solvent from a formulated product during use
(2) Fugitive emissions from filling storage vessels, drums and
equipment
(3) Fugitive emissions from process equipment and piping during
its use and recovery as an adjunct in manufacturing operations
(4) Vaporization from waste water, liquid streams and solid wastes.
Liquid wastes are of two types:
(1) Waste waters from azeotropic dehydration processes in which
benzene is soluble to the extent of about 0.07%
(2) By-product organic liquid streams contaminated with benzene.
Benzene loss to the soil is extremely rare. It can be due to the disposal of
solids from filtration, crystallization or solid extraction processes.
Benzene's two distinct applications (chemical adjunct versus
formulation or application) result in quite different emissions levels. This
difference is due to the use of pollution control devices in integrated
chemical plants which are usually not installed in non-chemical industries
employing benzene as a solvent. There are no controls for any consumer oriented
applications that might use benzene in the formulation.
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Environmental control in an integrated chemical plant will take the
following forms:
(1) A vent system to collect tank and process equipment emissions,
conveying them to an incineration unit or an adsorption unit
(2) Waste water treatment plants
(3) Incineration of benzene-containing organic by-products or
waste liquids
(4) Blending of benzene-containing organic liquid wastes into
another process stream.
Chemical and pharmaceutical manufacturing companies that employ benzene as
a solvent adjunct in chemical synthesis report make-up requirements at between
1 and 10% of the solvent circulated. However, because of the extensive use
of pollution control equipment actual environmental losses may vary between
10 and 40% of. the total benzene solvent make-up. The balance, 60 to 90%, is
destroyed in the control processes.
Table 5-1 compares benzene solvent consumption estimates for the
year prior to OSHA's proposed regulation, and that to be expected for the
present (1978) year, with estimated environmental losses for both periods
for each of the industrial and consumer applications.
5.2 GEOGRAPHIC DISTRIBUTION
Based on a review of benzene sales as reported both by distributors
and producers, and by consumers, industrial benzene consumption as a solvent
and environmental loss were in the following geographical areas in order of
decreasing use (the remaining 2% was consumed at disperse locations):
West South Central 51%
Middle Atlantic 31%
East North Central 10%
East South Central 5%
West North Central 1%
Over 90% of solvent benzene is consumed and lost in connection
with industrial processes. Environmental losses from these applications are
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concentrated at the industrial sites. The balance of the environmental losses
occur with the use of consumer products which would be distributed more
uniformly throughout the consuming area.
Figure 5-1 presents for 1976 the geographical distribution of
benzene consumption as a solvent at industrial sites (including the manufacture
of consumer products). This is shown as a percentage of the national
consumption. Even though the actual quantity of benzene loss to the environment
is less than the consumption because of the use of pollution control systems, the
regional percentage losses will follow the same pattern.
5.3 TRENDS
Benzene consumption as a solvent, and therefore its environmental
losses, have been decreasing at a steady-rate. Its use in formulating consumer
products has dropped to near zero following the issuance of the proposed regulation
by OSHA and the concurrent issuance of a regulation by CPSC banning benzene in
consumer products (Federal Register, 1978; OSHA, 1977).
Industrial uses of benzene as a solvent in such industries as
rubber, rubber tires, automotive and adhesives have been non-existent, according
to industry reports, for a number of years.
The major industrial solvent use area of benzene has been as an adjunct
in the manufacture of chemicals, in pharmaceutical organic chemical synthesis
and polymerization. Tables 3.1 and 3.3 show a more than 20% drop in benzene's
use as a solvent adjunct in general organic chemical processes, including
polymers, and over 60% drop in its use in connection with pharmaceutical
synthesis between pre-OSHA 1976 and post-OSHA 1978.
Industrial spokesmen reported that they are investigating alternate
solvents to benzene for its adjunct uses. In those cases where the processes
permit the use of alternate solvents, the companies are making or planning to
make the change.
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VO
;ST NORTH '
CENTRAL
WEST SOUTH
CENTRAL
Figure 5-1. Geographic Distribution of Solvent Benzene Consumption by Region, 1976
-------
REFERENCES
Advances in Chemistty Series 116 (1973), Azeotropic Data III, American Chemical
Society, Washington, DC, 461.
Chemical Marketing Reporter (1977), September 19, 9.
Chemical Week (1977), June 1, 27-29.
Chemical Week (1977), 1978 Buyers' Guide Issue, Part 2, 336.
Chemical Week (1976), "Changing Menu for Paintmakers," 119 (15), 76-77.
Code of Federal Regulations (1977), U.S. Department of the Treasury, Alcohol.
Tobacco Products and Firearms, Title 27, Part 212, 604-630.
Federal Register (1978), "Consumer Products Containing Benzene as an Intentional
Ingredient or as a Contaminant; Proposal to Ban", Consumer Product Safety
Commission, Vol. 43, No. 98, May 19, 21839.
Federal Register (1977), "Occupational Exposure to Benzene, Proposed Standards
and Notice of Hearing," Occupational Safety and Health Administration,
Department of Labor, Vol. 42, May 27, 27452.
Fick, James E. (1976), "To 1985: U.S. Benzene Supply/Demand," Hydrocarbon
Processing, July, 127-129.
Gunn, Thomas G., and Koon L. Ring (1977), "Marketing Research Report on Benzene,"
Chemical Economics Handbook, Stanford Research Institute, Menlo Park,
California.
Lowenheim, Frederick A., and Marguerite K. Moran (1975), Faith. Keyes, and Clark's
Industrial Chemicals, 4th Edition, Wiley-Interscience, Inc., New York.
Modern Tire Dealer (1978), January.
National Petroleum Refiners Association (1978), Personal Communication.
National Petroleum Refiners Association (1977), Personal Communication, July 12.
Newsfront (1970), 25,000 Leading U.S. Corporations, Year. Inc.
OSHA (1977), "Emergency Temporary Standard for Occupational Exposure to Benzene;
Notice of Hearing," Occupational Safety and Health Administration, Department
of Labor, Federal Register, Vol. 42, No. 85, May 3, 22516-22529.
Sittenfield, M., and Associates (1978), Personal Communications.
Texas Air Control Board (1977), Personal Communication, July 20.
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U.S. Consumer Product Safety Commission (1977), "Briefing Package and Related
Documents re Benzene," August.
U.S. Department of Commerce, Bureau of Census (1976), 1972 Census of Manufactures,
Volume II, Industry Statistics, Part 2, SIC Major Groups, Government
Printing Office, Washington, DC.
U.S. Department of Commerce, Bureau of Census (1971), 1967 Census of Manufactures,
Volume II, Industry Statistics, Part 2, SIC Major Groups, Government Printing
Office, Washington, DC.
U.S. Department of Commerce, Bureau of Census (1972-1978), U.S. Exports.
U.S. Department of Commerce, Bureau of Census (1972-1978), U.S. Imports for
Consumption and General. Imports, Report No. FT 246.
U.S. Department of Labor, OSHA (1977), Technology Assessment and Economic Impact
Statement of an OSHA Regulation for Benzene, May.
U.S. Department of Treasury (1976), Bureau of Alcohol, Tobacco Products and
Firearms, Summary Statistics, 22-23, 34-35.
U.S. Department of Treasury (1978), Bureau of Alcohol, Tobacco and Firearms,
"Use of Benzene in SDA Products," Industry Circular No. 78-4, April 11.
U.S. International Trade Commission (1978), "Synthetic Organic Chemicals:
United States Production and Sales, 1977," Preliminary Report, Government
Printing Office, Washington, DC.
U.S. International Trade Commission (1977), "Synthetic Organic Chemicals:
United States Production and Sales, 1976," U.S. International Trade
Commission Pub. 833, Government Printing Office, Washington, DC.
U.S. International Trade Commission (1977), "Synthetic Organic Chemicals: United
States Production and Sales, 1975", U.S. International Trade Commission Pub.
804, Government Printing Office, Washington, DC.
U.S. International Trade Commission (1976), "Synthetic Organic Chemicals: United
States Production and Sales, 1974", U.S. International Trade Commission
Pub. 776, Government Printing Office, Washington, DC.
U.S. International Trade Commission (1975), "Synthetic Organic Chemicals: United
States Production and Sales, 1973," U.S. International Trade Commission
Pub. 728, Government Printing Office, Washington, DC.
U.S. Tariff Commission (1974), "Synthetic Organic Chemicals: United States
Production and Sales, 1972," U.S. Tariff Commission Pub. 681, Government
Printing Office, Washington, DC.
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U.S. Tariff Commission (1973), "Synthetic Organic Chemicals: United States
Production and Sales, 1971," U.S. Tariff Commission Pub. 614, Government
Printing Office, Washington, DC.
U.S. Tariff Commission (1972), "Synthetic Organic Chemicals: United States
Production and Sales, 1970," U.S. Tariff Commission Pub. 479, Government
Printing Office, Washington, DC.
U.S. Tariff Commission (1971), "Synthetic Organic Chemicals: United States
Production and Sales, 1969," U.S. Tariff Commission Pub. 412, Government
Printing Office, Washington, DC.
U.S. Tariff Commission (1970), "Synthetic Organic Chemicals: United States
Production and Sales, 1968," U.S. Tariff Commission Pub. 327, Government
Printing Office, Washington, DC.
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APPENDIX I. NOTES ON CALCULATIONS FOR TABLE 1-4
Ethylbenzene;
"Calculated from styrene production
Conversion factors - Styrene from ethylbenzene - 1.17
Ethylbenzene from benzene - 0.76
Styrene prod, x 1.17 gives ethylbenzene consumed. Ethylbenzene must be
adjusted for amount not made from benzene (i.e., from mixed xylenes).
Find ethylbenzene capacity from mixed xylenes and multiply by plant
operating rate for each year to get amount of ethylbenzene isolated from
mixed xylenes.
Operating rate = styrene production
styrene capacity
Use styrene operating rate because ethylbenzene reporting is incomplete
(styrene and ethylbenzene rates should be alike). Subtract ethylbenzene
from mixed xylenes from total ethylbenzene. Multiply corrected
ethylbenzene consumption by conversion factor, 0.76, to obtain pounds
of benzene.
Cumene:
Conversion factor - 0.69
Cyclohexane:
Conversion factor - 0.93
80-85% of cyclohexane comes from benzene and the rest occurs naturally .
in hydrocarbon streams (Gunn, 1977). Take 82.5% of cyclohexane production
and multiply by the conversion factor.
Chlorobenzenes:
Conversion factors - mono-0.82, di^0.62
.Monochlorobenzene production figures are from USITC/USTC.
Di- figures for 1974. 1976, 1977 were calculated from mono- data, all
others are from USITC. (Di- figures were not reported in 1974.)
Calculations of di- data were made based on a di/mono ratio of .325, the
average ratio for 1971, 1972 and 1975. 1976 - Di-figure was adjusted
upward to .326 ratio because one company failed to report that year
(Gunn, 1977).
Aniline:
Conversion factor - 0.9
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Maleic Anhydride;
Conversion factor - 1.25
Beginning with 1975, increasing amounts of maleic anhydride were made from
materials other than benzene. The amounts from benzene are: 1975-95%;
1976-92.7%; 1977-78%. These figures were calculated based on reported
total capacity, newly built plants and plants converted from benzene feed
(Gunn, 1977).
Alkylbenzenes;
Conversion factor - 0.4 (both)
Production data for branched alkylbenzenes is based on data for linear
and calculated at a ratio of linear/branched = 2.64. Ratio is based on
1976 and assumed constant for all years.
Phenol (from Benzene Sulfonic Acid);
Conversion ratio - 1.0
Most phenol is produced from cumene. For phenol produced from benzene
sulfonic acid, take 50% of phenol production from other than cumene.
Note: Reichhold Chemicals, the only company producing phenol via this
route, closed its plant early in 1978.
Anthraquinone;
Use conversion factor of 1.37 and Vat Dye production to calculate benzene
consumed for anthraquinone.
Nitrobenzene (notfor aniline);
Conversion factor - 0.65
Assume 4% of total nitrobenzene is not used for aniline (Gunn, 1977).
Biphenyl, Hydroquinone, Resorcinol;
Use changes in benzene production as basis for calculation starting with
benzene consumption for a base year. These uses were considered to
exhibit little growth.
Biphenyl;
Base year, 1975 20,000,000 Ibs. of benzene consumed
Hydroquinone;
Base year, 1976 3,000,000 Ibs. benzene
Resorcinol:
Base year, 1976 30,000,000 Ibs. benzene
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APPENDIX II. LIST OF COMPANIES CONTACTED
The following companies were interviewed regarding their use of
benzene as a solvent. AAI is grateful to them for their assistance and
cooperation in the preparation of this study.
A & S Corp.
Ab'bott Laboratories
Able Industrial Products
Aceto Chemical Co., Inc.
Acme Hamilton
Acme Solvent Reclaiming, Inc.
Advance Finishes, Inc.
Air Products & Chemicals, Inc.
Akron Chemical Co.
Alabama By-Products Co.
Alcolac, Inc.
Alden Rubber Co.
Aldrich Chemical Co., Inc.
Alfa Div., Ventron Corp.
Allen Rubber Co.
Allied Chemical Corp.
Allied Oil
Alox Corp.
Alpine Aromatics International, Inc.
American Adhesives Products, Inc.
American Chemical Service
American Cyanamid Co.
American Hoechst Corp.
American Lacquer & Solvents Co.
of Miami
American Oil & Supply Co.
American Recovery Co.
American Synthetic Rubber Co.
Ames Laboratories, Inc.
AMF Voit, Inc.
Amoco Oil Co.
Amsco Div., Union Oil Co.
Angeles Chemicals Co.
Ansul Chemical Co.
Apco Industrial Solvents Co.
Arapahoe Chemicals, Inc., Subs.
Syntex Corp.
Arco Chemical Co.
Arco Industrial Corp.
Arenol Chemical Corp.
Aristo Laboratories, Inc.
Arivec Chemical Co.
Argo Chemicals, Inc.
Armak Co.
Armco Steel Corp.
Armstrong Rubber Co.
Arsynco Co., Inc.
Ashland Chemical Co.
Atlas Refining Co.
Atlas Rubber, Inc.
J.T. Baker Chemical Co.
Balboa Industries
Baltimore Paint & Chemical Co.
Barium & Chemicals, Inc.
Wm. M. Barr Co.
BASF - Wyandotte Corp.
Baxter Laboratories
Bearfoot Corp.
Bethlehem Steel Corp.
Better Monkey Grip Rubber Co.
Biochemical & Nuclear Corp.
Bofors America, Inc.
Borden Co., Borden Chemical Div.
Borden Remington Corp.
Borg-Warner Corp.
Bostik Div., USM Corp.
Bowes Pacific Corp.
Bowes Seal Fast Corp.
Bristol Labs, Inc.
Bucks County Solvents & Chemicals, Inc.
Buffalo Color Co.
Burroughs Wellcome & Co.
Burton Rubber Processing, Inc.
Butens
Calcasieu Chemical Corp.
Calsol, Inc.
Carolina By-Products Co., Inc.
Carroll, Ltd.
Carter Div., Dennison Mfg. Co.
Celanese Chemical Co.
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Central Solvents
Centrix Corp.
Certified Coating Products, Inc.
CF & I Steel Co.
Charter Chemicals, Charter
International Oil Co.
Chemetron Corp.
Chem-Fleur, Ine.
Chemical & Solvent Distillers
Co., Inc.
Chemical Commodities, Inc.
Chemical Dynamics Corp.
Chemical Leaman Tank Lines
Chemical Samples Co.
Chemisphere Corp.
•Chemol, Inc.
Chemtech Industries, Inc.
Chemway Corp.
Chevron Chemical Co.
Chromalloy
Ciba Pharmaceutical Co., Div.
Ciba-Geigy Corp.
Cincinnati Milacron Chemicals, Inc.
Cities Service Oil Co.
City Chemical Co.
Classic Chemical
Clayton Chemical
Clifton Adhesive, Inc.
Coastal Chemical Co.
Columbia Cement Co.
Commonwealth Oil Refining Co., Inc.
Composition Materials Co., Inc.
Cone Solvents, Inc.
Conoco Chemicals Div., Continental
Oil Co.
Converse Rubber Co.
Cooper Tire & Rubber Co.
Cordova Chemical Co.
Corson Rubber Products, Inc.
Cotler Distribution
CPC International, Inc.
CPS Chemical Co.
Crest Chemical Corp.
Crosby Chemicals, Inc.
Crowley Chemical Co.
CTC Organics
Curtiss Laboratories, Inc.
Cutter Laboratories
Cyclo Chemicals Corp.
Dan River, Inc.
Dart Industries, Inc., Aztec
Chemicals Div.
Dayco Corp.
Dayton Tire & Rubber Co.
Deccofelt Corp.
Degussa, Inc.
Delta Solvents
Diamond Shamrock Corp.
Dion & Son
Dixie Cap Rubber Co.
Dixie Chemical Co.
Dow Chemical Co.
DuPont Co.
East Falls
Eastern Rubber Reclaiming Co.
Eaton Corp., Air Controls Div.
H.B. Egan Manufacturing Co.
El Paso Products Co.
Elan Chemical Co.
Electric Hose & Rubber
Eli Lilly & Co.
Emery Industries, Inc.
Enerchem International
Ethyl Corp.
Evans Chemetics, Inc.
Exxon Co. U.S.A.
Fairmount Chemical Co., Inc.
Famis
Faultless Div., Abbott Laboratories
Ferro Corp.
Finetex, Inc.
Firestone Tire & Rubber Co.
Florida Distillers Co.
Florida Solvents
FMC Corp.
Foster Grant, Div. American Hoechst
Fritzsche Dodge & Olcott, Inc.
GAF Corp.
Ganes Chemicals, Inc.
Gates Rubber Co.
General Chemical Corp.
General Electric Co.
General Sealants, Inc.
General Tire & Rubber Co.
Georgia-Pacific Corp.
The Gillette Co.
Glidden-Durkee Div., SCM Corp.
Globe Solvents
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Glyco Chemicals, Inc.
Gold Shield Div., Detrex Chemical
Industries, Inc.
Goodall Rubber
B.F. Goodrich Tire Co.
The Goodyear Tire & Rubber Co.
W.R. Grace & Co.
Grain Processing Corp.
A. Gross & Co.
Guardian Chemical Corp.
Gulf Oil Chemicals Co.
H & S Solvent Corp.
Haarmann & Reimer Corp.
C.P. Hall Co.
Hamblett & Hayes
Hardwicke Chemical Co.
Harrelson Rubber Co.
Hart Products Corp.
Haven Chemical Co.
W.W. Henry Co.
Hercules, Inc.
Heterene Chemical Co., Inc.
Hodag Chemical Corp.
Hoffman-LaRoche
Hooker Chemical Corp.
Houston Solvents
ICI United States, Inc.
IMC Chemical Group, Inc.
Independent Refining Co.
Inland Chemical Corp.
Inmont Corp.
Inolex Corp.
International Flavors &
Fragrances
Intex Products, Inc.
Jefferson Chemical Co., Inc.,
Subs, of Texaco, Inc.
Jerdan Chemical Corp.
Johnston Distributors, Inc.
Joli Plastics & Chemicals
Jones & Laughlin Steel Corp.
Kalman Paint & Chemical Corp.
Kanoo, Inc.
Kay-Fries Chemicals, Inc.
Kelly-Springfield Tire Co., Subs.
Goodyear Tire & Rubber Co.
Kernstar Corp.
Kerr-McGee Chemical Co.
Kex Products, Inc.
King's Laboratories, Inc.
Kraft, Inc.
Kravex Manufacturing Co.
Lindsey & Hall
Long Mile Rubber Co.
Lonza, Inc.
M & J Solvents
M & T Chemicals, Subs. American
Can Co.
MacArthur Petroleum & Solvent Co.
Mackenzie Chemical Works, Inc.
Magichemical Co., Inc.
Magna Corp., Aquaness Chemical Div.
Mallinckrodt, Inc.
Malmstrom Chemicals
Mansfield Tire & Rubber Co./Inland
Rubber Corp.
Marathon Oil Co.
Maryland Chemical Co., Inc.
Matheson Scientific Div., Will Ross,
Inc.
Matlack
Mattiace Industrial Chemicals
May Co., Ltd.
Mazer Chemicals, Inc.
McBride Chemical Co.
McKesson Chemical Co.
Mellon Chemical Co.
Mercer Rubber Co.
Merck & Co.
Merichem Co.
Merril National Labs
Midwest Rubber Manufacturing, Inc.
Midwest Rubber Reclaiming Co.
Milliken & Co.
Mobay Chemical Co.
Mobil Chemical Co.
Monsanto Co.
John B. Moore Corp.
Mystic Tape Co., Div. Borden
Naarden, UOP Fragrances
Nalco Chemical Co.
Napp Chemicals, Inc.
Narco Corp.
National Solvent, Inc.
National Starch & Chemical Corp.
Nearpara Rubber Co.
N.L. Industries, Inc.
Nobs Chemical Co.
The Norac Co., Inc.
Norda, Inc.
Northern Petrochemicals Co.
Northwestern Chemical Co.
Norton Petroleum Corp.
Norwich Pharmaceutical Co.
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Norwood Chemical Co.
Noury Chemical Corp.
Occidental Chemical Co.
Oil & Solvent Process Co.
Olin Corp.
Organon, Inc.
Pacific Chemical Laboratories, Inc.
Paeco Rubber Co.
Para-Chem
Parke Davis & Co., Subs, of Warner-
Lambert Co.
Pasley Solvents & Chemicals, Inc.
Patch Rubber Co.
C.H. Patrick & Co., Inc.
PCR, Inc.
Pearsall Chemical Corp.
Pemaco, Inc.
Pemco Adhesives, Inc.
S.B. Penick & Co.
Pennwalt Corp.
Petrochemicals Co., Inc.
Pfizer, Inc.
Pharmacaps, Inc.
Pharma-Tech Industries, Inc.
Phillips Chemical Co.
Pickering Oil
Piedmont Chemical Industries
Pierce & Stevens Chemical Corp.,
Div. Pratt & Lambert, Inc.
Plough, Inc.
Polarome Manufacturing Co., Inc.
Polymer Application, Inc.
Polysciences, Inc.
PPG Industries, Inc.
Pressure Chemical Co.
Proctor & Gamble Industrial
Chemical Div.
Prodyne, Inc.
Publicker Industries, Inc.
Purity Organics
PVO International, Inc.
Pyrazine Specialties
Quaker Oats Co.
Quintana-Howell
Railchem Div.
Randolph Products Co.
Red Devil
Reheis Chemical Co., Div.
Armour Pharmaceutical Co.
Reilly Tar & Chemical Corp.
Research Products, Inc. of Alabama
J.E. Rhoades
Rho-Chem Corp.
Rhodia, Inc.
Richardson-Merrill Co.
Richmond Organics, Inc.
Riker Laboratories, Div. of 3M Co.
Roberts Solvent Co., Inc.
Robertson Trucking Co.
Robinson Wagner Co., Inc.
Rocson, Inc.
Rohm & Haas Co.
Rorer Pharmaceutical Co.
RSA Corp.
Ruan Transport
Saber Laboratories, Inc.
Santell Chemical Co.
SARAMCO-Samson Ray Materials Co.
Sartomer Industries, Inc.
Scher Bros., Inc.
Schering-Plough Corp.
Schrader Automotive Products Div.,
Scovill Mfg. Co.
Scientific Chemical Processing, Inc.
Searle Chemicals, Inc.
Shell Chemical Co.
The Sherwin Williams Co.
Siloo, Inc.
Skelly Oil (now Getty)
G. Frederick Smith Chemical Co.
Smith, Kline & French
Solvent Chemicals
Solvents Recovery Service of New
England
Solvents Recovery Service of New
Jersey
Southern Coast Chemical Corp., Gold
Coast Oil Corp.
Southland Solvents & Chemical Co.
Southwestern Oil & Chemical Co.
Southwestern Refining Co.
Spencer Kellogg Div., Textron, Inc.
E.R. Squibb Co.
Stabond Corp.
StaLube, Inc.
Standard Chemical Products, Div.
Henkel, Inc.
Stauffer Chemical Co.
Stephen-Roger, Inc.
W.H. Stevenson Co.
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Stoney-Mueller, Inc. Van Waters & Rogers
Suburban Chemical Co. Welch, Holme & Clark Co., Inc.
Sun Oil Company Western Eaton Solvents & Chemical Co.
Sunkist Whitaker Oil Co.
Superior Rubber Products Co. Wilhold Glues, Inc.
Super-Tire Willard Tire Co.
Swope Oil & Chemical Co. Witco Chemical Co., Inc.
Syntex Agribusiness, Inc. Wyeth Laboratories, Inc., Div.
Talon Adhesives Corp. American Home Products, Inc.
Tauber Oil
Tenneco Chemicals, Inc.
Texaco, Inc.
Texas Alkyls, Inc.,
Div. S£auffer~Chemical Co.
Texas Eastman
Texas Solvents
Textile Chemical Co.
Thiokol Chemical Corp.
31, Inc.
Thomas Solvent Co.
Thompson-Hayward
3M Co.
Tri-K Industries, Inc.
Triple R Industries
Tru-Flex Rubber Products Co.
Tumpeer Chemical Co.
Ungerer & Co.
Union Carbide Corp.
Union Rubber & Asbestos Co.
Union Rubber Co., Inc.
Uniroyal, Inc.
United Rubber Corp.
U.S. Industrial Chemicals Co.
U.S. Oil Co.
U.S. Pipe & Foundry
U.S. Rubber Reclaiming Co., Inc.
USS Chemicals Div., U.S. Steel Corp.
UOP Chemical Co.
Upjohn Co.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA 560/6-77-034
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Market Input/Output Studies:
Task V
Benzene Consumption as a Solvent
5. REPORT DATE
October, 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
M. Lynne Neufeld, Marcus Sittenfield (Marcus
Sittenfield & Assoc.),Rowland Henry,Susan Hunsicker
S. PERFORMING ORGANIZATION REPORT NO.
AAI 2378/79-105-FR-5
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
AUERBACH Associates, Inc.
121 N. Broad Street
Philadelphia, PA 19107
(AAI)
11. CONTRACT/GRANT NO.
EPA 68-01-1996
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Toxic Substances
U.S. Environmental Protection Agency
Washington, DC 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final Technical Report
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This study was conducted to determine the current status of the industrial and
consumer consumption of benzene as a solvent, and to identify where possible
any impact on its use as a solvent due to the OSHA Emergency Benzene Standard
(42 FR 27452, May 27, 1977). The report presents an overview of the technical
and commercial history of benzene and a. discussion of its marketing and dis-
tribution patterns into the small miscellaneous use market. Consumption
processes and patterns of benzene use, both before and after the OSHA regulations,
are examined in detail. Consideration is given to the use of benzene in formu-
lated products, such as adhesives and paint removers, and to benzene consumption
as a solvent and adjunct to manufacturing in processes such as esterification
and azeotropic dehydration. Possible alternatives to the use of benzene are
explored. Losses of benzene to the environment are analyzed and an estimate
of their geographic distribution is given.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Benzene
Consumption
Chemical Marketing Information
Denatured Ethanol
Anhydrous Alcohol
Aluminum AlkyIs
Pollution
Environmental Fate
Rubber Based Adhesives
Paint Removers
18. DISTRIBUTION STATEMENT
Document is available to the public
through the National Technical Informa-
tion-Service, Springfield, VA 22151
19. SECURITY CLASS (ThisReport/
Unclassified
21. NO. OF PAGES
116
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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