EPA 560/6-76-008
THE MANUFACTURE AND USE OF SELECTED ARYL
AND ALKYL ARYL PHOSPHATE ESTERS
TASK I
FEBRUARY 1976
FINAL REPORT
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF TOXIC SUBSTANCES
WASHINGTON, D.C. 20460
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EPA 560/6-76-008
THE MANUFACTURE AND USE OF SELECTED ARYL
AND ALKYL ARYL PHOSPHATE ESTERS
Task I
EPA Contract No. 68-01-2687
EPA Project Officer: Thomas Kopp
For
Environmental Protection Agency
Office of Toxic Substances
4th and M Streets, S.W.
Washington, D. C. 20460
February 1976
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REVIEW NOTICE
This report has been reviewed by the Office of Toxic Substances, EPA and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the Environmental Protection Agency, nor does
mention of trade names or commercial products constitute endorsement or recommenda-
tion for use.
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PREFACE
This report presents the results of Task I of a project entitled
"Study on Chemical Substances from Information Concerning the Manufac-
turing, Distribution, Uses, Disposal, Alternatives, and Magnitude of
Exposure to the Environment and Man." Task I, "The Manufacture and Use
of Selected Aryl and Alkyl Aryl Phosphate Esters," was performed by Mid-
west Research Institute (MRI) under Contract No. 68-01-1687 for the
Office of Toxic Substances of the U.S. Environmental Protection Agency.
This program had MRI Project No. 3955-C.
Task I was conducted from 1 September 1974 to 14 March 1975 by
Dr. T. We Lapp, Associate Chemist, who served as project leader and
prepared this report, under the supervision of Dr. E. W. Lawless, Head,
Technology Assessment Section^. Dr. I. C. Smith, Senior Advisor for En-
vironmental Science provided technical assistance and supervision.
MRI would like to express its sincere appreciation to the various
companies who provided technical information for this report and especi-
ally to Mr. Paul Levesque, FMC Corporation, for his valuable assistance
in this subject area.
Approved for:
MIDWEST RESEARCH INSTITUTE
L. J. Shannon, Assistant Director
Physical Sciences Division
5 February 1976
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CONTENTS
Preface .............................
List of Tables ......................... viii
List of Figures ......................... ix
Sections
I Introduction ......... .... 1
II Summary ...... ................. 3
III Historical Development and Future Outlook ...... 5
Historical Development .............. 5
Future Outlook ........... 7
References to Section III ............. 9
IV Market Input-Output Data .............. 10
Production .................... 10
Importation ............... 12
Exportation ....... ........ 12
Use Patterns ................... 14
Final Products .................. 16
References to Section IV ............. 18
V General Manufacturing Process ............ 19
Triaryl Phosphate Esters . ... 19
Alkyl Aryl Phosphate Esters ............ 23
Manufacturing Costs ................ 23
Environmental Management ............. 25
References to Section V ......... 31
11.
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Sections
CONTENTS (Continued)
VI
VII
VIII
Process Technology . „ .......... 32
General Production Capacity ............ 32
Specific Phosphate Esters ............. 35
Tricresyl Phosphate (TCP) ............ 36
Triphenyl Phosphate ............... 41
Cresyl Diphenyl Phosphate (GDP) ......... 45
Isopropylphenyl Diphenyl Phosphate ....... 49
Trixylenyl Phosphate .............. 52
2-Ethylhexyl Diphenyl Phosphate ......... 55
Isodecyl Diphenyl Phosphate ..,,,...... 58
Dibutyl Phenyl Phosphate ............ 60
Methyl Diphenyl Phosphate ............ 62
£-Chlorophenyl Diphenyl Phosphate ........ 64
Dimethyl Xylyl Phosphate ............ 65
Mono-0-Xenyl Diphenyl Phosphate ......... 66
Mixed Alkyl Aryl Phosphates ........... 67
Transportation and Handling ........... 68
References to Section VI ............. 69
Areas of Utilization ................ 70
Hydraulic Fluids and Lubricant Additives ..... 70
Fire Retardant Plasticizers ............ 86
Gasoline Additives ................ 101
Miscellaneous Use Areas .............. 102
References to Section VII ............. 105
Material Balance and Energy Consumption ....... 106
Raw Materials ................... 106
Energy Consumption ........... 106
Waste Material Produced .............. 108
Summary ...................... 109
Exposure to Man and the Environment ........ 109
References to Section VIII ............ 117
111,
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CONTENTS (Concluded)
Sections Page
IX Use Alternatives ....... ..... ...... 118
Alternative Raw Materials . ............
Alternative Manufacturing Processes ..... ... 118
Alternate Final Use Products .......«••• H9
References to Section IX ........-•••• 121
Appendix A - Results of the Written Questionnaire ........ 123
Appendix B - Airline Fleet Sizes ........ ..... ... 133
Appendix C - Mode of Degradation of Phosphate Esters ...... 138
iv.
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TABLES
No. Page
1 Annual Production of Various Phosphate Esters 11
2 Estimated Annual Consumption and Percentage Composition
by Use Area 15
3 Material Balance 21
4 Production Capacity 33
5 Usage of Phosphate Ester Hydraulic Fluids by Industry ... 78
6 Consumption of Dibutyl Phenyl Phosphate in Commercial
Aircraft 81
7 Major Markets for Poly(vinyl chloride); Percentage Con-
tribution of Each Market Area 91
8 End-Use Products for Phosphate Ester Compounded PVC
Resins 93
9 Producers of Phosphate Ester Compounded PVC Resins .... 94
10 Major Markets for Cellulosics; Percentage Contribution of
Each Market Area 96
11 Estimated Quantities of Phosphate Esters Used as Gasoline
Additives 102
B-l U.S. Airline Fleet Size 135
B-2 Foreign Airline Fleet Size 137
v.
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FIGURES
N°JL
1 Estimated Total Production and Future Growth of
Phosphate Esters .......... ..... 13
2 Production and Waste Flow Diagram for Tricresyl
Phosphate .............. 20
3 Raw Materials Consumed . . ......... 107
VI.
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SECTION I
INTRODUCTION
Organophosphate esters find widespread usage in numerous consumer-
oriented and industrial products where fire retardancy is a desirable
property or a mandatory requirement. In addition to the halogens, phos-
phorus is one of the most effective elements in combating the propaga-
tion of fire, and incorporation of phosphorus into organic compounds,
via organophosphate esters, has led to its widespread usage for that
purpose. In very general terms, organophosphate esters are used as
plasticizers in poly(vinyl chloride) plastic materials and in indust-
rial hydraulic fluids. Because of their use in poly(vinyl chloride),
as a flame retardant, they are found in numerous consumer products,
such as automobile and household goods, and in industries having wide
geographical coverage, such as the construction industry. The use of
these esters as fire resistant hydraulic fluids leads to a widespread
utility in industries operating hydraulic systems in the immediate
vicinity of high temperature sources.
The primary objectives of this study are to collect information
on the production quantities, manufacturers and their processes, users
and their processes, and the environmental management of both the pro-
ducers and users. This information is organized into a format which
will assist the government agencies in the evaluation of any regulatory
alternatives for these materials. The goal of Task I of the study has
been to assist the EPA in the evaluation of the potential for environ-
mental contamination by selected organophosphate esters.
Eleven aryl and alkyl aryl phosphate esters were selected for
investigation as potential environmental contaminants. These were:
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* Methyl diphenyl phosphate
* Isodecyl diphenyl phosphate
* Dimethyl xylyl phosphate
* Xenyl diphenyl phosphate
* _p_-Chlorophenyl diphenyl
phosphate
* Tricresyl phosphate
* Cresyl diphenyl phosphate
* Triphenyl phosphate
* Dibutyl phenyl phosphate
* Isopropylphenyl diphenyl
phosphate
* Octyl diphenyl phosphate
(2-ethylhexyl diphenyl
phosphate)
Throughout the literature and in discussions with personnel di-
rectly involved with the industry, two different terminologies--with
respect to phosphate esters is widespread. In the hydraulics industry,
fluids that resist flame propagation are termed fire resistant fluids
whereas in the field of plasticizers, phosphate esters are termed
fire retardant plasticizers. In this report, the term fire resistant
will be applied to discussions involving their use in hydraulic fluids
and fire retardant when discussing plasticizers. While this method is
rather inconsistent, it is the accepted terminology within the respec-
tive industries.
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SECTION II
SUMMARY
For the time period 1964 to 1973, approximately 847 million pounds
of phosphate esters were produced, of which tricresyl phosphate accounted
for about 396 million pounds. The other phosphate esters studied and their
respective approximate production figures, in million pounds, were iso-
propylphenyl diphenyl (46), cresyl diphenyl (167), triphenyl (96), dibutyl
phenyl (24), methyl diphenyl (37), 2-ethylhexyl diphenyl (58) and isodecyl
diphenyl (23). Nearly all of the production of these esters is utilized
in the United States with only approximately 2 to 3% being exported.
Essentially all of these esters are produced commercially by the
reaction of the appropriate alcohol or phenol with phosphoryl chloride.
Reaction conditions vary somewhat depending upon whether the triaryl or
alkyl aryl phosphate esters are being produced. Currently, the five com-
panies who produce these triaryl or alkyl aryl phosphate esters are FMC
Corporation, Monsanto Industrial Chemicals Company, Stauffer Chemical Com-
pany, Sobin Chemical Company, and Eastman Kodak Company, Of these, the
first three are the major producers with the latter two producing rela-
tively small quantities of selected esters.
The major areas of utilization of these esters are as fire retardant
plasticizers (resin modifiers) and fire resistant hydraulic fluids. These
two areas presently account for approximately 90% of the total use of
these esters. During the 10-year period from 1964 to 1973, the major use
of two of these esters, cresyl diphenyl and methyl diphenyl, was as gaso-
line additives for ignition control but this area has been inactive since
about 1971. Most of these phosphate esters are utilized in both of the
major use areas, however, some have singular uses in either one area or
the other. Dibutyl phenyl phosphate is used solely as an aircraft hydraulic
fluid and trixylenyl phosphate is utilized almost exclusively in the for-
mation of industrial hydraulic fluids. Methyl diphenyl phosphate is no
longer produced on a commercial basis. Triphenyl phosphate finds almost
sole utilization as a plasticizer in cellulosic and polyphenylene oxide
materials.
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During the middle 1960'ss the predominant areas of utilization of
these esters were as fire retardant plasticizers and gasoline additives.
In more recent years,, their use as gasoline additives has ceased and
their utility in fire resistant hydraulic fluids has increased dramati-
cally. Hydraulic fluid usage represents the largest contributor of these
esters into the environment. It is estimated that approximately 80% of
the annual "consumption" of hydraulic fluids occurs through leakage in
the hydraulic systems.
According to most observers directly related to this industry^ the
overall future growth of both the plasticizer and hydraulic fluid fields
is expected to be in the range of 8 to 10%/year. Since these two areas
constitute the major use of these phosphate esters, it appears that
future growth in production should also approximate this 8 to 10% fig-
ure in future years.
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SECTION III
HISTORICAL DEVELOPMENT AND FUTURE OUTLOOK
The historical development of selected aryl and alkyl aryl phosphate
esters as plasticizers, hydraulic fluids, and additives is reviewed. Their
future outlook, from 1974 to 1984, is discussed from a generalized viewpoint,
HISTORICAL DEVELOPMENT
Triaryl phosphate esters were first reported in the literature over
100 years ago and the utility of these esters as plasticizers for cellu-
losics was initiated about the turn of the century. The preparation of
triphenyl phosphate was first reported in 1854i' but remained little more
than another research chemical until 1910 when a patent was issued to the
Celluloid Company of New York—' for its use with cellulose acetate to
produce a "celluloid-like" material. It was hoped that this process would
overcome the dangers of flammability of celluloid by (a) using the acetate
instead of the nitrate and (b) plasticizing with triphenyl phosphate for
reinforcement and its nonburning properties. Shortly thereafter, in 1913,
Klatte in his pioneering patent demonstrated that useful and processible
forms of poly(vinyl chloride)' could be obtained when he employed tri-
phenyl phosphate as a plasticizer. In 1922 Laska and Brillwitzui/ were
issued patents for the production of tricresyl phosphate and cresyl di-
phenyl phosphate and in 1923 a patent was issued to St. John— for the
production of cresyl diphenyl phosphate. In this same time period tri-
phenyl phosphate and tricresyl phosphate began to find usage in plastics
and lacquers.—' In 1929 the Celluloid Corporation patented a mixture
comprising vinyl compounds and aryl phosphates, including tricresyl phos-
phate. Surprisingly, vinyl chloride was not mentioned as one of the vinyl
compounds.— However, in the following year a patent was issued to Du Pont
for a coating composition using tricresyl phosphate as a possible soft-
ener. By 1933 developmental quantities of poly(vinyl chloride) had been
introduced in a variety of product forms in the U.S. and Germany and
both tricresyl phosphate and dibutyl phthalate, patented in 1920 by
H. T. Clarke, were the recognized plasticizersJi'
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The discovery in 1933 by Dr. W. L. Semon, of B. F. Goodrich, that
poly(vinyl chloride) could be plasticized with high boiling esters,
including tricresyl phosphate, without the use of a lower boiling sol-
vent is considered to be one of the most important contributions to
the development of poly(vinyl chloride) as well as to the plasticizer
industry.!/ During the decade 1930 to 1940 there was a growing interest
and activity in the field of plasticizers and plasticized compounds
but it did not compare with the magnitude of research in subsequent
years*
The development of the hypoid gear for use in automobile rear
axles by the Gleason Works in 1925 provided the impetus for further
developmental work in the area of gear lubricants. Those gear lubri-
cants, which had previously proved quite satisfactory for spur and
bevel gears, were inadequate for hypoid gears. General usage of this
type of gear was delayed until a suitable class of extreme-pressure
(EP) lubricants was available.
By 1937 practically the entire production of automobiles in this
country and a large percentage of the trucks were using hypoid rear
axles. The increased developmental activity for extreme-pressure (EP)
lubricants led to the introduction of triaryl phosphate esters as EP
agents.
During the war years and those immediately subsequent, the interest
in plastics, particularily poly(vinyl chloride)s mushroomed and thousands
of compounds, many chosen empirically, were tested and evaluated for the
many new applications that appeared after the war. In 1941 the produc-
tion of tricresyl phosphate was less than 10 million pounds^/ but in-
creased rapidly to over 20 million pounds in 1943 to 1944 before fall-
ing back to about 10 million pounds after the war.
As in the case with plasticizers, the emphasis on developmental
research provided by World War II led to a broadening of the areas of
application for EP agents, including tricresyl phosphate. It was during
this time period that the use of phosphate esters first appeared as fire
resistant hydraulic fluids for the military in aircraft hydraulic sys-
tems and in launching catapults on aircraft carriers. After World War II
the usage of triaryl phosphate esters, predominantly tricresyl phosphate
and cresyl diphenyl phosphate, began a slow, gradual increase until the
latter 1960's.
In the years immediately following World War II, synthetic fluids
were applied to industrial hydraulic systems. By the early 1950rs, water-
glycol fluids were developed as low-cost substitutes for the synthetic
fluids and in the latter 1950's, water-in-oil emulsions were introduced
into the market.
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In 1950, the production of tricresyl phosphate was over 15 million
pounds and triphenyl phosphate was over 6 million pounds. The early 1950's
saw not only an increased interest as plasticizers, but the advent of
phosphate esters as gasoline additives. New alkyl aryl phosphate esters
appeared on the scene, such as 2-ethylhexyl diphenyl phosphate, dimethyl
phenyl phosphate, and methyl diphenyl phosphate. The latter two found
usage as gasoline additives as did cresyl diphenyl phosphate and tricresyl
phosphate. In 1953, Shell Oil Company commercially introduced tricresyl
phosphate as an additive for automobile fuels to control sparkplug fouling
and preignition.
During the 1950's the utilization of synthetic hydraulic fluids
decreased sharply, evidently due at least in part to being oversold,
and fell from favor with many hydraulic fluid users. In 1960, fire re-
sistant fluids probably accounted for about 2 to 3% of the total hy-
draulic fluid consumption. By 1964, fire resistant fluids had risen to
only approximately 6% of the total fluid consumption, with phosphate
esters accounting for only about 10% of the total fire resistant fluids
being used.
In general, from the mid-1950's to 1964, the major use areas of
aryl and alkyl aryl phosphate esters were as plasticizers, gasoline addi-
tives, lubricant additives, and functional fluids.
FUTURE OUTLOOK
The future use of the aryl and alkyl aryl phosphate esters, except
for tricresyl phosphate and cresyl diphenyl phosphate, appears to be in-
creasing at the present time. Usage as fire retardant plasticizers and
in fire resistant hydraulic fluids accounts for approximately 80 to 907o
of the annual consumption of these phosphate esters. The manufacturers
of these esters are predicting an average overall growth rate in both
of these fields of 8 to 10%/year for 1976 and further into the future.
Due to the present economic climate, use in the major areas fell from
1973 levels but should recover during 1975.
"* One of the overriding factors in all discussions with both producers
and users of these esters was the increase in cost, both in terms of raw
materials and the finished product. For producers, the shortages in the
supply of raw materials and their rapidly increasing cost are of great-
est concern since these costs are, in turn, passed on to the users.
Tricresyl phosphate and cresyl diphenyl phosphate should both show
declines in production during the next decade. Monsanto Industrial Chemi-
cals Company ceased the commercial sale of tricresyl phosphate in 1974
and reportedly will do the same with cresyl diphenyl phosphate in 1975.
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The reasons for this discontinuation were basically due to the shortage
of cresylic acid, increased costs, and their inability to control the
ortho isomer content. This decrease in production will, of course, cre-
ate further pressure on the supply of these two chemicals. However, it
should be noted that in view of the methods of production of triaryl
esters, production of either or both of these materials could commence
on very short notice.
Phosphate esters which find rather general utilization throughout
both of the major use areas are expected to increase in production at
a rate consistent with the increases for the two areas. Certain specialty
items, such as triphenyl phosphate, will probably not experience an aver-
age annual growth as high as the more general use esters.
Overall, the production and consumption of these phosphate esters
should be in the range of 8 to 10%/year for the next decade, assuming
that the current economic situation is clarified. The production of tri-
cresyl phosphate, however, is expected to decline rather sharply over
the next few years. Cresyl diphenyl phosphate will decline but probably
not as sharply as will tricresyl phosphate. Future legislation regard-
ing flammability requirements could alter the overall growth rate of
phosphate esters significantly. Likewise, the introduction of new products
will obviously affect the projected growth rate of specific materials.
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REFERENCES TO SECTION III
1. Williamson, Ann., 9_2:316 (1854).
2. Kaufman, M., The History of Polyvinylchloride, Maclaren and Sons,
London (1969), p. 100.
3. Laska, A. L., and H. H. C. Brillwitz, U.S. Patent 1,425,393 (1922);
CA, 16_:3314 (1922).
4. St. John, A. D., U.S. Patent 1,462,306 (1923); CA, 17^:3100 (1923).
5. Doolittle, A. K., The Technology of Solvents and Plasticizers,
John Wiley and Sons, New York (1954), p. 862.
6. Kaufman, M., The History of Polyvinylchloride, Maclaren and Sons,
London (1969), pp. 102-103.
7. Sarvetnick, H. A., Polyvinyl Chloride, van Nostrand Reinhold Company}
New York (1969), p. 67.
8. van Wazer, J. R., Phosphorus and Its Compounds, Vol. 2, Interscience,
New York (1961), p. 1231.
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SECTION IV
MARKET INPUT-OUTPUT DATA
Cumulative data are presented for the selected phosphate esters dur-
ing the time period 1964-1973. The data are considered in terms of produc-
tion, importation, exportation, use patterns, and final products of these
esters.
PRODUCTION
The total production quantities of each of the phosphate esters in-
cluded in this study on an annual basis and for the 10-year time span
(1964 to 1973) are shown in Table 1. In the United States, the three ma-
jor producers of aryl and alkyl aryl phosphate esters are FMC Corporation,
Stauffer Chemical Company, and Monsanto Industrial Chemicals Company.
Sobin Chemicals, Inc. (Montrose Chemicals Division), and Eastman Kodak
Company produce smaller quantities of selected aryl phosphate esters. In
terms of total production over the 10-year span, the three major phos-
phate esters are tricresyl phosphate, cresyl diphenyl phosphate, and tri-
phenyl phosphate.
As shown in Table 1, the total quantity of phosphate esters produced
during the 10-year span was approximately 847 million pounds. This does
not include any production data for either dimethyl xylyl phosphate or
mono-o-xenyl diphenyl phosphate. For the first material, no information
could be located concerning any production figures and only two references
to any possible utility with no information being available on current or
past actual usage. In the case of the latter material, the company who re-
portedly produced the material stated that they had never made any phos-
phate esters. The data reported in this table show some variance with the
figures reported in the U.S. International Trade Commission Reports on Syn-
thetic Organic Chemicals. It is believed that some, but not all, of the
production figures for the proprietary mixed alkyl aryl esters manufactured
by Monsanto Industrial Chemicals Company are included in the U.S. Interna-
tional Trade Commission Reports. Since the actual quantities of this mate-
rial are unknown to Midwest Research Institute, no consideration has been
given to this material in the tabulation and thus, certain discrepancies
will occur in a comparison of the total figures.
10
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Table 1. ANNUAL PRODUCTION OF VARIOUS PHOSPHATE ESTERS
(x 106 Ib/year)
Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
TCP
32.4
34.8
39.8
42.9
44.3
(43.5)
(41.0)
(40.8)
(38.2)
(37.8)
IPDP^7
_ _
--
--
__
__
(3)
(5)
(8)
(12)
(18)
CDP
16.1
19.7
20.0
18.2
19.8
11.1
12.7
20.4
14.6
14.2
TPP
9.0
(8.9)
8.8
8.7
7.9
9.2
10.6
(10)
(11)
(12)
DBPP
(1.6)
(1.8)
(2.0)
(2.4)
(2.8)
(2.3)
(2.5)
(2.7)
(2.9)
(3.1)
MDPP
(4.8)
5.8
(5.8)
(5.9)
(5.9)
6.0
(2)
(1)
--
--
ODPP
(9)
(9)
(8)
(8)
(5)
(4)
(4)
(3)
(3)
(5)
IDPP CPDP
__
__
__
(1) « 0.1
(1.5) « 0.1
(4)
(4.5)
(5)
(7)
Tt ISJ
72.9
80.0
84.4
86.1
86.8
80.7
81.8
90.4
86.7
97.1
Total (395.5)
(46)
166.8 96.1 (24.1) (37.2)
(58)
(23) « 0.2
(846.9)
( ) MRI estimates based on discussions with manufacturers
Abbreviations: TCP = tricresyl phosphate
IPDP = isopropylphenyl diphenyl phosphate
CDP = cresyl diphenyl phosphate
TPP = triphenyl phosphate
DBPP = dibutyl phenyl phosphate
MCPP = methyl diphenyl phosphate
ODPP = octyl diphenyl phosphate (2-ethylhexyl diphenyl phosphate)
IDPP = isodecyl diphenyl phosphate
CPDP = £-chlorophenyl diphenyl phosphate
a_l Some of the total figures will vary somewhat with the total figures reported in the U.S. Interna-
tional Trade Commission Reports on Synthetic Organic Chemicals. It is felt that a portion of
the proprietary alkyl aryl phosphate ester mixture produced by Monsanto is included in the Com-
mission Reports but is excluded from these totals.
b/ Throughout this report, this name will be utilized in all discussions and tables. Although this
name is the specific compound that is closest to the actual product, the different grades repre-
sent different ratios of isopropylphenols to phenol and the term "mixed isopropylphenyl phenyl
phosphate" is a more accurate representation.
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Future production of the phosphate esters is expected to follow the
predicted growth for the use areas of fire retardant plasticizers and
fire resistant hydraulic fluids. After a period of relatively zero growth
during 1974 and 1975, each of these areas should attain an annual growth
of 8 to 10%/year, Since these two areas represent the largest use of the
phosphate esters, it would be expected that production would increase at
approximately the same rate. Barring any further economic recessions,
this would indicate an annual production of 185 to 215 million pounds
per year by 1984 as shown in Figure 1.
IMPORTATION
Importation of phosphate esters over the 10 years from 1964 to 1973
have generally been negligible in relation to the total quantities of
aryl and alkyl aryl phosphate esters produced in the United States, A
U.S. International Trade Commission annual report!' lists the following
materials as having been imported.
Quantity imported (pounds)
Material JL973 1974 1971 1970 1969 1968
Trixylenyl phosphate 70,636 -
plus butyl benzyl
phthalate
Cresyl diphenyl - - 3,000
phosphate
Phosphate esters - - 43,726 -
Tricresyl phosphate - - - 1»565
The originating country for these imports was not specified but it is
very probable that it was the United Kingdom. As shown in the listing,
the quantities are extremely small* Phosphate ester manufacturers in-
dicate that phosphate esters are imported in greater quantities than
shown in the above listing but, overall, comprise less than 1% of the
total quantity of esters produced on an annual basis and should con-
tinue at approximately that level for the next 10 years,
EXPORTATION
From the detailed use patterns shown in the next subsection, the
quantities of phosphate esters being exported comprise approximately
3% of the total production. An appreciable percentage of the exports
are shipped to Canada for use by pipeline companies in gas pumping
12
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240 r
210 -
180
150
-o
o
§ 120 -
o
D
"O
O
O
"o
90
XX
60 h
30 -
i i
i i i i
J L
J L
J L
J I I I
1964
1966 1968
1970
1972 1974 1976 1978 1980
1982 1984
Year
Figure 1- Estimated total production and future growth of phosphate esters.
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systems in remote areas. Other areas importing phosphate esters from
the United States include Mexico, Japan, United Kingdom and some
European countries. The quantities of phosphate esters exported has
remained basically constant at about 3% or less of the total produc-
tion for the last 10 years and should remain at approximately that
level for the next 10 years.
USE PATTERNS
The five basic areas of utilization of the phosphate esters are
shown in Table 2 in terms of the estimated annual consumption for each
area and the percentage contribution of each area towards the total for
the respective year. As shown, the area of plasticizers has consistently
been the primary use, although recently the combined areas of hydraulic
fluids and lubricant additives are approximately the same as that for
plasticizers. Within the general area of plasticizers, several other use
areas are included which have a direct relationship to the plastics or
rubber industry. These areas include pigment dispersants, peroxide car-
riers, adhesives, and rubber plasticizers. Aircraft hydraulic fluids are
included in the general classification of hydraulic fluids. The category
of exports and miscellaneous includes, in addition to exportation, the
areas of air filter media, lacquer coatings, and wood preservatives.
A more detailed use pattern is shown below for the years 1970, 1972,
and 1973 for three phosphate esters; tricresyl phosphate, cresyl diphenyl
phosphate, and isopropylphenyl diphenyl phosphate,, Triphenyl phosphate,
dibutyl phenyl phosphate, isodecyl diphenyl phosphate, and octyl diphenyl
phosphate have basically singular uses.
Approximate percent utilization
of TCP, cresyl diphenyl phosphate
and isopropylphenyl diphenyl phosphate
Use area 1973 1972 1970
Hydraulic fluids 43 43 39
Lubricant additive 11 11 H
Plasticizer (PVC) 25 25 25
Air filter media 554
Rubber plasticizer 444
Coatings 222
Pigment dispersant 221
Adhesive, wood treatmentj
and peroxide carrier 223
Gasoline additive 4
Export 334
Miscellaneous 333
14
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Table 2. ESTIMATED ANNUAL CONSUMPTION AND PERCENTAGE COMPOSITION BY USE AREA
(quantities x 106 Ib/year)
Plasticizer
Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
Quantity
37.1
39.3
41.9
41.3
40.0
33.4
41.1
49.8
40.7
41.8
7o
50.9
49.1
49.6
48.0
46.1
41.4
50.2
55.1
46.9
43.1
Hydraulic
Quantity
11.6
15.3
17.3
18.9
20.5
21.3
23.0
24.7
31.9
40.1
fluid
7>
15.9
19.1
20.5
22.0
23.6
26.4
28.1
27.3
36.8
41.3
Lubricant
additive
Quantity
4.0
4.2
4.4
4.6
4.8
5.3
5.8
6.4
7.0
7.7
7o
5.5
5.3
5.2
5.3
5.5
6.6
7.1
7.1
8.1
7.9
Gasoline
additive
Quantity
17.7
18.7
18.2
17.7
16.9
16.0
5.0
2.5
-
-
7o
24.3
23.4
21.6
20.6
19.5
19.8
6.1
2.8
-
-
Export and
miscellaneous
Quantity
2.5
2.5
2.6
3.6
4.6
4.7
6.9
7.0
7.1
7.5
7=,
3.4
3.1
3.1
4.1
5.3
5.8
8.6
7.7
8.2
7.7
Total 406.4
48.0
224.6
26.5
54.2
6.4
112.7
13.3
49.0
-------
The three phosphate esters to which this listing is applicable comprise
approximately 65 to 75% of the total production of the phosphate esters
in this study. As shown above, the percentage utilization has not changed
appreciably over the last 4 years. This detailed compilation also indi-
cates the approximate utilization in several of the minor use areas.
Both the areas of fire retardant plasticizers and fire resistant
hydraulic fluid are anticipated to show an annual rate of growth of ap-
proximately 8 to 10% after 1976. During the period from 1974 to 1976, it
would be expected that both of these areas would show zero growth rate
or perhaps some decline in consumption. Assuming an 8 to 10% annual growth
rate, it could be expected that in 1984, the area of fire retardant plasti-
cizers would utilize 82 to 98 million pounds per year and the area of fire
resistant hydraulic fluids would consume an additional 76 to 91 million
pounds per year. The relatively minor use areas of lubricant additives
and miscellaneous uses are expected to approximately double their consump-
tion of these phosphate esters by 1984. All of these projected figures
assume that no severe economic recessions occur during the time period
1976 to 1984.
FINAL PRODUCTS
Currently, the ultimate uses of the phosphate esters in this study
are predominantly in plastic materials and hydraulic fluids (including
lubricant additives). In the plastics industry, about 90% of all the
esters used as plasticizers, except triphenyl phosphate, are used in
poly(vinyl chloride). Triphenyl phosphate is used in cellulosics and
modified polyphenylene oxide (Noryl) resins with cellulosics accounting
for approximately 60% of its total in 1973.
The major consumer products for phosphate ester plasticized poly-
(vinyl chloride) are in automotive and truck interiors, as vinyl-coated
fabric upholstery, vinyl film upholstery and dashboard coverings; wire
and cable coatings and insulation; wall coverings; and the construction
industry. In 1965, the major use areas for poly(vinyl chloride) were in
the construction and housing markets. Phosphate esters were used as plas-
ticizers where flame retardancy was a requirement such as in light dif-
fusers, wall coverings and flexible doors. These esters are still used
for such purposes at the current time but the automotive market has been
the major growth area from 1964 to 1973.
Prior to 1966, triphenyl phosphate was used almost exclusively in
cellulosics; however, since the introduction of Noryl, its application
as a plasticizer for this engineering plastic has been increasing steadily
and now constitutes approximately 40% of its utilization. Cellulosics are
used primarily in packaging; home applications such as photo albums, han-
dles on small tools, box lids for greeting cards and stationary; and
16
-------
safety face shields. During the time period 1964 to 1973, the quantity
used in the area of packaging decreased somewhat and the market for
safety face shields increased. The use of cellulosics in automobiles
has almost been entirely replaced by other plastics.
Noryl is an engineering thermoplastic and finds utility in areas
such as molded casings for home appliances, instruments, hand calcula-
tors, business machines and others; subway windows; windows in radar
ovens; and electrical fixtures.
During the past 10 years the use of fire resistant hydraulic fluids
has been the fastest growing area, in terms of percentage increase, for
phosphate esters. The areas of utilization have basically remained the
same, except for the area of gas turbines. Use of phosphate esters in
control systems and gas turbines in remote areas is an area of increasing
growth.
Industrial uses of fire resistant hydraulic fluids are found in the
basic metals industry, automotive industry in die casting equipment and
foundries, steel industry, and other industries using hydraulic fluids
where high temperature could pose a fire hazard if the hydraulic system
developed leakage.
17
-------
REFERENCES TO SECTION IV
1. U.S. International Trade Commission, "Imports of Benzenoid Chemicals
and Products," Annual Reports 1968-1972.
18
-------
SECTION V
GENERAL MANUFACTURING PROCESS
Five companies currently produce the aryl or alkyl aryl phosphate
esters under consideration in this study: Monsanto Industrial Chemicals
Company; FMC Corporation, Industrial Chemicals Division; Eastman Kodak
Company; Sobin Chemicals Inc. (Montrose Chemical Division); and Stauffer
Chemical Company, Specialty Chemical Division. Further information regard-
ing the different esters manufactured by each company, production sites,
capacities, and yearly production can be found in Section VI.
TRIARYL PHOSPHATE ESTERS
Many methods are available for the preparation of triaryl phosphate
esters.—' However, the universal manufacturing process presently in use
consists of the condensation of the aryl compound with phosphoryl chloride
in the presence of a metal chloride catalyst as exemplified in Eqffl (V-l).—*—
3 ArOH + POC13 catalyst> (ArO^PO + 3 HC1 (V-l)
Production is normally by the batch process although manufacturers
are striving to convert the system to a continuous process and have ac-
complished this in many phases of the operation. Aluminum chloride or
zinc chloride is commonly used as the catalyst at production sites in
the United States. A generalized flowsheet of the manufacturing process
is shown in Figure 2 and the material balance in Table 3. All of the
current manufacturers employ multipurpose plants designed to produce
all of the triaryl or alkyl aryl phosphate esters marketed by that com-
pany. The plants are not normally designed so that production can be
interchanged between triaryl and alkyl aryl phosphate esters.
19
-------
100°F
Inerts
Cresol Storage
2-20000 Go! 40 GPM
PCXIU Storage
30000 Go) Ni Clad
Feed Hearer
120 Sq Ft
0.7 MMBTU/Hr
Condenser
200 Sq Ft
0.2 MM BTU/H
.
— t
nu afor
(
©,-
^
9 C
1—
PM
)
HCI Abs
Karbofe
orpHon Columns
TCP Srorage
•> - 20000 Gal
©
20° Be HCI Storage
3 - 20000 Gal
Steam Ejector
Dowtherm
2.0 MM BTU/Hr
1 /
'< J
1 ^>
400° F
^===^
©
Gloss-Lined
Reactors
3 - 4000 Gol
Dowtherm
/^
_)
~J Heater
0.3 MMBTU/Hr
J
/
TCP FLOV. SHEET
40.000.000LBS/YR
Disposal
Figure 2. Production and waste flow diagram for tricresyl phosphate.
-------
Table 3. MATERIAL BALANCE^/
Stream number on Figure 2
Component
Cresylic acid
POC13
A1C13
HC1
C02
Tricresyl phosphate
Sludge^/
8
5,053
600
600
2,389
50
50 50
1,500
14
10
11
14
5,072 22 5,050 5,050
870 870
a/ Figures are pounds per hour for the stream number as shown in Figure 2. If the plant operates
24 hr/day, 330 days/year, the tricresyl phosphate production will be 40 x 10^ Ib/year. The
material balance is based on continuous flow for all streams, but in actual plant operation
some streams will not be continuous flow".
b/ Sludge refers to the still residue and is composed of spent catalyst (aluminum cresylates,
etc.) tars, and other ill-defined materials.
" ce: Similar figures for most of the other esters and the energy consumption for their production
can be found in Section VI under the respective phosphate ester.
Overall reaction yield is 88% based on cresylic acid input.
-------
As shown in the schematic diagram (Figure 2), the reactor is charged
with a mixture of phosphoryl chloride, aluminum chloride (catalyst) and
phenolic material. For triaryl phosphate esters in which the three aryl
groups are the ^ame, a slight excess of the phenolic material is employed
to favor complete esterification. In reactions involving mixed phenolic
materials (e.g., phenol and cresylic acid), the materials are added in
stoichiometric quantities. The temperature is slowly raised to approxi-
mately 400°F over a period of about 8 hr. During the last hour of the re-
action, the reactor vessel is flushed with an inert gas (N2 or C02) to
strip any remaining hydrogen chloride by-product. Because of the libera-
tion of hydrogen chloride during the reaction, corrosion is a serious
problem and glass-lined reactors are normally employed to circumvent this
potential problem. To prevent excessive loss of reaction materials in the
inert gas stream, the reactor is equipped with a reflux condenser where
the phosphoryl chloride and phenolic material are condensed and returned
to the reaction mixture.
The by-product hydrogen chloride effluent is passed through scrubbers
to recover the hydrogen chloride and remove any organic material which
passed through the reflux condenser. The hydrogen chloride is absorbed
by a solution of HCl in the first scrubber and fresh water in the second
scrubber. The scrubbers are constructed of Karbate to resist the corrosion
of hydrochloric acid. The by-product hydrochloric acid is then either sold,
retained for captive use within the company, or disposed in the waste
treatment system. The by-product hydrochloric acid will contain traces of
phenolic material.
After the reaction has progressed to completion, the contents of
the reactor are transferred to a nickel-clad still and the unreacted
cresylic acid is distilled under reduced pressure (50 mm). The pressure
is then reduced to 3 mm to permit distillation of the tricresyl phos-
phate. Unreacted cresylic acid is returned for further processing.
The steam from the ejector normally contains some quantities of
phenolic materials which have passed through the condenser during the
course of the distillation of the phosphate ester. This steam is con-
densed and the resulting liquid, along with the phenolic material, is
treated as liquid waste. After the distillation has been completed, the
still pot contains a mixture of aluminum chloride, spent catalyst (alu-
minum phenolates or cresylates), and possibly some polymeric materials.
These are removed and treated as solid waste.
The distilled phosphate ester is normally washed with a dilute (2%)
solutloT of sodium hydroxide or treated with a solid material to neutra-
lise ,, remove any hydrogen chloride, unreacted phenolic starting mate- *
rial, or partial estexification products which may have passed through
the distillation process. After neutralization, the aqueous solution (or
solid -oevtralizer) is separated and treated as a liquid (or solid) waste.
22
-------
The phosphate ester is then pumped to a second .water wash tank, dehydrated
by heating under reduced pressure, treated with charcoal (e.g., NuChar)
to remove traces of impurities and improve the color of the ester, and
finally treated with a filtering aid (e.g., Filteraide). After filtra-
tion, the finished phosphate ester is removed to storage tanks for process'
ing for shipment.
For triphenyl phosphate, the same procedures are used for the produc-
tion and purification except that processing temperatures above 50 C are
required to prevent solidification and zinc chloride is used as the catal-
yst. The finished triphenyl phosphate is sold in flaked form.
ALKYL ARYL PHOSPHATE ESTERS
In the manufacture of alkyl aryl phosphate esters, the same descrip-
tion as for the preparation and processing of the triaryl esters is ap-
plicable except for certain modifications of reaction conditions. For
these esters, the phenolic material is added in stoichiometric quanti-
ties to the phosphoryl chloride to form an aryl or diaryl phosphoryl
chloride. The reaction mixture is then cooled to below room temperature
and the alcohol is added in slight excess of stoichiometric quantities.
The hydrogen chloride by-product is removed under reduced pressure to
avoid cleavage of the ester groups. Purification processes are basically
the same as for the triaryl phosphate esters.
MANUFACTURING COSTS
The various cost factors related to the production of phosphate
esters is delineated in this subsection for a simulated facility as shown
in Figure 2. For the purposes of calculating these costs, the facility,
as shown, will have a production capacity of 40 million pounds of tri-
cresyl phosphate (TCP) per year and would operate 24 hr/day, 330 days/
year.
Utility Costs
Annual Cents/Lb TCP
Steam at $2.00/1,000 Ib $41,976 0.105
Gas at $1.00/1,000 cu ft 39,600 0.099
Electricity at 20/kw-hr 24,552 0.061
Raw Material Costs
Raw material costs have been computed using the following current
prices:
23
-------
Cresylic acid
POC13
AlCLj
Carbon dioxide
4%/lb
20<£/lb
6-l/4
-------
Fixed Costs
In arriving at the cost of the plant, it is assumed that steam
facilities would be present. It is, however, necessary to install a
Dowtherm boiler to provide heat for the glass-lined reactors and
nickel-clad stills. Plant investment includes the cost of major equip-
ment, plus its installation and the necessary process piping, electri-
cal and instrumentation for a completed plant. A building to house the
reactors and most of the equipment with the exception of storage tanks
is also included in the plant investment. The total plant investment,
based on today's construction costs, is $2,957,000 exclusive of the
cost of the plant site.
If the plant site is valued at $125,000, total investment will be
$3,082,000. Based on amortization over 10 years, and using an interest
rate of 12%, the fixed costs for the unit will be:
Yearly Cents/Lb TCP
Amortization, 10 years $308,000 0.771
Interest, 12% 237,314 0.593
Maintenance and overhead 462,300 1.156
Taxes and insurance 246,560 0.616
3.136
Total Manufacturing Costs
Total cost for manufacturing TCP in the facilities described is:
Operating Costs
Raw materials 60.327
Utilities 0.265
Labor 0.658
Waste disposal 0.429
61.679
Fixed costs 3.136
64.815^/lb TCP
ENVIRONMENTAL MANAGEMENT
In this subsection, the disposal methods, losses, and reclamation
process, if any, for each manufacturer of aryl or alkyl aryl phosphate
esters will be discussed.
25
-------
Eastman Kodak Company
The industrial park of Eastman Kodak has industrial waste "sewer"
lines leading from each production unit to a centralized treatment
plant. Liquid waste streams, resulting from different phases of the
production process, are combined into a single waste stream at the pro-
duction unit. There are two sampling points, one at the production unit
site and one at the discharge point into the river.
Liquid waste streams receive primary and secondary (activated
sludge) treatment at a centralized unit prior to discharge into an ad-
jacent river. The secondary treatment unit was put into operation in
1970 to remove traces of triphenyl phosphate; prior to that time, only
primary treatment (settling and clarification) was utilized before dis-
charge. In the questionnaire (see Appendix A), Eastman Kodak listed the
liquid wastes shown below.
Concentrat ion
Waste level Occurrence
Phenol 0.63% Process wash water
Triphenyl phosphate Trace Process wash water
The hydrogen chloride evolved during the reaction is scrubbed,
trapped in water, and recovered as 35% hydrochloric acid. The only
impurity in the recovered 357o hydrochloric acid was stated as being
0.002% (maximum) phenol.
Solid waste generated at the industrial park is presently inciner-
ated at 1200 F in a three-chambered incinerator with a water impingement
scrubber being utilized to clean the flue gases. In early 1976, a new
system for the incineration of solid waste will comprise a rotary kiln
with secondary combustion at 1500° to 1800°F. Auxiliary equipment will
include a prescrubber quench, high-energy variable throat ventyri scrub-
ber, an induced draft fan, a demister, facilities for ash handling and
waste material storage, transfer and classification.
Since 1970 the process settling pit sludge, which is the solid resi-
due from the reactor after distillation of the product, has been inciner-
ated. A company spokesman stated that it was unclear as to the method
of disposal of this sludge prior to 1970 but that it is probable that
the sludge received no treatment and was disposed either in a landfill
or the industrial sewer. Impurities in the process settling pit sludge
have been stated as being 0.14% phenol and 61% triphenyl phosphate. The
26
-------
sludge from the biological waste treatment (primary and secondary treat-
ment) is presently, and always has been, smelted for the recovery of-sil-
ver. This process would, presumably, destroy all organic materials present.
Celanese Corporation
This production facility was purchased by the Stauffer Chemical Com-
pany during 1964 and, thus, the environmental management procedures used
by this corporation will be the same as those stated for Stauffer during
the early stages of the operation of this facility.
FMC Corporation
The environmental management facilities at this production site con-
sist of a centralized covered aerated biological oxidation lagoon and
a settling pit prior to discharge into the Kanawha River. As part of a
program to clean the Kanawha River, FMC discontinued the production of
certain members of its product line in 1965. In 1968, the aerated lagoon
was constructed and became operational in the latter part of that year.
Prior to 1968, all waste product streams were discharged directly into
the Kanawha River without any prior treatment. The segregation of waste
materials resulting from the various production units was also initiated
as a part of Phase 2 of this program. A methanol recovery system was in-
stalled in 1969, but its use was discontinued in approximately 1972 when
the production of methyl diphenyl phosphate, as a gasoline additive, was
stopped. In Phase 3 of the cleanup plan, an equalization basin was installed
and the aeration lagoon was separated into two sections in 1973. The two
sections are operated in series with a settling pit between the last lagoon
and discharge into the river. Settleable solids from the settling pit are
recycled to the lagoon. Nonsetteable solids are discharged into the river.
In the production units, indirect condensers have been installed to reduce
the volume of water going into the process waste streams. The new Kronitex
plant has by-passed the wet refining of the triaryl esters and utilizes a
dry processing method which provides for a further decrease of the pollu-
tion load through a more efficient process and less waste water in the pro-
cess waste streams. In the questionnaire, FMC listed 50 to 4,000 ppm phenol
and 1 to 40% HC as components in the process waste stream. These stated fig-
ures do not represent a variation of that magnitude but rather relate to dif-
ferent sources of process waste streams; e.g., one source may produce a waste
stream containing 50 ppm phenol and 1% HC1 while another may produce 4,000
ppm phenol and 40% HC1. The potential sources of process waste streams were
discussed earlier in this section.
27
-------
Hydrogen chloride evolved during the reaction is scrubbed, trapped
in city water and recovered as 32% hydrochloric acid, which is either
consumed in a captive use or sold commercially. The only impurity in the
recovered hydrochloric acid was stated as being 1 to 200 ppm phenol.
Solid residues from the reactor, remaining after distillation of
the product material3 are low volume materials and are currently stock-
piled for future disposal. The solid residues were previously disposed
in a landfill but this practice ceased when the State of West Virginia
changed their landfill permit program,
Mobil Chemical Company
Production at the Edison, New Jersey, facility occurred during the
period 1965 to 1970 and was concerned only with the manufacture of rela-
tively small quantities of the phosphate esters. The hydrogen chloride
evolved during the reaction process was cleaned and sold. Mr. Brown, the
plant manager, also stated that no solid waste was produced by the reac-
tion process.
Monsanto Industrial Chemical Company
Monsanto Industrial Chemicals Company produces several of the phos-
phate esters selected for investigation. Production takes place at three
separate plant sites. In generals the following methods of treatment and
their approximate efficiency are employed at one or more of the produc-
tion facilities: biological oxidation (85 to 90%), absorption and re-
cycle (90 to 95%), and neutralization (100%). Below is a summary of the
environmental management techniques employed.
John F, Queeny Plant St. Louis, Missouri - The production of phosphate
esters at this site includes a rather effective phenol recovery system.
This recovery system utilizes solvent extraction of the phenol followed
by fractional distillation to recover the solvent and phenol. Approximately
90% of the phenol is recovered. The remaining aqueous raffinate contains
approximately 100 ppm phenol and small amounts of partial esters. This
stream is neutralized and sent to the St. Louis Municipal Sewer District.
At present, the Sewer District employs primary treatment before discharg-
ing to the Mississippi River. The hydrogen chloride evolved during the re-
action is scrubbed and partially used to neutralize in-process streams.
The excess acid is sewered. Still residue from the phenol recovery unit
is contract incinerated. Final product purification involves filtration
with filter aid. The filter aid contaminated with basically final product
is landfilled on Company property* The landfill material has passed acute
toxicity and leachate test.
28
-------
Delaware River Plant Bridgeport, New Jersey Presently, the aqueous
stream from the phosphate ester production department consisting of
HC1 from scrubbers, phenol, partial esters, salts, etc. is combined
with other plant waste streams and discharged to the Delaware River.
By the third quarter of 1975, the plant will have started up a new ac-
tivated sludge plant to handle the entire aqueous waste load of the
plant; in addition, solvent recovery of phenol is planned. Presently,
organic residues from the process are contract incinerated. Also, fi-
nal product purification filter aid is land filled on plant property.
Plans are to landfill this material at a New Jersey approved landfill
when final regulations of solid waste disposal become effective.
W. G. Krummrich Plant - Sauget, Illinois - The process employed at this
site produces only one aqueous stream - hydrogen chloride scrubber ef-
fluent. No attempt is made to recover this HC1 at present and the stream
is sewered to the Sauget Treatment Plant which employs primary settling.
The Treatment Plant discharges to the Mississippi River. Active plans are
to convert the Sauget Treatment Plant to a secondary treatment plant.
Solid residues - partial esters, salts, pyrophosphates - are landfilled
on Company property after passing acute toxicity and leachate testing.
Sobin Chemicals Incorporated (Montrose Division)
Process waste streams resulting from the manufacturing units are
presently collected in storage tanks for further processing. The solid
residue remaining after distillation of the product (still bottom) is
collected in steel drums and removed from the production site by a li-
censed scavenger (contract hauler) for disposal in a landfill.
The process waste streams, which have been collected in storage
tanks, are processed to recover the hydrogen chloride by passage through
a scrubber and absorption in water to produce 20 Be hydrochloric acid.
This hydrochloric acid is either consumed in a captive use or sold com-
mercially. Phenolic and cresylic compounds from the production process
are diluted to approximately 0.9 ppm and discharged directly into the
Passaic River without further treatment. The Passaic Valley Sewerage
Commission monitors the effluent discharge into the river.
Prior to acquisition in mid-1972 by Sobin Chemicals, Inc., the pro-
duction facility discharged all waste material, including the hydrogen
chloride, directly into the Passaic River. Since 1972, the hydrogen chlo-
ride recovery system has been added? improvements have been made with
regard to the discharge stream into the river and more waste material has
been, and will be, accumulated for off-site disposal by a licensed con-
tract hauler.
29
-------
Stauffer_Chemical Company
Currently, this production unit treats the liquid waste streams in
a double lagoon system followed by further treatment and recycling into
the production process* The liquid wastes, containing 10 to 50 ppm phenols,
are initially treated in an aerated lagoon of over 5 acres. Activated
sludge settles in this lagoon and requires periodic cleaning. From the
first lagoon, the liquid waste is pumped to a second smaller, aerated
(1.5 to 2.0 acre) lagoon and then to a 1 acre holding lagoon (2 x 10
gal.). From the holding lagoon, the liquid is gravity-fed to a Calgon
carbon treatment system and recycled back into the production process.
No liquid discharge of any type is introduced into the Ohio,River by
this process. A second large lagoon (4.5 acre) is presently in the plan-
ning stage. This will allow continuous operation while one lagoon is in-
operative for cleaning. Additionally, rotating discs (biological contac-
tors) are currently being tested in the larger lagoon at this production
site.
Prior to 1964, Celanese Corporation underwent a series of changes
within the production units to improve the recovery of starting materials
and hydrogen chloride. However, once the waste stream left the production
unit, it was pumped directly into the Ohio River. This procedure remained
in effect after the acquisition by Stauffer until 1967 or 1968, when plans
for a treatment facility were made. The double lagoon system became opera-
tional in late 1969 with the effluent from the second lagoon being dis-
charged into the Ohio River. In mid-January 1975, the recycling process
became operational.
As is the case for almost all other production facilities, the hydro-
gen chloride evolved during the reaction is scrubbed and absorbed in water
to form 35% hydrochloric acid, which is sold.
The solid waste, consisting of filter media and the residue from the
reactor after product distillation, is disposed in a landfill.
Vulcan Materials Company (Frontier Chemical Division)
This facility formerly was the Kolker Chemical Plant and was an active
phosphate ester production facility only in 1964. Since this facility was
in operation only the 1 year and was not resold for further use in the
production of phosphate esters, no information was obtained concerning
their waste management practices.
30
-------
REFERENCES TO SECTION V
1. Van Wazer, J. R., Phosphorus and Its Compounds, ^:1231, Interscience
(1961).
2. Faith, W. L., D. B. Keyes, and R. L. Clark, Industrial Chemicals,
3rd Ed., pp. 786-787, J. Wiley and Sons (1965).
3. Kirk, R. E., and D. F- Othmer, Eds., Kirk-Othmer Encyclopedia of
Chemical Technology, 2nd Ed., Vol. 15, Interscience Publishers,
New York, 1968, pp. 320-321.
31
-------
SECTION VI
PROCESS TECHNOLOGY
In this section, each of the aryl or alkyl aryl phosphate esters
is discussed individually with respect to the various aspects of its
manufacturing process and a very brief summary is presented with regard
to the usages. Since all of the phosphate esters under consideration
are manufactured by basically the same process, no detailed presenta-
tion is given with regard to the specific production process for an
individual material. A detailed discussion of the general manufacturing
process, applicable to all esters, was presented earlier in Section V.
Information relative to each phosphate ester which is presented in
this section includes the manufacturing company's corporate address and
production site, years of production and production figures, specific
preparative reaction, raw materials, type or grade of products, and
transportation and handling information.
GENERAL PRODUCTION CAPACITY
The production capacity for each manufacturer of aryl and/or alkyl
aryl phosphate esters is given in Table 4. Since all of the actual pro-
duction facilities are multipurpose plants, a production capacity for a
specific ester cannot be provided but will vary considerably dependent
upon demand for a specific ester during the year. Under the heading of
production years, the year 1964 does not denote that the facility began
production in that year but rather that 1964 was the earliest year for
the purposes of this report.
The U.S. Tariff. Commission Annual Report on Synthetic Organic Chemi-
cals shows Dow Chemical Company as a producer of xenyl diphenyl phosphate
during the years 1964 through 1967 and of triphenyl phosphate during 1965.
In response to the MRI questionnaire, Dow stated that they did not produce
any of the phosphate esters considered for this study. Additional personal
32
-------
Table 4. PRODUCTION CAPACITY
Manufacturer
FMC Corporation
Monsanto Industrial
Chemicals Company
Sobin Chemical Company
(Montrose Division)
Stauffer Chemical Company
Site
Nitro, West Virginia
Nitro, West Virginia
St. Louis, Missouri
Sauget, Illinois
Sauget, Illinois
Bridgeport, New Jersey
St. Louis, Missouri
Newark, New Jersey
Production years
1964 to 1974
1974 to present
1964 to 1969
1969 to present
1964 to present
Gallipolis Ferry, West Virginia 1964 to present
Capacity
x 106 Ib
30
60
40
50
12
35
Rochester, New York
1964 to present (5)
Eastman Kodak
Mobil Chemical Company
(also: Socony Paint
Products and Socony
Mobil Oil Company)
Celanese Corporation
Vulcan Materials Company
(Frontier Chemical
Division)
Dow Chemical Company
Chevron Chemical Company
Chemical Marketing Reporter, 2 May 1966, 16 August 1969, 17 April 1972, and private industry
sources.
() MRI estimate based on information from manufacturers.
Edison, New Jersey
Point Pleasant, West Virginia
Newark, New Jersey
Midland, Michigan
Belle Chasse, Louisiana
1964 to 1970 (5)
1964 sold to Stauffer (20)
1964 (10)
-------
contact with Dow resulted in the statement that to their knowledge Dow
has never, during the time period of the study, produced either of the
two aforementioned materials. Chevron Chemical Company (Additives and
Industrial Chemicals Division) is listed in the Tariff Commission Re-
port on Synthetic Organic Chemicals as a producer of dibutyl phenyl
phosphate for the years 1969 to present. Response from Chevron stated
that they do not manufacture the dibutyl phenyl phosphate. For these
reasons, data for the years of production and production capacity have
been omitted in Table 4 for Dow Chemical Company and Chevron Chemical
Company.
The Celanese Corporation production facility at Gallipolis Ferry,
West Virginia, was sold to the Stauffer Chemical Company, who assumed
production in October 1964. Thus, the production capacity figures for
Stauffer Chemical Company and Celanese Corporation listed in Table 4
for 1964 are, in reality, for the same production facility but with
different owners. During subsequent years, the capacity of the facility
was increased from approximately 20 x 10° to 30 x 10° Ib/year. This does
not represent a major expansion of the plant but rather probably a se-
ries of de-bottlenecking and other streamlining of the production pro-
cesses which have gradually occurred over the 10-year span of this report.
Monsanto Industrial Chemicals Company presently has three plants
in operation: Sauget, Illinois; -Bridgeport, New Jersey; and St, Louis,
Missouri. As shown in Table 4, the Bridgeport facility was first reported
in 1969 with a corresponding increase of the combined production capacity
from 40 x 10 to 50 x 10 Ib/year. This does not represent an actual pro-
duction capacity for the Bridgeport facility of only 10 x 10 Ib/year,
but rather a considerable rearrangement in production planning with pro-
duction responsibilities for selected materials being shifted from the
Sauget plant to the new Bridgeport facility and the Sauget plant increas-
ing production of nonphosphate esters with the physical equipment previ-
ously used to produce the phosphate esters. These types of switch-offs
are feasible since the production facilities are multipurpose plants.
Thus, the ultimate total production capacities of these three plants is
unknown at the present time but is presumably greater than the listed
50 x It)6 Ib/year.
Using the figure of 50 x 106 Ib/year for Monsanto Industrial Chemi-
cals Company, the present total production capacity for all plants manu-
facturing phosphate esters is approximately 162 x 106 Ib/year.
34
-------
SPECIFIC PHOSPHATE ESTERS
In this subsection, each phosphate ester will be reviewed with
respect to its method of production, manufacturers, raw materials
utilized, waste materials produced, trade names, production quanti
ties, and future growth. A brief summary of the areas of use is also
presented.
35
-------
TRICRESYL PHOSPHATE (TCP)
Manufacturers
Manufacturer
Corporation
office site
Celanese Corporation New York, New York
Vulcan Materials Com-
pany (Frontier Chem-
icals Division) Wichita, Kansas
FMC Corporation New York, New York
P=0
Production site
Gallipolis Ferry,
West Virginia
Years
produced
1964
Newark, New Jersey
Nitro? West Virginia
Monsanto Industrial
Chemicals Company
Sobin Chemical
Company
Stauffer Chemical
Company
St. Louis, Missouri Sauget, Illinois
Newark, New Jersey
Boston,
Massachusetts
Westport,
Connecticut
Gallipolis Ferry,
West Virginia
1964
1964-
present
1964-
present
1964-
present
1964-
present
Production Process
It is very difficult to specify a production process for TCP since
many companies manufacture a product which is designated as being TCP
but in reality is a complex mixture of several materials. In addition,
the cresol (cresylic acid) used as the starting material is normally pro-
duced from coal tar refining and is not a pure material. The cresol often
contains xylenolsj, along with many other aromatic phenolic type materials
and that there are at least six to eight different "types" of TCP. Most
36
-------
manufacturers do state that the cresols must contain 1% or less of the
ortho isomer but this does not represent a refined material,, The process
presented below represents an "idealized" situation and in reality is
not the actual process which occurs due to the variability in the com-
position of the cresol starting material*
OH + POC1,
catalyst
0-4— P=0 -f 3HG1
Required Raw Materials
Basis: 1 ton of tricresyl phosphate
Cresylic acid (cresol): 2,001 Ib
Phosphoryl chloride: 946 Ib
Aluminum chloride: 20 Ib
Waste Materials produced
HC1 by-product: 594 Ib
Sludge: 373 Ib
Energy Consumed
Gas: 1,980 cu ft; steam: 1,049 Ib; and electricity: 61.4 kw-hr.
Production Quantities
The production quantities reported in the U.S. Tariff Commission
Annual Report on Synthetic Organic Chemicals are inaccurate particularly
with regard to the last 4 or 5 years. Almost all manufacturers will add
annual production figures for certain materials into the production fig-
ures for another material and report the resultant sum as the total pro-
duction for one of the materials. Tricresyl phosphate is a case in point.
Since 1969, the reported annual production figures for TCP also includes
annual production figures for isopropylphenyl diphenyl phosphate and tri-
xylenyl phosphate. Some companies regard the isopropylphenyl diphenyl and
trixylenyl esters as merely a "type" of tricresyl phosphate and thus do
not report them as separate materials.
37
-------
Year Celanese Vulcan
1964 (7) (< 1)
1965
1966
1967
1968
1969
1970
1971
1972
1973
FMC
(10)
(10)
(12)
(12)
(13)
<13)
(11)
(10)
(10)
(10)
Monsanto
(11.42)
(12.8)
(14.3)
(15)
(15.3)
(15)
(13)
(12.8)
(8.2)
(6.3)
Sobin
(1)
(1)
(1.5)
(1.9)
(2)
(2)
(1.5)
(1.5)
(1.5)
(1.5)
Stauf f er
(2)
(11)
(12)
(14)
(14)
(13.5)
(12.5)
(14.5)
(17.5)
(18)
Total
quantity x
106 lb
32.4
34.8
39.8
42.9
44.3
(43.5)
(38.0)
(38.8)
(37.2)
(35.8)
() = MR I estimate based on information from manufacturers,
a/
Price History~
Year Price/lb
Total value
(million dollars)
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
$0.27
0.30
0.30
0.31
0.34
0.32
0.33
0.33
0.33
0.36
8.7
10,4
11.9
13.3
15.1
13.9
12.5
12.8
12.3
12.9
a/ U.S. International Trade Commission
Annual Reports, 1964 to 1972] 1973
1/1/74 issue of Chemical Marketing
Reporter.
Trade Names
Stauffer Chemical Company: Lindol (0.1% ortho isomer); Phosflex
179 (plasticizer and lube grade).
Monsanto Industrial Chemicals Company: Generic.
FMC Corporation: Kronitex AA and I.
Sobin Chemicals Company: Generic; electrical and regular grade.
38
-------
Note: TCP is commonly produced in three grades: plasticizer, Lub-
ricant, and electrical. Other grades, such as Lindol (0.1% ortho isomer),
are produced for specialty items but would not be considered common grades.
Not all manufacturers produce all three common grades, depending upon their
markets.
OSHA Standards—
3
TLV =0.1 mgm/m of air
8-hr exposure limit for tri-ortho isomer
Test procedure: An impinger in 15 ml of ethylene glycol is used
at a test rate of 1 liter/min for 100 min. Analysis is obtained by gas
chromatography.
2/
NIOSH Standards-7
LDL = 1,000 mgm/kg oral - human
TLL = 6 mgm/kg oral - human
LDL and LD^g limits for mixed isomers of TCP may be found in the
following reference: NIOSH Toxic Substance List, 1974 edition, p. 608,
TC91000 and TD01750.
Physical Properties
Specific gravity at 25° C: 1.160-1.175 at 20° 0^ 1.157-1.17 3^
Refractive index at 25°C: 1.553-1.556
Vapor pressure (mm Hg): 0.50 at 200°C
Boiling range (°C): 241-255 at 4 mm 420 at 760 mm
Flash point (°C): 225 243
Melting point (°C): -33
Viscosity (cp): 78-185 at 20° C 89.0 at 25°C
Density at 25°C; (Ib/gal): 9.7
Use Areas
Tricresyl phosphate is presently used extensively in both of the
broad categories of functional fluids and fire retardant plasticizers.
It also is used as an air filter medium and adhesive for commercial air-
conditioning units. During the latter 1950's and early 1960's, it was
used extensively as a gasoline additive but later was replaced by cresyl
diphenylphosphate for economic reasons.
39
-------
Future Growth
Tricresyl phosphate, as we have defined the material, apparently
is decreasing in usage, particularly in the area of fire retardant plast-
icizers. Monsanto Industrial Chemicals Company has ceased the commercial
sale of this material, although they presumably are still producing some
quantities for captive uses such as a lubricant additive and in some hy-
draulic fluids. One industry source stated that TCP is being used to a
very minor extent in polyvinyl chloride and is just holding its own in
hydraulic fluids. As other phosphate esters such as isopropylphenyl di-
phenyl and Monsanto's proprietary mixture increase their share of the
hydraulic fluid market, TCP will find decreasing utility in this area.
Due to TCP's high cost and reliance on the availability of cresylic acid,
substitutes are being sought for TCP in the lubricant additives area.
This has been one area where TCP was the dominant phosphate ester but
apparently will begin to suffer decreasing utility in this field. By 1984
it is conceivable that, with new products being developed, tricresyl phos
phate will be produced only in very small quantities for specialty items.
Assuming that TCP will still be used to a certain extent as a fire resis-
tant hydraulic fluid and lubricant additive, an annual production of 12
to 16 million pounds in 1984 is probably reasonable.
40
-------
TRIPHENYL PHOSPHATE
CH— p=o
Manufacturers
Manufacturer
Celanese Corporation
Eastman Kodak
Monsanto Industrial
Chemicals Company
Sobin Chemicals
Company (Montrose
Division)
Stauffer Chemical
Company
Corporation
office site
New York, New York
Rochester, New
York
St. Louis, Missouri
Boston,
Massachusetts
Westport,
Connecticut
Years
Production site produced
Gallipolis Ferry, 1964
West Virginia
Rochester, New York 1964-
present
Sauget, Illinois 1964-
present
Newark, New Jersey 1967
Gallipolis Ferry, 1964-
West Virginia 1973
41
-------
Production Process
+ 3HC1
Required Raw Materials (88% yield)
Basis: 1 ton of triphenyl phosphate
Phenol: 1,966 Ib
Phosphoryl chloride: 1,068 Ib
Zinc chloride: 20 Ib
Waste Materials Produced
HC1 by-product: 671 Ib
Sludge: 383 Ib
Energy Consumed
Gas: 1,980 cu ft; steam: 1,049 Ib; and electricity: 61.4 kw-hr.
Production Quantities
Year Celanese
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
(2.5)
Ea s tman
Kodak Company
(2.7)
(2.7)
(2.7)
(2.6)
(2.4)
(2.8)
(3.2)
(3.2)
(3.3)
(3.5)
Monsanto Stauffer Sobin
(3.3)
(3.1)
(3.1)
(3)
(2.7)
(3.2)
(3.3)
(3.3)
(4.7)
(6.5)
(0.5)
(3.1)
(3)
(3)
(2.8)
(3.2)
(4.1)
(4)
(3)
(2)
(0.1)
Total,. .
6/
quantity" x
106 Ib
9.0
(8.9)
8.8
8.7
7.9
9.2
10.6
(10.5)
(11)
(12)
( ) = MRI estimate based on industry estimates.
42
-------
Price History
Year Price/Ib
a/
Total value
(million dollars)
3,2
3.7
3.7
3.6
3.3
3.8
4.4
4.4
4.1
4.4
U.S. International Trade Commission
data; all other prices are from
December issues of Chemical Marketing
Reporter.
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
a/
$0.36-
0.415
0,415
0.415
0.415
0.415
0.415
0.415
0.37
0.37
Trade Names
Stauffer Chemical Company; Phosflex TPP.
Monsanto Industrial Chemicals Company: Generic.
Eastman Kodak Company: Generic.
Sobin Chemical Company: Generic.
OSHA Standards—'
l/
3
TLV = 3 mgm/m of air
8-hr exposure limit; sampled as a dust rather than vapor,
Test Procedure
An impinger in 15 ml of ethylene glycol is used at a test rate of
1 liter/min for 100 min. Analysis obtained by gas chromatography.
NIOSH Standards-
TCL : 3.0 mgm/m (human inhalation)
Physical Properties
Specific gravity at 25°C: 1.185-1.202-/
Refractive index at 25°C: 1.552-1.563
1,550 at 60 C
43
-------
Flash point (°C)j 225
Vapor pressure (mm Hg): 190 at 200°C ^.
Boiling range (°C): 220 at 5 m 370 at 760 rom-
Melting point (°G); 49.2 48.5-' 4/
Viscosity (cp): 9.9 at 55°C 7.8 at 55° C-'
Density at 25°C (Ib/gal): 10.5-'
Use Areas
At the present time triphenyl phosphate is used exclusively as a
plasticizer primarily with cellulosics, such as cellulose acetate and
cellulose nitrate. It also finds use in the newer rigid thermosetting
materials, such as polyphenylene oxide, and in synthetic rubbers. In
the mid-1960's (1964 to 1966), Shell Oil Company used it as an additive
to their motor oil.
Future Growth
The production of triphenyl phosphate from 1949 to 1973 increased
at an average growth rate of 4.4%/yea'r. Industry sources indicate that,
barring any unforeseen circumstances, the growth should continue as in
the past since TPP is regarded as a type of speciality plasticizer, i.e.,
does not have a universal-type application area. This limitation in use
area is due to the fact that TPP is a solid and would present problems
in the formulation and processing of several resins. Projected produc-
tion figures, based upon a 4 to 5% yearly growth rate after 1975, would
indicate an annual production of 15.5 to 17 million pounds by 1984.
44
-------
CRESYL DIPHENYL PHOSPHATE (GDP)
Manufacturers
Manufacturer
Celanese Corporation
FMC Corporation
Monsanto Industrial
Chemical Company
Sobin Chemical
Comp any
Stauffer Chemical
Company
Mobil Chemical
Company""
Corporation
office site
New York, New York
New York, New York
St. Louis, Missouri
Boston,
Massachusetts
Westport,
Connecticut
Richmond, Virginia
Production site
Years
produced
1964
Gallipolis Ferry,
West Virginia
Nitro, West Virginia 1964-
present
Sauget, Illinois 1964-
present
1964-
present
1964-
present
1964-
1970
Newark, New Jersey
Gallipolis Ferry,
West Virginia
Edison, New Jersey
* Same as Socony Paint Products (1964) and Socony Mobil Oil Company (1964-
1970).
Production Process
OH + 2
"r
+ 3HC1
45
-------
Required Raw Materials
yield)
Basis: 1 ton of cresyl diphenyl phosphate
Cresylic acid: 718 Ib
Phenols 1,250 Ib
Phosphoryl chloride: 1,018 Ib
Aluminum chlorides 20 Ib
Energy Consumed
Waste Materials Produced
HC1 by-product; 677 Ib
Sludge: 329 Ib
Gas: 1,980 cu ft; steam: 1,049 Ib; and electricity: 61,4 kw-hr,
Production Quantities
Year Celanese Mobil FMC Monsanto Sob in ^tauff_er
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
(2.5)
(4)
(5)
(5)
(4)
(3)
(2)
(2)
-
-
-
(3)
(3.5)
(3.5)
(3)
(4)
(2)
(2)
(4)
(2)
(2)
(4.5)
(5.7)
(6)
(5.9)
(6.8)
(4.1)
(4.4)
(8.4)
(7.1)
(8.7)
(1.6)
(2.0)
(2.0)
(1.8)
(2,0)
(1.0)
(1 = 3)
(2.0)
(1.5)
(1.5)
(0.5)
(3.5)
(3.5)
(3.5)
(4)
(2)
(3)
(6)
(4)
(2)
Total
quantity x
106 Ibl/
16.1
19.7
20.0
18.2
19.8
11
12
20
14.6
14.2
) = MRI estimate based on production capacities.
Mobil Chemical stated that all of their GDP was used only in a cap-
tive process as a gasoline additive and that production ranged from ap-
proximately 5 x 10° Ib during the mid-1960's to approximately 2 x 10° Ib
at the end of the use of phosphate esters as gasoline additives. Other
manufacturing sources feel that Mobil's captive use could not have ex-
ceeded 3 million pounds in any year and that any quantities over this
figure were sold to other companies as a gasoline additive (eag.s Shell
Oil Company).
46
-------
a/
Price History—
Total value
Year Price/lb (million dollars)
4.0
5.1
5.2
5.1
5.5
3.0
3.4
5.1
3.9
3.8
_a/ U.S. International Trade
Commission data.
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
$0.25
0.26
0.26
0.28
0.28
0.27
0.27
0.25
0.27
0.27
Trade Names
Stauffer Chemical Company: Phosflex 122.
Monsanto Industrial Chemicals Company: Santicizer 140.
Sobin Chemicals Company: Generic.
FMC Corporation: Kronitex MX, Kronitex K-3*
Physical Properties
o /
Specific gravity at 25°C: 1.204-1.208-
Refractive index at 25°C: 1.560
Flash point (°C): 233-237
Vapor pressure (mm Hg): 0.08 at 200°C
Boiling range (° C) : 253 at 10 mm 390 at 760 mm-
Melting point (°C): -38
Viscosity (cp) : 33.0 at 25°C
Density at 25°C (Ib/gal): 10.
Kronitex K-3 is a mixed phosphate ester containing cresylic and phe-
nolic groups in varying ratios probably dependent upon the desired
viscosity for the final product. Most likely a mixture of cresyl
diphenyl and dicresyl phenyl phosphate in variable ratios.
47
-------
Use Areas
Cresyl diphenyl phosphate presently is used extensively in both the
broad categories of functional fluids and fire retardant plasticizers.
During the 1960's and very early 1970's, it was used as a preignition
control additive in gasoline.
Future Growth
While the growth of fire retardant plasticizers and functional fluids
will probably increase over the next 10 years, but not at the rate observed
for the past 3 to 4 years. This growth probably will come at the expense
of GDP. Cresyl diphenyl phosphate is considered one of the "old-line" plas-
ticizers and hydraulic fluid components and is being replaced by newer ma-
terials in both fields. The apparent decision by Monsanto Industrial Chemi-
cals Company to cease production of GDP during (or at the end of) 1975 is
probably indicative of the relative future growth for this material. While
usage of this material will not cease totally, it is difficult to predict
a positive growth unless new areas of usage are created. For this reason,
a gradual decrease of 2 to 4%/year has been predicted. However, if other
manufacturers follow the lead of Monsanto, the decrease could be even more
rapid than predicted. The annual production figures for 1975 and 1976 could
be very indicative of the future of cresyl diphenyl phosphate. The projected
annual production in 1984 is approximately 8.4 to 10.6 million pounds.
48
-------
ISOPROPYLPHENYL DIPHENYL PHOSPHATE*
[CH(CH3)2]X
X = 1 or 2
* Throughout this report, this name will be utilized in all discussions
and tables. Although this name is the specific compound that is
closest to the actual product, the different grades represent dif-
ferent ratios of isopropylphenols to phenol and the term "mixed iso
propylphenyl phenyl phosphate" is a more accurate representation.
Manufacturers
Manufacturer
FMC Corporation
Stauffer Chemical
Company
Corporation
office site
Production site
Years
produced
New York, New York Nitro, West Virginia 1969-
present
Westport, Gallipolis Ferry, 1971-
Connecticut West Virginia present
Production Process
x
CH3CH=CH2 + (Cjy-OK Catalyst >
x = 1 or 2
Freidel-Craft type alkylation. The mono-, or disubstituted, or mixture
of mono- and disubstituted phenols are produced depending upon the de-
sired viscosity of the final product.
49
-------
Required Raw Materials (88%- yield)
Basis: 1 ton of isopropylphenyl diphenyl phosphate.
Waste Materials Produced
Mono- Di-
Mono-
subst.
Di-
subst.
Isopropylphenol: 837 Ib 990 Ib
Phenol: 1,158 Ib 1,039 Ib
Phosphoryl chloride: 943 Ib 847 Ib
Aluminum chloride: 20 Ib 20 Ib
HC1 by-product: 592 Ib 532 Ib
Sludge: 366 Ib 364 Ib
Energy Consumed
Gas: 1,980 cu ft; steam: 1,049 Ib; and electricity: 61.4 kw-hr.
Production Quantities
Total quantity
Year
FMC
Stauffer
x 10b Ib
1969
1970
1971
1972
1973
(3)
(5)
(7)
(ID
(16)
-
(1)
(1)
(2)
(3)
(5)
(8)
'12)
(18)
Price/Ib
($)
0.29
0.29
0.29
0.29
0.29
Net value
(million dollars)
0.9
1.5
2.3
3.5
5.2
( ) = MRI estimate based on industry sources.
Trade Names
FMC: Kronitex 100
For reporting purposes to the U.S. Tariff Commission, FMC has al-
ways added the yearly production figures for the isopropylphenyl di-
phenyl phosphate into the figures they reported for tricresyl phosphate.
Thus, the figures quoted in the Tariff Commission Report on Synthetic
Organic Chemicals for TCP are not true values for TCP alone but also
contain figures for other phosphate esters, notably the one discussed
here and trixylenyl phosphate.
50
-------
Physical Properties
3 /
Specific gravity at 25° C: 1.150-1.165-
Refractive index at 25°C: 1.5521/
Flash point (° C) :
Vapor pressure (mm Hg) :
Boiling range (° C) : 220-270-
Melting point ( C):
Viscosity (cp) :
Density at 25° C (Ib/gal): (9.5-9.7)
( ) = MRI estimate.
Use Areas
Minor quantities of isopropylphenyl diphenyl phosphate were imported
by FMC Corporation from Ciba-Geigy in England prior to 'its production in
the United States. During the period of importation and the early years
of its production in the United States, it was used primarily in the for-
mulation of hydraulic fluids. However, in the last 3 to 4 years, its use
as a fire retardant plasticizer has increased steadily. In 1973 approxi-
mately 50% of the production of isopropylphenyl diphenyl phosphate was
for use as a plasticizer. Small quantities may also be used in the field
of lubricant additives
Future Growth
The growth of isopropylphenyl diphenyl phosphate is expected to in-
crease at a steady rate, although not at the same rate as for the last
5 years. If the synthetic fluids area of fire resistant hydraulic fluids
continues to grow at the predicted rate, then the production of isopropyl-
phenyl diphenyl phosphate will increase at the same or faster rate. With
the addition of Stauffer Chemical Company as a producer, this material
could make further inroads into that portion of the synthetic fire resis-
tant hydraulic fluids market now held by other triaryl phosphates, i.e.,
tricresyl phosphate, cresyl diphenyl phosphate, and trixylenyl phosphate.
In the area of fire retardant plasticizers, isopropylphenyl diphenyl phos-
phate should continue to replace materials such as TCP and GDP. Overall,
isopropylphenyl diphenyl phosphate could be expected -to grow at an average
annual rate of approximately 11 to 13%/year after 1975. If tricresyl phos-
phate and cresyl diphenyl phosphate show sharp decreases in production,
this rate could increase more rapidly than predicted. The projected figures
for the average annual production, t oed on 11 to 13%/ year, would lead to
an annual production of 39 to 49 million pounds in 1984.
51
-------
Manufacturers
Manufacturer
TRIXYLENYL PHOSPHATE
2CH3
Corporation
office site
Production site
Years
produced
FMC Corporation New York, New York Nitro, West Virginia 1970-present
Production Process
OH + POC13
Lewis
acid
catalyst
=0 + 3HC1
FMC considers this material to be a high molecular weight, low specific
gravity grade of TCP* No 296~isomers are present in the product. The most
reactive isomers are the 3,5 (m,m) and 3,4 (m,p) and the final product is
a mixture of these two isomers»
Required Raw Materials (88% yield)
Basis; 1 ton of trixylenyl phosphate
Xylenol: 2,028 Ib
Phosphoryl chloride: 849 Ib
Aluminum chlorides 20 Ib
Energy Consumed
Waste Material Produced
HC1 by-product: 533 Ib
Sludge: 364 Ib
Gas: 1,980 cu ft; steam: 19049 Ib; and electricity: 61.4 kw-hr,
52
-------
Production Quantities
Total quantity Price/lb
Year x 106 Ib* ($)
1970 (3)** 0.32
1971 (2) 0.34
1972 (1) 0.34
1973 (2) 0.36
Net value
(million dollars)
1.0
0.7
0.3
0,7
Trade Names
FMG: Kronitex TXP.
Physical Properties
Specific gravity at 25
Refractive index at
Flash point (°C):
Vapor pressure (mm Hg):
Boiling range ( C):
Melting point ( C) :
Viscosity (cp):
25° C:
1.130-1.145-^
1.551-1.555-
23S3-/
270 at 3 mm~
-35 (pour point)—
190 at 20° C3/
3/
Density at 25 C (Ib/gal): (9.4-9.6)
Use Areas
Trixylenyl phosphate is used almost exclusively in the formulation
of fire retardant hydraulic fluids and lubricant additives.
Future Growth
Trixylenyl phosphate is considered one of the "old-line" fire re-
sistant hydraulic fluids, along with tricresyl phosphate and cresyl di-
phenyl phosphate. In view of the apparent static growth potential of these
older materials in the fluids area, it would be difficult to predict any
significant increase in production quantities for trixylenyl phosphate.
If areas of application as a fire retardant plasticizer could be found,
perhaps the production could increase. However, this material has been
( ) - MRI estimate.
* FMC Corporation could have imported some of this quantity; most
likely from Ciba-Geogy in England.
** In Section IV, Table 1, the quantities for the years 1970 t- i-
are included with TCP.
53
-------
on the market for at least 4 years and any increased usage as a plastici-
zer would be at the expense of established materials and/or any new product,
It does not appear likely that this new growth will materialize. It is es-
timated that the production quantities will remain relatively constant at
approximately 2 million pounds per year for the next 10 years.
54
-------
2-ETHYLHEXYL DIPHENYL PHOSPHATE
(Octyl Diphenyl Phosphate)
0
CH3(CH2)3CHCH2OP
CH2CH3 V
Manufacturers
Manufacturer
Monsanto Industrial
Chemicals Company
Production Process
Corporation
office site
Production site
St. Louis, Missouri Bridgeport, New
Jersey
St. Louis,
Illinois
Years
produced
1968-
present
1964-
present
CH3(CH2)3CHCH20
H + POC1
+ 3HC1
Lewis
acid
catalyst
Two-step process. Diaryl phosphoryl chloride intermediate not isolated.
Required Raw Material (88% yield)
Basis: 1 ton of octyl diphenyl phosphate
2-Ethylhexanol: 816 Ib
Phenol: 1,181 Ib
Phosphoryl chloride: 962 Ib
Aluminum chloride: 20 Ib
Waste Materials Produced
HC1 by-product: 604 Ib
Sludge: 375 Ib
Energy Consumed
Gas: 2,772 cu ft; steam: 1,049 Ib; and electricity: 71.3 kw-hr.
55
-------
Production Quantities
Year
Total quantity
x 106 Ib
Estimated
price/Ib
($)
0.35
0.35
0.35
0.35
0.35
0.35
0.35
0.35
0.35
0.36
( ) = MRI and industry contact estimates.
Trade Names
Monsanto: Santicizer 141.
8/
NIOSH Standard-
Estimated net value
(x 106 dollars)
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
(9)
(9)
(8)
(8)
(5)
(4)
(4)
(3)
(3)
(5)
LDL =272 mg/kg IVN-rbt
o
Physical Properties
Specific gravity at 25 C:
Refractive index at 25 C:
Flash point (°C):
Vapor pressure (mm Hg) :
Boiling point ( C) :
Melting point ( C):
Viscosity (cp):
Density at 25°C (lb/gal.):
Use Areas
1.08-1. 09-'
1. 506-1. 512-'
1.3 at 200° C-'
21-23-'; 16.4 at
3.2
3.2
2.8
2.8
1.8
1.4
1.4
1.1
1.1
1.8
2-Ethylhexyl diphenyl phosphate is used principally as a plastici-
zer for synthetic rubbers and plastics. It is regulated under the pro-
visions of the U.S. Food and Drug Administration for use in adhesive and
in certain coatings for food products. This product is also utilized in
the formulation of fire resistant functional fluids (hydraulic fluids).
56
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Future Growth
Future production quantities of this material should proceed at a
pace consistent with the anticipated growth for each of the areas of
plasticizers and hydraulic fluids. This would project an average future
growth of approximately 8 to 10%/year after 1975, and show an annual
production of 8.5 to 10 million pounds in 1984.
57
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ISODECYL DIPHENYL PHOSPHATE
Manufacturers
Manufacturer
Corporation
office site
Production site
Monsanto Industrial St. Louis, Missouri Bridgeport, New
Chemicals Company Jersey
Years
produced
1968-
present
Production Process
(CH3)2CH(CH2)6CH2t)H + 2
Lewis
POC13 acid
catalyst
+ 3HC1
Two-step process. Diaryl phosphoryl chloride intermediate not isolated.
Required Raw Material (88% yield)
Basis: 1 ton of isodecyl diphenyl phosphate
Isodecyl alcohol: 921 Ib
Phenol: 1,095 Ib
Phosphoryl chloride: 892 Ib
Aluminum chloride: 20 Ib
Waste Materials Produced
HC1 by-product: 560 Ib
Sludge: 368 Ib
Energy Consumed
Gas: 2,772 cu ft| steam: 1,049 Ib; and electricity: 71.3 kw-hr.
58
-------
1968
1969
1970
1971
1972
1973
(1.0)
(2.0)
(4.0)
(4.5)
(5.0)
(7.0)
Production Quantities
Estimated
Total quantity price/lb Estimated net value
Year x 106 Ib ($) (x 106 dollars)
0.275 0.3
0.275 0.6
0.275 1.1
0.275 1.2
0.275 1.4
0.285 2.0
( ) = MRI and industry contact estimates.
Trade Names
Monsanto: Santicizer 148.
Physical Properties
3/
Specific gravity at 25°C: 1.07-3/
Refractive index at 25°G: 1.506—
Flashpoint (°C): 241 3/ 4/
Vapor pressure (mm Hg): 0.5 at 200°C~ 10.0 at 200°C-7
Boiling range (°C): 245 at 10 mm^/
Melting point (° C) : - -/
Viscosity (cp): 22.5 at 25°C~
Density at 25°C (Ib/gal): 8.9-/
Use Areas
Isodecyl diphenyl phosphate is used principally as a fire retardant
plasticizer for plastics and synthetic rubbers.
Future Growth
Since isodecyl diphenyl phosphate finds rather general usage as a
fire retardant plasticizer, particularly where low temperature flexibility
is a factor, it would be expected that the future production of this mate-
rial would approximate that for fire retardant plasticizers in general.
Thus, an average annual growth rate of approximately 7 to 9%/year could
be anticipated after 1975. At this average annual growth rate, the pro-
duction quantity in 1984 would be approximately 11 to 13 million pounds.
59
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DIBUTYL PHENYL PHOSPHATE
[CH3(CH
2'2
Manufacturers
Manufacturer
Corporation
office site
Production site
Years
produced
Monsanto Industrial St. Louis, Missouri St. Louis, Missouri 1964-
Chemicals Company present
Production Process
2 CH3(CH2)2CH2OH
POC1,
Lewis
acid
catalyst
+ 3HC1
Two-step process. Aryl phosphoryl dichloride intermediate not isolated.
Required Raw Material (88% yield)
Basis: 1 ton of dibutyl phenyl phosphate Waste Materials Produced
1-Butanol: 1,176 Ib HC1 by-product: 764 Ib
Phenol:
Phosphoryl chloride:
Aluminum chloride:
747 Ib
1,217 Ib
20 Ib
Sludge:
396 Ib
Energy Consumed
Gas: 2,772 cu ft; steam: 1,049 Ib; and electricity: 71.3 kw-hr.
60
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Production Quantities
Year
Total guantity
x io6
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
(1.6)
(1.8)
(2.0)
(2.4)
(2.8)
(2.3)
(2.5)
(2.7)
(2.9)
(3.1)
Estimated
price/lbk/
(I)
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.37
Estmated net value
(x IO6 dollars)
0.6
0.6
0.7
0.9
1.0
0.8
0.9
1.0
1.0
1.1
a_/ As will be discussed in Section VII-A (aircraft hydraulic
fluids), it is felt that these values are low by 50 to
60%.
b/ Price estimated on the basis of annual raw material costs
and price markup of other alkyl aryl compounds.
Use Areas
Dibutyl phenyl phosphate is used almost exclusively in commercial
aircraft hydraulic fluid formulations. It is possible that very small
quantities may be used in industrial hydraulic fluids.
Future Growth
This phosphate ester is directly dependent upon the commercial air-
line industry and its future growth will be linked to that industry. The
current manufacturer of dibutyl phenyl phosphate anticipates a future
growth rate of 5 to 7%/year. It is doubtful that this growth rate was
attained in 1974 or will be in 1975, however, after 1975 this growth rate
could be assumed. The annual production in 1984 would be in the range of
5 to 6 million pounds per year based upon the production figures in this
subsection and an average annual growth rate of 5 to 77o. If the stated
production figures are low by 50%, then the projected annual production
in 1984 t.ould be 7 to 8.5 million pounds. FMC Corporation has recently
begun production of dibutyl phenyl phosphate and their entry into the
market could increase the production quantities of this material higher
than the predicted figures.
61
-------
Manufacturers
Manufacturer
METHYL DIPHENYL PHOSPHATE
Corporation
office site
Production site
Years
produced
Monsanto Industrial St. Louis, Missouri St. Louis, Missouri 1964-1971
Chemicals Company
FMC Corporation New York, New York Nitro, West Virginia 1964-1971
Production Process
Lewis
OH
catalyst
H3co—P
+ 3HC1
Two-step process* Diaryl phosphoryl chloride intermediate not isolated.
Required Raw Materials (88% yield)
Basis; 1 ton of methyl diphenyl phosphate Waste Materials Produced
Methanol; 275 Ib HC1 by-product: 828 Ib
Phenols 1,619 Ib Sludge: 404 Ib
Phosphoryl chloride; 1,318 Ib
Aluminum chloride: 20 Ib
Energy Consumed
Gas: 2,772 cu ft; steam: 1?049 Ib; and electricity: 71.3 kw-hr.
62
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Production Quantities
6
Year Monsanto FMC Total quantity x 10 Ib
1964 (2.4) (2.4) (4.8)
1965 (2.9) (2.9) 5.8
1966 (2.9) (2.9) (5.8)
1967 (2.9) (3.0) (5.9)
1968 (2.9) (3.0) (5.9)
1969 (3) (3) 6.0
1970 (1) (1) (2.0)
1971 (0.5) (0.5) (1..0)
( ) = MRI estimates; other data supplied by Mr. Paul Levesque, FMC Corpora-
tion, New York, New York.
Price History
Estimated Estimated total value
Year price/lb^ (million dollars)
1964 $0.31 1.5
1965 0.31 1.8
1966 0.31 1.8
1967 0.31 1.8
1968 0.31 1.8
1969 0.31 1.9
1970 0.30 0.6
1971 0.30 0.3
_a/ Price estimated on the basis of annual raw
material costs and price markup of other
alkyl aryl compounds.
Use Area
During the years 1964 to 1971, methyl diphenyl phosphate was used
almost exclusively as a preignition control gasoline additive. In a re-
cent book concerning flame retardancy of polymers,—' this material was
listed as a plasticizer for vinyl films; however, this use probably ac-
counted for only a very minor part of its total usage during that time
interval.
63
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5-CHLOROPHENYL DIPHENYL PHOSPHATh
Manufacturers
Manufacturer
Corporation
office site
Production site
Years
produced
Monsanto Industrial St. Louis, Missouri St. Louis, Missouri 1968-1969
Chemicals Company
Production Process
OH + POC1
+ 3HC1
catalyst
Production Quantities
Year
Total quantity x 10 Ib
1968
1969
(
-------
DIMETHYL XYLYL PHOSPHATE
2CH3
0
II
0 —P-
Two patents have been issued for the use of this material: one in
1958 for use as an anti-knock additive fluid—-' and one in 1970 for use
as an anti-wear jet fuel additive.—'
127
Industrial sources— indicate that they are unaware of any company
who has produced or is currently producing this material on a commercial
basis. It is possible that small quantities of this ester were produced
in the latter 1950's or very early 1960's as a gasoline additive. If this
was the case, the ester never received any widespread usage and very pos-
sibly was produced in very small quantities for the company's captive use.
65
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MONO-0-XENYL DIPHENYL PHOSPHATE
13/
The U.S. Tariff Commission Reports— show that this material was
produced by Dow Chemical Company during the years 1964 to 1967. Dow Chemi'
cal Company has stated, in both written and oral communication, that they
do not and never have produced any of the phosphate esters of interest
to this study including specifically the mono-o-xenyl diphenyl phosphate
ester.
147
The National Institute for Occupational Health and Safety— lists
a LDL value of 50 mg/kg (mice) for this ester.
66
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MIXED ALKYL ARYL PHOSPHATES
Monsanto Industrial Chemicals Company manufactures an alkyl aryl
phosphate for use as a component in hydraulic fluids and as a plastici-
zer. It is a complex mixture resulting from the use of nonyl alcohol,
isodecyl alcohol, phenol, cumenol, and perhaps some additional higher
molecular weight alcohols in the Cn-C,0 range. The exact composition of
this fluid is variable dependent upon the viscosity requirements of the
particular customer for the finished material. For use as a plasticizer,
Monsanto distributes this material under the trade name of Santicizer 145.
67
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TRANSPORTATION AND HANDLING
The Code of Federal Regulations, Title 49, Transportation (1 October
1973) does not list any of the phosphate esters contained in this report
as being hazardous materials and no special labeling or handling of the
shipping containers is required. A revised Section 311 (b)(2)(B) of the
Federal Water Pollution Control Act Amendments of 1972 (Federal Register,
22 August 1974) also does not list any of these phosphate esters as being
hazardous substances,,
Within the production facility, the finished product is pumped to
storage tanks for packaging or bulk shipment. All transfers of the esters
from the storage tanks to packaging are conducted through pipelines and
no appreciable quantitites of the esters are handled or transported in
open containers. The packaging area is the only place where contact with
the ester would occur and that would happen basically through broken or
leaking containers.
When packaged for shipment, the^phosphate esters are normally packaged
and shipped in either 55 gal. unlined steel drums, railway tankcars, or
truck tankwagons. One manufacturer estimated that 60% of their shipments
were in bulk quantities (tankcar or tankwagon) and 40% were in steel drums,
Triphenyl phosphate, a solid, is normally shipped in either 250 Ib fiber
drums or 1,200 Ib reinforced cardboard containers. Both of these containers
are lined on the interior with plastic sheeting. Experimental quantities
are available in smaller containers but the quantity shipped is negligible
compared to the other methods.
-------
REFERENCES TO SECTION VI
1. Private communication with Mr. Charles Adkins, OSHA Regional Office,
Kansas City, Missouri.
2. "NIOSH Toxic Substances List," p. 608, 1974 ed., TD 03500.
3. Modern Plastics Encyclopedia, McGraw-Hill, Inc., New York, p. 781
(1974-1975).
4. Monsanto Industrial Chemicals Company, "Fire Retardant Plasticizers
and Resin Modifiers," Bulletin IC/PL-358, July 1974.
5. "NIOSH Toxic Substances List," p. 746, 1974 ed., 18972; see also
p. 608, TC 84000.
6. U.S. International Trade Commission Annual Report, "Synthetic Or-
ganic Chemicals," (1964, 1966-1970).
7. U.S. International Trade Commission Annual Report, "Synthetic Or-
ganic Chemicals," (1964-1973).
8. "NIOSH Toxic Substances List," p, 607, 1974 ed., TC 61250.
9. Kuryla and Papa, Flame Retardancy of Polymeric Materials, Marcel
Dekkar, New York (1973).
10. Ethyl Corporation, Brit. 872820, 9 December 1958; CA, 56_, 6250i
(1962).
11. Vermillion, H. E., and G. W. Eckert (Texaco, Inc.), U.S. 3,510,281,
5 May 1970; CA, 7_3, 17150d (1970).
12. Industrial Source, private communication.
13. U.S. International Trade Commission, "Synthetic Organic Chemicals"
(1964-1967).
14. "NIOSH Toxic Substances List," p. 605, 1973 ed., TB 66500,
69
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SECTION VII
AREAS OF UTILIZATION
In this section, each of the primary areas of utilization for the
general group of aryl and alkyl aryl phosphate esters under considera-
tion will be discussed. The main areas of hydraulic fluids and lubricant
additives, fire retardant plasticizers, and gasoline additives (area
ceased in 1971) will be discussed as separate sections and minor use
areas such as exports, wood preservatives, air filter media, and others
will be treated individually but under the general subsection of Miscel-
laneous Usess
HYDRAULIC FLUIDS AND LUBRICANT ADDITIVES
The discussion of hydraulic fluids and lubricant additives will be
separated into three sections; (a) general hydraulic fluids; (b) air-
craft hydraulic fluids} and (c) lubricant additives. Aircraft hydraulic
fluids will be treated separately because only one of the phosphate es-
ters under study is utilized in aircraft hydraulic systems whereas most
of the phosphate esters find usage in the general hydraulic fluid field.
Industrial Hydraulic Fluids
The general field of hydraulic fluids can be divided into the two
primary sections of petroleum-based fluids and fire resistant fluids.
Shortly after their introduction in the late 1940!s, users became dis-
enchanted with the poor performance of the phosphate esters compared to
petroleum fluids. Some portion of this disenchantment may have been due
to* the misapplication of the fluids or to faulty hydraulic system design.
Regardless of the specific reasons, this initial experience had an in-
hibiting effect on the acceptance, and thus the sales growth, of fire
resistant fluids. By 1966, fire resistant fluids had claimed only about
6% of the total market.—' A survey published in mid-1965 showed fire re-
sistant fluids with approximately 6% of the total market for hydraulic
fluids.—' From mid-1965, however, a resurgent interest in fire retardant
fluids occurred as evidenced by a new edition of this survey in 1970,—'
which showed fire resistant fluids to have approximately 22% of the total
hydraulic fluids market. This latter figure, at least combined with the
data for phosphate esters, is probably too high and will be discussed
in more detail later in this section.
70
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The classification of fire resistant hydraulic fluids is comprised
basically of four "types" of materials: (a) water-glycol systems; (b)
water-hydrocarbon oil emulsions: (c) phosphate esters; and (d) phosphate
ester-hydrocarbon oil blends.-!-^' The groupings of phosphate esters and
the phosphate ester-hydrocarbon blends are often termed "synthetics" or
"synthetic fluids" and "oil-synthetic blends."
The results published in the two surveys,r-i-^.' and tabulated below,
shows the percentage distribution of the usage of fire resistant hydrau-
lic fluids in 1964 and 1970. The number of plants responding to this sur-
vey was relatively small, both with respect to the overall field of hy-
draulic fluids and to the fire resistant fluids. However, the percentage
values should be useful in the prediction of trends within the category
of fire resistant fluids.
Type of fire
resistant
fluid 1964 1970
Emulsion:
Total 46.8% 47.1%
Oil-in-water - 5.2%
Water-in-oil - 41.9%
Water-glycol 34.5% 13.1%
Phosphate ester 8.9% 28.8%
Phosphate ester based 1.6% 11.0%
Other 8.2%
Total number of companies
responding 84 123
Water-Glycols - The water-glycols fluids consist essentially of a four
component system of water, glycol, a high molecular weight water-soluble
polyglycol, and an additive package to impart corrosion resistance,'metal
passivation, anti-wear properties, lubrication, and bacteria and fungi
protection to the overall mixture. The water generally accounts for 35
to 50% of the total mixture and the glycol, either ethylene or propylene
glycol, is added to improve low temperature properties. Water-soluble
polyglycols are added as thickeners to provide the desired viscosity for
the final system. These materials are true solutions, not emulsions.
Performance differences between fluids from different sources are di-
rectly related to the differences in the proprietary additive packages.
71
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Emulsion fluids These fluids are two-phase systems containing oil and
water, and are easily recognized by their "milky" appearance. Two types
of systems are available: (a) water-in-oil ("invert") emulsions; and
(b) oil-in-water emulsions. Of the two classess the oil-in-water emul-
sions were developed first and have been utilized for many years in the
metal industries.
In the strictest sense, oil-in-water emulsions are not actually
classified as hydraulic fluids. These emulsions generally consist of
water and an emulsifiable fluid concentrate or "soluble oil" which con-
tains base oils and additives in 2 to 5% concentration to impart cor-
rosion protection and oiliness characteristics to the water. Since the
basic component of this system is water, the low viscosity of this fluid
does not permit its use in medium- and heavy-duty equipment.
The other types of emulsions are the water-in-oil fluids ("invert"
emulsions), which are relatively recent developments in the field of hy-
draulic fluids. These fluids are formulations consisting of oil plus an
additive package emulsified with approximately 35 to 40% water. In these
emulsions, water is the dispersed phase and the oil is the continuous
phase as opposed to the previous system in which water was the continuous
phase. The additive package provides the normal protections against wear
and rust as well as emulsifying agents and other additives.
Phosphate Ester-Oil Blends - These fluids, comprised of a mixture of phos-
phate ester and refined petroleum stocks, are finding increasing use as a
practical approach to the need for less hazardous hydraulic fluids where
the fire hazard is moderate. As currently formulated, they consist of 30
to 50% triaryl phosphate ester plus petroleum oil and a coupling agent to
create solution stability. These fluids are generally available in a wide
range of viscosity grades dependent upon the quantity and type of oil used
in the blend. The blend normally contains additives which improve corrosion
resistance and oxidation stability. The triaryl phosphate esters utilized
in these blends are the same as those used in the normal phosphate ester
fluids.
Phosphate Esters These materials are often termed "synthetic" or "straight
synthetic" fluids because the fluids are man-made and may possess definite
chemically identifiable structures. Those companies who market the phosphate
esters list the following reasons for the use of synthetics as opposed to
the other types of fire resistant hydraulic fluids:
1. Excellent fire resistance properties;
2. Excellent stability;
72
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3. Excellent lubricity;
4. Requires minimum maintenance; and
5. Can be readily reclaimed.
However, these fluids have the disadvantages of high relative cost and
the need for special seals and gaskets of Viton or butyl or propyl
elastomers.
The main phosphate esters used as fire retardant hydraulic fluids
are tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate,
isopropylphenyl diphenyl phosphate, and Monsanto's proprietary, mixed
alkyl aryl phosphate ester. The first three materials are the "older"
types of hydraulic fluids while the latter two materials are more recent
additions to the field.
Estimated consumption figures, prices, and net value for the four
phosphate esters in hydraulic fluids from 1964 to 1973 are shown in the
following list.
Total quantity consumed Average Net value
Year (x 106 Ib) price/lb (millions of dollars)
1964 10.0 $0.30 3.0
1965 13.5 $0.33 4.5
1966 15.3 $0.33 5.0
1967 16.5 $0.34 5.6
1968 17.7 $0.36 6,4
1969 19.0 $0.35 6.7
1970 20.5 $0.36 7.4
1971 22.0 $0.36 7.9
1972 29.0 $0.36 10.4
1973 37.0 $0.36 13.3
The price per pound figures are estimated average values. Several dif-
ferent phosphate ester fluids are available, depending upon the vis-
cosity and additive requirements, and all are priced individually.
Since the precise quantity of phosphate ester utilized in each of the
several types is unknown, an average price was used.
Information from representatives of companies in the field of hy-
draulic fluids state, that until 3 to 4 years ago, the annual growth
was approximately 5 to 10%/year and that from about 1971, the growth
rate was 10 to 20%/year with the rate closer to 20 than 10%.
73
-------
Earlier in this section, reference was made to two surveys conducted
in the area of hydraulic fluids, one for 1964 and one for 1970. In the
1964 survey, it was found that 6.6% of the total hydraulic fluids in use
were of the fire resistant type and within the fire resistant group, 8.9%
were phosphate ester and 1.6% were phosphate ester-based fluids (50% ester).
This leads to a total percentage of phosphate ester in use of 9.7%. In 1964,
approximately 150 million gallons of hydraulic fluids were used for indus-
trial and military purposes or a utilization of about 960,000 gal. of phos-
phate ester. Assuming a density of approximately 10 Ib/gal, 9.6 million
pounds of phosphate ester was used in hydraulic fluids in 1964. For 1970,
the survey indicated that 21.8% of all hydraulic fluids were fire resistant
and that phosphate esters comprised 34.3% of all the fire resistant fluids.
Using the annual consumption of 197 million gallons stated by Tovey—' and
the same density values as above, the calculated total usage of phosphate
esters in 1970 would be approximately 147 million pounds. The 1970 estimated
figure in this study, of approximately 20 million pounds per year, is in
agreement with phosphate ester manufacturers' estimates.
Process technology of phosphate esters - The processing of phosphate
ester hydraulic fluids consists basically of a physical mixing operation.
For formulation, the esters are pumped from storage through automatic
weighing devices to a blender, proprietary additive packages added, and
the components are agitated by electrical stirrers to insure complete mix-
ing of the various components. After the mixing operation, the fluid is
pumped either to storage tanks for bulk shipment by railway tankcar or
truck tankwagons or to the packaging area where the fluid is placed in
containers. Losses of the fluids within the formulation plants are very
minimal due to the lack of physical handling of the materials throughout
the entire process.
The formulated fluids are packaged in 1-qt cans (24/case), 1-gal.
cans (six/case), 5-gal. cans (individually and in shrink-wrapped pallets
of 24), 55-gal. steel drums (interior spray coated), truck tankwagons,
and railway tankcars. Very little hydraulic fluid is shipped in the smal-
ler containers and the vast majority is shipped either in the shrink-
wrapped pallets or larger containers (drums, tankcars, etc.).
The three major formulators of phosphate ester hydraulic fluids are
shown below with each of the various fluids produced by that company.
74
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Products
Company
E. F. Houghton and Company
Philadelphia, Pennsylvania
Monsanto Industrial Chemicals Company
St. Louis, Missouri
Stauffer Chemicals Company
Gallipolis Ferry, West Virginia
Synthet ic
Houghto-Safe
1010
1055
1115
1120
1130
Pydraul-E
10-E
29-E-LT
30-E
50-E
65-E
90-E
115-E
Fyrquel
90
150
220
300
550
Ester blend
Vital
23
29
5310
Pydraul-C
230-C
312-C
540-C
MC
Fyrtek
295
These three companies are estimated to formulate over 95% of all
fire resistant hydraulic fluids containing the phosphate esters being
considered in this study. E. F. Houghton formulates its fluids primarily
from isopropylphenyl diphenyl phosphate and trixylenyl phosphate, both
of which are purchased primarily from FMC Corporation. Stauffer Chemicals
Company uses primarily tricresyl phosphate and cresyl diphenyl phosphate
in its formulations and Monsanto Industrial Chemicals Company formulates
the majority of its fluids from their mixed aryl and alkyl aryl proprietary
mixture. It is thought that Monsanto may also use some quantities of octyl
diphenyl phosphate in hydraulic fluid formulations.
Other companies who formulate phosphate ester hydraulic fluids but
on a much smaller scale are shown in the following list:
75
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Company
Mobil Oil Company
Exxon Oil Company
Gulf Oil Company
Metal Working Lubricants
D, A. Stuart Oil Company
Standard Oil of California
Location
Edison, New Jersey
Bayonne and Bayway, New Jersey
(formulated and packaged for them by
Stauffer)
Detroit, Michigan
Chicago, Illinois
Belle Chasse, Louisiana
Prior to about 1969, most of the phosphate ester hydraulic fluids
were formulated from tricresyl phosphate with some smaller quantities
of cresyl diphenyl phosphate and trixylenyl phosphate being used. Since
that times isopropylphenyl diphenyl phosphate, originally imported in
small quantities by FMC from Ciba-Geigy in England, and Monsanto's pro-
prietary mixture have gained in popularity and at the present time share
the market with the "older" type materials. Industry sources indicate
that, in 1973, the market for phosphate ester hydraulic fluids was ap-
proximately split equally between the "older" type esters (TCP, GDP, and
trixylenyl), the isopropylphenyl diphenyl ester and the Monsanto propri-
etary mixture.
Phosphate ester use areas -.Phosphate ester hydraulic fluids are
used primarily in industries where a significant fire hazard would exist
if a rupture or leak would occur in a hydraulic line. Examples are pro-
vided below for various fields in which the fluids would be used in hy-
draulic systems.
* Military uses
MIL-H-19457B (ships) for use on aircraft carriers in aircraft
catapult systems, flight deck elevators, and other hydraulic sys
terns on the flight deck.
*
4
Industrial uses
Die-casting equipment--other than automotive
Steel mill equipment such as hydraulic doors on blast furnaces,
continuous casting equipment, etc.
Molding equipment—plastics industry
Die-casting equipment and foundries—automotive industry
Continuous casting equipment in basic metals industry
Mobile equipment such as endloaders, bulldozers, etc., in ser-
vice near sources of high temperature (e.g., endloaders used
near blast furnaces in the steel industry)
Gas turbine bearing lubricant (main bearings)
Industrial air compressor lubricant
Control fluids for steam turbines (electrical generation)
76
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The automotive and steel industry use approximately 65 to 70% of all
phosphate esfer hydraulic fluids. Gas turbines and electrical power
generation represent the fastest growing use areas,
It has been estimated that approximately 80% of the annual consump-
tion of phosphate ester hydraulic fluids occurs due to leakages in the
hydraulic system. In certain industries, the companies feel that it is
more economical to continually add hydraulic fluid to the system than
to shut down the system and its associated equipment, repair the leak-
age, refill the system, and start the system anew.
In the 1970 report by Hydraulics and Pneumatics magazine,2,1 a list-
ing of the companies responding to the survey was made by industry SIC
number, the number of responding companies, and the total gallons used
by those companies. In Table 5 data are shown for those companies indi
eating a usage of phosphate ester or phosphate ester-blend hydraulic
fluids as reported in that survey.
Reprocessing - Small quantities of phosphate ester hydraulic fluids
are reprocessed each year but this quantity probably represents only
about 10% of the total amount of phosphate ester hydraulic fluids sold
each year. Most of the reprocessing is done on a toll basis. Some of the
formulating companies have an agreement with the customer to reprocess
the fluid and the fee is incorporated into the selling price. The four
companies shown below are the major reprocessors; however, some companies
in specific industries, such as automotive and steel, reprocess their own
hydraulic fluids. These quantities are not included in the 10% figure.
Company Location
E. F. Houghton and Company Philadelphia,, Pennsylvania
Radco Corporation St. Charles, Illinois
Findett Incorporated St. Charles, Missouri
Wallover Oil Corporation East Liverpool, Ohio
Future growth - The use of the phosphate esters in this report in
synthetic fire resistant hydraulic fluids had followed a fairly nominal
growth rate until 1971. From 1971 to 1973, the growth rate increased sub-
stantially due to increased concern regarding fire hazards and recent new
legislation regarding flammability. With the economic recession of 1974
and thus far in 1975, it is anticipated that the consumption of phosphate
esters will decrease somewhat from the top of 1973. Provided that the econ^
omy corrects itself in 1975, it could be anticipated that the use of these
77
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Table 5. USAGE OF PHOSPHATE ESTER HYDRAULIC FLUIDS BY INDUSTRY^/
SIC Industry
19 Ordinance
20 Food
22,23 Textile, Apparel
28 Chemicals
29 Petroleum
32 Stone, clay, and glass
33 Primary metals
34 Fabricated metal products
35 Total Machinery (except electrical)
351 Engines and turbines
352 Farm machinery and equipment
353 Construction and mining equip-
ment
354 Metalworking machinery
355 Special machinery, except
metalworking
356 General industry machinery
357 Office and accounting machinery
358 Service industry machinery
359 Misc. machinery (except elec.)
36 Electrical machinery
37 total Transportation equipment
371§/ Motor vehicles
37227 Aircraft (missiles)
38 Instruments
Phosphate ester
Plants Gallons
Phosphate ester
Plants Gallons
4
1
3
11
4
17
3
3
2
1
4
2
1
1
3
12
4
3
1
1,400
1,500
1,135
100,175
2,000
18,370
1,200
850
600
500
1,260
1,300
660
12,000
1,500
1,583,475
1,007,000
67,000
150
2
1
12
4
1
4
1
100
150
550
3,050
5,450
1,000
135,269
128,844
650
500
2,275
500
2,500
200
501,300
500,000
300
10,005
aj Includes gallonage reported as the total company usage in all plants by two auto-
mobile manufacturers. The number of manufacturing plants to which these figures
apply is not known.
_b/ Includes commercial aircraft, which is treated separately in this study.
78
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phosphate esters will increase at an average annual rate of 9 to 11%.
This growth rate would lead to an annual consumption of 74 to 88 million
pounds in 1984. This anticipated growth rate does not imply, of course,
that all phosphate esters will increase at that rate. Tricresyl phosphate
and cresyl diphenyl phosphate will likely show a decreased usage in this
area while the isopropylphenyl diphenyl ester will probably increase as
will other proprietary mixtures. The search for new phosphate esters will
continue and the introduction of new products could have a profound effect
upon these projected quantities.
Aircraft Hydraulic Fluids
Aircraft hydraulic fluids have been considered separately in this
report for two reasons: (a) the fluids for aircraft normally are not
the same as those for industrial uses; and (b) only one of the phosphate
esters considered in this study is used in formulations for aircraft hy-
draulic fluids, dibutyl phenyl phosphate. All other phosphate esters used
in aircraft formulations are trialkyl esters. Normal phosphate ester in-
dustrial hydraulic fluids cannot be used with commercial aircraft for sev-
eral reasons, the major ones of which are temperature, environment, servo-
system considerations, weight, design, performance, reliability, and
maintenance.
At the present time, there are two dibutyl phenyl phosphate base
aircraft hydraulic fluids approved by the Federal Aviation Administration
(FAA) for use in aircraft: Skydrol 500A (Monsanto) and Hijet W (Chevron).
Aerosafe 2300 W is reported to contain small quantities of tricresyl phos-
phate to produce more desirable flow characteristics in the formulated
fluid. It is likely low density (LD) Skydrol also contains some triaryl
or alkyl aryl phosphate ester additives for the same reason.
Efforts to determine the quantities of dibutyl phenyl phosphate,
or aircraft hydraulic fluids in general, used each year were uniformly
unsuccessful. Except for rare exceptions, the Armed Forces do not use
phosphate ester base hydraulic fluids in their aircraft. From discus-
sions with a manufacturer—' of private U.S. jet aircraft, it was de-
termined that essentially all small private jet aircraft use the equiva-
lent of MIL-H-5606, a hydrocarbon-base fluid, as the hydraulic fluid.
Airline companies provided information regarding their usage but none
for the entire industry.
The American Air Transport Association provided data on the fleet
sizes of all member airlines for the years 1963, 1968, and 1972 to 1974
(see Appendix B). Similar data was obtained from the International Air
Transport Association (IATA) for the years 1972 through 1974. Information
79
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supplied by Trans World Airlines was used for the hydraulic system capac-
ities of each type of aircraft and, from TWA, it was determined that es-
sentially all airlines purchase sufficient quantities of hydraulic fluid
for three refills of the hydraulic system per year.
Table 6 shows the calculated data for the consumption of dibutyl
phenyl phosphate for the years 1964 to 1974. A density of 9 Ib/gal of
dibutyl phenyl phosphate was assumed. The estimated figures for all
other international airlines were determined by taking the ratio be-
tween the U.S. and the international figures for 1972 to 1974 and ap-
plying this ratio to earlier U,Se consumption, as suggested by the
International Air Transport Association.
It is felt that the annual consumption data in Table 6 is low,
probably by 50 to 607oS but no reason for this is readily apparent.
Process Technology - Aircraft hydraulic fluid are formulated in basi-
cally the same manner as that described for industrial phosphate ester
hydraulic fluid. All handling and packaging procedures are the same ex-
cept that aircraft hydraulic fluids are not shipped in bulk but packaged
in 1 and 5 gal. containers and in 55 gal. drums. The major producer,
Monsanto Industrial Chemicals Company, has been previously identified
in this subsection. Chevron does not produce any dibutyl phenyl phosphate
but rather purchases the fluid from Monsanto and repackages it into their
containers.
Future Growth - From 1970, the use of dibutyl phenyl phosphate has in-
creased at an annual growth rate of approximately 8%/year. During this
period, the trend of passenger and freight airline was towards the large
capacity planes, such as the B-747 and L-1011, which have a considerably
larger hydraulic system capacity than the B-727, and others of this type.
However, from recent reports, it appears that airline companies are under-
going flight consolidations, interchanging of air routes between airlines,
and general changes to provide a more economical basis for the operation
of the airlines. It is projected that fleet sizes will be modified to ac-
commodate the new economy moves by the airlines and that rapid expansion
of fleet sizes will not occur for the next few years. Thus, a leveling
effect could occur over the next 2 to 3 years followed by a period of
slower growth (approximately 5 to 7% annual growth) which would lead to
a consumption of approximately 5.4 to 6.4 million pounds by 1984, based
on the figures for 1974 in Table 6. If the figures in Table 6 are low by
approximately 50%, as we believe, then the consumption would have been
4.5 million pounds in 1973 and 5.0 million pounds in 1974. Using these
figures and an average annual growth rate of 5 to 7%, the consumption
in 1984 would be in the range of 8.3 to 10 million pounds per year.
80
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Year
Table 6. CONSUMPTION OF DIBUTYL PHENYL PHOSPHATE IN
COMMERCIAL AIRCRAFT (x 106 Ib)
United States
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
0.99
(1.13)
1.24
(1.52)
1.74
(1.44)£/
(1.55)
(1.65)
1.74
1.83
1.92
All other international
(0.59)
(0.68)
(0.74)
(0.91)
(1.04)
(0.92)
(1.02)
1.12
1.23
1.41
Total
1.58
1.81
1.98
2.43
2.78
2.
2.47
,67
,86
,06
3.33
() - MRI estimate.
a/ Assumes 75% usage of dibutyl phenyl phosphate fluids from 1968 to
1974 and 100% prior to 1968.
81
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Lubricant Additives
The area of lubricant additives is an extremely broad field, cover-
ing almost all industries where heavy or precision machinery is involved.
Phosphate ester lubricant additives can be divided into three areas:
(a) extreme pressure (E.P.) agents; (b) anti-wear agents; and (c) stick-
slip moderators. The first two agents or additives are used in systems
involving some type of gears while the third is generally utilized in
nongear situations. One also finds the term "boundary lubricant" in the
literature and for the purposes of this study, boundary lubricants will
be considered to be a part of extreme pressure additives.
The distinction between extreme pressure and anti-wear additives
is not a clear-cut division. "Anti-wear" agent or additive is the term
usually applied when reference is being made to systems operating under
light to moderate loads at medium to high gear speeds. For systems operat-
ing under heavy loads at relatively slow gear speeds, the term "extreme
pressure" (E.P.) additive or agent is usually applied. "Stick-slip moder-
ator" is a new term generally applicable to additives for nongear systems.
The written definitions appear to be clear-cut but in practice this is
not found to be the case. A stick-slip moderator functions to reduce the
lubricity, and hence slippage, while maintaining a lubricant film between
the metal surfaces.
Of the phosphate esters that have been or are being used as lubricant
additives, tricresyl phosphate has been the most common for many years and
still is the predominant ester in this field. Small quantities of trixylenyl
phosphate may be used in some applications but the extent of its usage is
quite small. Among the three types of additives, anti-wear and extreme pres-
sure additives comprise approximately 45% each and stick-slip moderators
comprise the remaining 107o.
The usage of lubricant additives from 1964 to 1973, and even previous
to 1964, has been marked by a rather slow, steady growth. From 1964 to
about 1968, the annual growth rate was approximately 5%/year and from
1968 to present, it has progressed at a rate of about 10%/year as shown
below for the years 1964 to 1973. As with hydraulic fluids, no figures
could be found in the literature relative to the quantity of phosphate
esters utilized during this time span; therefore, the quantities are "best
estimates" based on discussions with manufacturers of phosphate esters
and the annual growth rate previously discussed.
82
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Year Quantity of phosphate ester (x 10" Ib)
1964 4.0
1965 4.2
1966 4.4
1967 4.6
1968 4.8
1969 5.3
1970 5.8
1971 6.4
1972 7.0
1973 7.7
Formulation Technology - The formulation of phosphate esters as lubricant
additives into lubricating oils or military fluids occurs by predominately
three methods. One method is that the large producers of phosphate ester
hydraulic fluids (i,e., Stauffer, Houghton, and Monsanto) produce lubri-
cating oils, containing anti-wear or extreme pressure additives, according
to the specifications of a particular company or according to the military
specifications. A second method of "formulation" consists of the sale of
prepackaged phosphate esters, which the customer adds directly to their
lubricating oil. An example of this is "Syn-O-Ad" produced by Stauffer
Chemical Company. The third method involves the sale of quantities of
phosphate ester to companies^ such as Lubrizol, Viscosity Oils, and the
major oil companies, who add the esters to lubricating oils or petroleum-
based hydraulic fluids in accordance with their customer's specifications
or military specifications. Examples of this latter method would be the
Lubrizol Corporation, which purchases quantities of tricresyl phosphate,
for incorporation (in concentrations of about 2%) into the farm tractor
hydraulic and transmission fluid they produce for John Deere Companyo The
same procedure applies to Viscosity Oils for the fluid they formulate for
International Harvester, except that in this instance the tricresyl phos-
phate is present in concentrations of 3 to 4%.
To assemble a listing of all users of triaryl phosphate esters as
lubricant additives would be extremely complex. The situation in this use
aijea is not akin to that in hydraulic fluids where three companies produce
the vast majority of the phosphate ester fluids. With lubricant additives,
a large number of companies utilize basically relatively small quantities
of triaryl phosphate esters either for their own use or for the formulation
of fluids according to definite specifications. For the most part, the ma-
jor hydraulic fluid producers (i.e., Stauffer, Monsanto, and Houghton),
Lubrizol Corporation, Viscosity Oils Company, and most major oil companies
(e.g., Shell, Exxon, or Mobil) are the major consistent users of triaryl
phosphate esters as lubricant additives. Other companies, who bid on mili-
tary contracts for fluids containing triaryl phosphates, will employ these
esters if they receive the contract but otherwise would use very little of
the material.
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Use Areas - Examples of current nonmilitary uses for triaryl phosphate
esters in lubricants are provided in the following list. In almost all
cases5 tricresyl phosphate is present in concentrations of 0.5 to 2.0%j
as an anti-wear or extreme pressure (E.P.) additive.,
Cutting oils in. metal fabrications
Machine' oils (particularly for copper and brass)
Steam turbine oils
Farm machinery hydraulic and transmission fluids
Marine-type gear oils
Automotive and truck transmission fluid
Some types of shock absorbers on railway freight cars
Cooling lubricants for commercial refrigeration
The use of triaryl phosphate esters in transmission fluids serves a dual
function. In addition to providing anti-wear properties, the ester also
acts to maintain tight seals in the transmission.
In addition to commercial and industrial uses, the military uses
appreciable quantities of tricresyl phosphate as an anti-wear additive
in its fluids® A partial listing is given below of military specifica-
tions on fluids requiring the use of tricresyl phosphate as an additive.
MiL-L-7808 Main Engine Oil for Jet Aircraft (2% TCP)
MiL-L-23699 Naval Equivalent to 7808 (2% TCP)
MiL-H-5606 Hydrocarbon Hydraulic Fluid (aircraft) (2% TCP)
MiL-H-83282 Replacement Fluid for 5606
MiL-F-17111 Power Transmission Fluid (2% TCP)
MiL-L-83176 Instrument Bearing Lubricant
MiL-H-46004 Petroleum-Based Missile Hydraulic Fluid (0.5 + 0.1% TCP)
MiL-H-27601 High Temperature, Petroleum Base Hydraulic Fluid (2% TCP)
For some of the larger volume fluids, such as 5606, 7808, 46004, and
1/111, the companies listed below are examples of those usually on one or
more qualified product list*
Standard Oil of California
Pennsylvania Refining Company
Royal Lubricants Company
Oronite Division, California Research Corporation
Exxon Oil Company
Bray Oil Company
Kendall Refining Company
For the military fluids shown above, the Defense Fuel Supply Center
has provided figures for the quantities of each fluid purchased during
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the past four fiscal years. This data, and the calculated quantity of
TCP, are shown in the following list.
Fluid
MiL-L-7808
MiL-L-23699
MiL-H-5606
MiL-H-83282
MiL-F-17111
MiL-H-27601
MiL-L-83176
MiL-H-46004
Quantity of
466,148
Quantities purchased (gal.)
FY-1974*
1,051,735
531,400
764,660
53,050
1,980
FY-1973
838,800
685,250
1,908,000
165,100
3,300
FY-1972
2,375,050
1,154,250
2,172,500
81,000
22,500
FY-1971
1,362,200
1,062,860
2,4803600
190,250
1S925
No history of any purchase
No history of any purchase
698,487
1,126,228
988,980
* FY-1974 denotes fiscal year 1974.
** Quantity of TCP (Ib) calculated from percentage added according to
specifications.
Future Growth - The future of triaryl phosphate esters as lubricant addi-
tives may very well find itself entering a period of slow growth or actual
declining usage. At the present time, one major manufacturer has already
ceased commercial sale of TCP, cresylic acid feedstock is in limited sup-
ply, and the cost of cresylic acid (and thus TCP) is increasing rapidly.
If other manufacturers follow the lead of Monsanto and reduce the produc-
tion of TCP in favor of the synthetic materials for hydraulic fluids, sup-
plies of TCP could become extremely limited and expensive. At the present
time, companies using TCP as an additive are searching for alternate
phosphorus-containing materials as anti-wear and extreme pressure substi-
tutes, particularly those producing fluids for farm machinery. However.
current military specifications will act as a buffer to a drastic down-
ward trend. All of the military fluids listed above specify tricresyl
phosphate and the process of qualifying a new material as a substitute
for TCP is somewhat lengthy.
In view of current conditions, it does not appear likely that lubri-
cant additives, in the form of TCP, can maintain a 10% annual growth rate
for an extended period of time. A leveling of the growth rate would seem
appropriate for 2 to 3 years, followed by either a decline, if ouier com-
panies drastically reduce production of TCP, or a period of s1 ~.wer growth,
depending upon the decision of the other manufacturers wi th r-aop .-•.:: to tri-
cresyl phosphate. The next 2 to 3 years will be rather decisi.^ _-ariing
the future growth of triaryl phosphate ester in this area. If the triaryl
85
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phosphate esters can continue to participate in this area, it could be
anticipated that their annual consumption in this area would reach ap-
proximately 14 million pounds per year by 1984.
FIRE RETARDANT PLASTICIZERS
General Discussion
Production of plasticizers in the United States exceeds 1.35 billion
pounds per year and worldwide production is in excess of 2.3 billion pounds
per year. Worldwide, there are over 500 different plasticizers. Phthalate
esters constitute approximately 63% of the total production of plasticiz-
ers.—' Between two-thirds and three-fourths of all plasticizer production,
and 807o of the phthalate esters are used in flexible polyvinylsix' with
the production of poly(vinyl chloride) being more than 85% of the produc-
tion of polyvinyls JLI'
Unplasticized poly(vinyl chloride) (PVC) is a rigid, flame retar-
dant plastic, with its inherent flame retardancy due to the high chlorine
level contained in the molecule. However, the majority of the uses of PVC
require a flexible film which, of course, necessitates the use of a plas-
ticizer at about 20 to 35 phr (parts per hundred parts resin). The most
common plasticizer for PVC is dioctyl phthalate (DOP). The use of this
plasticizer, in quantities sufficient to provide a flexible-film, also
"dilutes" the chlorine level of resultant plastic such that it no longer
is flame retardant. Therefore, an additional plasticizer with flame retar-
dant properties or a synergist must also be combined into the resin mix-
ture. The addition of only a flame retardant plasticizer is also used in
numerous applications. It is important to note that all monomeric plasti-
cizers 3 except those containing halogens or phosphorous, increase flamma-
bility.
The rate of flame retardant resin consumption has accelerated rapidly
in recent years with the increased demand being prompted by the establish-
ment of fire safety regulations. Imparting a specified level of flame re-
tardancy to a plastic composition, in general^ can be accomplished with
relative ease. However, it is considerably more difficult to develop a
flame retardant plastic composition that is economical, easily processed,
and provides the desired properties. Factors to be considered in formulat-
ing a new flame retardant plastic include: (a) flame retardancy; (b)
physical properties! (c) processabilityj and (d) economics. Flame retar-
dantss classified by functions, can be divided into three main categories:
reactive, additive, and synergistic types. Reactive flame retardants con-
tain functional groups which permit their incorporation directly into the
polym r.hain through chemical reaction. Additive flame retardants are
incorporated into resins by compounding and one additive may be potenti-
ally useful in a variety of polymer systems. This multipurpose usefulness
86
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is in opposition to the reactive types which are relatively specific
for a given polymer system. Aryl and alkyl aryl phosphate esters are
this type of flame retardant. Synergism is the phenomenon in which the
combined effect of two agents working together is greater than that pre-
dicted by evaluation of the effect of each additive employed individually.
A synergist is frequently used to enhance the effectiveness of the princi-
pal flame retardant. Antimony oxide is the most widely recognized example
of this product class and is used primarily in combination with halogenated
organics.
Triaryl phosphates, such as tricresyl phosphate and cresyl diphenyl
phosphate, are among the most effective flame retardant plasticizers; in
addition, they enhance the processability of polymer compositions (pre-
dominately PVC) and reduce volatility. Alkyl aryl phosphates, such as 2-
ethylhexyl diphenyl phosphate and isodecyl diphenyl phosphate, offer a
compromise of flame retardance and overall plasticizing properties, since
some triaryl phosphates have rather poor low temperature properties. Tri-
aryl and alkyl aryl phosphates provide self-extinguishment in flame tests
when employed at a level of approximately 257o replacement of dioctyl phtha-
late (DOP) in a typical flexible formulation of poly(vinyl chloride). Phos-
phate esters do, however, have the disadvantage that they tend to increase
smoke production in polymer systems.
Phosphate Esters
The principal phosphate esters that are being, or have been, used as
flame retardant plasticizers in polymeric systems are:
Tricresyl phosphate (TCP)
Cresyl diphenyl phosphate (GDP)
Triphenyl phosphate
Isopropylphenyl diphenyl phosphate
2-Ethylhexyl diphenyl phosphate
Isodecyl diphenyl phosphate
Due to recent price increases for cresylic acid feedstock, the price of
tricresyl phosphate has increased considerably and, as a result, has lost
a portion of its market to other triaryl phosphate esters, such as cresyl-
diphenyl and isopropylphenyl diphenyl. Similar cost increases are also
true for cresyl diphenyl phosphate but the feedstock price increases should
have a smaller impact on its price due to the lower cresylic acid content.
Isopropylphenyl diphenyl phosphate, prepared from propylene, phenol, and
phosphoryl chloride, is not dependent upon the supply of cresylic acid and
thus is offered as a substitute for the other triaryl phosphates.
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Phosphate esters are utilized as plasticizers almost exclusively for
their fire retardant properties. Phosphate esters account for a rather
minor fraction of all plasticizers used by the plastics industry. The
overall use in the plastics industry of all of the esters listed in this
subsection in 1973 was approximately 42 million pounds; by comparison,
the production of the most common plasticizer, dioctyl phthalate (OOP),
was approximately 430 million pounds in the same year.
The total quantity of nonhalogenated phosphate esters used as fire
retardant plasticizers has increased from 34 million pounds in 1964 to ap-
proximately 70 million pounds in 1973 as shown below in data taken from
the annual summaries of "Modern Plastics."
Nonhalogenated phosphate
Year esters (x 1Q6 Ib)
1964 34.0
1965 38.0
1966 41.0
1967 43.0
1968 47.0
1969 50.7
1970 57.0
These data provide information for all nonhalogenated phosphate esters
and include data for any trialkyl esters used as plasticizers. In the
1967 "Modern Plastics" summary, it was stated that tricresyl phosphate,
cresyl diphenyl phosphate, and triphenyl phosphate comprised about 857»
of all nonhalogenated phosphate esters used as fire retardants and that
the quantities used were 19.0, 6.0, and 9.0 million pounds, respectively,
with all other esters totaling 9.0 million pounds. This same issue (1967)
also stated that 10.5 million pounds of 2-ethylhexyl diphenyl phosphate
was used in 1966 and estimated that 12 million pounds would be used in
1967. Information acquired from various industry sources indicates that
these figures for 2-ethylhexyl diphenyl phosphate are too high and that
a figure of approximately 8 million pounds for each year is more realis-
tic. The quoted figures, at least for the years 1969 to 1974, are felt to
be too high unless considerable quantities, of the order of 10 to 20 mil-
lion pounds per year, of trialkyl phosphate esters are included in these
figures, or if the production data from the U.S..International Trade Com-
mission is considerably understated. From past overall usage figures, it
appears unlikely that the trialkyl esters would be used in those quanti-
ties. Based on information acquired from various trade publications and
phosphate ester manufacturers, the data listed below represents the MRI
estimate of the total quantities used as plasticizers for the six phos-
phate esters listed previously in this section.
88
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Year Quantity (x 10^ Ib)
1964 37.1
1965 38.3
1966 41.9
1967 41.3
1968 40.0
1969 33.4
1970 41.1
1971 49.8
1972 40.7
1973 41.8
To facilitate the discussion of the utilization of the phosphate
esters in the plastics industry, there are generalizations which can be
applied. All of the phosphate esters used as plasticizers, except for
triphenyl phosphate, have the same basic use pattern and, for the most
part, are interchangeable. The alkyl aryl phosphate esters impart better
low temperature properties but are not as flame retardant as the triaryl
esters.
For general usage as a flame retardant plasticizer, in which flame
retardant characteristics and low temperature flexibility would not be
overriding factors, all of these plasticizers would function equally well
and the ultimate choice would be made on economic factors, i.e., the cost
per pound.
In poly(vinyl chloride), the fire retardant of choice normally is an-
timony oxide. However, the use of this material has been restricted by
the availability of the oxide. It has been estimated that the plastics in-
dustry could have used 30 to 407° more of this synergist in 1974, since it
is used in conjunction with almost all other flame retardant plasticizers «-i=
The use of antimony oxide also has certain disadvantages, with the principal
one being that it imparts an opaqueness to the plastic and thus cannot be
utilized if a clear plastic is the desired end product. It is also undesir-
able if the final product requires a delicate coloration (low pigmentation),
In these two areas, clear plastics and delicate coloration, aryl and alkyl
aryl phosphates are the plasticizers of choice.
For the phosphate esters under consideration at this point, namely
TCP, GDP, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate,
and isopropylphenyl diphenyl phosphate, approximately 85 to 90% of their
use in the plastics industry occurs as a fire retardant plasticizer with
poly(vinyl chloride) and they are used either in conjunction with dioctyl
phthalate (OOP) or as a substitute for OOP, depending upon the flame re-
tardance requirements of the end product. The remaining 10 to 15% of their
89
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use is generally spread over other systems such as other polyvinyl films
(formals and butyrals), cellulosics, and, to some extent, in thermoplas-
tics.
In addition to their usage as a fire retardant plasticizer in plas-
tics, these esters also find minor use in other areas related to this
industry. These areas include plasticizers for synthetic rubbers (3),
pigment dispersants (1.5), peroxide carriers (0.5), adhesives (1), and
nonlacquer coatings (0.5). The figures in parentheses represent approxi-
mate usage, in million pounds, for each area in 1973« Additional discus-
sions will be presented later in this subsection concerning each of these
areas.
Poly(vinyl chloride) Film and Sheets - Polyvinyl film and sheeting is the
largest plasticizer-consuming industry segment. In 1973, producers used
more than 1 billion pounds of PVG requiring in excess of 500 million pounds
of plasticizers,, This represents nearly one-third of the total plasticizer
sales for that year.
Poly(vinyl chloride) film is produced by basically three techniques:
casting, extrusion, and calendering. The majority of the film is produced
by calendering, with extrusion being next and the least amount is by cast-
ing. Blown extrusion and solution casting processes produce the thinnest
films while heavier gage film is produced almost entirely by calendering.
Triaryl phosphates (TCP, CDP3 and isopropylphenyl diphenyl) are used as
PVC resin solvents in the production of solution cast films where complete
dissolution of the resin and any additive ingredients is extremely impor-
tant.
The major market areas for the poly(vinyl chloride) industry and the
percentage contribution of each specific area is given in Table 7 for the
years 1964 to 1974. For 1973, an approximate percentage utilization of
the phosphate esters within more defined use areas is given below:
Percentage Use area
31 to 35 Automotive (vinyl upholstery, dashboard covering,
etc.)
13 to 14 Wire and cable covering
14 to 16 Floor and wall coverings
14 to 16 Belting (coated fabric conveyor belts used in mines,
etc.)
5 to 6 Industrial fabric coating ("Brattice" cloth in mines,
etc.)
8 to 9 Other film and sheeting applications
8 to 9 Miscellaneous
90
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Table 7. MAJOR MARKETS FOR POLY(VINYL CHLORIDE); PERCENTAGE CONTRIBUTION OF EACH MARKET AREA~
a/
Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
( )
a/
b/
Building and
construction
(30.2)
(30.0)
29.9
29.7
29.4
30.1
33.2
35.5
39.7
43.6
41.8
MRI estimate.
Electrical Household
uses uses
(10.
(10.
11.
11.
13.
14.
14.
11.
10.
9.
7.
Excludes exports.
Examples of miscellaneous
6)
8)
0
1
3
9
0
7
3
0
9
category
(22.1)
(21.8)
21.4
20.4
19.5
18.9
16.9
17.2
14.5
10.5
11.0
include:
Packaging
(3.7)
(4.0)
4.4
5
7
8
9
8
7
7
7
.3
.1
.4
.0
.7
.9
.2
.2
agricultural
Transportation
(8.8)
(8.6)
8.5
8
8
8
7
7
6
5
5
.0
.7
.6
.4
.7
.1
.6
.7
uses (including
Consumer
goods
(18
(17
17
15
16
13
14
13
12
11
11
pipe).
.2)
.8)
.0
.9
.5
.8
.0
.3
.1
.4
.5
credit
Misc .
(6.4)
(7.0)
7.8
9.5
5.4
5.2
5.4
5.9
9.5
12.7
14.9
cards,
garden hose, laminates, medical tubing, novelties, stationary supplies, tools and hardware,
and other small uses.
-------
Examples of specific end-products using phosphate ester plasticized PVC
are listed in Table 8. It should be stressed again that the choice of
plasticizer may be dictated by a specific end use for the product.
In view of the rather varied applications for phosphate esters in
the poly(vinyl chloride) industry and the large number of PVC processors
who may use these plasticizers, it would be extremely time-consuming and
outside the scope of this study to list all users over the past 10 years
and all of their processing sites. It was estimated in 1972 that PVC prod-
ucts were produced by over 8S000 fabricators, either from purchased com-
pounded resins or from compounded resins that the fabricators prepared
themselves JL5/ Obviously, not all 8,000 would use phosphate esters and
delineating those who did use them would be extremely complicated. There-
fore, a compilation is given in Table 9 for the major companies who are
thought to use phosphate esters in the compounding of PVC resins.
Due to the nature of the compound process (physical mixing), it
should be noted that these figures represent the capacity for compounding
PVC resins in general without regard to a specific plasticizer. The pro-
duction of phosphate ester compounded PVC resins is highly variable and
subject to considerable variation in demand both for captive use and com-
mercial sales®
Production of Compounded PVC Resins - The process by which phosphate
esters, or any other plasticizers, are incorporated into the poly(vinyl
chloride) resin is based upon physical mixing. Phosphate esters are nor-
mally purchased in either railway tankcar or tanktruck lots which, upon
receipt at the processing facility, are pumped directly into storage
tanks„ When the particular ester is to be compounded with the resin, it
is piped through an automatic weighing device into a closed, vented mixer.
Poly(vinyl chloride) resin and other ingredients, such as heat stabiliz-
ers, pigmentation, lubricants, fillers, impact modifiers, and processing
aids, are added to the mixer and the entire contents, at approximately
300°F, are stirred for a specified period of time to insure complete coat-
ing of each PVC resin particle. After mixing is complete, the compounded
resin is piped directly to the bagging operation where the resin is placed
in lined paper containers or is piped directly to a bulk storage container
for shipment by either railway cars or tanktruck. Upon completion of the
mixing operation, the mixer is cleaned and any residual resin is retained
in drums and reworked into similar compounding operations at a later da.te.
The compounded resin is now ready to be used in an extrusion or calender-
ing operation to produce the final end product. This basic processing pro-
cedure is used by all compounders of PVC plasticized resins and has not
changed appreciably over the past 10 years,,
92
-------
Table 8. END-USE PRODUCTS FOR PHOSPHATE ESTER COMPOUNDED
PVC RESINS
End-use product Comments
Shrink film packaging for cartons and
boxes
Vinyl automobile and truck upholstery Very heavy usage in this area
Vinyl dashboard covering Very heavy usage in this area
Vinyl coatings on fabric upholstery
in automobiles and trucks Very heavy usage in this area
Lightweight rainwear: "bubble"
umbrellas
Insulation facing material in
construction
Vinyl tarpaulins enclosing buildings
under construction
Pipe and conduit wrappings
Wire and cable coatings and
insulation
Some vinyl wall coverings
Vinyl floor covering industry
"Brattice" cloth in mining industry
Plastic adhesive bandages
Plastisols for casting certain
automotive parts
93
-------
Table 9. PRODUCERS OF PHOSPHATE ESTER COMPOUNDED PVC
Capacity
Company (x 1()6 lb/year)jL/
Borden, Inc.
Borden Chemicals Division 470
Illiopolis, Illinois
Leominster, Massachusetts
B, F. Goodrich Company
B. F9 Goodrich Chemical Company 980
Long Beach, California
Henry,, Illinois
Louisville, Kentucky
Avon Lake, Ohio
Pedricktown, New Jersey
Diamond Shamrock
Deer Park, Texas 328
Delaware City, Delaware
Firestone Tire and Rubber Company
Firestone Plastics Division 366
Perryville, Maryland
Pottstown, Pennsylvania
Goodyear Tire and Rubber Company 228
Niagara Falls? New York
Occidental Petroleum Corporation
Hooker Chemical Corporation (Ruco Division) 180
Burlington, New Jersey
Stauffer Chemical Company
Plastics Division 300
Delaware City, Delaware
Uniroyal Rubber Company 118
Painesville, Ohio
a/ These are published capacity figures and do not correspond very
closely with actual plant capacities because design capacities
presume continuous production of one material and no allowances
are made for production shutdowns.
94
-------
In the production of PVC cast films, triaryl phosphate esters are
piped to a closed mixer in sufficient quantity to completely solubilize
the PVC resin and any additives into a form of "gel." The liquid mixture
is then pumped to a casting machine in which the heated gel is placed on
a mirror-surfaced roller in a very thin film. Upon cooling, the gel "sets
up" to form a very thin, highly plasticized vinyl film of normally less
than 1 mil thickness. Such films exhibit good dimensional stability,
clarity, and high gloss surfaces.
Cellulosics and Other Thermoplastics - Because it is a solid, the util-
ity of triphenyl phosphate is severely restricted in areas such as poly-
(vinyl chloride) unless a suitable solvent can be found which would not
cause interference under processing conditions. The area of thermoplas-
tics represents the greatest utility for triphenyl phosphate although
some use of this material is made in the plasticization of rubber and in
adhesives. Triaryl and alkyl aryl phosphate esters have been used to a
minor extent with cellulosics and certain specific applications of other
thermoplastics. At one time 2-ethylhexyl diphenyl phosphate was used as
a plasticizer in cellulose propionate. For triphenyl phosphate, the areas
of greatest utilization are in cellulose acetate, cellulose acetate-
butyrate, and modified polyphenylene oxide (Noryl) materials.
Noryl is a rather new molding and extrusion resin, having been in-
troduced by General Electric Company in 1966. It is basically a modified
polyphenylene oxide resin'intended for applications not requiring the
extra-high temperature resistance of normal polyphenylene oxide. Noryl
is classified as an engineering thermoplastic and finds utilization in
areas normally employing materials such as acrylonitrile-butadiene-
styrene (ABS) resins.
The major market areas for the cellulosics industry and the percent-
age contribution of each specific area is given in Table 10 for the years
1964 to 1974. As in the case for the other phosphate esters with poly-
(vinyl chloride), triphenyl phosphate is employed as a plasticizer almost
exclusively for its fire retardant properties since it is not an effici-
ent general plasticizer for cellulose acetate and cellulose acetate-
butyrate. One exception to this statement is in the formation of optical
frames where triphenyl phosphate is added to the normal diethyl phthalate
plasticizer to provide better flow characteristics for the melted resin.
In 1973, approximately 60% (7.2 million pounds) of the annual production
of triphenyl phosphate was consumed as a plasticizer for cellulose est-
ers. In the generalized use areas listed in Table 10, specific uses would
normally be limited to those applications in which the cellulosic materials
are required to display fire retardant properties. Examples of specific
end products for triphenyl phosphate plasticized cellulosics are as shown
in the following list.
95
-------
Table 10. MAJOR MARKETS FOR CELLULOSICS; PERCENTAGE CONTRIBUTION OF EACH MARKET AREA
vo
cr-
Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
( )
Automotive
(4)
4.5
(5.5)
6.0
9.0
9.0
9.0
12.0
11.5
11.3
10.6
MRI estimate;
Electrical
appliances
(7)
6.0
(4.5)
4.0
4.0
4.0
4.0
2.0
2.4
2.5
2.5
all others
Industrial
sheeting
(9)
10.0
(12.0)
13.0
13.0
13.0
13.0
12.0
11.5
11.4
Optical
goods
(12)
12.0
(11.0)
11.0
7.0
7.0
7.0
9.5
10.3
10.6
Packaging
(25)
27.0
(29.0)
31.0
31.0
32.0
33.0
30.5
27.9
27.8
11.6 11.0 27.9
from Modern Plastics, January issues
Personal
itemai'
(23)
21.0
(20.0)
19.0
20.0
20.0
20.0
20.5
21.9
22.4
23.1
except for
Toys
(3)
3.0
(3.0)
2.0
2.0
2.0
2.0
4.5
4.1
3.5
Tubing
(6)
6.0
(6.0)
6.0
6.0
6.0
6.0
5.0
6.1
6.1
3.3 5.6
1971 (April 1972
Other
(11)
10.5
(9.0)
8.0
8.0
7.0
6.0
4.0
4.4
4.4
4.4
issue)
Examples of personal items include: hand tools, toothbrush handles, hairbrush handles, pens,
pencils, etc.
-------
Blister packaging
Face shields for industrial and recreational purposes
Box lids for greeting cards, stationary, etc.
Protective film in photographic albums
Microfilm jackets and holders
Hairdryer handles
Handles on small tools
Optical frames for eyeglasses and sunglasses
In the middle to late 1960's, cellulose esters were used in automobile
and truck steering wheels, interior knobs and buttons, blister packaging,
toothbrush handles, comb and brush sets, and toys. These markets were
gradually either partially or completely replaced by other plastic mate-
rials more suitable for the end use product.
Production of Compounded Cellulosics - Unlike other common synthetic plas-
tics, the cellulosic plastics are not manufactured by the polymerization
of a monomer but rather by the chemical modification of cellulose, a na-
tural polymer. Cellulose esters are commonly prepared by the reaction of
chemical cellulose with the appropriate acid and acid anhydride with sul-
furic acid normally present as a catalyst. For the production of plastic-
grade cellulosics, some acid groups are removed from the product by hy-
drolysis. The plastic grades of cellulose acetate contain 38 to 40%, acetyl,
whereas the same grade of cellulose acetate-butyrate contains 26 to 39%
butyryl and 12 to 15% acetyl.
In the preparation of the compounded cellulose esters, the appropri-
ate ester is mixed with the plasticizer and other additives by physical
mixing in the same general manner as with poly(vinyl chloride). The resul-
tant mixture is heated to its softening point and blended into a homogene-
ous melt which is then formed into small rods or strips. The rods or strips
are cut into 1/8 in. cylindrical or cubical pellets which can be extruded
or solution cast into the final end use product. The pelletized esters are
piped to either bulk storage containers for shipment by tankcar and tank-
truck or to the bagging operation where the pellets are placed in paper
containers for shipment to the numerous fabricators of cellulose esters.
97
-------
The major compounders of cellulosics and their estimated capacity
are:
Company Capacity (x 10 Ib)
Celanese Corporation
Celanese Plastics Company Division 12
Newark, New Jersey
Belvidere, New Jersey
Cumberland, Maryland
Eastman Kodak Company
Eastman Chemical Products, Inc. 20 to 25
Kingsport, Tennessee
Polymer Materials, Inc. 6
Farmingdale, New York
In 1972, Celanese Corporation ceased production of compounded cellulosic
esters. The capacity listed for Celanese is an estimate of their capacity
in 1971, while the figures for Eastman Chemical Products and Polymer Ma-
terials, Inc., are estimated current capacities. There are several other
small suppliers of compounded cellulosic esters but the two listed above
are estimated to currently produce 80 to 90% of the total quantity. Poly-
mer Materials, Inc., estimates that they currently supply approximately
15 to 207o of the market. If the various smaller companies supply approxi-
mately 10% of the current market, then Eastman Chemical Products would
produce about 70 to 75% of all of the triphenyl phosphate compounded cel-
lulosic esters. As in the case for poly(vinyl chloride), the figures pre-
sented above for the compounding capacities represent figures for plasti-
cized cellulosic esters, not necessarily only triphenyl phosphate.
Noryl is the registered tradename for General Electric Company's
modified polyphenylene oxide resin introduced in 1966. Compared to other
more general, consumer-oriented plastics, such as PVC, polyethylene,
polystyrene, and others, it is very expensive and, as an engineering
thermoplastic, finds its greatest utility in close tolerance fabrications
having high heat resistance requirements. Noryl is commonly plasticized
with triphenyl phosphate and in 1973, approximately 40% (4.8 million
pounds) of the annual production of triphenyl phosphate was consumed for
this purpose.
Examples of specific uses for Noryl are given in the following list:
Small household appliances
Molded handles for hand-held hairdryers
Housings for electric blenders
Spray humidifier housing
98
-------
Spray-steam iron casings
Home hair-setting kits with steam curlers
Housings for hand and desk calculators
Computer cash register housings
Rear window shelf in automobiles
Casing and some internal parts of medical instruments
Washing machine control panels and internal parts
Cabinet, base, doors of portable dishwashers
Portable clothes washer tubs
Certain internal parts in television sets
Windows in radar ovens and subway cars
Lighting fixtures requiring high impact resistance
Housing for lighting fixtures
Extruded moldings for electrical and air conditioning
applications
Production of Compounded Noryl - Plasticization can occur in two ways
for this material depending upon the method of fabrication of the final
end product. In thermosetting the resin and plasticizer are mixed at ele-
vated temperatures to give a homogeneous softened material which is fed
directly into the thermosetting machine. For extrusion molding processes,
the resin and plasticizer are mixed at elevated temperatures to give a
homogeneous mixture in the same manner as that described previously for
the cellulosic esters.
The sole producer for Noryl in the United States is the General Ele-
ctric Company. Estimates for the annual consumption of triphenyl phosphate
in this material by General Electric are given in the following list.
~?\
Year Estimated annual consumption"
1966 (0.1)
1967 (0.1)
1968 (0.3)
1969 (0,7)
1970 (1.5)
1971 (2.5)
1972 (4)
1973 (4,8)
* Values are in million pounds per year.
99
-------
MiscelJLaneous Use in the Plastics Industry - In addition to their use as
plasticizers, some of the phosphate esters have additional minor uses in
areas directly related to the plastics industry. The use of certain phos-
phate esters as a plasticizer in the rubber industry will also be dis-
cussed here because of its similarity to the plastics industry.
Pigment Dispersant - Minor quantities, generally less than 1.5 million
pounds per year, of triaryl phosphate esters are used as a dispersing me-
dium for color pigments. Tricresyl phosphate, cresyl diphenyl phosphate,
and isopropylphenyl diphenyl phosphate are normally used for their sol-
vent properties to provide a uniform dispersion of the pigments in vari-
ous thermoplastics such as acrylonitrile-butadiene-styrene (ABS).
Peroxide Carriers - Prior to the polymerization of monomers such as vinyl
chloride, the peroxide to be utilized to initiate the polymerization pro-
cess is often dissolved or suspended in a liquid medium. Small amounts of
tricresyl phosphate, less than 500,000 Ib/year, are used-to provide a
high boiling medium and to protect the peroxide from possible contamina-
tion with other materials.
Adhesive - In the construction of materials such as laminates., the ad-
hesive is often plasticized with phosphate esters when flame retardancy
properties are a requirement for the end product. Cresyl diphenyl phos-
phate and tricresyl phosphate find some usage in this area. Isodecyl di-
phenyl phosphate is also used if the flame retardancy requirements can
be met. In general, this area would utilize approximately 1% (1 million
pounds in 1973) of the total annual production. Triphenyl phosphate finds
usage in formulations for adhesives used in the binding of books, period-
icals, and other similar materials*,
Rubber Plasticizer - Triaryl phosphate esters, in particular tricresyl
phosphate, have been used for many years as a general plasticizer in the
rubber industry. Tricresyl phosphate and cresyl diphenyl phosphate have
good solvating properties, good compatibility, impart fire resistance,
and good oil and grease resistance. As with PVC, however, they lack low
temperature properties so are somewhat restricted in their usage. Iso-
decyl diphenyl phosphate provides better low temperature properties but
sacrifices some flame retardancy characteristics. All of the aryl and
alkyl aryl phosphate esters, except triphenyl phosphate, find a varying
degree of usage in vinyl nitrile synthetic rubbers. They are used both
as general plasticizers and as flame retardants. Examples of use areas
in vinyl nitrile rubbers are in appliance gaskets, ignition wires, cable
jackets, shoe soles and sponge for insulation. Cresyl diphenyl phosphate
and isodecyl diphenyl phosphate are used to provide flexibility and flame
retardancy properties to styrene-butadiene rubber (SBR) used as foam
carpet-backing materials.
100
-------
Uses in the rubber industry have normally consumed approximately
4 to 67<, of the total annual production of aryl and alkyl aryl phosphate
esters. This percentage has held rather steady in this range for the
past 10 years. As would be expected, the major users of the phosphate
esters are the large rubber producing companies such as B. F. Goodrich,
Firestone Tire and Rubber Company, Uniroyal, and others.
Future Grox^th - The future growth of phosphate esters as plasticizers
is, of course, very highly dependent upon the future production of poly-
(vinyl chloride). Should the recent OSHA standards for vinyl chloride
monomer result in a sharp decrease in production, the phosphate esters
will suffer the same fate, at least as plasticizers. Future legislation
regarding flamrnability requirements could have a very positive effect
upon the consumption of phosphate esters as plasticizers*
If it is assumed that the production of vinyl chloride monomer and
consequently, poly(vinyl chloride) remains at a normal growth rate, the
continued emphasis on flame retardancy would indicate, on the surfaces
increased consumption of the phosphate esters. It should be remembered
that antimony oxide is the flame retardant of choice with poly(vinyl
chloride) and that its growth has been hampered by the lack of supply.
New halogenated flame retardants are also beginning to find usage in
areas previously dominated by the phosphate esters.
From a consideration of past history and current factors affecting
the usage of aryl and alkyl aryl phosphate esters as plasticizers, it is
estimated that a future growth rate of 8 to 107o/year is probable but in
could be greater than this if new legislation on flammability would be
enacted. This average annual growth rate would indicate a usage in 1984
of 80 to 95 million pounds per year,
GASOLINE ADDITIVES
Aryl and alkyl aryl phosphate esters were utilized for preignition
control in additive packages in gasoline. The preignition control proper-
ties were dependent upon the phosphorus content of the additive material.
Basically three phosphate esters have been utilized in this area: tri-
cr'esyl phosphate (TCP), cresyl diphenyl phosphate (GDP),, and methyl di-
phenyl phosphate. Very small quantities of dimethyl xylyl phosphate may
have been used by the Ethyl Corporation, but if so, this ester did not
receive any widespread usage. By 1961, almost all of the tricresyl phos-
phate had been replaced by cresyl diphenyl phosphate and was no longer
in use as a gasoline additive. The test properties of TCP and GDP were
essentially identical and, thus, when the price of phenol dropped below
that of cresylic acid, GDP became the replacement additive. Methyl di-
phenyl phosphate was produced only for usage as a gasoline additive. The
estimated quantities of cresyl diphenyl phosphate and methyl diphenyl
phosphate used during the time period 1964 to 1973 are shown in Table 11.
101
-------
Table 11. ESTIMATED QUANTITIES OF PHOSPHATE ESTERS
USED AS GASOLINE ADDITIVES
Year Cresyl diphenyl phosphate Methyl diphenyl phosphate Total
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
12.9
(12.9
12.4
11.8
11.0
(10. o
3.0
1.5
0
0
4.8
(5.8)a/
5.8
5.9
5.9
(6.0)^
2.0
1.0
0
0
17
18
18.2
17.7
16.9
16.0
5.0
2.5
0
0
a./ Data from Paul Levesque, FMC Corporation; the rest are MRI estimates.
Note: All figures represent million pounds.
During the time period 1964 to 1971, one major oil company adver-
tised a gasoline additive package under the tradename "TCP." Discussion
with a representative of this company_IJ>/ revealed that this tradename
did not relate directly to the generic name for the additive but rather
was used to denote that a phosphate ester (GDP) was being added to their
gasoline for preignition control.
MISCELLANEOUS USE AREAS
In addition to the current and past primary use areas discussed pre-
viously, phosphate esters have been utilized in several other areas dur-
ing the past 10 years; however, the volume of ester used in each of these
areas is considerably smaller than for those previously described. The use
areas discussed in this section include industries related to air filtra-
tion, lacquer coatings, and wood preservation. The exportation of phosphate
esters will also be briefly discussed.
Air Filtration
Tricresyl phosphate is the only phosphate ester that has been used
during the past 10 years in industrial air conditioning applications. TCP
is used in two forms in these units: as a gel and as the liquid. One
company, American Air Filter Corporation (AAF), uses approximately 60% of
all TCP (gel and liquid) employed in this application and controls 100%
102
-------
of the market for the liquid TCP baths* In 1973, approximately 3.5 x 10
lb of TCP was used in the air filtration industry, with American Air Fil-
ter Corporation using 2.1 x 10" lb of this total. Based on estimates by
a spokesman for AAF, they sell approximately 20,000 gal. of liquid TCP
nationally per year, or, at 9.7 Ib/gal, 194,000 Ib/year. This corresponds
to approximately 9% of the total sales of TCP by AAF; the remainder, 1.9
x 10° lb, are used in the gel form. The remaining 40% of the total mar-
ket for TCP in air filtration is not concentrated in a few companies but
is widely spread among various companies who use relatively small quanti-
ties of the gel form.
The two processes of AAF which utilize TCP are the multiduty filter
(liquid) and the glass fiber filter (gel). With the multiduty filter, a
series of metal sheets are attached to a chain-operated conveyor type as-
sembly. The screens (3 to 6 ft long and 0.5 ft wide) pass through a bath
containing TCP, and are coated with a film of the liquid. These coated
screens then pass in front of the air intake duct and the particulate
matter in the air adheres to the screen. The screens are rotated back to
the bath, dipped to remove the particulate matter, and receive a fresh
film coating of liquid. The used TCP from the baths is generally not re-
processed at the present time and very likely is stored in drums for re-
moval by a contract hauler.
Use of the gel form on glass fiber filters is basically the same
type of process as used in home air conditioning except on a much larger
scale. The glass fiber filters are sprayed with the TCP gel to provide a
certain "tackiness" to the filter and improve the efficiency for collec-
tion of the particulate matter from the air.
The use of tricresyl phosphate as an air filter adhesive has been
increasing over the past 10 years from an estimated less than 1% in 1966
to approximately 47» in 1969 to 7% in 1972. Future use of TCP in this area
of application, however, will probably not be as rapid as past growth.
With the overall decline in the production of tricresyl phosphate, the
percentage of its use going to this application over the next 10 years,
may increase at about the same, or greater, rate than in the past 10 years,
An overall growth rate of 5 to 670/year could be anticipated. If a suit-
able substitute could be found, this value would decrease very rapidly.
Wood Preservation
The wood treatment (preservation) industry utilized very small quan-
tities of triaryl phosphate esters each year. It is estimated that less
than 500,000 lb are used annually by this industry. The phosphate esters,
probably very low grade or still bottom type materials, are mixed with
creosote and pentachlorophenol for impregnation of railroad ties, posts,
and other similarily treated lumber products.
103
-------
Coatings (lacquers)
Tricresyl phosphate has been the principal phosphate ester used in
this industry and is used primarily in acrylic lacquer automobile paints
and, more recently, in nitrocellulose lacquers for furniture finishes.
Annual consumption of TCP in this industry has remained almost constant
at approximately 1 million pounds per year for the last 10 years.
Exportation
The exportation of aryl and/or alkyl aryl phosphate esters has not,
within the past 10 years, been a significant factor in their utilization.
During -discussion with persons closely aligned with the phosphate ester
industry, it was a consensus of opinion that less than 5% of the total
production of the phosphate esters being considered in this study were
exported in any 1 year and that a range of 3 to 5% was realistic.
Tricresyl phosphate and cresyl diphenyl phosphate are the principal
phosphate esters exported, with the majority of these esters probably be-
ing sent to Canada, either as hydraulic fluids or to be formulated into
hydraulic fluids. Isopropylphenyl diphenyl phosphate and trixylenyl phos-
phate may be exported in the future. Lesser quantities of tricresyl phos-
phate and cresyl diphenyl phosphate are also shipped to Japan, Mexico,
and Europe.
Dibutyl phenyl phosphate is exported, probably already formulated as
"Skydrol" aircraft hydraulic fluids to most countries having a major air-
line, and future exportation should follow a rate consistant with the pre-
dicted increase in production of dibutyl phenyl phosphate.
104
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REFERENCES TO SECTION VII
1. MRI Project No. 2992-D Final Report, 31 January 1967-
2. "Selection and Use of Hydraulic Fluids," Hydraulics and Pneumatics
Marketing Department, April 1965.
3. "Selection and Use of Hydraulic Fluids," Hydraulics and Pneumatics
Marketing Department, February 1971.
4. Brink, Jr., E. C., "Fire Resistant Hydraulic Fluids," Lubrication,
58:77 (1972).
5. Millett, W. H., "Fire Resistant Hydraulic Fluids," paper presented
at 29th National Conference on Fluid Power, Cleveland, Ohio (1973),
6. Tovey, G. R., "Trends in Hydraulic and Circulating Fluids," pre-
sented at the National Fuels and Lubricants Meeting, New York,
September 1971.
7. Mr. Siefert, Lear Jet Corporation, Wichita, Kansas.
8. Alper, E. A., Senior Technical Officer, International Air Transport
Association, 1155 Mansfield Street, Montreal, PQ, Canada.
9. Modern Plastics Encyclopedia, McGraw-Hill, Inc., New York, p. 418
(1972 to 1973).
10. Modern Plastics, McGraw-Hill, Inc., New York, p. 62, September 1974.
11. Modern Plastics Encyclopedia, McGraw-Hill, Inc., New York, p. 244
(1974 to 1975).
12. Modern Plastics, McGraw-Hill, Inc., New York, p. 59, September 1974.
13. Directory of Chemical Producers, Stanford Research Institute.
14. Modern Plastics, McGraw-Hill, Inc., New York, January issues of each
year.
15. Modern Plastics Encyclopedia, McGraw-Hill, Inc., New York (1973).
16. A. L. Larsen, Shell Oil Company, Houston, Texas.
105
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SECTION VIII
MATERIAL BALANCE AND ENERGY CONSUMPTION
This section will briefly discuss the total quantities of raw ma-
terials and energy required for the manufacture of those phosphate es-
ters for which production quantities were published or estimated by
MRI. The exception to this is _p_-chlorophenyl diphenyl phosphate which
was produced in very small quantities and would have little impact on
the resultant figures* Estimated total energy consumption and waste
material production are also considered. In these calculations, an
overall reaction yield of 88% was assumed, a figure which appears to
be close to the actual production yield for both triaryl and alkyl
aryl .esters. The total production of all phosphate esters in this re-
port was approximately 846.9 million pounds for the time period 1964
to 1973. Triaryl phosphate ester production was 704.6 million pounds
and alkyl aryl esters were 142.3 million pounds.
RAW MATERIALS
The calculated total quantity of each of the raw materials con-
sumed in the manufacture of these esters is shown in Figure 3 for
the years of production from 1964 to 1973. Cresylic acid (cresol),
phenol, and phosphoryl chloride are used in the manufacture of more
than one ester and the total quantities of each of these materials
consumed are shown below for the 10-year span. All other materials
are used only in the production of specific esters and their total
quantities can be obtained by referring to the above list.
ENERGY CONSUMPTION
The total energy consumed, as gas, steam, and electricity, in
the production of these phosphate esters is given below for the years
1964 to 1973.
106
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Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
Cresol
38.20
41.89
47.00
49.45
51.44
47.50
42.58
46,14
42.46
40.92
447.6
Phenol
28.71
31.74
31.32
30.33
29.49
26.79
28.21
33.02
32.12
38.51
310.2
POC13
36.79
40.49
42.60
43.40
43.70
40.44
40.14
44.25
42.13
46.90
420.8
Xylenol
-
-
-
-
-
3.05
2.03
1.02
2.03
8.1
Isopropyl
phenol
-
-
-
-
1.37
2.28
3.65
5.48
8.22
21.0
2- Ethyl
hexanol
3.67
3.67
3.26
3.26
2.04
1.63
1.63
1.22
1.22
2.04
23.6
Isodecyl
alcohol
0.46
0.92
1.84
2.07
2.30
3.22
10.8
1-Butanol
0.94
1.06
1.18
1.41
1.65
1.35
1.47
1.59
1.71
1.82
14.2
Methanol
0.66
0.80
0.80
0.81
0.81
0.83
0.28
0.14
-
_
5.1
A1C13
0.64
0.72
0.76
0.77
0.79
0.72
0.72
0.81
0.76
0.85
7.5
ZnCl2
0.09
0.09
0.09
0.09
0.08
0.09
0.11
0.10
0.11
0.12
1.0
Total
109.7
120.5
127.0
129.5
130.5
121.6
122.3
135.0
129.3
144.6
1,270.0-
Total
a_l Values are in million pounds.
_b/ Total figures may disagree by 0.1 due to rounding.
Figure 3. Raw materials consumed^/
-------
Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
Total
a/
Steanr-
38.3
41.5
44.3
45 . 2
45.5
42,3
42.9
47.4
45.5
51.0
443.9
b/
Gas~
78.3
84.4
89.8
91.7
91.7
85.3
85.9
93.9
90.2
102.1
893.3
c/
Electricity"
26.6
_a/ Values in million pounds.
_b/ Values in million cubic feet.
c/ Values in million kw-hr.
Energy consumption by type for the individual phosphate esters can be
found in Section VI in the discussion of the respective esters.
WASTE MATERIAL PRODUCED
The only waste material or by-product which is usually recovered
from this process is hydrogen chloride. A sludge or residue is found
in the bottom of the still after distillation of the product. This
still bottom consists of some undistilled products spent catalyst in
the form of the phenolate or alcoholate, perhaps some unreacted cata-
lyst., and other ill-defined tarry residues. The residual still bot-
toms are collected and either incinerated by the manufacturer, land-
filled, or removed from the production facility by a contract hauler.
For the specific methods of disposal for individual companies, see the
subsection on Environmental Management in Section V. Small quantities
of waste products resulting from the phenol scrubber, caustic wash,
and condenser are subjected to the waste treatment procedures employed
at the various production facilities. In some instances, phenolic wastes
are neutralized prior to treatment. Details concerning the specific meth-
ods of treatment may be found in the Environmental Management subsection.
The calculated annual quantities (in million pounds) of hydrogen
chloride and still residue (termed sludge) are shown in the following
list.
108
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Year HCl Sludge Total
1964 23.41 13.39
1965 25.81 14.65 40.5
1966
1967
1968
1969
1970
1971
1972
1973
27.12
27.60
27.81
25.81
25.48
28.18
26.74
29.71
15.47
15.83
15.89
15,01
15.06
16.46
15.87
17.81
42.6
43.4
43.7
40.9
40.5
44.6
42.6
47.5
Total 267.67 155.50 423.1
SUMMARY
The data presented thus far with respect to raw materials consumed,
waste materials produced, and the production of aryl and alkyl aryl phoS'
phate esters are summarized as shown.
Raw materials Total product Waste materials
Year (x 106 Ib) (x 10° Ib) (x 106 Ib)
1964 109.7 72.9 36.8
1965 120.5 80.0 40.5
1966 127.0 84.4 42.6
1967 129.5 86.1 43.4
1968 130.5 86.8 43.7
1969 121.6 80.7 40.9
1970 122.3 81.8 40.5
1971 135.0 90,4 44,6
1972 129.3 86.7 42.6
1973 144.6 97.1 47.5
Total 1,270.0 846.9 423.1
EXPOSURE TO MAN AND THE ENVIRONMENT
The aryl and alkyl aryl phosphate esters considered in this study
are generally end products within themselves and do not undergo further
chemical modification prior to their utilization in consumer products.
109
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Their use as plasticizers (modifiers) and hydraulic fluids constitute
the bulk of the annual consumption of these esters.
Of the 846.9 million pounds total production during the 10-year
span from 1964 to 1973, 112.7 million pounds were used as gasoline ad-
ditives for ignition control. This quantity of ester was obviously de-
stroyed during the ignition process in the engine. The remaining 734.2
million pounds were used as plasticizers (406.4), hydraulic fluids
(224.6), lubricant additives (54.2), and miscellaneous (49.0). The fig-
ures in parentheses are in million pounds.
The principal sources of exposure of the phosphate esters to man
and the environment are mainly the waste streams from the manufacturing
process and the final disposal or usage of consumer products. Some air
emissions from manufacturing sites probably do occur but, to our knowl-
edge, no specific data are available on the quantities emitted. Particu-
late triphenyl phosphate is likely present in the air in the vicinity
of the drying and packaging operations within the manufacturing site
but this exposure would be limited to a relatively small number of
people.
Since all of the phosphate esters are insoluble in water and the
liquids are heavier than water? they will settle out in lagoons and
traps for possible recovery. However, due to their insolubility in wa-
ters phosphate esters biodegrade very slowly. When dispersed in water
and biodegradation does occur, the esters exhibit a rather heavy oxygen
demand on the system with typical BOD values in the range of 35,000 ppm
of oxygen.
Degradation products resulting from the hydrolysis of these esters
and impurities present in the finished products are perhaps of greater
concern than the phosphate esters themselves. As shown in Appendix C,
degradation results in the formation of the corresponding alcoholic and/
or phenolic materials and inorganic phosphate. Quantities of free phenolic
materials are also present in the final phosphate ester. These impurities
and degradation products can be extracted into the aqueous phase. The ex-
tent of this extraction is dependent upon the degree of contact with ef-
fluent water and the degree of dilution.
Plasticizers (Modifiers)
The use of phosphate esters as plasticizers (modifiers) and in other
applications directly related to the rubber and plastics industry consumed
approximately 406.4 million pounds during the period 1964 to 1973. Estimated
annual quantities were presented in Section XV»
110
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There are two modes of ultimate destruction of the esters in plastics,
incineration and environmental degradation by hydrolysis. Exposure of the
esters to the environment occurs by migration of the plasticizer to the
surface of the plastic material and then either vaporization into the at-
mosphere or a hydrolytic action occurring on the surface of the plastic.
The diffusivity of plasticizers in plastic food containers has been esti-
mated at 10~H sq cm/sec,— which is comparable with the values for many
bimetal diffusion systems.
21
A study— on the recycling and reuse of plastics has stated that an-
nually about 90% of all household, commercial, and industrial solid wastes
are landfilled; the remaining 10% are incinerated. This study also estimated
the average service life of plastic products. Selected examples are shown
in the following list.
Assumed annual
Estimated service consumption of ,
Product life (years) ester by product"
Packaging < 1 6%
Construction (film) 2 20%
Construction belting (MRI estimate) 2 10%
Apparel 4 4%
Household goods 5 4%
Toys 5 1%
Automotive 10 30%
Furniture 10 10%
Wire and cable 15 15%
a/ MRI data.
The A. D. Little report referenced a study of the lifetime of plastics
buried in a dump for 5 years in which it was found that after 5 years,
heavy plastic parts were intact but thin plastic film had disappeared.
It was also found that, after the 5 years, the molecular weight of PVC
in refuse was two-thirds of the original weight.
For purposes of calculation, the following assumptions are made:
(a) 55% of all phosphate ester plasticized PVC has a service life greater
than 10 years; (b) 45%, of all ester plasticized PVC will have a service
life less than 10 years depending upon specific product; (c) 10%, of all
PVC is incinerated in the year of production; (d) all products are land-
filled immediately after their service life; and (e) all buried PVC film
will completely degrade within 5 years with a linear degradation rate.
Using these assumptions and consumption data, the following quantities
(in million pounds) are calculated.
Ill
-------
Year
Total ester
consumption
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
37.1
39.3
41.9
41.3
40.0
33.4
41.1
49.8
40.7
41.8
Total
406.4
Quantity
incinerated
3.7
3.9
4.2
4.1
4.0
3.3
4.1
5.0
4.1
4.2
40.6
Quantity still in
use after 10 years
18.4
19.5
20.7
20.5
19.8
16.6
20.4
24.6
20.1
20.7
201.3
Quantity to be exposed
to environment
during 10 years
15.0
15.9
17.0
16.
16.
13.
20,
16,
16.6
16.9
164.5
The quantity of phosphate ester incorporated into PVC, which was in-
cinerated, was assumed to be completely destroyed, Plasticizer migration
has occurred in the PVC still in use 10 years after production but the an-
nual quantities exposed to the environment by this method are unknown.
From the previous data and assumptions, the total annual quantity, in mil-
lion pounds, of phosphate ester exposed to the environment from consumer
products with a service life of less than 10 years is estimated in the
following tabulation.
Year
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
Total quantity
of ester
15.0
15.9
17.0
16,
16,
13.
20,
16,
16.6
16.9
Quantity exposed
to environment
0.18
1.27
2.47
3.67
5.16
6.44
6.65
6.99
7.49
112
-------
These calculated values are only the contribution from esters pro-
duced from 1964 to 1973 and would represent a minimum value since the
earlier years (1964 to 1968) would also have contributions from phos-
phate esters incorporated prior to 1964 into consumer products of less
than 10 years service life. The later years would also be increased
from consumer products produced prior to 1964 with a service life of
greater than 10 years. These calculated figures should provide an in-
sight into the order of magnitude of the emissions resulting from poly-
(vinyl chloride) and other polymeric materials.
Hydraulic Fluids and Lubricant Additives
For the purposes of this discussion, these two areas can be com-
bined since their ultimate modes of utilization are very similar. Ap-
proximately 80% of the annual "consumption" of these fluids, especially
hydraulic fluids, occurs due to leakage from the mechanical system and
thus is exposed directly to the environment.
It is assumed that, prior to 1969, the quantity of hydraulic fluid
reprocessed each year was negligible and that from 1969 to 1973, an in-
creasing quantity of the annual production of hydraulic fluid is repro-
cessed. There is no information available which indicates that any of
the lubricants or oils, in which phosphate esters are an additive, are
reprocessed. The quantity of these fluids which is collected and dis-
posed in a landfill is unknown but probably accounts for less than 20%
of the total amount. Thus, like hydraulic fluids, approximately 8070 of
the total annual quantity is discharged into an industrial sewer or in-
troduced, by other means, directly into the environment.
Based on these assumptionss the estimated annual distribution (mil-
lion pounds) of phosphate esters entering the environment from this end
use are shown in the following tabulation.
Estimated total Reprocessed fluid Quantity leaked Quantity disposed
Year quantity _% Quantity into environment in landfill
<1964 15.6 0 0 12.5 3.1
1965 19,5 0 0 15.6 3.9
1966 21.7 0 0 17.4 4.3
1967 23.5 0 0 18.8 4.7
1968 25.3 0 0 20.2 5.1
1969 26.6 5 1.1 20.4 5.1
1970 28.8 5 1.2 22.1 5.5
1971 31.1 10 2.5 22.9 5.7
1972 38.9 10 3.2 28.6 7.1
1973 47.8 15 6.0 33.4 8.4
Total 278.8 14.0 211.9 52.9
113
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The quantity of hydraulic fluid collected, during replacement of
the fluid, is presumably placed in storage drums and disposed in a land-
fill. This method of disposal would delay its direct introduction into
the environment. The length of time that the fluids would remain con-
tained in the landfill before leaking from the containers is unknown and
thus it is not possible to accurately gauge when these fluids would be
introduced into the immediate environment of the landfill.
Emissions to the Media
For the phosphate esters incorporated as plasticizers in poly(vinyl
chloride) and other polymeric material, the major source of entry into
the environment would be in the soil and groundwater within the landfill
area. Unknown quantities of plasticizer will, however, be emitted to the
atmosphere during the service life of the polymer due to migration of the
plasticizer to the polymer surface. Without specific diffusion data, it
would be very difficult to estimate the quantity lost in this manner.
With hydraulic fluids and lubricant additives, an estimated 207o of
the annual consumption is collected, stored, and disposed in a landfill.
As with the plasticizers, the primary affected areas would be the soil
and groundwater of the landfill area. For uncovered landfills, rupture
of the containers would permit emissions to the atmosphere. However,
since all of the phosphate esters used as hydraulic fluids and/or lubri-
cant additives are liquids with rather high boiling points and low vapor
pressures at ambient temperatures, emissions to the atmosphere by vapor-
ization would probably be small.
The greatest factor in the "consumption" of hydraulic fluids and lu-
bricant additives is leakage from the mechanical system. For industrial
systems, the quantities lost from the mechanical system would likely be
fairly well contained within the industrial plant and discharged into
the sewer system. Emissions to the atmosphere of the industrial plant
would also be more likely in these situations since, for hydraulic flu-
ids, their main use is near sources of high temperature. Therefore any
leakage would occur in an area considerably above ambient temperatures
resulting in an increase in the vapor pressure and consequently greater
vaporization into the plant atmosphere.
114
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While the use of hydraulic fluids and phosphate ester containing
lubricants in industrial plants comprises a very large percentage of
the total consumption of these fluids (probably 85 to 90% based on use
areas), other uses of hydraulic fluids and lubricants, containing phos-
phate esters as additives, can result in emissions to the soil and
groundwater. Leakages from transmissions of tractors and trucks, air-
craft hydraulic systems, military uses, and others, are examples of
discharges to nonlocalized areas. As stated above, it is estimated that
10 to 15% of all phosphate ester hydraulic fluids and lubricants are
discharged to the environment in nonlocalized areas and 85 to 90% are
from localized areas, such as industrial plants. These estimates are
based on the various applications of these fluids discussed earlier in
Section VII.
Residence in the Environment
Triaryl and alkyl aryl phosphate esters probably degrade very
slowly under environmental conditions. These esters are relatively in-
soluble in water (0.002 weight percent at 23"C) so that hydrolytic
degradation is limited by the solubility of these materials in water.
No reliable hydrolysis rate data could be found for these specific
phosphate esters. However data was found— for tris (£-nitrophenyl)
phosphate. Using the second order rate data for the hydrolysis of
this compound and an assumed initial concentration of 10 ppm, a hy-
drolysis half-life was calculated to be approximately 1 year. Since
nitro groups are known to be electron withdrawing groups, a weaken-
ing of the carbon-oxygen-phosphorus bonding would be expected. This
should lead to a more rapid hydrolysis rate than might be expected
for the phosphate esters included in this study. Based on the data
for the _£-nitrophenyl compound, a hydrolytic half-life of approxi-
mately 2 years might be more reasonable for the compounds in this
study. This value would be only for hydrolytic action and does not
consider any biological, photolytic, or other possible factors that
would influence the rate of hydrolysis.
Impurities
Triaryl and alkyl aryl phosphate esters contain quantities of
unreacted alcoholic and phenolic starting materials which may be of
greater concern than the esters. Two of the major manufacturers have
stated that phenolic impurities are present in the finished products
at concentrations up to 3,500 ppm. Plasticrzer grade phosphate esters
undergo more purification than does the lubricant grade of the same
ester so that the level of phenolic materials in the plasticizer grade
is approximately one-third of that found in the lubricant grade. For
plasticizer grades, phenolic impurity levels can range up to about
1,000 ppm while for lubricant grade, the level can be up to 3,500 pprn.
115
-------
If an average phenolic impurity level of 500 ppm is assumed for the
plasticizer grade, then approximately 430 Ib of unreacted phenolic and/or
alcoholic impurities are present per 1 million pounds of plasticizer. For
an annual plasticizer production of 50 million pounds, 21,500 Ib of impurity
would be present. Lubricant grade esters have approximately four times the
impurity level as does the plasticizer grade* Based on an assumed level of
2,000 ppm, about 1,720 Ib would be present per 1 million pounds of lubri-
cant grade ester. For an annual production of 50 million pounds, 86,000 Ib
of impurities would be present. The two grades combined yield about 108,000
Ib per 100 million pounds of ester or an approximate concentration of 0.17o«
As hydraulic fluids and lubricants are used, the acid content (phenolic
content) of the fluids increases rapidly so that at the time of replacement,
the phenolic impurity content is considerably higher than for the fresh
fluid. If the impurity content increased by a factor of 10 during its use,
then for an annual consumption of 50 million pounds per year, the total phe-
nolic and/or alcoholic impurity level would be approximately 860,000 Ib,
Summary
Of the phosphate esters considered in this study, the tri (_o-cresyl)
phosphate has the greatest toxicity. However, due to its low concentration
in the final product and its low solubility in water, it is very unlikely
that sufficient quantities of this material could be consumed in natural
food to pose a general health hazard. Isolated incidences of ingestion of
tri (jD-cresyl) phosphate have occurred.— In spite of their widespread in-
dustrial use, there have been few reports of symptoms in workers handling
these esters,—'
The contribution of phosphate to the environment from these materials
is very smalls in comparison to phosphates from such high volume materials
as fertilizers and detergents. Being ubiquitous, phosphates derived from
this source should not pose any hazard to the environment or to man.
The alcoholic and/or phenolic impurities, on the other hand, may pose
a concern. Such chemicals are often responsible for taste and odor problems
in drinking water. Threshold limits for detection of.odors in aqueous solu-
tions are 25 ppm for phenol and 2.5 ppb for cresol.— These threshold limits
in food and water are sufficiently low that there would be little likelihood
of sufficient quantities of contaminated food and drink being consumed to
create a widespread health problem. There is no specific evidence of human
cancer attributable to phenols or substituted phenols; however, some car-
cinogenicity to mice has been observed.
116
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REFERENCES TO SECTION VIII
1. Piver, W. T., Environmental Health Perspectives, 4_:61, June 1973.
2. Arthur D. Little, Inc., "Incentives for Recycling and Reuse of
Plastics," Environmental Protection Agency, 1972, NTIS PB-214045.
3. Ketelaar, J. A. A., H. R. Gersmann, and F. Hartog, Rec. Trav. Chim.,
7JJ1253 (1952).
4. Patty, F. A., ed., "Industrial Hygiene and Toxicology," Vol. II, John
Wiley and Sons, New York, 1963, p. 1363, 1922.
117
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SECTION IX
USE ALTERNATIVES
In this section, possible alternate methods of production and alter-
nate end use materials are discussed. Topics include alternate raw mate-
rials and production processes3 as well as alternate materials for the
current end uses of the phosphate esters.
ALTERNATIVE RAW MATERIALS
Very little work has been reported recently regarding new synthetic
methods for the production of aryl or alkyl aryl phosphate esters which
could utilize present production facilities. The apparent attitude is
that the present process uses inexpensive raw materials; is a reasonably
uncomplicated single-step reaction; and the reaction gives good overall
yields,,
ALTERNATIVE MANUFACTURING PROCESSES
In general, the present attitude towards new processes for these
phosphate esters is approximately the same as discussed above regarding
new raw materials. Two newer methods for the preparation of specific
phosphate esters are shown in Eqs. IX-ll/ and IX-2..2/
Vx^'N
\Cy)~0TPO + CH2 = CHCH3 ~^^-> isopropylphenyl derivatives (.IX-I)
•/•*
0 s, v X 0
•PN3 + CH3(CH2)2CH2OH2 > ( (r^)yo7-plo(CH2)3CH3 + HN3 (IX-2)
Vs ' Si
118
-------
For the reaction in Eq. IX-1, the catalyst was Al2C>3, Al(00)3,
Zr(00)4, or m-(HC>3S)2C6H4. No indication was given with regard to reac-
tion conditions, overall yield, or product distribution. The reaction of
the 0,0-diphenylphosphoryl azide with 1-butanol (Eq. IX-2) provides es-
sentially a quantitive conversion to butyl diphenyl phosphate by simply
refluxing the azide in a large excess of butanol for 6 hr. At the end of
the reflux period, the butanol is evaporated under vacuum and the product
extracted from the residue with ether. The azide is quite stable and can
be distilled at 157"C at 0.17 mm without decomposition. While butyl di-
phenyl phosphate is not used to any significant extent commercially and
was not included in this report, it is entirely possible that similar re-
sults could be obtained with other alcohols. To our knowledge, neither of
the above reactions is currently practiced on an industrial scale. For
Reaction IX-2, it is doubtful that the azide starting material is avail-
able in commercial quantities.
ALTERNATE FINAL USE PRODUCTS
In several use areas of aryl and alkyl aryl phosphate esters, other
commercial products are available which could be used as alternates for
these esters. Areas in which other products are not readily available
would be as air filter media, lubricant additives, coating applications,
and to a certain extent in aircraft hydraulic fluids.
For fire resistant hydraulic fluids, water-glycol and emulsion
fluids could be used an an alternative in certain applications. The con-
version from one fluid to another, however, is far from just draining one
fluid and filling with another. Many factors must be considered in the
selection of the proper hydraulic fluid. These factors include resistance
to ignition and combustion, stability in service and storage, pump dynam-
ics, chemical compatibility, bulk and vapor phase corrosion, physical prop-
erties, and cost.—'
In 1973, phosphate ester synthetic fluids were priced from about
$3.50/gal and up; the phosphate ester based fluids were in the range of
$2 to $3/gal. At the same time, water-glycol systems were priced at about
50% that of the phosphate ester fluids ($1.50 to $2.50/gal.). According
to a recent article,—' a nonflammable hydraulic fluid priced at $0.30 to
$0.50/gal. has been developed. This new fluid reportedly is compatible
with standard seals and hoses, nontoxic, noncorrosive and has excellent
stability. In certain instances, silicone oils may be possible alterna-
tives to phosphate ester synthetic fluids. These oils are more expensive
than the synthetic fluids ($6 to $8/gal.) and there is some question as
to their fire resistance.
119
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Each of the commonly used fire resistant hydraulic fluids require
specialized disposal techniques. Emulsion type fluids must be separated
by acid or certain salts into the oil and water layers. The oil layer is
handled like-petroleum oil and the water layer neutralized, followed by
specific treatment dependent upon the contents. Water-glycol systems are
completely water soluble and should be oxidized or degraded prior to dis-
charge into a stream since they often have BOD values ranging from 50,000
to 500,000 ppm. Phosphate ester synthetic fluids are insoluble in water
and heavier than water. As such, they can be settled out in lagoons or
traps and reprocessed but due to the phenolic constituents present in
the molecule, contact time with water should be held to a minimum to re-
tard hydrolysis.
There are numerous commercially available fire retardant plasticiz-
ers which could be substituted for the phosphate esters. Tris(chloroalkyl)
phosphate esters ($0.70 to $0.80/lb), such as the beta-chloroethyl and
dichloropropyl esters, generally are compatible with about the same poly-
mer resins as are the triaryl and alkyl aryl esters. The use of chlorinated
paraffins (approximately $0.13/lb) with antimony oxide ($0.87 to $1.00/lb)
could also be substituted for many of the present uses of phosphate esters.
The corresponding brominated alkyl compounds (about $1.00/lb) and paraffins
are also compatible with may of the plastic resins now employing triaryl
and ..alkyl aryl phosphate esters. Zinc borates, at $0.42/lb, can be substi-
tuted in specific instances for antimony oxide. Monsanto has developed a
solid phosphorus-halogen compound, Phosgard LSV, at $0.50/lb, which could
replace phosphate esters in certain applications. Although many substitutes
can be suggested, there are some problems to be considered. One of the ma-
jor considerations must be cost of the plasticizer. Many of these suggested
alternatives are more expensive than the phosphate esters and thus will
increase the cost of the final consumer product. In addition, many of these
possible substitutes may not provide the same degree of fire retardancy as
the phosphate esters. To treat the subject of plasticizer substitutes in
the most plausible manner, each specific use area should be considered with
regard to economics, actual fire retardancy requirements, temperature flex-
ibility, desired final properties of the plastic and other significant cri-
teria. The specific criteria for each individual use varies considerably
and in this manner, certain tradeoffs could be made within the use area
and the best alternatives selected. A study of this nature is beyond the
scope and intent of this report, however, the brief listing presented ear-
lier could be used as a general guideline regarding the various types of
materials which may serve as possible alternatives.
120
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REFERENCES TO SECTION IX
1. Leston, G. (Koppers Company, Inc.), Ger. Offen. 2,254,399, 17 May
1974; U.S. Patent Appl. 196,728; _CA, 7^, p. 42146p (1973).
2. Cremylyn, R. J. W., Aust. J. Chem., 26_: 1,591 (1973).
3. Foitl, R. J., and W. J. Kucera, Iron and Steel Engineer, July 1964,
p. 117.
4. Anonymous, Coal Age, May 1973, p. 68.
121
-------
APPENDIX A
RESULTS OF THE WRITTEN QUESTIONNAIRE
123
-------
SURVEY OF INDUSTRIAL PROCESSING DATA
Midwest Research Institute is presently conducting a program for
the Office of Toxic Substances of the U.S. Environmental Protection Agency
under Contract No. 68-01-2687. The primary purpose of this program is to
assimilate information relative to the production/formation, use and release
into the environment of aryl phosphates.
The following aryl phosphates have been identified as being pert-
inent to this study;
tricresyl phosphate (TCP) dibutylphenyl phosphate
triphenyl phosphate (TPP) diphenyloctyl phosphate
cresyldiphenyl phosphate tri-isopropylphenyl phosphate
2-ethylhexyldiphenyl phosphate isodecyldiphenyl phosphate
mono-o-xenyldiphenyl phosphate p_-chlorophenyldiphenyl phosphate
The MRI study is based on available information in the literature
and private communications with industry personnel, via telephone, letters,
and questionnaire. In order to attain a statistically reliable overview of
the industrial situation on the subject, it is important that we contact as
many industries as possible. We, therefore, respectively solicit your
cooperation in completing this questionnaire; your early response (within
4 weeks) will be sincerely appreciated.
If your department cannot supply the requested information, please
forward to other departments which can respond to this questionnaire. If
any questions should arise concerning this questionnaire, please contact
Dr. Thomas Lapp at (816) 561-0202.
Please return the completed questionnaire to:
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
Attn: Thomas W. Lapp
Thank you very much for your assistance and cooperation.
124
-------
QUESTIONNAIRE PREPARED FOR OFFICE OF TOXIC SUBSTANCES
U.S. ENVIRONMENTAL PROTECTION AGENCY
(Please fill in the details and check the appropriate blanks.)
1. Parent Corporation Name;
Mailing Address:
2. Person to contact regarding information supplied in questionnaire.
Dr /Mr /Ms:
Address:
Telephone:
3. If your company manufactures, or has manufactured within the past _10
years, any of the chemicals listed in the cover letter please com-
plete the following form:
Listed
Chemical Production Site: City or Town and State
a.
b. . .
C. :
d.
125
-------
3. Concluded,
Listed
Chemical Production_Sj.t^__Cj1tXJgJLJ'own anci State
f.
i.
j.
£v e
4. For the product(s) listed in Item 3, please state the year span
during which they were manufactured and the type(s) or grade(s)
produced.
From To Type(_s) or Grade (s)
b.
c.
126
-------
5. Does your company export or import any of the phosphate esters'
Import: yes no Export: yes_ no_____
6. If your company produces or has produced tricresyl phosphate (TCP),
what is(was) the maximum limit of the ortho-isomer in the finished
product?
ortho-isomer 7=
7. What type(s) of container(s) is(are) utilized for the transportation
of the finished product to the customer?
(a). Has any chemical analysis ever been made on any of your products,
by-products* or process waste material to determine the presence of
Phenols HCl
yes no_ yes no
(b) . If the above answer is "no", then based upon your experience, do
you think that any phenols or HCl may be contained in any of your
products, by-products* or process waste material?
Phenols HCl
yes no yes no__
9. Where would the phenols and/or HCl occur?
In finished product(s)? yes no_
In by-products? yes_____ no.
In process waste materials? yes no_
* By-products are also referred to as co-products,
127
-------
10. Has any chemical analysis ever been made on any of your by-products
or waste material to determine the presence of the phosphate ester
produced during the reaction process?
In by-products? yes______ no_
In process waste material? yes no
11. For each "yes" answer to any category in Questions 9 and 10, please
identify compound(s) by name(s) and form(s) (i.e., solid, liquid or
gas). Also, please indicate the plant location(s) for each.*
Compound(s) Form(s) Plant Location(s)
* If additional space is required, please use the back of this sheet.
12. For each item listed in Question 11, please indicate the approximate
concentration level of each compound(s) and where the material appears
(i.e., finished product, by-product, or process waste material). If
any compound appears in two or more instances, please distinguish
between the entries.
Compound(s) Concentration Level Where Material Occurs
128
-------
12. Concluded.
Compound(s) Concentration Level Where Material Occurs
13. To the extent possible, within the constraints of proprietary considera^
tions, for each product identified in Item 3, please describe briefly
the production process used and the approximate annual production.
Process Description (e.g.. Approximate
major reactions carried out Annual Production
Product or U.S. Patent Number) (tons)
129
-------
14. What waste disposal techniques do you use?
Please describe techniques briefly and also comment on their effective-
ness in preventing the release into the environment (e.g., landfill,
waste pond, deep-well injection, incineration). If incineration is
used, please indicate operating conditions such as temperature, reten-
tion time, gas scrubbing procedure, etc.
15. To the extent possible within the constraints of proprietary considera-
tions, please indicate in as much detail as possible, the end uses of
the aryl phosphates manufactured by your company.
16, To your knowledge,, in what industry or industries would aryl phosphates
occur as a manufacturing process by-product or process waste material?
Any assistance you can provide in this area would be sincerely appre-
ciated.
130
-------
A discussion and summary of the replies to this written inquiry
is presented in the following paragraphs.
1. Eastman Kodak Company: Eastman Kodak produces only triphenyl
phosphate. The product is present as a major constituent (61%) in still bot-
toms (sludge) and in trace quantities in the process wash water. Phenol is
present as an impurity in the finished product (0.03% maximum), in the re-
covered hydrogen chloride (0,002% maximum), and in the process wash water
(0.63%) as well as in the sludge (0.14%). Hydrogen chloride is recovered as
35% hydrochloric acid. The liquid process wastes receive primary and second-
ary treatment prior to discharge into the environment. Solid wasta (sludge)
is incinerated at 1200°F in a 'three-chambered incinerator and the flue gases
cleaned with a water impingement scrubber.
2- FMC Co_rp_qrajtion; FMC produces tricresyl phosphate, cresyl
diphenyl phosphate, dibutyl phenyl phosphate, and isopropylphenyl diphenyl
phosphate. They produced methyl diphenyl phosphate during the period of its
use in gasoline. FMC reported a 1% maximum (< 0.5% typical) concentration of
ortho isomer in tricresyl phosphate. Phenolic materials occur as impurities
in the finished products (300 to 1,500 pprn), recovered hydrogen chloride (1
to 200 pprn), and in process waste materials. Hydrogen chloride is recovered
as 327o hydrochloric acid and is also present in process waste materials. Waste
disposal treatment consists of absorption, neutralization, separation, and
biological oxidation.
3 » Monsanto Industrial Chemicals Company: Monsanto manufactures
octyl diphenyl phosphate, dibutyl phenyl phosphate, and isodecyl diphenyl
phosphate. They stated that tricresyl phosphate, cresyl diphenyl phosphate,
and triphenyl phosphate production ceased in 1970. Methyl diphenyl phosphate
was manufactured during its use as a gasoline additive. Small quantities of
_p_-chlorophenyl diphenyl phosphate were produced for 2 years. Monsanto pro-
vided no information regarding quantities of waste products.
4. Sobin Chemicals^ InCoS Sobin produces tricresyl phosphate and
cresyl diphenyl phosphate. They report their tricresyl phosphate contains
less than 1%, ortho isomer. Phenolic materials occur in the process wastewater
(•-'0.02%,) but not in the still bottoms. Hydrogen chloride is recovered as 20
Be hydrochloric acid and is sold. Solid residues (still bottom or sludge) is
removed by a contract hauler. Aqueous waste material is diluted and discharged
into the sewer system,
5. Stauffer Chemical Company: This company manufactures tricresyl
phosphate, triphenyl phosphate, cresyl diphenyl phosphate,, and isopropyl-
phenyl diphenyl phosphate. They stated that at one time, die ortho content
of tricresyl phosphate was as high as 15 to 18%, but is now reduced to less
than 1% in all grades. Hydrogen chloride is recovered as 35% hydrochloric
acid and sold. Free phenolic materials are present in both the plasticizer
grade products (up to 1,000 ppm) and the lubricant grade products (up to
131
-------
3,500 ppm) as well as in the effluent to the treatment system (10 to 50
ppm). Waste disposal treatment consists of degradation, carbon treatment,
and landfill.
Chevron Chemical Company and Dow Chemical both stated that they
did not manufacture any of the phosphate esters contained in this study.
All of the companies contacted by letter responded to our inquiries.
132
-------
APPENDIX B
AIRLINE FLEET SIZES
133
-------
The fleet sizes for the U.S. airlines listed below are given in
Table B-l for the 6 years in which data were available. All information
regarding the number of aircraft was obtained from the Air Transport As-
sociation of America, Washington, D.C. The hydraulic system capacities
for the various aircraft were supplied by Mr. George Moore, Engineer,
Trans World Airlines, Kansas City, Missouri. Member airlines of the ATA
are as follows:
Alaska Airlines
Allegheny Airlines
Aloha Airlines
American Airlines
Braniff International Airways
Continental Airlines
Delta Airlines
Eastern Airlines
The Flying Tiger Line
Frontier Airlines
Hawaiian Airlines
Hughes Airwest
National Airlines
North Central Airlines
Northwest Orient Airlines
Ozark Airlines
Pan American World Airways
Piedmont Airlines
Southern Airways
Texas International Airlines
Trans World Airlines
United Airlines
Western Air Lines
¥ien Air Alaska
Air Canada (associate)
Canadian Pacific Air (associate)
Fleet sizes for foreign airlines were obtained from the Interna-
tional Air Transport Association, Montreal, Canada (Table B-2). A list-
ing of the specific airlines included in this data would be very lengthy
but the data accounts for all of the major non-U.S. airlines plus many
smaller airlines. Soviet-bloc countries, such as Yugoslavia and
Czechoslovakia, are included if they utilized U.S. or European-built air-
craft. No Soviet Union aircraft are included in this data.
134
-------
Table B-l. U.S. AIRLINE FLEET SIZE
_ — . _ _ _
Ty_p_e
B-707
B-720
B-727
B-737
B-747
DC-8
DC-9
DC-10
L-1011
Convair 880
Convair 990
BAG 1-11
Convair 580/660
Fairchi.ld F-27
Fairchild F-227
L-188
L-100
Caravelle
Viscount
YS-11
Constellation
Super Constel.
Martin 404
Convair 240
Convair 340/440
DC-3
DC-4
DC-6
DC-7
CL-44
Others
Total
Capacity3-'
35
35
35
35
176
35
20
20
136
25
25
20
18
15
15
25
25
20
20
15
20
25
10
10
13
10
10
15
20
25
17
1974
No.
311
23
732
146
119
225
389
105
70
--
__
32
113
14
33
15
--
--
__
21
--
--
12
__
__
--
__
__
--
__
12
Total^7
32,655
2,415
76,860
15,330
62,832
23,625
23,340
6,300
28,560
__
_.
1,920
6,102
630
1,485
1,125
--
--
__
945
_ =
„„
360
__
--
-_
__
--
--
--
612
285,096
1973
No.
315
44
710
134
109
207
335
86
48
37
__
43
129
24
31
19
1
__
_„
23
--
_«
14
__
6
--
__
3
__,
__
42
Total
33,075
4,620
74,550
14,070
57,552
21,735
20,100
5,160
19,584
2,775
__
2,580
6,066
1,080
1,395
1,425
75
__
__
1,035
__
__
420
„_
234
--
__
135
„„
__
2,142
270,708
1972
No.
337
56
662
134
106
227
329
59
17
41
__
58
135
29
32
19
3
_„
__
32
--
__
17
1
7
2
--
3
._
__
51
Total
35,385
5,880
69,510
14,070
55,968
23,835
19,740
3,540
6,936
3,075
__
3S480
4,290
1,305
1,440
1,425
225
_ =
__
990
--
--
510
30
273
60
_„
135
_„
__
2,601
257,703
a_/ Approximate capacity of hydraulic system in gallons.
b_/ Total quantity of hydraulic fluid used; capacity x number of aircraft x 3,
135
-------
Table B-l. (Concluded)
Type
B-707
B-72G
B-727
B-737
B-747
DC-8
DC-9
DC-10
L-1011
Convair 880
Convair 990
BAG 1-11
Convair 580/660
Fairchild F-27
Fairchild F-227
L-188
L-100
Caravelle
Viscount
YS-11
Constellation
Super Constel.
Martin 404
Convair 240
Convair 340/440
DC-3
DC -4
DC-6
DC-7
CL-44
Others
Total
a/
Capacity—
35
35
35
35
176
35
20
20
136
25
25
20
18
15
15
25
25
20
20
15
20
25
10
10
13
10
10
15
20
25
17
1968
No.
380
134
516
66
__
217
260
__
__
41
6
60
148
47
55
86
9
20
19
9
__
__
46
3
46
14
__
7
15
14
79
Total^7
39,900
14,070
54,180
6,930
__
22,785
15,600
„_
„_
3,075
450
3,600
7,992
2,115
2,475
6,450
675
1,200
1,140
405
„„
--
1,380
90
1,794
420
„_
315
900
1,050
4,029
193,020
1966
No.
212
126
223
__
__
135
25
_«,
_«
47
17
38
45
60
__
116
__
20
55
_„
21
62
77
44
138
137
4
179
54
18
115
Total
22,260
13,230
23,415
--
__
14,175
1,500
__
__
3,525
1,275
2,280
2,430
2,700
__
8,700
__
1,200
3,300
__
1,260
4,650
2S310
1,320
5,382
4,110
120
8,055
3,240
1,350
5,865
137,652
1963
No.
133
104
--
__
__
104
__
„_
__
46
19
__
__
50
--
117
„_
20
60
„_
40
111
75
49
153
197
14
217
164
21
118
Total
13,965
10,920
._
--
_„
10,920
__
__
_„
3,450
1,425
__
__
2,250
--
8,775
__
1,200
3,600
__
25400
8,325
2,250
1,470
5,967
5,910
420
9,765
9,840
1,575
6,018
110,445
a_/ Approximate capacity of hydraulic system in gallons
b/ Total quantity of hydraulic fluid used; capacity x number of aircraft x 3
136
-------
Table B-2. FOREIGN AIRLINE FLEET SIZE
Type
B-707
B-720
B-727
B-737
B-747
DC-8
DC-9
DC-10
L-1011
Convair 990
BAG 1-11
Convair 580/660
Fairchild F-27
F-28
L-188
Vanguard
Caravelle
Viscount
YS-11
VC-10
HS-748
DHC-6
Convair 340/440
DC-3
DC-4
DC-6
Trident
Total
i
Capacity—
35
35
35
35
176
35
20
20
136
25
20
18
15
20
25
15
20
20
15
35
15
10
13
10
10
15
20
No.
244
48
209
138
122
163
261
78
6
--
55
4
155
28
16
--
121
30
21
24
71
22
14
57
25
13
69
1974
Total.1!/
25,620
5,040
21,945
14,490
64,416
17,115
15,660
4,680
2,448
__
3,300
216
6,975
1,680
1,200
--
7,260
1,800
945
2,520
3,195
660
546
1,710
750
585
4.140
208,896
1973
No .
230
39
184
104
94
172
236
29
--
6
56
4
135
25
15
--
131
44
20
34
65
12
25
88
20
25
74
Tot,-)]
24,150
4,095
19,320
10,920
49,632
18,060
14,160
1,740
—
450
3,360
216
6,075
1,500
1,125
—
7,860
2,640
900
3,570
2,925
360
975
2,640
600
1,125
4,440
182,838
1972
No.
230
26
125
89
75
179
210
1
— -
7
50
4
135
10
16
17
159
57
24
36
67
11
43
127
36
43
70
Tota ]
24, 150
2,730
13,125
9,345
39,600
18,795
12,600
60
*- «
525
3,000
216
6,075
600
1,200
765
9,540
3,^.20
1.080
3,780
3,015
330
1,677
3,810
1,080
1,935
4,200
166,653
aj Approximate capacity of hydraulic system in gallons.
b/ Total quantity of hydraulic fluid used; capacity x number of aircraft x 3
137
-------
APPENDIX C
MODE OF DEGRADATION OF PHOSPHATE ESTERS
138
-------
The chemical degradation of organophosphorus compounds, in general,
proceeds primarily by the process of hydrolysis although oxidation or f
isomerization of sulfur-containing phosphorus compounds may also occurs'
Sulfur analogs of organophosphate esters, used primarily as insecticides,
have a much more rapid hydrolysis rate than the relatively nontoxic normal
phosphate esters.
Hydrolysis of phosphate esters occurs at a relatively slow rate, as
stated above in comparison to the sulfur analogs, and varies in mechanism
and position of bond cleavage from one class of esters to another. The most
reactive of the ortho-phosphate esters are the tri-substituted esters. Hy-
drolysis occurs by bond cleavage predominately between the phosphorus and
oxygen atoms in basic solution via an overall second-order reaction. At
low pH, however, the H20 attacks the ester grouping resulting in cleavage
of the carbon to oxygen bond in a pseudo-first-order reaction. Two mech-
anisms have been postulated for the hydrolysis of trisubstituted esters.
They are:
(1) A nucleophilic attack similar to SN2 reactions
OH" +
0
HO" P OR
/\
OR OR
(RO) P02 + ROH
(2) An addition reaction followed by elimination
0"
(RO)OPO + OH"
RO-P
OH
OR
OR
ROH
Most evidence supports mechanism (1); however, the two mechanisms are
essentially indistinguishable if the addition and elimination process,,
mechanism (2), are extremely rapid.
No hydrolysis rates were given for aryl or alkyl aryl phosphate est-
ers. Hydrolysis rates were given only for low molecular weight crialkyl
esters, such as trimethyl, triethyl, etc.
T/ Griffith, E. jT, A. Beeton, J. M. Spencer, and D. T. Mitch,
Phosphorus Handbook, pp. 241 and 255, Jo.ha \.
and Sons (1973).
139
-------
BIBLIOGRAPHIC DATA
SHEET
1. Report No.
EPA 560/6-76-008
3. Recipient's Accession No.
4. Title and Subtitle
The Manufacture and Use of Selected Aryl
and Alkyl Aryl Phosphate Esters
5. Rep.ort Date
iruary, 1976
6.
7. Author(s)
T. W.
Lapp
8. Performing Organization Rept.
No.
9. Perfprming Organization Name and Address
Midwest ^Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
0. Prpiect/Task/Work Unit No.
11. Contract/Grant No.
12. Sponsqr-ing Organization Name and Address
Environmental Protection Agency
Office of Toxic Substances
401 M Street, S.W.
Washington, D. C. 20460
13. Type of Report & Period
Covered
14.
15, Supplementary Notes
16. Abstracts
Eleven aryl and alkyl aryl phosphate esters were selected for investigation as
potential environmental contaminants. Information was collected on the production
quantities, manufacturers and their processes, users and their processes, and
the environmental management of both the producers and users. Alternatives for
selected organophosphate esters are considered.
17. Key Words and Document Analysis. 17a. Descriptors
Tricresyl phosphate
Cresyl diphenyl phosphate
Triphenyl phosphate
Dibutyl phenyl phosphate
Isopropylphenyl diphenyl phosphate
Octyl diphenyl phosphate
17b. Identifiers/Open-Ended Terms
Organic Chemistry
Production & Use
Exposure
Substitucas
Methyl dipshenyl phosphate
Isodecyl diphenyl. phosphate
Dimethyl xylyl phosphate
Xenyl diphenyl phosphate
p-Chlorophenyl diphenyl phosphate
18. Availabilir "-tment
19. Security Class (This
Report)
UNCLASSIFIED
20. Security Class (This
Page
UNCLASSIFIED
FORM NTI&-3B |