Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Parts 704 and 799

[OPPTS-42038A; FRL 3883-41

RIN: 2070-AbO7

Aryl Phosphate Base Stocks;

Proposed Test Rule Including

Reporting and Recordkeeplng

Requirements

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Proposed rule.

SUMMARY: EPA proposes that

manufacturers, importers and

processors of chemical substances in the

category of aryl phosphate base stocks

be required, under section 4 of the Toxic

Substances Control Act (TSCA), to

conduct testing. For this Proposed Rule,

aryl phosphate base stocks are

phosphate esters or combination of

esters resulting from the reaction of a

phenol, mixtures of phenols, or a

combination of alkyl-substituted

phenols or, in some cases, phenols plus

an alcohol, with phosphorus oxychloride

(POCl3) or other phosphoric acid

derivatives. This definition includes

triaryl and mixed aryl/alkyl esters

(where one or two of the three ester

groups are alkyl). Base stocks are

initially manufactured aryl phosphates

from which other aryl phosphate

products are produced, and are often

commercially available. The proposed

testing includes chemical analysis and,

at certain production volumes, chemical

fate and health and environmental

effects. This is a category rule to which

every substance fitting the above

definition would be subject. EPA is also

proposing, under TSCA section 8(a), that

manufacturers and importers of aryl

phosphate base stocks be required to

report to EPA the volume of substances

manufactured and imported, in

accordance with 40 CFR part 704, to

allow EPA to determine when certain

tests are to be performed. This rule is

being proposed under the authority of

TSCA sections 4(a)(1)(A) and (B), 8(a),

and 26(c)(2). This rule requires that

testing be conducted to develop data

with respect to health and

environmental effects for which there is

an insufficiency of data and experience

and which are relevant to a

determination that the manufacture,

distribution in commerce, processing,

use, or disposal of such substances or

mixture, or that any combination of such

activities, does or does not present an

unreasonable risk of injury to health or

the environment.

DATES: Submit written comments on or

before April 16, 1992. If persons request

an opportunity to submit oral comments

by April 1, 1992, EPA will hold a public

meeting on this proposed rule in

Washington, DC. For information on

arranging to speak at the meeting, see

Unit VII of this preamble.

ADDRESSES: Submit written comments,

identified by the document control

number OPPTS-42038A, in triplicate, to:

TSCA Public Docket Office (TS-793),

rm. NE-G004, Office of Pollution

Prevention and Toxics, Environmental

Protection Agency, 401 M St., SW.,

Washington, DC 20460. A public version

of the administrative record supporting

this action (with confidential business

information deleted) is available for

inspection at the above address from 8

a.m. to 12 noon, and 1 p.m. to 4 p.m.

Monday through Friday except legal

holidays.

FOR FURTHER INFORMATION CONTACT:

David Kling, Acting Director,

Environmental Assistance Division (TS--

799), Office of Pollution Prevention and

Toxics, Environmental Protection

Agency, rm. E-543B, 401 M St., SW.,

Washington, DC 20460, (202) 554-1404,

TDD (202) 554-0551.

SUPPLEMENTARY INFORMATION: Under

section 4(a) of TSCA, EPA shall, by rule,

require testing of a chemical substance

or mixture (substance) to develop health

or environmental data if the

Administrator makes certain findings

described in TSCA under section

4(a)(1)(A) or (B). Detailed discussion of

the TSCA section 4 findings are

provided in EPA's first and second

proposed test rules, which were

published in the Federal Registers of

July 18, 1980 (45 FR 48524) and June 5,

1981 (46 FR 30300). The aryl phosphate

category proposed for chemical

analysis, chemical fate, environmental

effects and health effects testing

includes any chemical fitting the

category definition in this proposal that

is listed now or in the future in public or

confidential portions of the TSCA

section 8(b) Inventory of Chemical

Substances.

EPA is also proposing, under TSCA

section 8(a), that manufacturers and

importers of these substances report

annual production and/or importation

volumes. This information will be used

by EPA to trigger testing at levels

predetermined by EPA.

The aryl phosphates are a

complicated category of chemicals that

present unique factors to consider in

developing an appropriate test rule. EPA

expects to seriously weigh all

alternative approaches and may

promulgate a test rule that is

substantially different from today's

proposal.

I. Introduction

This rule requires manufacturers of

aryl phosphate base stocks to analyze

them chemically and test them for

chemical fate, environmental and health

effects. The testing requirements are

divided into two stages. Stage one is to

determine the chemical identity of the

base stocks being produced during the

period this rule is in effect. Stage one

testing requires chemical analysis of

base stocks by gas chromatography/

mass spectrometry (GC/MS). All

manufacturers of aryl phosphate base

stocks must perform stage one testing on

each base stock they manufacture and

report the results to EPA. Since these

analytical data may be unique to each

manufacturer's product they can not be

jointly developed. EPA will use these

data to determine equivalency of test

substances for stage two testing.

Manufacturers of base stocks EPA

judges to be equivalent may jointly

sponsor stage two testing.

Stage two testing is to determine the

chemical fate, environmental effects and

health effects of aryl phosphates. To

minimize the economic impact of the

rule, stage two testing is divided into

three levels based upon the annual

production volume of the base stock.

Aryl phosphate base stocks produced at

or above 1 million pounds per year are

subject to level one testing

requirements. Level one consists of 120-

day post-hatch rainbow trout early life

stage testing (ELS), three hen

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

neurotoxicity assays, and a twogeneration reproductive effects study.

Level two testing is triggered by a

production volume of 5 million pounds

or higher. It includes anaerobic

biodegradation, chronic Daphnia, and

subchronic toxicity testing. Aryl

phosphate base stocks produced at or

above 10 million pounds would be

subject to level three testing. Level three

includes aerobic biodegradation,

microcosm effects, developmental

toxicity, and the subchronic rat

neurotoxicity battery.

To determine if base stocks have met

the trigger levels, EPA is proposing a

section 8(a) reporting requirement. EPA

would notify manufacturers when the

production triggers were met.

A. Definitions

"aryl phosphate" for this proposed

rule is a phosphate triester of phenol or

of an alkyl-substituted phenol. This

definition includes triaryl and mixed

aryl alkyl esters (where one or two of

the three ester groups are alkyl), and

can denote structurally unique

substances, base stocks, or downstream

products.

"Aryl phosphate base stock" means

the phosphate ester or combination of

esters resulting from the reaction of a

phenol, mixtures of phenols, or, in some

cases, phenols plus an alcohol, with

phosphorus oxychloride (POCL} or other

phosphoric acid derivatives (see Unit

I.C.1 of this preamble for a fuller

discussion). This definition includes

triaryl and mixed aryl/alkyl esters

(where one or two of the three ester

groups are alkyl). This reaction can

produce a near-pure triaryl phosphate

such as triphenyl phosphate (when

phenol is used), a mix of aryl

phosphates (as when a mix of an

alkylphenol and phenol is used] or a mix

of isomeric esters such as ortho-, metaand paracresyl phosphates. Mono and

dicresyl esters would also be possible

reaction products in the latter example.

Base stocks are initially manufactured

aryl phosphates from which other aryl

phosphate products are produced and

are often commercially available. The

base stock components remain

unreacted in these aryl phosphate

products. Thus, when an aryl phosphate

product is released into the

environment, the base stock components

in the product are released into the

environment. Likewise, when humans

are exposed to aryl phosphate products,

they are exposed to the base stock

components that are in the products.

"Chemical" means any organic or

inorganic substance of a particular

molecular identity.

"Complex substance" means a "chemical substance" as defined under

section 3 of TSCA that is composed of

related chemicals produced as ..... a

result of a chemical reaction." Most aryl

phosphate base stocks, as defined in

this proposal, are complex substances.

The names of these substances

generally refer to the major component.

"Component" and "constituent" are

used Interchangeably, and mean one of

the individually identified chemicals

that, together with other components,

comprise a complex substance.

"Feedstocks" are alcohols or phenols

used in the manufacture of aryl

phosphate base stocks. They may be

single or mixed alcohols.

"Isomer" means one of two or more

chemical compounds containing the

same numbers of atoms of the same

elements, but differing in structural

arrangement. For example, triorthocresyl phosphate (TOCP], with its

methyl substituent at the ortho position

of the phenyl group, is one of three pure

tricresyl phosphate isomers (the others

being the tri-meta and tri-para isomers).

"Mixture" is defined in TSCA section

3(8). In the case of aryl phosphate

products, a mixture includes

combinations of two or more aryl

phosphate base stocks, or of an aryl

phosphate base stock and other

chemicals, but does not include those

defined in this proposed rule as "complex substances".

"Product" means the final

commercially manufactured substance.

It may be a single base stock, a mixture

of different base stocks or a mixture of a

base stock with an unrelated substance.

The product Phosflex 370, for example,

is a mixture of the base stocks isodecyl

diphenyl phosphate and tert-butylphenyl

diphenyl phosphate.

"Substituent" means an atom or group

that replaces another atom or group in a

molecule. In xylol (dimethylphenol), two

hydrogens of the phenyl moiety are

replaced by two methyl substituents.

B. Background

1. ITC designation. The Interagency

Testing Committee (ITC) designated the

aryl phosphate category for priority

testing consideration in its second

report. The reasons for this designation

are discussed in the Federal Register of

April 19, 1978 (43 FR 16684).

The ITC defined the category as

"** phosphate esters of phenol or of

alkyl-substituted phenols. Tri-aryl and

mixed alkyl and aryl esters are included,

but tri-alkyl esters are excluded." The

ITC recommended testing for

"carcinogenicity, mutagenicity,

teratogenicity, other chronic effects,

environmental effects and

epidemiology."

2. Advance Notice of Proposed

Rulemaking (ANPR)-a. Summary. The

Agency published an ANPR on aryl

phosphates on December 29, 1983 (48 FR

57452), following discussions with the

Industry Ad Hoc Aryl Phosphate Ester

Committee (IAPEC}. The ANPR

proposed testing nine aryl phosphate

complex substances because they had

been "identified by industry as being

constituents of commercial products

currently in production."

The nine substances proposed for

testing in the ANPR were: (1) Tricresyl

phosphate (TCP}, mixed isomers (tritolyt

phosphate, CAS Nos. 1330-78-5 and

68952-35-2); (2) Trixylenyl phosphate

(TXP), mixed isomers (trixylyl

phosphate, CAS Nos. 25155-23-1 and

68952-33-0); (3) Triphenyl phosphate

(TPP) (CAS No. 115-86-6); (4)

Nonylphenyl diphenyl phosphate (NDP),

mixed isomers (CAS No. 38638-05-0); (5)

Dimethylbenzylphenyl diphenyl

phosphate, mixed isomers (CAS No.

34364-42-6); (6] Isopropylphenyl

diphenyl phosphate (IPP), mixed isomers

(CAS No. 28108-99-8); (7) tertButylphenyl diphenyl phosphate (BDP),

mixed isomers (CAS No. 56803-37-3); (8)

Isodecyl diphenyl phosphate (IDP} (CAS

No. 59800-46-3); (9) 2-Ethylhexyl

diphenyl phosphate (EDP) (CAS No.

1241-94-7). All were base stocks as

defined in this proposed rule.

The ITC designated these chemicals

because they were ".. produced in

[aggregate] quantities exceeding 65

million pounds/year," NIOSH had

estimated exposure of over 2 million

workers, and certain members of this

chemical class had known toxicities.

Testing proposed for aryl phosphates

in the ANPR included: chronic effects - 90-day subchronics; mutagenicity--all

substances for some aspect of

mutagenicity; oncogenicity (triggered by

mutagenicity or data from the 90-day

subchronics); teratogenicity for TCP,

and for TXP, IPP, BDP, IDP, and EDP if

triggered by TCP; reproductive effects

for TCP and others if triggered by TCP

results; 90-day subchronic neurotoxicity

for TCP and TXP; environmental effects - field monitoring studies, tissue

residue analyses of biota exposed to

water and sediment collected from sites

known to contain aryl phosphates at

measurable levels and testing on

terrestrial organisms. Epidemiology

studies were not considered for proposal

in the ANPR.

b. Comments. EPA requested

comments on eight issues in the ANPR,

and received comments from eight

sources: IAPEC, five corporations (Ciba2139
Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

Geigy, Eastman Kodak, FMC, Monsanto,

Stauffer), the Environmental Defense

Fund (EDF), and D. Muir of the

Canadian Fisheries and Wildlife

Service. Summaries of the issues and

comments submitted and the Agency's

response to each appear below.

1. Issue. EPA requested information

on persons exposed to aryl phosphates

from synthetic feedstocks, the type of

exposure, notable changes in production

of individual substances over the last 5

years, new applications planned for any

of these substances and projected

growth rate over the next 5 years.

Comments. The IAPEC commented

that aryl phosphate production reflects a "mature product category and market

growth rate is projected below GNP

levels." It stated that production

declined between 1979 and 1982, and

that EPA should use this production

decline when predicting the future trend.

IAPEC estimated that fewer than 200

workers are involved in production. It

was also exploring a "user survey to

address possible concerns" (the Agency

has not received any such survey to

date). Eastman Kodak Company and

FMC also commented about the reduced

production. Kodak commented on the

lack of justification for a 4(a)(1)(B)

finding. Stauffer Chemical Company

commented that fewer than 90 of its

employees are exposed to aryl

phosphates and that downstream

worker exposure is insignificant.

Stauffer also estimated exposure levels

of less than 1.0 part per billion (ppb) to

air-borne aryl phosphates during each

working day. Stauffer estimated that

dermal exposure ocou's during less than

20 percent of the day, and that this is

minimized by protective clothing worn

by its employees. Stauffer also

commented that low vapor pressure

(typically <0.1 mm Hg at 100 F] of

listed aryl phosphates reduces the

potential for inhalation exposure to an

insignificant level under typical

operating conditions.

EPA Response. The ANPR gave levels

of projected production in 1980 as 100 to

140 millon pounds. Manufacturers

subsequently submitted production

levels of individual substances to EPA

as confidential business information

(CBI). However, EPA's current estimate

of aggregate category production, 72.1

million pounds, is available (Ref. 6).

A 1986 EPA report provided

information indicating that, although the

production levels of individual aryl

phosphates dipped to an all-time low in

1982, they subsequently grew 10 percent

or more by 1984 (Ref. 38). Information in

the Partial Inventory Update Rule

(Chemical Update System, CUS) (Ref,

69) shows that, in 1986, levels were

down from the highs mentioned in the

ITC report, but not to the extent that

manufacturers were predicting.

According to EPA's assessment,

production of this category remains

substantial. There has, however, been a

reduction in production of some

individual base stocks listed in this

proposed rule.

IAPEC commented that only about 200

workers are exposed. However, this

reference was to manufacturing workers

only. Many more workers are exposed

while using the end product(s). The 1980

National Occupational Hazard Survey

(NOHS) update shows more than 2

million workers may be exposed to aryl

phosphates (Ref. 51). It is difficult to

evaluate exposure numbers in

subsequent data, e.g., the National

Occupational Exposure Survey (NOES)

(Ref. 52), because of inconsistent

reporting terminology.

For purposes of reporting to the TSCA

section 8(b) Chemical Inventory, EPA

allows manufacturers of a complex

substance to report it as such or as its

individual components. This makes it

difficult to ensure acquisition of all the

information relating to the complex

substance. For example, NOES [Ref. 52)

shows 69 workers exposed to IPP (CAS

No. 2810-99-8), one of the substances

listed in the ANPR. However, NOES

also shows 46,948 workers exposed to

"isopropylated phenol, phosphate (3:1)"

(Cas No. 68937-41-7), a complex

substance that may contain varying

amounts of isopropylphenyl diphenyl

phosphate (IPP), bis(isopropylphenyl)

phenyl phosphate, and/or

tris(isopropylphenyl) phosphate.

depending upon the degree of

propylation required for the desired end

properties.

Exposure in the workplace occurs via

dermal contact and inhalation. EPA

estimates inhalation exposure of TPP

may be as high as 150 mg/day (Ref. 35).

The 1986-1987 issue of the American

Conference of Governmental Industrial

Hygienists (ACGIH) Threshold Limit

Values reference book (Ref. 3) listed two

aryl phosphates, TPP and TOCP. ACGIH

recommends a time-weighted average

(TWA) threshold limit value {TLV) of 3

mg/ms (cubic meters) for TPP in air, and

a TWA TLV of 0.1 mg/m for akin

contact with TOCP. Most aryl phosphate

base stocks are liquids with high boiling

points, but they may be volatile or form

an aerosol in certain applications. For

example, a NIOSH walkthrough of a

General Motors Die Cast Department In

Rochester, NY, in which aryl phosphatecontaining hydraulic fluids were used at

100 °F, found TPP and [PP in the air at

0.57 and 0.013 milligram (mg)/cubic

meter (ml, respectively (Ref. 75,).

Aircraft maintenance workers may

have frequent dermal contact with

hydraulic fluids containing aryl

phosphate base stock&. EPA estimates

such exposure to be in the 1300 to 3900

mg/day range if no protective clothing is

worn (Ref. 35). EPA described this

exposure pattern in its proposed test

rule for tributyl phosphate (TBP) (Ref.

71). EPA believes exposure level

estimates for users of aircraft hydraulic

fluids containing TBP are applicable to

users of those containing aryl phosphate

base stocks.

2. Issue. Would analytical data from

the manufacturers of commercial TCP

showing the TOCP level of their

commercial product, when combined

with the results of EPA's proposed 90-

day subchronic neurotoxicity study

using three dose levels of TOCP, enable

the Agency to reasonably determine or

predict the neurotoxicity of a TCP

commercial product?

Comments. EDF recommended

subchronic testing of TOCP and the TCP

mixture, while [APEC and Stauffer

mentioned the difficulty and expense of

testing pure isomers and suggested

testing products instead. Stauffer

discussed the use of acute toxicity and

percent ortho-cresol as an acceptable

neurotoxicity approximation rather than

the subchronic test. Stauffer also

mentioned a 7-dose-level TOCP toxicity

study published in conjunction with the

Delayed Neurotoxicity Workshop it

recently co-sponsored.

EPA Response. EPA is not proposing

toxicity testing of pure TOCP at this

time, but is proposing the produced base

stock which may or may not include

TOCP. EPA did consider the multi-dose

study of TOCP (Ref. 56 and 57):

however, published data on the test

substance and methodology do not give

enough information for EPA assessment.

The ANPR also stated that a 90-day

subchronic test of TOCP, then under

way as a positive control to FMC's 90-

day study of IPP, was not an appropriate

neurotoxicity test for TCP because it

was only a single-dose study. The

testing scheme discussed in the ANPR

would have required a full 3-dose study

of TOCP. The FMC TOCP study

received in 1986,.although a 2-dose

study, was therefore still unacceptable

(Ref. 24).

Studies performed on individual

tricresyl phosphate isomers indicated

the major neurotoxicant was TOCP (Ref.

63). Manufacturers, therefore,

endeavored to reduce the TOCP content

of their products. However, a -recent

TSCA section 8(e) submission 4ReL 40)

indicates TOCP-reduced tiess than D.1

percent) products have neurotoxic

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effects on the hen similar to those

arising from exposure to pure TOCP.

EPA believes aryl phosphate testing

should focus, at this time, on the

complex substances to which people

may be exposed. This proposed rule

would require testing of base stocks, but

not individual chemical constituents or

product mixtures (see Unit I.C.3 of this

preamble for fuller discussion of test

substances]. Thus, for isopropylated

phenyl phosphates, three base stocks

are proposed for testing:

isopropylphenyl diphenyl-,

bis(isopropylphenyl) phenyl-, and

tris(isopropylphenyl) phosphate. Each of

these base stocks contains smaller but

significant amounts of one or both of the

other isopropylated phenyl phosphates.

EPA would use test data obtained on

base stocks to help determine whether

or not testing individual constituents

would be necessary.

3. Issue. Does the potential for human

exposure to certain consumer products

%,ontaining acutely neurotoxic TXP

components warrant subchronic

neurotoxicity testing?

Comments. EDF commented that all

organophosphates should be tested for

subchronic neurotoxicity, not just those

selected on the basis of acute data. It

specifically suggested testing of IPP and

TXP. IAPEC stated that "the

neurotoxicity of TXP has been

determined," and that ". human

exposure is insignificant. As commercial

production continues to decline, no

further testing is warranted." Stauffer

commented that subchronic testing

would be appropriate if exposure were

significant, but in any case, an acute test

should be performed to determine if

subchronic testing is necessary.

EPA Response. EPA believes that

acute organophosphorus induced

delayed neuropathy (OPIDN) testing

combined with acute neurotoxic

esterase testing is a valid predictor for

the OPIDN syndrome. The subchronic

testing is primarily for risk assessment

purposes.

EPA does not believe the

neurotoxicity of TXP has been

adequately determined, and is proposing

testing of this complex substance in this

test rule. In the case of IPP, the ANPR

did not discuss possible subchronic

neurotoxicity testing because, at the

time, FMC was planning a 90-day

subchronic assay of IPP in the hen that

was expected to reasonably predict or

determine IPP neurotoxicity. However,

the data FMC submitted to EPA

characterizing the composition of the

test material was insufficient for

evaluation of the study (see Unit II.C.2

of this preamble).

4. Issue. Is TOCP the only agent

responsible for the suggested

reproductive and teratogenic effects of

TCP? Should it be tested separately? Do

the existing data for TOCP provide

sufficient evidence to implicate other

aryl phosphates?

Comments. EDF said all aryl

phosphates should be tested. The IAPEC

took the position that because no

scientific data indicate TOCP or

tricresyl phosphates have reproductive

or developmental effects, there is no

justification for further testing. It stated

that because five important commercial

aryl phosphates were negative in

teratogenicity studies, there was no

need for further testing. Stauffer stated

that the information on TOCP did not

justify any type of reproductive or

developmental toxicity testing. The

company asserted that validity of

seminiferous tubule degeneration

observed in a study of male rabbits and

dogs with TCP (Ref. 14] must be

questioned. Without knowing what was

tested, it is difficult to draw any

meaningful conclusions. Finally, Stauffer

stated testing TOCP had no relevance to

predicting the effect of exposure to

compounds in commercial production.

EPA Response. EPA is not proposing

testing of any component, including

TOCP, of any of the complex substances

in this test rule. EPA agrees with

Stauffer that testing single components

of an aryl phosphate is not appropriate

at this time, and instead proposes

testing of actual manufactured aryl

phosphate base stocks (see Unit I.C.3 of

this preamble).

The data IAPEC referred to included

minimal chemical analysis on the

products tested and is of limited use for

assessment of hazard potential.

Three recent studies have

demonstrated the reproductive toxicity

of TCP in several species and strains of

laboratory animals (Refs. 12. 13, and 15).

The National Toxicology Program (NTP)

and National Institute of Environmental

Health Sciences (NIEHS) studies both

used TCP with less than 0.1 percent

TOCP, while the TCP in the EPA study

contained less than 9 percent TOCP. All

three studies showed effects on male

reproductive parameters, and

histopathologic effects were seen in the

ovaries in the EPA-sponsored study.

Both the EPA-sponsored and NIEHSsponsored studies demonstrated

developmental toxicity, while the

NIEHS study also showed effects in the

F, generation at the lowest dose. A

confidential TSCA section 8(e) study

was submitted to EPA in 1990

demonstrating similar reproductive

effects with an additional aryl

phosphate.

5. Issue. Is it possible to reduce the

testing burden by forming subcategories

of similar aryl phosphates or by testing

a subset that spans the structural

spectrum of the aryl phosphates

category?

Comments. EDF stated that

information about possible toxicity of

these compounds was insufficient to

justify such approaches. Kodak

suggested a decision to choose

subcategories should be based on

quantities being manufactured and

potential exposure, and it would be

inappropriate for EPA to decide this

matter until these data were available.

IAPEC stated that structural subsets

could be developed if a need for further

testing was demonstrated, and added

there was no need to conduct separate

tests for each chemical.

EPA Response. EPA has decided not

to pursue these possibilities for aryl

phosphates at this time. The use of

subcategories or subsets for testing

implies that the results of such surrogate

testing would be valid for all the

chemicals not tested. EPA is not

convinced there is a sufficient

understanding at this time of the

relationship of structure and observed

toxicity to subcategorize aryl phosphate

base stocks for testing.

6. Issue. EPA sought comments on

criteria used to evaluate the industrysponsored monitoring study. These

included: (i) Detection limit sensitivity;

(ii) quality assurance evaluation; (iii)

location and selection of sampling sites;

(iv) statistical treatment of data

obtained; (v) analytical method; and (vi)

interpretation of results.

Comments. IAPEC commented on the

six criteria as follows:

a. Detection limit sensitivity. IAPEC

contends the monitoring study they

submitted demonstrates adequate

margins of safety, and while recoveries

were variable for experimental field

spikes, standard laboratory spiking and

storage showed good recoveries.

b. Quality assurance evaluation. Their

quality assurance (QA) effort, which

involved spiking samples from all

aquatic strata tested, was sound and

provided valid QA for the

environmental monitoring program.

IAPEC contends that EPA's concern as

to the insufficiency of a 29 percent

recovery for "the phosphate esters

spiked or sediment samples carried to

the field and spiked in the field" is

inappropriate. This description referred

to early testing involving only six

samples, whereas the overall

experimental recovery rate was 70

percent.

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c. Lnctinand seetion of sampling

sites. Sample site selection was agreed

upon by industry and EPA, the

collections were conducted exactly as

agreed upon, and calculated safety

factors for each site (based on rainbow

trout MATC) ranged from 2 to 10.

d. Statistical treatment of data

obtained. Q-test was used to identify

extraneous or outlying values in the

water data set. All of the monitoring

data were given to the Agency,

including the raw data from the

appendices of the monitoring report.

Thus the Agency can apply whatever

statistical treatment it considers

appropriate.

e. Analytical method. All methods

were validated according to state-of-theart validation procedures. Information

on methods, detection limits and quality

assurance was provided to the Agency

before the program began. IAPEC

received no cmments, questions or

suggestions for changes.

f. Interpretation of results. This study

provides evidence for no concern for

exposure through the water column.

IAPEC believes that aryl phosphates

would be adsorbed to sediment and

desorb very slowly, meaning that any

potential enironmental problems would

be to sediment-dwelling organisms.

EPA Response. EPA is not proposing

monitoring in this test rule.

Following the ANPR, EPA conducted

a Good Laboratory Practices (GLP)

Inspection/Study Audit Report on the

aryl phosphate monitoring study '(Ref.

68), which reported numerous GLP

compliance deviations and reporting

inconsistencies. In addition, while

overall experimental recovery rate was

70 percent, the recovery for the fieldspiked sediments was only 29 percent.

The minimum recovery specified by the

ACS guidelines for reliability (Ref. 2a) is

60 percent. A lower recovery could

result in a large occurrence of false

negative results. These shortcomings

caused EPA to dismiss the monitoring

report.

7. Issue. How useful is a site-specific

aquatic ecotoxicity test procedure

compared to standard laboratory

ecological tests? Is there a need for

terrestrial testing in addition to aquatic

testing for a site-specific effect?

Comments. IAPEC commented that a

site-specific test was not feasible,

because in their monitoring study, five

of the esters proposed for testing were

not found in water, four were not found

in sediment and three were not present

in sediment or water. in addition, where

aryl phosphates were found, the

presence of 'other organic contaminants

would dominate any effects of aryl

phosphates. IAPEC held that

conventional risk assessment using

standardized protocols was preferae.

It also contended terrestrial organism

testing was not needed, as there was no

significant exposre.

EPA Response EPA is not proposing

site-specific aquatic ecotoxicity testing

in this test rule. EPA agrees with the

comment on testing procedures. This

proposed test rule includes standards

for environmental testing and chemical

fate studies. There has been some

evidence of terrestrial exposure,

particularly in the vicinity of aryl

phosphate manufacturing plants (Ref.

18), but EPA is not proposing terrestrial

testing at this time.

8. Issue. Should an oncogenicity

testing requirement be based on results

of selected mutagenicity tests or rather

on a section 4(a)(1)(B) finding?

Comments. EDF concluded the use of

mutagenicity data as the sole basis 'for

choosing chemicals for oncogenicity

testing was inappropriate, and stated

that any chemical with substantial

human exposure should be tested for

oncogenicity and in vitro and in viva

mutagenicity. YAPEC and Stauffer

doubted aryl phosphate exposure would

support a section 4(a)(1)(B) finding, and

IAPEC suggested that, because all

mutagenicity information was negative,

oncogenicity testing should not be

considered.

EPA Response. NTP is performing a

2-year bioassay on TCP, and EPA will

examine the results before deciding

whether further oncopenrcity esting on

any other aryl phosphate is needed.

C. Substances to Which the Rule

Applies

1. Chemistry of aryl phosphates. Aryl

phosphate base sock&, as defined in

Unit L.A of this preamble, are phosphate

esters of phenol or of alkyl-substituted

phmnols. They are produced by reaction

of a phenol, alkylated phenol, and/or an

aliphatic alcohol with phosphorus

oxychioride (POCI6) at elevated

temperatures in the presence of a

catalyst. Mixed aryl phosphate esters

are produced by reacting fOCI, with

controlled quantities of appropiate

phenols. Variations in feedstock,

starting proportions or reaction

conditions will result in batch-to-batch

differences that could account for

disparities in the physical properties of

these mixed esters (Refs. 42 and'50).

A second alkyl substituent in the

starting phenol greatly increases the

number of possible components in the

final product; there are more than ,0 for

trixylyl (tris-dimethylphenyl) phosphate,

for exampile. When the feedstock is a

mixture of non-isomeric phenols. the

possibilities may multiply even further.

The names applied to aryl phosphate

base stocks can be confusing. For

example, as described in Unit i.A of this

preamble, a pheny4 group can be

alkylated in the ortho, meta, or pars

position, so that "tricresyl phopi-ate

[tritolyl phosphate, trimethylphenyll

phosphate] could be either tri-metacresyl phosphate (TMCP) (one of the

isomers), the corresponding triortho-

(TOCP) or tri-para- (TPCP) ester, or a

mixed ester where two or three of the

cresyl isomers are present in the same

molecule. In practice, because

commercial TCP may be manufactured

from a blend of ortho, meta, and paracresol, it may contain up to 10 possible

tricresyl phosphates, in proportions that

depend not only on the proportions of

starting cresol isomers, but also on their

relative reactivity under the

manufacturing conditions employed. Socalled "tricresyl phosphate" is a

complex substance containing TOCP

TMCP, and TPCP (though certain

commercial mixtures may be primarily

the para isomer with I percent or less of

the ortho isomer), plus some dicresyl

phenyl phosphate, cresyl diphenyl

phosphate, and triphenylphosphate that

reflect the presence of some

unsubstituted phenol in the feedstock. I

the complex substance is primarily

TOCP, but contains some TMCPand

TPCP, it is generally called TOCP.

2. Category. Under TSCA section 26,

EPA has authority to take any action

authorized or required to be taken wit

respect to a chemical substance or

mixture with respect to a category of

substances or mixtures. TSCA section

26(c)(Z) defines "category of chemical

substances" to mean

a group of chemical substances the

members of which are similar in molecular

structure, in physical, chemical, or biological

properties, in use, or in mode of entrance into

the human body or into the environment, or the members of which are in some other way

suitable for classffication as such for

purposes of this Act, except that such term

does not mean a group of chemical

substances which 'are grouped logether solely

on the basis of their beingnew chemical

substances. Thus, the term '!category of

chemical substances" is quite broad.

This proposed rule would require

testing of the aryl phesphate base stock

category under sections 41a)(1)[A) end

(B) of TSCA for both existing members

of the category and future entries to it.

The category is based on chemical

structure. EPA believes that the

phosphotriester function common to al

aryl phosphates justifies using toxicity

data identffying a hazard for one aryl

phosphate substance to stggest a hazard

potential for other aryl phosphate

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Federal Register / Vol. 57, No. 12 / Friday. anuary 17, 1M / Proposed Rules

category members. In evaluating the

testing needs for the aryl phosphate

base stock category, EPA considered all

available data, including: production

volume: ue; release: exposure; test

data; information included in the ITC's

report; TSCA section 8[a), (d) and (e)

data; comments received following the

publication of the ANPR; recent

publications in the literature; any EPAgenerated monitoring; and additional

information.

EPA, by taking the category approach,

will assure that any newlymanufactured aryl phosphate base stock

meeting the category definition, such as

chemicals on the TSCA Inventory but

not being produced, or any aryl

phosphate base stocks that are "new

chemical substances" under TSCA

section 5, would also be subject to the

rule. This approach should preclude the

necessity of a new test rule if changes in

production processes yield differences

in aryl phosphate components.

For instance, in a 1984 report by Muir

(Ref. 50), cresyl diphenyl phosphate

(CAS No. 26444-49--5) was given as the

major component in two commercial

phosphate esters, and the 1980-81 NOES

(Ref. 52) reported 13,370 employees

exposed to this substance. However,

although this substance is on the TSCA

Inventory, no production was reported

in the 1986 Chemical Update System

(CUS). Without the category finding,

cresyl diphenyl phosphate production

could easily be resumed without the

substance being subject to testing.

3. Test substances. Promulgating a

test rule for aryl phosphates raises

several important policy issues. One of

the most difficult is the question of what

to test. Data may be difficult or

impossible to evaluate if the test

substances are not appropriately chosen

and their composition not adequately

specified.

EPA considered several different test

substance options: individual isomers,

aryl phosphate componerts of base

stocks listed on the inventory, aryl

phosphate base stocks, and commercial

products.

a. Individual isomers. Because most

aryl phosphate base stocks marketed

are complex substances whose

components may have varying

toxicities, EPA considered requiring

testing of each isomeric component. The

Agency abandoned this approach

because of the diversity of some

complex substance such as trixylenyl

phosphate, which may have 50 or more

isomers. The cost and complexity of

testing hundreds of isomers would be

prohibitive, and the time required for

such testing would significantly delay

EPA's evaluation of the data.

b. Base stock componenrts. The 1077

TSCA Non-Confidential Inventory

includes 58 individual base stock

components meeting the chemical

definition (Ref. 55). Several of the 58 aryl

phosphates on the inventory are

components of the base stocks listed in

this proposed test rule but are not

reported in production. Although the

number of inventory components is

substantially less than the number of

possible isomers, the same obiections

(high cost and testing program delays)

apply. In addition, the benefits of such

testing may be even fewer then for

testing of individual isomers if the

toxicity of aryl phosphates is an isomerspecific phenomenon.

c. Commercial products. EPA also

rejected testing of commercial aryl

phosphate products. These may be aryl

phosphate base stocks or mixtures of

aryl phosphate base stocks and other

substances. Since EPA is interested in

aryl phosphate toxicity it does not seem

wise to test substances that may contain

non-aryl phosphate components or that

are mixtures of base stocks. In addition,

the number, and often the complexity, of

commercial products exceeds that of

base stocks, makhig this a more

expensive option.

d. Base stocks. EPA is proposing aryl

phosphate base stocks as the test

substances. EPA believes that this

approach strikes a balance between the

need to characterize aryl phosphate

toxicity, the unacceptably high cost of

the other options considered, and the

potential difficulties of any case-by-case

test substance selection process. Base

stocks, as defined in ths proposed rule,

include all the individual aryl

phosphates to which people or the

enviromnent may be eiosed as a restt

of activities involving aryl phosphate

base stocks or downstream aryl

phosphate-containing consumer or

industrial products. Finally, if test

results on a base stock suggest a need

for more detailed characterization, EPA

can require by separate rulemaking

testing of individual or combined aryl

phosphates, guided by the analytical

date and other results an all the base

stocks initially tested. Thus, this

proposed rule can be considered a type

of screening rue. The aryl phosphate base vtocks now

in production include seven of the Win

aryl phosphates listed in the ANPR -(see

Unit I.B.2.a of this preamble). The other

two, NDP and DBDP, are not being

produced (Ref. 55) and thus would not

be subject to the testing requirements

unless production resumed. The more

recent additions to the list of inproduction category members m da - butyl) phenyl phosphate (DBP), and four

aryl phosphate base stocks closely

related to IDP and BP.

Thus, the Agency has identified 12

members of the aryl phosphate base

stock category that it believes to be in

production (Ref. 55] for which it is

proposing testing at this time. They are

as follows (see Unit 111.B of this

preamble for more information):

i. tort-Butylphenyl diphenyl phosphate.

ii. bis-1twe-Butyhenylj phenyl phosphate.

iii. tris-(tert-Butylphweyl) phosphate.

iv. Di-n-butyl phenyl phosphate.

v. 2-Ethyihexyl diphenyl phosphate.

vi. isodecyl dipheayl phospohate.

vii. Isopropylphenyl diphenyl phosphate.

viii. bis-Ilsopropylphenyl) pheny

phosphate.

ix. tris.(Isopropylphenyl) phosphate.

x. Tricresyl phosphate.

xi. Triphenyl phosphate.

xii. Trixylyl phosphate.

4. TSCA section 8(a) reporting and

triggering of testing. EPA recognizes

costs of the oomplete testing for some

category members may be burdensome

(see Unit V of this preamble) and has

prioritized the proposed test

requirements (see Unit IIH of this

preamble). EPA believes most or all

current manufacturers of base stocks

can afford the tests in Level 1, some can

support the additional tests in Level 2,

and a few can afford Level 3 testing. For

this reason, EPA proposes a trigger

mechanism that ties testing

requirements to specified production

levels.

To facilitate this approach, EPA is

proposing, under section B(a) of TSCA, a

Preliminary Assessment Information

Rule (PAIR) to require annual reporting

by manufacturers and importers of

production and importation volumes for

all substances meeting the definition of

this chemical category which are now.

or become, listed on the public or

confidential portion of the TSCA

Chemical Substances Inventory.

5. Synergism and antoeonisrm

Synergism and antagonism among

components may also affect the toxicity

of the final product. To scme extent this

will be reflected in the tating of base

stocks however, testih expressly for

these phenomena would require tests of

individual components and

combinations of components at different

levels. The prohibitive cost of testing

components individually (Unit I.C.3.a of

this preamlie) would also apply to any

study of synergism and antagonism.

II. F'ndings

EPA is basing its proposed testing for

members of the aryl phoophate category

on the authority of sections 4(a)I(A)

II I II I I I III I I I I I I ! II I

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

and 4(a)(1)(B) of TSCA through the use

of TSCA section 26(c).

A. Findings Under TSCA Section 4(a)(1)(B)(i)

Pursuant to section 4(a)(1)(B) of

TSCA, EPA finds that aryl phosphate

base stocks are produced in substantial

quantities and that the use of aryl

phosphate base stocks may result in

substantial human exposure and/or

substantial release to the environment.

Under TSCA section 26(c), EPA

proposes to make a section 4(a)(1)(B)

finding for the entire aryl phosphate

base stock category, including (1) all

such substances on the TSCA Inventory,

both public and confidential, and (2) any

substance not yet produced that would

fit the definition of aryl phosphate base

stocks (see Unit I.C.2 of this preamble).

EPA believes that this is an

appropriate category of substances

under section 26(c) because they are

similar in molecular structure and in use

and because their common phosphate

triester functionality confers the

potential for similar biological activity.

This category is also "suitable for

classification" because the ITC

designated aryl phosphates as a

category for priority consideration for

testing.

EPA is developing a general policy

under TSCA section 4(a)(1)(B) (the "B"

policy) in which it will articulate its

criteria for making findings under this

provision. The "B" policy is being

developed in response to the April 12,

1990, decision in CMA v. EPA, 899 F.2d

344 (5th Cir. 1990), in which the Court

remanded the TSCA section 4 rule for

cumene to EPA to "articulate the

standards or criteria on the basis of

which it found the quantities of cumene

entering the environment from the

facilities in question to be 'substantial'

and human exposure potentially

resulting to be 'substantial."' Although

not required to do so by the cumene

decision, EPA also will be articulating

the criteria for 'substantial production'

and 'significant human exposure.' EPA

has recently published the criteria for

public comment (56 FR 32294).

EPA has decided to move forward in

proposing this aryl phosphate test rule

under both TSCA sections 4(a)(1)(B) and

(A), without waiting for notice and

comment on the generic "B" policy. The

Court in CMA made it clear that EPA

need not adopt a definition applicable to

all cases, but may choose to proceed on a case-by-case basis, if it rationally

explains its exercise of discretion. Thus,

because this proposal articulates the

criteria used in making findings under

TSCA section 4(a)(1)(B) for aryl

phosphate base stocks, it is not

necessary to wait for publication of a

generic policy before proposing this test

rule.

TSCA does not provide EPA with

much guidance on what criteria and

standards to use in making "B" findings.

The statute does not define the terms "significant" or "substantial." The

policy section of TSCA, however, makes

it clear that Congress considered testing

of chemical substances to be an

important aspect of the Act. This section

provides:

[that] adequate data should be developed with respect to the effect of chemical

substances and mixtures on health and the

environment and that the development of

such data should be the responsibility of

those who manufacture and those who

process such chemical substances and

mixtures.

The legislative history of TSCA also

provides some guidance on what criteria

are to be used in making "B" findings.

The legislative history states that "[t]he

conditions specified in TSCA section

4(a)(1)(B) reflect the Committee's

recognition that there are certain

situations in which testing is desirable

even though there is an absence of

information indicating that the

substance or mixture may be harmful."

H.R. Rept. No. 1341, 94th Cong. 2d Sess.

(1976), at 18 reprinted in, A Legislative

History of the Toxic Substances Control

Act (Comm. Print 1976) ("Leg. Hist.") at

425, and "there are certain situations in

which testing should be conducted even

though there is an absence of

information indicating that the

substance or mixture per se may be

hazardous." H.R. Conf. Rept. No. 1679,

94th Cong. 2d Sess. (1976), reprinted in,

Leg. Hist. at 674. The legislative history

also provides that EPA "is not limited to

consideration of sheer volume of

production or exposure at a specific

point in time. The duration of exposure,

the level of intensity of exposure at

various periods of time, the number of

people exposed, or the extent of

environmental exposure are among the

considerations which may be relevant in

particular circumstances." [Leg. Hist. at

425.] EPA believes that it is reasonable

to interpret the duration of exposure and

level of intensity of exposure as relating

to "significant" human exposure, the

number of people exposed ag relating to

"substantial" human exposure, and the

extent of environmental exposure as

relating to "substantial" environmental

release.

EPA recognizes that it must not define

"significant" and "substantial" in ways

that would require the Administrator to

make findings for every substance in

commerce, or the statute would have

simply required testing for all

substances. Nevertheless, TSCA section

4(a)(1)(B) is designed to support risk

management activities under the other

provisions of TSCA. Thus, it is

reasonable to interpret TSCA section

4(a)(1)(B) as authorizing EPA to require

testing for every substance whose

environmental or human exposure is of

such magnitude or type that it may need

to be regulated if test data reveal

adverse effects.

EPA believes that, for this category of

chemical substances in which certain

members are structurally similar, may

be used interchangeably, and in which

some individual members of the

category are produced in substantial

quantities, it may be reasonable to

require testing of a category of

substances that collectively is or will be

produced in substantial quantities,

greater than I million pounds per yeai

and that either collectively may be

released to the environment in

substantial quantities, greater than 1

million pounds per year, or to which

collectively there may be significant oi

substantial human exposure, over 1,001,

workers, 10,000 consumers or 100,000

people. Furthermore, if EPA made

findings only on individual substances

that met the thresholds for substantial

production, substantial release, and

significant or substantial human

exposure, persons subject to the rule

could avoid providing the required data

by switching to substances not in

current production. Thus, EPA would

have to propose another test rule every

time a manufacturer switched to an aryl

phosphate base stock not otherwise in

production. Theoretically, the persons

subject to the rule could continue

switching the substances they make and

process, and EPA would never catch up.

To prevent this, EPA believes it is

appropriate, in this special case, to

make the findings for the category as a

whole, using the same criteria for

making such findings that would be used

for individual chemical substances and

mixtures. However, for other chemical

categories EPA may decide not to make

the substantial exposure or quantities

finding for the category as a whole,

instead considering exposure on a

subcategory or individual chemical

basis.

EPA specifically solicits comment on

whether EPA should use the same

section 4(a)(1)(B) finding numerical

thresholds for a category of chemicals

as are used for individual chemicals, or

instead require higher thresholds. When

this rule is promulgated, EPA will

address all comments on the proposed

criteria that are relevant to this rule as

well as comments on this proposed rule.

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

1. EPA finds that the category of aryl

phosphate base stocks is produced in

substantial quantities. Manufacturers

recently submitted production, levels of.

individual category members to EPA as confidential business information.

However, a nonconfidential EPAestimated aggregate category production

total of 72.1 million pounds is available

(Ref. 6).

EPA is reserving discussion on what it

considers to be the minimum production

volume that can be considered "substantial" until it promulgates its "B'"

policy. Nevertheless, EPA finds that 72.1

million pounds per year clearly is above

the minimum level that can be

considered "substantial." EPA believes

it is reasonable to interpret substantial

production to mean large production,

and that 72.1 million pounds is a large

amount of production. Although EPA

does not know the exact percentage of

chemical substances in commerce with

production volumes above 72.1 million

pounds per year, the TSCA section 8(b)

inventory of the substances in

commerce shows that only 4.5 percent of

the listed substances have production

volumes over 10 million pounds,

together accounting for over 95 percent

of the total production of all substances

produced in the United States (see 56 FR

32294, 15 July 1991). Moreover, the

inventory shows that only about 1.5

percent of the listed chemical

substances in commerce have

production volumes over 100 million

pounds per year. Thus, EPA believes

that substances with production

volumes of at least 72.1 million pounds

per year comprise somewhere between

1.5 percent and 4.5 percent of the

substances in commerce, and together

account for over 95 percent of the total

production of all substances produced in

the United States. EPA believes thatit is

reasonable to conclude that this small

group of substances (i.e., the top 1.5 to

4.5 percent according to production

volume), which account for the vast

majority of all production, clearly are

substances with substantial production.

2. EPA finds that the use of aryl

phosphate base stocks in various

products results in substantial human

exposure to these base stocks. Aryl

phosphate base stock components

generally comprise 0.5 to 20 parts per

hundred parts of resin, or up to 45

percent by weight of plastic

forrmlations lRef. 73), and 0.5 to 100

percent of functional fluids (Ref. 35) (0.5

to 4 percent as antiwear additives and

100 percent as hydraulic fluids).

Exposure potential in the workplace is

substantial. The 1980 National

Occupational Hazard Survey (NOHS)

update indicates more than 2 million

workers are exposed to aryl phosphate

base stock components {Ref. 51).

Although it is difficult to evaluate

exposure numbers in subsequent data,

e.g., NOES (Ref. 52), because of

inconsistent reporting terminology (see

Unit LD.2 of this preamble), EPA does

not know of any reason why the number

of workers would have changed

significantly between 1980 and 1991.

Exposure in the workplace occurs via

inhalation and dermal contact. While

most of the aryl phosphate base stocks

are high boiling-point liquids, they may

be volatile or form aerosols in certain

applications. For example, a NIOSH

walk-through of a General Motors Die

Cast Department in Rochester, NY, in

which aryl phosphate-containing

hydraulic fluids were used at 100 *F.

found TPP and IPP at concentrations of

0.57 and 0.013 mg/m 3, respectively (Ref.

75).

EPA estimates workers having dermal

exposure to aryl phosphate base stocks

may have 1300 to 3900 mg/day exposure

if no protective clothing is worn (Ref.

35). Aircraft maintenance workers

frequently work with hydraulic fluids

and may be at particular risk. EPA

described this exposure pattern in its

proposed test rule for TBP (Ref. 71). The

Tributyl Phosphate Task Force, an

industry group, sponsored a survey of

aircraft worker exposure to tributyl

phosphate, and provided estimates that

2,200 employees in tis industry are

routinely exposed to aircraft hydraulic

fluid and 43,000 mechanics may, at

various times, be exposed (Ref. 34). EPA

believes exposure estimates provided

for users of aircraft hydraulic fluids

containing TBP are applicable to users

of those containing aryl phosphate base

stocks, as the applications of so&me of

the aryl phosphate base stocks are

similar.

Some of these functional fluids are manufactured to meet military

specifications. Responding to a recent

query by EPA, the U.S. Army responded

that there was potential TOCP exposure

at 19 bases involving 196 military and

146 civilian workers (Ref. 74).

In addition to worker exposure, the

general population uses plastic in many

forms and is potentially exposed to ryl

phosphates from base stocks used as

plasticizers. The beat in a cdosed

automobile can volatilize plasticizers

used in upholstery or other plastic

components, and has been shown to

produce a visible film of TCP on the

inside of automobile windshields (Ref.

17). This means millions of Americans

may be inhaling TCP in automobiles on

a regular basis, particularly on hot days.

Room temperature water can leach

plasticizers out of plastics (Refs. 2 and

7]. Thus, people who drink out of plastic

glasses, wash plastic items or handle

any such plastic items containing aryl

phosphate plasticizers, may be exposed

to aryl phosphates through that water.

Disposal of plastics generates

additional general population exposure

potential, as aryl phosphates may leach

out of plastics in landfills and enter

groundwater (Ref. 7). Thus, human

populations near landfills may be

exposed to aryl phosphates in their

drinking water. Incineration may cause

aryl phosphates to volatilize (Ref. 7)

potentially causing populations of

people living near incinerators to be

exposed to aryl phosphates in the air.

One EPA report has postulated that as

much as 80 percent of plasticizers may

volatilize or leach out (Ref. 73). General

population exposure is further confirmed

by the detection of aryl phosphates in

human adipose tissue {Ref. 64).

EPA believes that it is reasonable to

interpret the term "substantial human

exposure" to mean widespread human

exposure, or in other words, exposure f

a large number of people. EPA believes

that exposure of 2 million workers is

substantial exposure because, where

millions of workers are exposed to a

chemical substance, it is reasonable that

EPA should have data n the potential

hazards associated with the substance

so that EPA can implement appropriate

risk management efforts where

necessary to protect workers against

unreasonable risk. As a general matter.

EPA has found that workers tend to be

subject to routine or episodic exposure

over a long period of time. The Court in

CMA recognized that there could be

some -verlap between substantial and

significant hIman exposure. "it is not

necessarily clear that 'significant' and 'substantial' as used inclause (II) must

be understood in a way that prevents

their respective meanings or requires

that any factor relevan to one may be

necessarily irrelevant to the other."

CM0A at 350, note 17. Thus, exposure, to

be considered substantial, does not have

to be as widespread for workers as for

consumers or the general population.

EPA beleves that exposure of 2 milion

workers is widespread mough to

necessitate testing for the potential

hazards of the substances to evaluate

whether worker protection efforts are

necessary.

Moreover, EPA believes that millions

of consumers may be exposed to aryl

phosphate base stocks due to their

presence in plastics and that millions of

members of the general population may

be exposed to myl phosphte base

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

stocks that leach out of plastics in

landfills and are released into the air

during incineration of plastics. EPA

believes that potential exposure of

millions of consumers and members of

the general public to aryl phosphates is

substantial exposure because where

millions of people are exposed to

chemical substances, it is reasonable

that EPA should have data on the

potential hazards associated with the

substance so that EPA can implement

appropriate risk management efforts

where necessary to protect consumers

and members of the general public

against unreasonable risk.

3. EPA finds that aryl phosphate base

stocks used in various products are

released to the environment in

substantial quantities. An EPA report

estimated that I to 3 million pounds of

aryl phosphate base stocks may enter

the environment annually (Ref. 42].

TPP has been detected in surface

waters from the San Francisco Bay (Ref.

39) to the Delaware River (Ref. 60). Los

Angeles rainwater was found to contain

TPP (Ref. 33). A 1986 survey found TPP

in at least three major waterways, in

both sediment and fish (Ref. 72].

Substantial release is indicated by the

presence of aryl phosphates (TPP, IPP,

TXP, TCP) in water (Refs. 31, 39, 41, and

60), sediment (Refs. 39, 18, 31, 41, and 72)

and fish (Refs. 37, 39, and 72).

IPP was detected in soil and

vegetation samples near production

sites (Ref. 18).

The presence of TPP and EDP in

foodstuffs (Refs. 19, 26, 27, 28, and 29)

and of TPP in human adipose tissue

(Ref. 64) suggests the possibility of

ingestion of these chemicals.

TPP has been found in the waterextractable fraction from items such as plastic car upholstery (Ref. 2). Disposal

of such plastics through landfills or

incineration adds to environmental

exposure, as leaching of plasticizers or

volatilization may occur (see Unit II.A.2

of this preamble].

4. Evidence for substantial production,

substantial human exposure and

substantiai environmental release. EPA

believes that the phrase "released into

the environment in substantial amounts"

is intended to capture substances with

extensive release to the environment,

which in itself would be sufficient

reason to require testing in the absence

of any information that the substance

may be hazardous to human health or

the environment. In other words, as with

substantial production, release of

substantial quantities means large

release. Aryl phosphate base stocks are

released into the environment in

quantities of 1 million to 3 million

pounds per year. EPA finds that I

million to 3 million pounds of release to

the environment is a sufficiently large

release that EPA should require testing

to determine whether measures should

be taken to reduce risk to the

environment. Moreover, the Toxics

Release Inventory (TRI), under the

Emergency Planning and Community

Right-to-Know Act, 42 U.S.C. section

11023, shows that 37 percent of the listed

substances have releases over I million

pounds, accounting for over 99 percent

of the total reported releases on the TRI

by volume released. Because the TRI

does not include all substances, less

than 37 percent of all substances would

have releases above I million pounds.

EPA believes that it is reasonable to

conclude that this small group of

substances (i.e., less than 37 percent),

which accounts for over 99 percent of all

releases, clearly are substances with

substantial releases.

B. Findings Under TSCA Section 4(a)C1)(A)16)

Pursuant to section 4(a)(1)(A)(i) of

TSCA, EPA finds that the

manufacturing, processing, use,

distribution in commerce, and disposal

of aryl phosphate base stocks used in

various prcducts may present an

unreasonable risk of injury to human

health and the environment.

1. Evidence of potential for adverse

human health effects. Subchronic

toxicity testing of TPP, the most acutely

toxic aryl phosphate, demonstrates

effects in liver, kidney and adrenals

(Ref. 30). TCP demonstrates the same

toxicities as TPP (liver, Refs. 30 and 54;

kidney and adrenals, Refs. 54 and 59),

and also affects the immune system

(Ref. 10). Long-term treatment with DBP

damages liver, kidneys and blood (Refs.

46 and 49). Santicizer 148 (a mixture of

87 to 91 percent isodecyl diphenyl

phosphate, 5 to 7 percent di(isodecyl]

phenyl phosphate and 4 to 6 percent

TPP) affects both the liver and the

hematologic system (Ref. 48).

Since the 1930s, various individual

and combined aryl phosphates have

demonstrated neurotoxicity, including phenol-type syndrome (muscular

tremors, hyperexcitability, spadtic

rigidity, muscular weakness and

generalized flaccid paralysis, perhaps

due to degradation to the phenol or

cresol) (Refs. 62], as well as OPIDN, the

well-known human syndrome caused by

certain individual aryl phosphates (see

Ref. 32). Several cases in humans,

primarily due to the tricresyl

phosphates, have been reported (see

Ref. 1). Studies performed on individual

tricresyl phosphate isomers indicated

the major neurotoxicant was TOCP

(Refs. 61 and 63). Manufacturers,

therefore, reduced the TOCP content of

their products. However, a recently

submitted TSCA section 8(e) hen study

(Ref. 40) indicates that complex TCPcontaining aryl phosphates containing

less than 0.1 percent TOCP have

neurotoxic effects similar to those

arising from exposure to pure TOCP.

Three recent studies have

demonstrated the reproductive toxicity

of TCP in several species and strains of

laboratory animals (Refs. 12, 13 and 15).

The NTP and NIEHS studies both used

TCP with less than 0.1 percent TOCP,

while EPA's study used TCP with less

than 9 percent TOCP. All three studies

showed effects on male reproductive

parameters, and histopathologic effects

were seen in the ovaries in the EPAsponsored study. Both the EPAsponsored and NIEHS-sponsored

studies demonstrated developmental

toxicity, while the NIEHS study also

showed reproductive effects in the F,

generation at the lowest dose.

A two-generation reproductive and

fertility study has also been performed

on dibutyl phenyl phosphate (Ref. 29a).

In the Fo generation survivability of pups

was decreased in both the mid-level and

high dose, while in the F generation,

only the high dose was so affected.

A confidential TSCA section 8(e)

study was submitted to EPA in 1990

demonstrating similar reproductive

effects with an additional aryl

phosphate.

TOCP has been tested in a standard

rat developmental toxicity study (Ref.

67), with significant increases in mean

pup body weight at doses as low as 87.5

mg/kg. Further, the two-generation

reproductive study on TCP in mice

showed significant developmental

effects in the pups, with decreases in

litter size and live-born pups as well as

decreased body weight (Ref. 15). A onegeneration study in Long-Evans rats

with TCP (Ref. 12) also indicated

developmental toxicity effects:

decreases in percent of mothers

delivering live-born young, and

decreases in litter size and pup viability.

2. Evidence of potential for

environmental toxicity. Mayer et al.

(1981) reported rainbow trout exposed to

Pydraul 50E (aryl phosphate-containing

hydraulic fluid), Pydraul l!5E (aryl

phosphate-containing hydraulic fluid), or

either of their major aryl phosphate

components, NDP and cumylphenyl

diphenyl phosphate (CDP), developed

cataracts after 90 days' exposure. These

complex substances also affected bone

development and bone collagen content.

Reduced growth and survival rates were

seen with the two mixtures and also

with CDP. With Pydraul 115E, exposure

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to 16 pg/L (microgram/liter) and above

also caused impaired swimming and

feeding activities. This study also

examined lake trout fed Pydraul 50E for

120 days and observed cataract effects

and growth reduction at 5 pjg/L, and

effects on vertebral collagen at 2.6 Pg/L.

Growth and survival were affected in

fathead minnows exposed to Pydraul

50E for 30 days at 752 ug/L. Precursors

to eye cataracts were seen histologically

at 317 ,g/L. The most sensitive endpoint

in this series of tests was the reduced

vertebral collagen in rainbow trout

following 90 days of exposure to CDP at

0.22 Pg/L (Ref. 39).

A 4-month feeding study on Pliabrac

521, an aryl phosphate containing TPP.

TCP, TXP and cresyl diphenyl

phosphate, indicated reproductive

toxicity in the minnow (Phoxinus

phoxinus) (Ref. 5).

A 4-month exposure to IMOL S-140

(composed of TCP, TXP, and assorted

other phosphates) in rainbow trout

resulted in chronic toxicity, indicated by altered feeding behavior, increased

serum enzyme levels of serum glutamic transaminase and lactic dehydrogenase

(LDH), presence of muscle LDH in serum

and discoloration of internal fatty tissue

(Ref. 36).

Ninety-day studies in the fathead

minnow for several aryl phosphate base

stocks showed differing responses (Ref.

16). The authors indicated that for

Santicizer 148 (IDP, TPP), the most

sensitive endpoint was growth, while for

Fyrquel GT (BDP, TPP), Phosflex 31P

(TPP, IPP), and Pydraul 50E (NDP, CDP).

the most sensitive endpoint was

survival. Gross observation of the

minnows did not demonstrate the

cataract problems reported in 1981 by

Mayer et al. (Ref. 39).

3. Evidence of potential for

unreasonable risk. In determining that a

substance may present an unreasonable

risk, EPA must consider both the

potential hazard of the substance and

the potential for human and

environmental exposure to the

substance. EPA estimates that 2 million

workers and additional millions of

consumers and members of the general population may be exposed to aryl

phosphate base stocks. In fact, EPA

finds that the amount of human

exposure to aryl phosphate base stocks

is substantial. It is not necessary for

human exposure to be "substantial" to

support a finding of potential

unreasonable risk. Nevertheless, where

human substantial exposure does exist,

that exposure necessarily is widespread

enough to support the exposure

component of a potential risk finding. As

discussed above, aryl phosphates have

been shown to cause human

neurotoxicity, and the potential for

others such as liver, kidney, adrenal and

blood effects, reproductive toxicity and

developmental toxicity. The widespread

human exposure coupled with the

potential human hazards associated

with aryl phosphates indicates that aryl

phosphate base stocks may present a

risk to human health.

EPA estimates aryl phosphate base

stocks are released into the environment

in quantities of 1 million to 3 million

pounds per year. In fact, EPA finds that

1 million to 3 million pounds of aryl

phosphate base stocks released into the

environment per year constitutes

substantial release into the

environment. It is not necessary for

release into the environment to be "substantial" release to support a

finding of potential unreasonable risk to

the environment. Nevertheless, where

substantial release into the environment

exists, that release necessarily is large

enough to support the exposure

component of the potential risk finding.

As discussed above, aryl phosphate

base stocks have been shown to cause

cataracts, reduced growth and survival

rates, impaired swimming and feeding

activity, reproductive toxicity, chronic

toxicity, and reduced vertebral collagen

in fish. The large release into the

environment coupled with the potential

environmental hazards associated with

aryl phosphate base stocks indicates

that aryl phosphate base stocks may

present a risk to the environment.

From the information presented above

on the hazard potential of aryl

phosphate base stocks and the amount

of potential human and environmental

exposure to aryl phosphate base stocks

that are used in various products, EPA

finds that the manufacturing, processing,

use, distribution in commerce, and

disposal of aryl phosphate base stocks

may present an unreasonable risk of

injury to human health and the

environment.

C. Findings Under TSCA Section

4(a)(1)(A)(ii) and (B)(i)

Pursuant to section 4(a)(1)(A)(ii) and

(B)(ii) of TSCA, EPA finds that, for all

substances comprising the aryl

phosphate base stock category, data are

insufficient to determine or predict the

effects of manufacturing, processing,

distribution in commerce, or use of these

substances on health and on the

environment.

In evaluating the testing needs for the

aryl phosphate base stock category, EPA

considered all available data including

information in the ITC's report, TSCA

section 8(d) and 8(e) data, comments

received following the publication of the

ANPR, and recent scientific

publications. An EPA review (Ref. 66) of

information available through early 1987

is available. Later sources are included

in the docket for this rulemaking.

Without more complete information

regarding what was actually tested, and

in some cases, how the studies were

performed, none of the studies discussed

in Unit II.B of this preamble are

acceptable to EPA for the purpose of

risk assessment.

1. Subchronic effects. Monsanto

submitted a 3-month feeding study on

DBP with Sprague-Dawley rats in March

1987 (Ref. 49). The study was not

conducted according to EPA guidelines,

as EPA's GLPs require a detailed

analysis of all components in the tested

compound. However, the report only

identified the components (DBP, butyl

diphenyl phosphate and TBP) and gave

no percentage composition. Analyses of

test material in food reported only the

levels of DBP.

Similarly, two other subchronic

studies, one on TCP (Ref. 59) and the

other on Santicizer 148 (Ref. 48), appear

to meet the Agency's guidelines (or their

equivalent), but inadequate test

substance identification.

A subchronic study on tertbutylphenyl diphenyl phosphate (Ref.

43) may have an appropriate test

protocol, but the high dose (1000 ppm in

the diet) induced no treatment-related

effects. EPA guidelines require that the

high dose for a subchronic study induce

some significant toxicity. In lieu of this

EPA needs evidence that an appropriate

high dose level was selected. In some

cases EPA has accepted studies that use

a level that exceeds potential human

exposure by at least a factor of a

hundred. These conditions have not

been met for this study.

2. Neurotoxicity. Standard acute hen

studies demonstrated OPIDN for TCP,

TXP and IPP. Subsequently, FMC

conducted a 90-day subchronic assay in

the hen with Kronitex 50 (IPP) that may

have been sufficient to reasonably

predict or determine IPP neurotoxicity,

but information on the material tested

was insufficient for EPA to evaluate the

study. The study in question describes

the material tested simply as C8096-126-

1 Phosphate Ester from FMC. However,

FMC's cover letter stated this was

Kronitex 50 (Ref. 24). The Material

Safety Data Sheet (MSDS) (Ref. 25)

gives the composition of Kronitex 50 as

phenol, isopropylated, phosphate (3-1)

(Cas No. 68937-41-7). EPA has three

technical listings of the chemical

analysis of Kronitex 50 (none associated

with this study): two from the

manufacturer (Refs. 20 and 21) and one

from the published literature (Ref. 53).

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The three listings are significantly

different. For instance, the level of

triphenyl phosphate in the three papers

ranges from 24.9 to 33 percent. This

difference may not affect the final

toxicity result, but EPA is requesting

comment on this issue (Unit IV.A.1 of

this preamble).

A multi-dose study of TOCP has been

performed in England, but published

data on the methodology do not give

enough information for EPA's needs

(Refs. 56 and 57).

Acute neurotoxicity results on the

tert-butylphenyl phosphates are mixed.

Of the 12 studies on various forms of

tert-butylphenyl phosphate, 7 are

negative but 5 show diverse levels of

OPIDN (Refs. 22, 23, 44, and 65 [two

reported in Ref. 22]).

EPA does not propose repeating acute

hen neurotoxicity studies for those aryl

phosphate base stocks for which

acceptable studies have already been

completed and reviewed for the ANPR.

However, DBP, one of the chemicals

subject to this proposed rule, was acutely tested by Industrial Bio-Test.

Tests carried out by the latter laboratory

are questionable, but if the results were

independently and appropriately

audited, and the test substance

adequately defined, EPA will decide if it

is acceptable or whether further testing

is required.

3. Reproductive effects. A twogeneration reproductive study on TCP

has been performed by NIEHS (Ref. 15).

This was a continuous breeding study in

mice using TCP with less than 0.1

percent TOCP. Reproductive effects

were seen in both sexes, with sperm

motility decreases seen in the F1

generation at the lowest dose tested. A

recent section 8(e) study (claimed as

CBI) on another aryl phosphate base

stock showed similar effects.

A two-generation reproductive and

fertility study has also been performed

on dibutyl phenyl phosphate (Ref. 29a).

This study also was done using EPA

guidelines, except for lack of

information on the test substance. In the

Fo generation survivability of pups was

decreased in both the mid-level dose

and the high dose, while in the F

generation, only the high dose was so

affected.

These studies may be acceptable to

EPA for risk assessment if submitters

can demonstrate that the test

substances used were equivalent to

what is now manufactured.

The studies on developmental toxicity

submitted to EPA also lack adequate

identification of test substance.

Monsanto reported on studies for two

plasticizers, Santicizer 141 and

Santicizer 148 (Ref. 58). The study

protocols are adequate, but the 3000 mg/

kg/day high dose for the Santicizer 148

did not cause significant maternal

toxicity. EPA guidelines require that

significant maternal toxicity be elicited

at the highest dose, to determine

whether developmental toxicity will

occur at levels below those that are

toxic to the mother. That is, if no

developmental effects are seen, then

regulating the dose affecting the mother

will protect the child. As with the

subchronic toxicity guidelines, if the

dose is high enough to guarantee a

hundred-fold level above potential

human exposure, then EPA may

consider the study adequate.

Monsanto performed two additional

developmental toxicity studies, on

Santicizer 154 (Ref. 47) and BDP (Ref.

45), but neither produced maternal

toxicity.

4. Environmental effects. EPA

believes acute fish toxicity information

is adequate for the substances tested.

Because information from the ELS

testing will include acute range-finding

data, EPA is not proposing acute toxicity

testing for untested aryl phosphate base

stocks. However, data on long-term

effects are deficient, and more

information is needed for risk

assessment. Fish toxicity data discussed

in Unit II.B of this preamble are

primarily from European studies on

marketed products; the test substances

for which analytical information was provided did not appear to include any

aryl phosphate base stocks presently

marketed in the United States.

D. Findings Unders TSCA Sections

4(a)(1)(A)(iii) and (B)(iii)

Pursuant to section 4(a)(1)(A)(iii) and

(B)(iii) of TSCA, EPA finds that testing

of these substances is necessary to

determine or predict the effects of

manufacturing, processing, use,

distribution in commerce and disposal

of all substances in the aryl phosphate

base stocks category.

Under section 4(a)(1)(A)(iii) and

(B)(iii), EPA finds that testing aryl

phosphate base stocks is necessary to

develop data for chemical analysis,

organophosph. rus-induced delayed

neuropathy, two-generation

reproductive and fertility effects, 120-

day post-hatch rainbow trout ELS

effects, anaerobic biodegradation,

chronic Daphnia toxicity, subchronic

toxicity, aerobic biodegradation,

microcosm effects, subchronic

neurotoxicity and developmental

toxicity. EPA believes that data

resulting from this testing will be

relevant to a determination as to

whether manufacturing, processing,

distribution in commerce, use and

disposal of aryl phosphate base stocks

does or does not present an

unreasonable risk of injury to health or

the environment.

III. Proposed Rule

A. Proposed Testing and Test Standards

On the basis of the findings in Unit II

of this preamble, EPA is proposing a test

rule for aryl phosphate base stocks that

meet the category definition specified in

Unit L.A of this preamble.

This would be a two-stage test rule.

First, the rule would require submission

of chemical analysis data obtained by

GC/MS. EPA would require for firststage information any individual aryl

phosphate positional isomer, except

TOCP, or any other substance present in

a base stock, to be identified and

quantitated if present at a concentration

of 1 percent or greater, quantitation for

TOCP would be required to ±0.5

percent. TOCP would have to be

quantitated, to ±h0.05 percent, unless

present at less than 0.10 percent. The

Agency would notify manufacturers by

certified mail if: (1) A particular

chemical to be tested demonstrates

equivalence to another manufacturer's

product and testing costs may be

shared; or, (2) the chemical in question

does not demonstrate equivalence to

another aryl phosphate base stock and

testing costs may not be shared.

EPA would evaluate the analytical

chemistry data and determine whether

any base stock is equivalent to another.

EPA proposes as equivalence criteria

that any two base stock substances be

considered equivalent if all the

individual aryl phosphate components

of the two substances are within 2

percent of each other, unless, for a

situation involving three or more base

stocks, this results in a range greater

than 4 percent for any component. In

such a case. EPA would apply its best

scientific judgement.

Because of the economic impact of

certain of these tests on some category

members, EPA has prioritized the

second-stage tests, providing three

levels of testing. Level I is the base set

of required testing for aryl phosphate

base stocks having aggregate annual

production volumes of at least I but less

than 5 million pounds: 120-day posthatch rainbow trout ELS test; three hen

neurotoxicity tests - acute neurotoxic

esterase (NTE), acute organophosphate

delayed neuropathy, and subchronic

organophosphate delayed neuropathy

(lriggered by a positive NTE or positive

acute OPIDN study); and a twogeneration reproductive test. Level 2

includes additional tests required for

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aryl phosphate base stocks having

aggregate annual production volumes of

at least 5 but less than 10 million

pounds: anaerobic biodegradation;

chronic Daphnia; and subchronic

toxicity. Level 3 includes additional

testing for aryl phosphate base stocks

having aggregate annual production

volumes of at least 10 million pounds:

aerobic biodegradation; microcosm;

developmental toxicity; subchronic rat

neurotoxicity - functional observation

battery (FOB), motor activity (MA) and

neuropathology (NP). EPA would notify

manufacturers when they meet trigger

levels, as determined from the proposed

section 8(a) production reporting.

Present and future aryl phosphate base

stock manufacturers would be subject to

testing requirements.

Proposed Test Standards CFR citations

Level I ............................................ 120-Day post-hatch trout 40 CFR 797.1600

ELS.

Neurotoxicity in the hen ........... Acute NTE .............................. 40 CFR 798.6450

Acute OPIDN ......................... 40 CFR 798.6540

Subchronic OPIDN, if trig- 40 CFR 798.6560

gered.

Two-generation reproduction 40 CFR 798.4700

and fertility effects.

Level 2 ......................... Anaerobic biodegradation ........ 40 CFR 796.3140

Chronic Daphnia ........................ 40 CFR 797.1350

Subchronic toxicity .................... 40 CFR 798.2650

Level 3 ............................................ Aerobic biodegradation ............. 40 CFR 799.700

(Bourquin paper

(Ref. 9)

incorporated by

reference)

Microcosm ecosystem .............. 1797.3050

(proposed)

Neurotoxicity in the rat (may

be combined with subchronic per specific guideline

instruction; FOB and MA

acute testing required). FOB ......................................... 40 CFR 798.6050

MA ........................................... 40 CFR 798.6200

NP ........................................... 40 CFR 798.6400

Developmental toxicity .............. 40 CFR 798.4900

The original ITC designation also

recommended EPA investigate

mutagenicity and oncogenicity and

conduct epidemiology studies. However,

considerable mutagenicity testing on

aryl phosphates before and after the

ANPR has been predominately negative,

and EPA is not proposing such testing at

this time. NTP is testing TCP for

oncogenicity, and EPA has decided to

await the outcome of this study before

deciding if oncogenicity testing on other

aryl phosphate base stocks is necessary.

Any subsequent oncogenicity

requirement would be the subject of a

separate rulemaking. Epidemiology is

discussed in Unit IV.5 of this preamble.

New aryl phosphate base stocks

subject to TSCA section 5 would also be

subject to this rule. Section 5(b) of TSCA

requires that if a person submits a notice

to EPA under section 5(a)(1) before the

manufacture or processing of a chemical

substance, and the substance is subject

to a section 4 test rule promulgated

before the submission of such notice, the

data required by the section 4 test rule

shall be submitted at the same time

notice is submitted in accordance with

section 5(a)(1). In other words, anyone

making a "new" aryl phosphate base

stock must first do the chemical analysis

under § 799.700(e) and submit that

analysis with the premanufacture

notification to comply with

§ 799.700(c)(2). New chemical

manufacturers will not be required to do

tiered testing, however, until EPA has

evaluated the chemical analysis data

and determined if that aryl phosphate

base stock is equivalent to any other

substance, and if an aggregate

production volume triggering stage 2

testing for that group of equivalent

substances has been met. If, at the time

a final test rule is promulgated, a

substance has already been submitted

to EPA and is being reviewed pursuant

to section 5(a), EPA requires that the

submitter provide the data required by

this test rule. Category members subject

to a section 5(e) order (i.e., already

reviewed by EPA and being regulated)

will be re-reviewed by EPA to determine

if data required by the test rule are

necessary.

B. Test Substances

All aryl phosphate base stocks, as

defined by this rule, would be subject to

this test rule. EPA has identified 12 aryl

phosphate base stocks that are in

production at this time (Ref. 55). Base

stocks differing from one another by

more than 2 percent in a single

component (0.1 percent for TOCP)

would be considered different base

stocks for purposes of this rule. Any

other base stock meeting the definition

of aryl phosphate base stocks that EPA

is not aware of or that comes into

production in the future would also be

subject to this test rule. See Unit I.C.3.d

of this preamble for a more complete

discussion of the background and

decisions for the following substance

listings.

The 12 aryl phosphate base stocks

EPA believes are in production are as

follows:

1. tert-Butylphenyl diphenyl

phosphate (CAS No. 56803-37-3) or

isobutylenated phenol, phosphate (3:1)

(CAS No. 68937-40-6) (based on a 1:3

mol ratio isobutylene to phenol).

2. bis-(tert-Butylphenyl) phenyl

phosphate (CAS No. 65652-41-7)or

isobutylenated phenol, phosphate (3:1)

(CAS No. 68937-40-6) (based on a 2:3

mol ratio isobutylene to phenol).

3. tris-(tert-Butylphenyl) phosphate

(CAS No. 78-33-1) or isobutylenated

phenol, phosphate (CAS No. 68937-40-6)

(based on a 1:1 mol ratio isobutylene to

phenol).

4. Di(n-butyl) phenyl phosphate (CAS

No. 2528-36-1).

5. 2-Ethylhexyl diphenyl phosphate

(CAS No. 1241-94-7).

6. Isodecyl diphenyl phosphate (CAS

No. 29761-21-5).

7. Isopropylphenyl diphenyl

phosphate (CAS No. 2810&-99--8) or

phenol, isopropylated, phosphate (3:1)

(CAS No. 68937-41-7) (based on a 1:3

mol ratio propylene to phenol).

8. bis-(Isopropylphenyl) phenyl

phosphate [CAS No. 28109-00-4) or

phenol, isopropylated, phosphate (3:1)

(CAS No. 68937-41-7) (based on a 2:3

mol ratio propylene to phenol).

9. tris-(Isopropylphenyl) phosphate or

phenol, isopropylated, phosphate (3:1)

(CAS No. 68937-41-7) (based on a 1:1

mol ratio propylene to phenol).

10. Tricresyl phosphate (CAS No.

1330-78-5), or tar acids, cresylic, phenyl

phosphate (CAS No. 68952-35-2).

11. Triphenyl phosphate (CAS No.

115-86--6).

12. Trixylyl phosphate (CAS No.

25155-23-1) or tar acids, cresylic, C-8

rich, phenyl phosphate (CAS No. 68952-

33-6).

For this proposed rule, EPA would not

require testing of pure chemicals, but

rather the base stocks to which persons

(manufacturing workers, users,

consumers, general populace, etc.), or

the environment are actually exposed.

EPA would require chemical analysis as

the first stage of testing to help define

equivalence for category members.

Any substance meeting the aryl

phosphate base stock category

definition, even if not named in the final

rule, would be considered a member of

this category and subject to this test

rule.

C Persons Required to Test

Because of the findings in Unit II of

this preamble, EPA is proposing that

persons who manufacture (including

persons who import) or process or

intend to manufacture and/or process

an aryl phosphate base stock as defined

by this rule, at any time from the

effective date of the final test rule to the

end of the reimbursement period, be

subject to the testing requirements

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contained in this proposed rule. This

period is defined in 40 CFR 791.3(h).

Each manufacturer of a specific aryl

phosphate base stock would pay a pro

rata share of the aggregate cost of

testing that specific test substance In

proportion to its market share.

Manufacturers (including importers)

potentially subject to this rule should

consult the procedures in 40 CFR part

790. As explained in 40 CFR part 790,

initially manufacturers, but not

processors, of one or more of these

substances would be required to submit

letters of intent or exemption

applications. Pursuant to a recent

amendment to part 790, small quantity

research and development

manufacturers are not required to

submit letters of intent or exemption

applications. Such manufacturers should

consult the Federal Register at 55 FR

10881, May 7, 1990, for further details.

Product compositions may change

because of feedstock or processing

changes, and the toxicity of individual

aryl phosphate components can vary

widely. For this reason, chemical

analysis data are needed to define the

test substance and to prove equivalence

of products if there are two or more

manufacturers. As new manufacturers

move into the market, they would also

have to demonstrate equivalence, or

conduct testing. The Stage I chemical

analysis would be required for each inproduction aryl phosphate base stock in

this category.

D. Reporting Requirements

As required under 40 CFR 799.10, EPA

is proposing that all data developed

under this rule must be reported in

accordance with its GLP standards

which appear in 40 CFR part 792.

As required by TSCA section

4(b)(1)(c), EPA is proposing specific

reporting requirements for each of the

proposed test standards as follows:

Final reports for the first stage of this

test rule, the chemical analysis data,

would be due no later than 6 months

after the date of publication of the final

rule.

Final reports for second stage studies

would be due at Intervals specified

below following the notification of

manufacturers by EPA by certified mail

that the second stage of testing should

begin on their substance or that

production volume had triggered

another level of testing.

Proposed Test Standards

Level ............. ...................................... ....... ......................................................................................... 120-Day post-hWAt trout ELS ....... ........ ..... . .......................... ........... . ....................................

Neurotoxicity in the hen ................. Acute NTE ............................

Acute OPIDN ........................

Subchronic OPIDN.............

Two-generation reproduction and

Anaerobic bodegdatlon .............................................................................. Chronic Daohna ................ .............. . .. ........ ................... .......................... ......... . ...... ..

Subchronic toxicity .........................................................................

Level 3 . ... . .. .... . ....... . .. ............ .... .............................................................................................

Aerobic biodegradation ........................ ..........................................................................................

M icrocosm ecosystem .........................................................................................................................

Neurotoxicity in the rat (may be 'combined with subchronic per spectlicguldeline instruction;

FOB and MA acute testing required). FOB ......................................................... .................................................................................

M A .................................................................................................................

NP ................i........i.........................................................................................

Developm ental toxdcily ........... ........ ....... .............. ...................................................................................

Reporting Requirements

18 months

6 months

6 months

18 months

24 months

12 months

12 months

18 months

12 months

24 months

18 months

18 months

18 months

12 months

Progress reports on these tests would

have to be submitted to EPA every 6

months, beginning 6 months after EPA

notifies the manufacturers testing must

proceed, until the final report is

submitted.

TSCA section 14(b) governs EPA's

disclosure of all test data submitted

pursuant to section 4 of TSCA. Upon

receipt of data required by this rule,

EPA will publish a notice of receipt in

the Federal Register as required by

section 4(d) of TSCA.

IV. Issues for Comment

A. Issues Relating to Choice of Test

Substances

1. EPA requests comments on EPA's

approach to choosing test substances.

Most aryl phosphate toxicity testing

has been performed on multicomponent

technical grade substances. EPA

considered requiring testing of

individual components because the

literature has documented differences in

toxicity between components and

between individual isomers, but rejected

this approach as impractical and too

expensive. Instead EPA is proposing to

require testing of aryl phosphate base

stocks. These may vary significantly

from manufacturer to manufacturer and

perhaps between batches. EPA is

proposing that base stocks differing

from one another by more than 2 percent

in a single component (0.1 percent for

TOCP) be considered different base

stocks for purposes of this rule. Would

this result in an unnecessary or

burdensome amount of base stock

testing? Are there better ways or more

appropriate criteria to define and

differentiate base stocks?

2. How should the specific test

substances be chosen?

EPA is proposing the first stage of this

two-stage rule to enable the Agency to

assess the identity and proportions of

constituents of individually

manufactured aryl phosphate base

stocks. EPA is addressing this issue up

front rather than through the exemption

application process. To assure equitable

sharing of second-stage testing

responsibilities and costs among

manufacturers in cases where multiple

manufacturers produce aryl phosphate

base stocks judged by EPA to be

equivalent, the Agency would have

three alternative courses of action, as

follows:

- To have EPA or the manufacturers

choose one of equivalent substances for

testing.

................... ............................. .................... .... ............... ......... ...................................................................................................

.............. ............................... ....... ...... ............ .......

fer" effectB ......................... ......

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rides

- To require testing of a composite

mixture of equivalent aryl phosphate

base stocks. - To define a "standard" test

substance for each group of equivalent

substances.

EPA is proposing in this Notice that

EPA will choose one of the equivalent

substances for testing, but desires

comment on this.

3. What level of quantitation should

EPA require in the chemical analysis?

Should there be a requirement to

quantitate any chemical component

other than TOCP of an aryl phosphate

base stock more precisely than ±2.0

percent?

Except for TOCP, the rule would

require chemical analysis with

identification of all components of the

manufacturers' products present at a

level of 1.0 percent or greater. However,

data reported in Ref. 40 suggest that

observed neurotoxicity from TCP may be due to TOCP present at less than 0.1

percent. Thus, the Agency is proposing

to require quantification for TOCP if its

concentration is 0.10 percent or greater. For comparison, the Office of Pesticide

Programs (OPP) requires identification

of all chemicals present in the test

material at or above 1.0 percent

concentration.

4. How detailed should EPA make the

chemical analysis requirement, and

what are the most useful techniques?

Should EPA allow each submitter to

supply justification for the methods he

chooses, or require a specific method?

EPA is proposing to require for the

chemical analysis GC/MS, which may be the best method for conducting

chemical analyses for these compounds,

as all these aryl phosphate base stock

components are sufficiently volatile.

However, isomers in products such as

TCP and TXP are difficult to separate

even on capillary columns.

Determination of specific components such as TOCP, and analysis of phenolic moieties by gas-liquid chromatography

following alkaline hydrolysis of the

phosphate esters has been proposed (Ref. 50). Alternatives to GC include: - Gel permeation chromatography. . High performance liquid

chromatography.

• Supercritical fluid chromatography.

Alternatives to MS (which may be too

destructive of the separated particles for

good analysis) include:

" Nuclear magnetic resonance.

• Infrared radiation.

" Ion track detector.

Should any of these methods be

considered as alternatives, particularly

if the proposed method may cause

destruction of the sample?

5. Does the exposure information on

aryl phosphates support testing for all

identified base stocks? Could results of

more limited testing be used as a screen

to develop whether or not it is necessary

to test additional base stocks?

B. Issues Related to Required Testing

1. Should EPA propose another level

that would have no production trigger

and would include only the hen

subchronic neurotoxicity and a onegeneration reproductive toxicity test for

those chemicals where economic impact

is severe?

According to information received by

EPA. some of the aryl phosphate base

stocks do not have an aggregate

production level that EPA has

determined will adequately support the

required Level I testing costs. The tests

proposed in Level I are based on known

toxicity for the category, and, In some

instances, on toxicity of certain

components of the base stocks.

2. Should EPA require developmental

neurotoxicity testing of aryl phosphate

base stocks?

EPA is requiring both hen (acute

delayed neurotoxicity and NTE, and

subchronic delayed neurotoxicity, if

triggered) and rat (FOB, MA, NP)

neurotoxicity studies, but is not

proposing to require developmental

neurotoxicity testing at this time. EPA's

Science Advisory Panel recommended

that one criterion for requiring the

developmental neurotoxicity screen be

"*** test substances that produce

neuropathology in developing or adult

animals." and another criterion be "'

strong structure-activity relationships

with known neurotoxicants" (Ref. 70).

Should EPA propose a developmental

neurotoxicity test requirement in a

subsequent rulemaking if neurotoxicity

test results in the rat are positive?

3. Should EPA again consider

Investigating whether some form of

epidemiological study is indicated?

EPA did not suggest epidemiological

neurotoxicity studies in the ANPR

because available information suggested

that a valid cohort was too difficult to

identify. However, the Agency is

interested in determining if a valid

cohort may now be identified.

Epidemiological studies of neurotoxic

and/or reproductive effects may be

warranted because of the suggestive

new toxicity data in these areas.

4. Should EPA require that the

rainbow trout ELS test be expanded to

include histopathological examination

specifically for cataracts, bone

development and bonercollagen deficits

as seen in Ref. 39, or carried for a longer

post-hatch period, e.g., 6 months, to

better ensure that any such effects will

be observed?

EPA is proposing to extend the usual

90 day post-hatch duration of the ELS

test in the trout to 120 days post-hatch

as a surrogate for a chronic fish test, for

which EPA has no guideline. Cataracts

and reduced vertebral collagen were

seen in long-term studies of at least 3 to

4 months in trout, but not detected in a

30-day study in minnows, although

histological precursors were detected

(Ref. 39).

5. Should EPA require additional

testing for the aryl phosphate base

stocks to address memory and other

neurobehavioral deficits if brain and

blood acetylcholinesterase inhibition is

significant?

The proposed subchronic toxicity test

would include tests for blood and brain

acetyicholinesterase (AChE) inhibition.

References cited in the 1971 ACGIH

Documentation of the Threshold Limit

Values reported significant decreases in

plasma cholinesterase in workers

exposed to TOCP and of red blood cell

cholinesterase in workers exposed to

TPP, even though the authors found no

other effects (Ref. 4). Of more concern, a

recent study on an organophosphate

pesticide, diisopropylfluorophosphate,

showed significant effects on short- and

long-term memory, impaired matching

accuracy and lengthened response times

at levels at which the only other effect

observed was depressed brain AChE

(Ref. 11). and only after extended

treatment with the chemical.

6. Is there a CBI problem if EPA

informs all manufacturers of a given

base stock substance that there are

other manufacturers of the same

substance and who those manufacturers

are, and that an aggregate production

volume trigger was met for that

substance?

7. EPA is aware of the

interchangeability of some aryl

phosphates for the same end use. To

gain a greater understanding of this

factor which plays a role in the

evaluations of the economic impact of

this proposed rule, EPA is requesting the

submission of additional data relating to

interchangeability.

C. Other Issues

1. Should EPA require reporting of

exposure and release information

beyond that proposed in the test rule?

EPA is proposing TSCA section 8(a)

PAIR reporting for manufacturers of the

aryl phosphate base stocks to enable

EPA to make better decisions on which

base stocks can support the testing.

Preliminary information indicates that a

great deal of human exposure and

I I II I I I I

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

environmental release results from

processing and use of products

containing aryl phosphate base stocks,

suggesting that EPA may miss important

information by not requiring processors

to report.

2. EPA has defined three productionlevel triggers, one at I million pounds for

potential unreasonable risk findings, one

at 5 million pounds and one at 10 million

pounds for additional testing. EPA

solicits comment on whether these

triggers comport with manufacturers'

ability to pay for the level of testing. Is it

appropriate to use these triggers based

on a high production/high exposure

concern? If an exposure value should be

included, what should it be and how

could EPA apply it as a triggering

mechanism?

V. Economic Analysis of Proposed Rule

EPA has prepared an economic

analysis of this proposed rule (Ref. 6).

The analysis estimates the costs of

conducting the proposed testing for each

of the chemicals, including both

laboratory and administrative costs, and

evaluates the potential for economic

impacts as a result of these test costs,

using a comparison between a

chemical's annualized test costs and its

annual revenues.

The estimated total cost of the

maximum possible testing for each

chemical is $1,076,988 to $1,656,638.

In order to evaluate the potential

economic impacts of the proposed

testing, test costs are annualized and

compared with annual revenues from

the chemicals. The annualized test costs,

using a 7 percent cost of capital over a

period of 15 years are $53,974 to $81,167

for Level 1; for Levels 1 and 2, the costs

are $86,681 to $99,516; for all 3 Levels,

the costs are $118,247 to $181,890. The

costs of chemical analysis were not

estimated because no protocols were

identified for this test. Therefore these

costs may be underestimated.

The comparison between annual costs

and revenues suggests that for four

chemicals, the maximum test cost may

have no significant adverse economic

impacts. For the remaining chemicals,

the test costs do appear to pose some

potential for adverse economic impacts.

Please refer to the economic analysis

contained in the public record for this

rulemaking for more details on test cost

estimations and the evaluation of

economic impacts. EPA's proposed

festing and standards devised to reduce

the impact of testing costs is described

in Unit III.A of this preamble of this

notice.

VI. Availability of Test Facilities and

Personnel

EPA has determined that test facilities

and personnel are available to perform

the testing specified in this proposed

rule. (Ref. 8).

VII. Public Meeting

If requests for oral comments are

submitted, as indicated in the dates

section, EPA will hold a public meeting

after the close of the public comment

period in Washington, DC. Persons

wishing to present comments or attend

the meeting should call Mary Louise

Hewlett, (202) 260-8162. The meetings

are open to the public, but active

participation will be limited to those

who requested to comment and EPA

representatives. Participants are

requested to submit copies of their

statements by the meeting date. These

statements and a transcript of the

meeting will become part of EPA's

record for rulemaking.

VIII. Comments Containing Confidential

Business Information

All comments will be placed in the

public file unless they are clearly

labeled as Confidential Business

Information (CBI) when the comments

are submitted.

While a part of the record, CBI

comments will be treated in accordance

with 40 CFR part 2. A sanitized version

of all CBI comments should be

submitted to EPA for the public file.

It is the responsibility of the

commenter to comply with 40 CFR part 2

in order that all materials claimed as

confidential may be properly protected.

This includes, but is not limited to,

clearly indicating on the face of the

comment (as well as on any associated

correspondence) that CBI is included,

and marking "CONFIDENTIAL", "TSCA

CBI" or similar designation on the face

of each document or attachment in the

comment that contains CBI. Should

information be put into the public file

because of failure to clearly designate

its confidential status on the face of the

comment, EPA will presume any such

information that has been in the public

file for more than 30 days to be in the

public domain.

IX. Rulemaking Record

EPA has established a record for this

rulemaking, (docket number OPPTS42038A). This record contains the basic

information considered by the Agency in

developing this proposal and

appropriate Federal Register notices.

This record includes the following

information:

A. Supporting documentation

(1) Federal Register notices pertaining

to this rule consisting of:

(a) Notice containing the ITC

designation of the chemical category of

aryl phosphates to the Priority List (43

FR 16684, April 19, 1978).

(b) Rule requiring TSCA section 8(a)

reporting on the chemical category of

aryl phosphates (47 FR 26992, June 22,

1982).

(c) Rule requiring TSCA section 8(d)

reporting on the chemical category of

aryl phosphates (47 FR 38780, September

2, 1982).

(d) TSCA test guidelines cited as

proposed test standards for this rule, 40

CFR parts 796, 797, and 798.

(e) Notice of final rule on EPA's TSCA

Good Laboratory Practice Standards (54

FR 34034, August 17, 1989).

(f0 Notice of interim final rule on

single-phase test rule development and

exemption procedures (50 FR 20652, May

17, 1985).

(g) Notice of final rule on data

reimbursement policy and procedures

(48 FR 31786, July 11, 1983).

(h) Advance notice of proposed

rulemaking for aryl phosphates (48 FR

57452, December 29, 1983).

(i) Notice of Inventory Update Rule

(51 FR 21447, June 12, 1986).

0) Notice of Agency's first and second

proposed test rules (45 FR 48510, July 18,

1980 and 46 FR 30300, June 5, 1981).

(2) Communications before proposal

consisting of:

(a) Written public comments and

letters.

(b) Contact reports of telephone

conversations.

B. References

(1) Abou-Donia, M.B. and D.M. Lapadula.

Mechanisms of organophosphorus esterinduced delayed neurotoxicity. Annual

Review of Pharmacology and Toxicology

30:405-440 (1990).

(2) Ahrens, V.D., Henion. J.D., Maylin, G.A.,

Leibowitz, L, St. John, LE., Jr., and D.J. Lisk.

A water-extractable toxic compound in vinyl

upholstery fabric. Bulletin of Environmental

Contamination and Toxicology 20:418-422

(1978).

(2a) American Chemical Society Committee on Environmental Improvement. Guidelines

for data acquisition and data quality

evaluation in environmental chemistry.

Analytical Chemistry 52:2242-2249 (1980).

(3) American Conference of Governmental

Industrial Hygienists. TLVs: Threshold limit

values and biological exposure indices for

1986-1987. American Conference of

Governmental Industrial Hygienists,

Cincinnati, OH (1986).

(4) American Conference of Governmental

Industrial Hygienists. Documentation of the

threshold limit values for substances in

workroom air. American Conference of

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Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

Governmental Industrial Hygienists.

Cincinnati. OH (1974).

(5) Bengtsson, B.E., Tarkpea, M., Sletten, T.,

Carlberg, G.E., Kringstad, A. and L. Renberg.

Bioaccumulatlon and effects of some

technical triaryl phosphate products in fish

and Nitocra spinipes. Environmental

Toxicology and Chemistry, 5:853-.1 (1986).

(6) Blake-Hedges, L Economic analysis of

proposed test rule for twelve aryl phosphates

(non-CBI version). CBI version DCN

20911000422. Regulatory Impacts Branch,

Office of Pollution Prevention and Toxics

(OPPT), United States Environmental

Protection Agency (USEPA) (April 26, 1991).

(7) Boethling, R.S. and J.C. Cooper.

Environmental fate and effects of triaryl and

tri-alkyl/aryl phosphate esters. Residue

Reviews 94:49-99 (1985).

(8) Booz, Allen & Hamilton Inc. EPA census

of the toxicological testing industry (draft

report). EPA Contract 68D8-0111 for Office of

Policy Analysis for the Office of Pollution

Prevention and Toxics, USEPA (June 1990).

(9) Bourquin. A.W., Hood. M.A. and R.L.

Games. An artificial ecosystem for

determining effects and fate of toxicants in a

salt-marsh environment. Development in

Industrial Microbiology 18:185-191 (1977).

(10) Brinkerhoff, C.R., Sharma, R.P., and

D.R. Bourcier. The effects of tri-ortho-tolyl

phosphate (totp) on the immune system of

mice. Ecotoxicology and Environmental

Safety. 5:368-376 (1981).

(11) Bushnell, P.1., Padilla, S.S., Ward, T,

Pope, C.N. and V.B. Olszyk. Behavioral and

neurochemical changes in rats dosed

repeatedly with diisopropylfluorophosphate.

Journal of Pharmacology and Experimental

Therapeutics. 25&741-750 (1991).

(12) Carlton, B.D., Basaran, A.H., Mezza,

LE. and M.K. Smith. Examination of the

reproductive effects of tricresyl phosphate

administered to Long-Evans rats. Toxicology.

46.321-328 (1987).

(13) Carlton, B.D., Irwin, R., Hejtmancik, M.,

Deskin. R., Ryan, M. and A.C. Peters.

Reproductive toxicity of tricresyl phosphate

in male rats & mice by two dosing routes.

Toxicologist. &292 (1986).

(14) Carpenter, H.M., Jenden. D.J.. Shulman,

R. and J.R. Turman. Toxicology of a triaryl

phosphate oil. Archives of Industrial Health,

20:234-252 (1969).

(15) Chapin, R.E., George, J.D.. and J. C.

Lamb, IV. Reproductive toxicity of tricresyl

phosphate in a continuous breeding protocol

in Swiss (CD-1) mice. Fundamental and

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(16) Cleveland. L, Mayer, F.L., Buckler,

D.R.. and D.U. Palawaski. Toxicity of five

alkyl-aryl phosphate ester chemicals to four

species of freshwater fish. Environmental

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(17) Crockett A.B. Preliminary report on

aryl phosphate monitoring with attachment.

Memorandum from A.B. Crockett,

Environmental Monitoring and Support

Laboratory, Office of Research and

Development (ORD), Las Vegas, NV to M.P.

Halper, OPPT, USEPA (1978).

(18) Crockett. A.B. Analysis of aryl

phosphate samples. Memorandum from

Environmental Monitoring and Support

Laboratory, ORD, Las Vegas, NV to Pat

Hilgard, OPPT, USEPA (March 6, 1979).

(19) Daft, J.L Identification of aryl/alkyl

phosphate residues in foods. Bulletin of

Environmental Contamination and

Toxicology. 29:221-227 (1982).

(20) FMC Corporation. Gas

chromatographic-mass spectral assay of

Kronitex isopropylphenyl phosphates.

Technical report No. CGP-75-10. Princeton,

NJ. (1975).

(21) FMC Corporation. Kronitex 50 -

Mutagenicity test screening test Salmonella

microsomal assay (Ames test). Princeton, NJ

(1977).

(22) FMC Corporation. Neurotoxicity study

in hens on commercially available phosphate

ester products. TSCA section 8(d) submission

878210588 (1977).

(23) FMC Corporation. Neurotoxicity study

in hens on commercially available phosphate

ester products. TSCA section 8(d) submission

878210587 (1977).

(24) FMC Corporation. Cover letter and

unpublished study, the subchronic (90 day)

neurotoxicity of C8096-126-1 phosphate ester

to the domestic hen. TSCA section 8(d)

submission 878214930 (1988).

(25) FMC Corporation. Kronitex (R) 50,

Material safety data sheet (1988).

(26) Gartrell, M.J., Craun, I.C., Podrebarac,

D.S. and E.L Gunderson. Pesticides, selected

elements, and other chemicals in infant and

toddler total diet samples, October, 1979-

September, 1980. Journal of the Association

of Official Analytical Chemists. 8:1183-1183

(1985).

(27) Gartrell, M.J.. Craun, J.C., Podrebarac,

D.S. and E.L Gunderson. Pesticides, selected

elements, and other chemicals in adult total

diet samples, October, 1979-September, 1980.

Journal of the Association of Official

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D.S. and E.L. Gunderson. Pesticides, selected

elements, and other chemicals in infant and

toddler total diet samples. October, 1980-

March, 1982. Journal of the Association of

Official Analytical Chemists. 69:123-145

(1986).

(29) Gartrell, M.J., Craun, J.C., Podrebarac.

D.S. and EL. Gunderson. Pesticides, selected

elements, and other chemicals in adult total

diet samples, October, 1980-March, 1982.

Journal of the Association of Official

Analytical Chemists. 69:146-161 (1986).

(29a) Healy, C.E., Nair, R.S., Lemen, J.K.,

and F.R. Joharmsen. Subchronic and

reproduction studies with dibutyl phenyl

phosphate in Sprague-Dawley rats.

Fundamental and Applied Toxicology.

16:117-127 (1991).

(30) Hierholzer, K., Noetzel, H. and L

Schmidt. Comparative toxicological

investigation of triphenyl phosphate and

tricresyl phosphate. Amneimittel-Forschung.

7:585-588 (1957).

(31) Jadlocki. J.F. The environmental fate

and effects of aryl phosphates and phenolics

in wastewaters from the production of

Kronitex phosphate esters. FMC, Industrial

Chemicals Division. Princeton. NJ (1980).

(32) Johnson, M.K. Organophosphorus

esters causing delayed neurotoxic effects.

Archives of Toxicology. 34.259-288 (1975).

(33) Kawamura, K. and I.R. Kaplan.

Organic compounds in the rainwater of Los

Angeles, Environmental Science and

Technology. 17.497-501 (1983).

(34) Kneiss, J. Letter from Managing

Director of the Tributyl Phosphate Task Force

to M. McCommas, OPPT, USEPA (July 11,

1988).

(35) Lambrecht, L. Summary engineering

report. Test rule exposure assessment aryl

phosphates. Chemical Engineering Branch,

Economic and Technology Division, Office of

Pollution Prevention and Toxics. USEPA

(August 14, 1989).

(36) Lockhart, W.L., Wagemann, R.,

Clayton, J.W., Graham, B. and D. Murray.

Chronic toxicity of a synthetic tri-aryl

phosphate oil to fish. Environmental

Physiology and Biochemistry 5:361-309

(1975).

(37) Lombardo, P. and I.j. Egry.

Identification and gas-liquid chromatographic

determination of aryl phosphate residues in

environmental samples. Journal of the

Association of Official Analytical Chemists.

62:47-51 (1979).

(36) Mathtech. Aryl phosphates market

profile (non-CBI version) (July 14,1986).

(39) Mayer, F.L., Adams, W.I., Finley, M.T..

Michael, P.R., Mehrle, P.M. and V.W. Saeger.

Phosphate ester hydraulic fluids: an aquatic

environmental assessment of Pydrauls 50E

and 115E. Aquatic Toxicology and Hazard

Assessment: Fourth Conference, ASTM STP

737, D.R. Branson and K.L. Dickson, Eds.,

American Society for Testing and Materials,

pp. 103-123 (1981).

(40) McCullough, J.P. TSCA section 8(e)

notification on tricresyl phosphate (TCP) Cas

Registry number 1330-78-5. 8EHQ0788-0744S.

Mobil Research and Development

Corporation (July 21,1988).

(41) Michael, P.R. and W.I. Adams. Final

report of the 1982 industry-EPA phosphate

ester aquatic surveillance program. Monsanto

(1982).

(42) Midwest Research Institute (MRI).

Assessment of the need for limitation on

triaryl and trialkyl/aryl phosphates. EPA

Contract No. 68-01-4313 (May 15, 1979).

(43) Monsanto Company. 90-Day subacute

oral toxicity study with BPDP (tertbutylphenyl diphenyl phosphate) in albino

rats (1974).

(44) Monsanto Company. Neurotoxicity

study with Santicizer XP 728, Lot No. MIC

248788 in chickens with package of materials

relating to validation of Industrial Bio Test

Laboratories Report TSCA section 8(d)

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(45) Monsanto Company. Teratology study

in rats (IRD-77252). International Research

and Development Corporation (1979).

(46) Monsanto Company. Ninety day

feeding study in rats. TSCA section 8(d)

submission 878211005 (1980).

(47) Monsanto Company. Teratology study

in rats with test article Santicizer 154 with

cover.letter dated August 7, 1981.

International Research and Development

Corporation (1981).

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of Santicizer 148 plasticizer administered in

the diet to albino rats. TSCA section 8(d)

submission 868600001 (1986).

(49) Monsanto Company, Three month

feedin study with dibutylphenyl phosphate

with Sprague-Dawley rats. TSCA section 8(d)

submission 86870000222 (1980).

I

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Federal Register / Vol. 57, No. 12 / Friday, )anuary 17, 1992 / Proposed Rules

(50) Muir, D.C.G. Phosphate esters. The

Handbook of Environmental Chemistry, Vol.

3, Part C. 0. Huntzinger, ed., pp. 41-46 (1984).

(51) National Institute for Occupational

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updated August 6, 1980).

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Department of Health and Human Services,

NIOSH (July 1, 1990).

(53) Nobile, E.R., Page, S.W. and P.

Lombardo. Characterization of four

commercial flame retardant aryl phosphates.

Bulletin of Environmental Contaminant

Toxicology. 25:755-761 (1980).

(54) Oishi, I., Oishi, S. and K. Hiraga.

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rats. Toxicology Letters. 13:29-34 (1982).

(55) Podall, H.E. Memorandum

"Arylphosphates Associated with Specific

Uses" (sanitized version), with corrections.

Industrial Chemistry Branch, Office of

Pollution Prevention and Toxics, to Carol

Glasgow, Test Rules Development Branch,

OPPT, USEPA (April 6, 1990 and April 9,

1991).

(56) Prentice, D.E. and S.K. Majeed. A

subchronic study (90 day) using multiple

dose-levels of tri-ortho-cresyl phosphate

(TOCP): Some neuropathological

observations in the domestic hen.

Neuro Toxicology. 4:277-282 (1983).

(57) Roberts, N.L., Fairley, C. and C.

Phillips. Screening, acute delayed and

subchronic neurotoxicity studies in the lien:

Measurements and evaluations of clinical

signs following administration of TOCP.

Neuro Toxicology. 4:263-270 (1983).

(58) Robinson, E.C., Hammond, B.G.,

Johannsen. F.R., Levinskas, G.J. and D.E.

Rodwell. Teratogenicity studies of alkylaryl

phosphate ester plasticizers in rats.

Fundamental and Applied Toxicology. 7:138-

143 (1986).

(59) Saito, C., Kato, T., Taniguchi, H., Fujita,

T., Wads, H. and Y. Mori. Tests of the

subacute toxicity of tricresylphosphate (TCP)

in rats. aye Yakuri 8:107-118 (1974).

(60) Sheldon, L.S. and R.A. Hites. Organic

compounds in the Delaware river.

Environmental Science and Technology.

12:1188-1194 (1978).

(61) Smith, M.I., Engel, E.W. and E.F.

Stohlman. Further studies on the

pharmacolngy of certain phenol esters with

special reference to the relation of chemical

constitution and physiologic action. NIH

Bulletin. 160:1-53 (1932).

(621 Smith, M.I., Elvove, E., and W.H.

Frazier. The pharmacological action of

certain phenol esters, with special reference

to the etiology of so-called ginger paralysis.

US Public Health Report. 45:2509-24 (1930).

(63) Smith, M.I., Elvove, E., Valer, P.J.,

Frazier, W.H, and G.E. Mallory.

Pharmacological and chemical studies of the

cause of so-called ginger paralysis. US Public

Health Report. 45:1703-16 (1930).

(64) Stanley, .S. Broad scan analysis of the

FY82 national human adipose tissue survey

specimens. Volume III Semivolatile organic

compounds. EPA-560/5-86-037, pp, 84-85

(December 1986).

(65) Stauffer Chemical Company. Acute

delayed neurotoxicity study with Phosflex

51B in adult hens (T-6681) (1980).

(66) Syracuse Research Corporation.

Technical support document for aryl

phosphates. SRC TR-88-028 (January 29,

1988).

(67) Tocco, D.R., Randall, J.L., York, R.G.

and M.K. Smith. Evaluation of the teratogenic

effects of tri-ortho-cresyl phosphate in the

Long-Evans hooded rat. Fundamental and

Applied Toxicology. 8:291-297 (1987).

(68) USEPA. Report of a TSCA GLP

compliance laboratory inspection and data

audit. Office of Compliance Monitoring

(March 4-6, 1985).

(69) USEPA. Chemical update system.

Confidential retrieval of reporting

information of aryl phosphates from 1985:

DCN 20-901000040 (October 11, 1989).

(70) USEPA. Federal Insecticide, Fungicide,

and Rodenticide Act Scientific Advisory

Panel Subpanel: A set of scientific issues

being considered by the Agency concerning

neurotoxicity testing under FIFRA (October

16, 1987).

(71) USEPA. Tributyl phosphate; proposed

test rule. 52 FR 43346 (November 12, 1987).

(72) USEPA. STORET, Triphenyl

phosphate. Data retiieved (October 24, 1990).

(73) Versar. Untitled draft report on aryl

phosphates. Washington, DC: Office of

Pollution Prevention and Toxics, USEPA,

Contract 6801-5791 (1980).

(74) Walker, L.D., Deputy Assistant

Secretary of the Army (Environment, Safety

and Occupational Health, letter to M.

Dominiak, Chemical Control Division, Office

of Pollution Prevention and Toxics,

Environmental Protection Agency (September

5,199).

(75) Zumwalde, R.D. and C. Cottrill.

Industrial hygiene walk-through survey report

on organophosphorus exposures at Rochester

Products Division, General Motors

Corporation, 1000 Lexington Avenue,

Rochester, New York. Cincinnati, OH: U.S.

Department of Health and Human Services,

NIOSH (1980).

X. Other Regulatory Requirements

A. Executive Order 12291

Under Executive Order 12291, EPA

must judge whether a rule is "major"

and therefore subject to the requirement

of a Regulatory Impact Analysis. EPA

has determined that this test rule would

not be major because it does not meet

any of the criteria set forth in section

1(b) of the Order, i.e., it would not have

an annual effect on the economy of at

least $100 million, would not cause a

major increase in prices, and would not

have a significant adverse effect on

competition or the ability of U.S.

enterprises to compete with foreign

enterprises.

This proposed regulation was

submitted to the Office of Management

and Budget (OMB) for review as

required by Executive Order 12291. Any

written comments from OMB to EPA,

and any EPA response to those

comments, are included in this record.

B. Regulatory Flexibility Act

Under the Regulatory Flexibility Act

(15 U.S.C. 601 et seq., Pub. L. 96-354,

September 19, 1980]. EPA is certifying

that this test rule, if promulgated, would

not have a significant impact on a

substantial number of small businesses

because: (1) There are only a small

number of known small manufacturers,

(2] any small processors are not

expected to perform testing themselves

or to participate in the organization of

the testing effort, (3] they will

experience only very minor cost in

securing exemption from testing

requirements, and (4) they are unlikely

to be affected by reimbursement

requirements.

C. Paperwork Reduction Act

OMB has approved the information

collection requirements contained in this

proposed rule under the provisions of

the Paperwork Reduction Act of 1980, 44

U.S.C. 3501 et seq., and has assigned

OMB control number 2070-0033.

Public reporting burden for this

collection of information is estimated to

average 14,174 hours per response,

including time for reviewing

instructions, searching existing data

sources, gathering and maintaining the

data needed, and completing and

reviewing the collection of information.

The total public reporting burden is

estimated to be 170,088 hours for all.

Send comments regarding the burden

estimates for any other aspect of this

collection of information, including

suggestions for reducing this burden, to

Chief, Information Policy Branch, PM223, U.S. Environmental Protection

Agency, 401 M St., SW., Washington DC

20460; and to the Office of Management

and Budget, Paperwork Reduction

Project (2070-0033), Washington, DC

20503. The final rule will respond to any

OMB or public comments on the

information collection requirements

contained in this proposal.

List of Subjects in 40 CFR Parts 704 and

799

Chemicals, Chemical fate, Chemical

export, Environmental effects,

Environmental protection, Hazardous

substances, Health, Laboratories,

Recordkeeping and reporting

requirements, Testing, Incorporation by

Reference

Dated: December 26, 1991.

Victor J. Kimm,

Acting Assistant Administrator for

Prevention, Pesticides and Toxic Substances.

Therefore, it is proposed that 40 CFR

Chapter I be amended as follows:

2154
Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

1. In part 704:

PART 704-[AMENDED]

a. The authority citation for Part 704

would continue to read as follows:

Authority: 15 U.S.C. 2607

b. By adding § 704.32 to read as

follows:

§ 704.32 Aryl Phosphate Base Stocks.

(a) Substances for which reporting is

required. The chemical substances for

which reporting is required under this

rule consist of the category of aryl

phosphate base stocks, as defined in

§ 799.700 of this chapter, that are now

listed on, or in the future are added to,

the public or confidential portions of the

TSCA Inventory of Chemical

Substances maintained by EPA under

TSCA section 8(b) at any time after the

effective date of the final rule. New

chemical substances meeting this

definition shall also be subject to this

section once entered into the TSCA

Inventory of Chemical Substances.

(b) Persons who must report. The

following persons, unless exempt as

provided in § 704.5, are subject to the

reporting requirements of this rule; a

person may be required to report more

than once under this section. Those

persons who are small manufacturers as

defined in § 704.3 are also required to

report.

(1) Initial reporting. Persons who

manufacture or import any substance

identified in paragraph (a) of this section

for commercial purposes during the

person's latest complete corporate fiscal

year prior to (the effective date of the

final rule) are required to report.

(2) Subsequent reporting. Persons who

manufacture or import any substance

identified in paragraph (a) of this section

for commercial purposes after (the

effective date of the final rule) are

required to report. The persons

described in this paragraph (b)(2)

include persons who report initially in

response to paragraph (b)(1) of this

section and persons who commence the

manufacture or importation of any

substance identified in paragraph (a) of

this section after (the effective date of

the final rule).

(c) When to report-(1) Initial

reporting. Persons described in

paragraph (b)(1) of this section must

submit an initial report within 60 days of

(the effective date of the final rule).

(2) Subsequent reporting. Persons

described in paragraph (b)(2) of this

section must submit a report within 60

days of the completion of each corporate

fiscal year during which they

manufacture or import any substance

identified in paragraph (a) of this

section. Persons shall submit a separate

report for each corporate fiscal year in

which they are subject to this section.

(3) Duplicative reporting. Persons

reporting under this section are exempt,

pursuant to § 710.35 of this chapter, from

duplicative reporting for the Inventory

Update Rule.

(d) What information to report. All

persons subject to this section shall

report the following information to EPA:

(1) Company name and headquarters

address.

(2) Name, address, and telephone

number (including area code) of the

company's principal technical contact.

(3) The chemical name and Chemical

Abstracts Service Registry Number

(CAS number) of each chemical

substance identified in paragraph (a) of

this section manufactured or imported

during the latest complete corporate

fiscal year.

(4) The quantity (in pounds) of each

such substance manufactured or

imported during the latest complete

corporate fiscal year.

(5) A cross reference to any letter of

intent to test that has been submitted for

that substance under 40 CFR 799.700(d).

(e) Where to send reports. Reports

must be submitted to the U.S.

Environmental Protection Agency,

TSCA Document Processing Center (TS790), Rm. L-100, Office of Pollution

Prevention and Toxics, 401 M St., SW.,

Washington, DC 20460, Attn: TSCA

section 4, Aryl phosphates.

2. In Part 799:

PART 799--[AMENDED]

a. The authority citation for part 799

would continue to read as follows:

AUTHORITY: 15 U.S.C. 2603, 2611, 2625.

2. By adding § 799.700 to read as

follows:

§ 799.700 Aryl phosphate base stocks.

(a) Scope and purpose. This section

requires persons who manufacture,

import, or process a chemical substance

in the "aryl phosphate base stocks"

chemical category to conduct chemical

analysis and testing for health effects,

environmental effects, and chemical fate

of the substance. The extent of testing

for an individual aryl phosphate base

stock depends upon its aggregate annual

production volume. The testing

requirements are divided into two

stages. Stage one, which is required of

all manufacturers, importers, and

processors, involves chemical analysis

that will determine the chemical identity

of the base stocks produced during the

period this rule is in effect. Stage two,

which is subdivided into three levels

triggered by production volume,

involves testing for health and

environmental effects, and chemical

fate.

(1) Stage one. (i) All persons who

manufacture, import, or process, or

intend to manufacture, import, or

process a particular aryl phosphate base

stock will be responsible for conducting

chemical analysis of that substance - pursuant to paragraph (e) of this section.

(ii) From the results of these analyses,

EPA will determine whether two or

more chemicals are equivqlent and

whether further tests can be jointly

sponsored. For purposes of this section,

base stocks with greater than 2 percent

variation in a single component (0.1

percent for TOCP) will be considered

different base stocks. As provided in

paragraph (d)(3) of this section affected

persons will be notified of such

decisions by certified mail.

(2) Stage two-(i) Level 1. When the

aggregate annual production volume for

all manufactures and importers of a

particular aryl phosphate base stock is,

or reaches, 1 million pounds, all persons

who manufacture, import, or process

that substance will be responsible for

conducting the following testing of the

substance pursuant to paragraphs

(g)(1)(ii), (h)(2)(i)(B) and (h)(3)(i) of this

section: a 120-day post-hatch rainbow

trout early life stage (ELS) test, three

hen neurotoxicity assays, and a twogeneration reproductive effects study.

(ii) Level 2. When the aggregate

annual production volume for all

manufacturers and importers of an aryl

phosphate base stock substance is, or

reaches, 5 million pounds, all persons

who manufacture, import, or process

that substance will be responsible for

conducting the following testing of the

substance pursuant to paragraphs (f)(1), (g}€1l(i} (g}(1}{ii}, (h)(1), {h}{2}Ci}CB}, and

(h)(3)(i) of this section: all Level 1 testing

plus anaerobic biodegradation, chronic

Daphnia, and subchronic toxicity

studies.

(iii) Level 3. When the aggregate

annual production volume for all

manufacturers and importers of an aryl

phosphate base stock substance is, or

reaches, 10 million pounds, all persons

who manufacture, import, or process

that substance will be responsible for

conducting the following testing of the

substance pursuant to paragraphs (f),

(g), and (h) of this section: all Level 1

and Level 2 testing plus aerobic

biodegradation, a microcosm ecosystem

test, and developmental toxicity studies,

and the subchronic rat neurotoxicity

battery.

(b) Definitions. In addition to the

definitions in section 3 of TSCA and the

definitions of § 790.3 of this chapter, the

2155
Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

following definition also applies to this

section.

(1) "Aryl phosphate base stocks" are

phosphate esters or combination of

esters resulting from the reaction of a

phenol, mixtures of phenols, or a

combination of alkyl-substituted

phenols or, in some cases, phenols plus

an alcohol, with phosphorus oxychloride

(POCi3) or other phosphoric acid

derivatives. This definition includes

triaryl and mixed aryl/alkyl esters

(where one or two of the three ester

groups are alkyl).

(2) [Reserved)

(c) Identification of test substance. (1)

This section applies to any chemical

substance within the aryl phosphate

base stock category. The chemical

substances in this category listed on the

TSCA section 8(b) public inventory are

identified in this paragraph. Any aryl

phosphate base stock substance that

meets the category definition in

paragraph (b)(1) of this section shall be

tested in accordance with this section.

Base stocks differing from one another

by more than 2 percent in a single

component (0.1 percent for TOCP) shall

be considered different base stocks for

purposes of this rule.

(2) This section also applies to any

new chemical substance within the aryl

phosphate base stock substance

category. Persons subject to this section

by virtue of their intention to

manufacture or import a new chemical

substance in the category of aryl

phosphate base stock substances must

comply with this section before

submitting a premanufacture

notification (PMN) under TSCA section

5(a) for such substance.

(3) The following currently

manufactured base stock substances

meet the category definition and shall

be tested:

(i) tert-butylphenyl diphenyl

phosphate (CAS No. 56803-37-3), or

isobutylenated phenol, phosphate (3:1)

(CAS No. 68937-40-6) (based on a 1:3

mol ratio isobutylene to phenol).

(ii) bis-(tert-butylphenyl) phenyl

phosphate (CAS No. 65652-41-7), or

isobutylenated phenol, phosphate (3:1)

(CAS No. 68937-40-) (based on a 2:3

mol ratio isobutylene to phenol).

(iii) tris-(tert-Butylphenyl) phosphate

(CAS No. 78-33-1), or isobutylenated

phenol, phosphate (CAS No. 68937-40-6)

(based on a 1:1 mol ratio isobutylene to

phenol).

(iv) Di-n-butyl phenyl phosphate (CAS

No. 252&-36-1-).

(v) 2-ethylhexyl diphenyl phosphate

(CAS No. 1241-94-7).

(vi) Isodecyl diphenyl phosphate (CAS

No. 29761-21-5).

(vii) lsopropylphenyl diphenyl

phosphate (CAS No. 28108-99-8). or

phenol, isopropylated, phosphate (3:1)

(CAS No. 68937-41-7) (based on a 1:3

mol ratio propylene to phenol).

(viii) bis-(Isopropylphenyl) phenyl

phosphate (CAS No. 28109-00-4). or

phenol, isopropylated, phosphate (3:1)

(CAS No. 68937-41-7) (based on a 2:3

mol ratio propylene to phenol).

(ix) tris-(Isopropylphenyl) phosphate

or phenol, isopropylated, phosphate (3:1)

(CAS No. 68937-41-7) (based on a 1:1

mol ratio propylene to phenol).

(x) Tricresyl phosphate (CAS No.

1330-78-5), or tar acids, cresylic, phenyl

phosphate (CAS No. 68952-35-2)

(xi) Triphenyl phosphate (CAS No.

115-8)-6).

(xii) Trixylyl phosphate (CAS No.

25155-23-1), or tar acids, cresylic, C-8

rich, phenyl phosphate (CAS No. 68952-

33-6).

(d) Persons required to submit study

plans, conduct tests, submit data, and

the EPA notification plan-(1) Chemical

analysis. All persons who manufacture

(including persons who import) or

process or intend to manufacture or

process any aryl phosphate base stock

substance that meets the definition in

paragraph (b)(1) of this section

including, but not limited to, those listed

in paragraph (c)(3) of this section, from

the effective date of this section to the

end of the reimbursement period, are

subject to chemical analysis testing and

shall submit letters of intent to test.

submit study plans, conduct tests and

submit data as described in this section,

subpart A of this part, and parts 790 and

792 of this chapter for single-phase

rulemaking.

(2) Chemical fate, environmental

effects and health effects tests. All

persons who manufacture, import or

process, or intend to manufacture,

import or process any aryl phosphate

base stock substance that meets the

definition in paragraph (b) of this

section, from the effective date of this

section to the end of the reimbursement

period, shall submit letters of intent to

test, submit study plans, conduct tests

and submit data as described in this

section, subpart A of this part, and parts

790 end 792 of this chapter for singlephase rule-making.

(e) Chemical analysis-(1) Required

testing. GC/MS analysis shall be

performed on every aryl phosphate base

stock substance. The provisions of

§ 792.105(a) of this chapter require that

for each study done under Good

Laboratory Practice Standards, the

identity, strength, purity and

composition stability shall be

determined for each batch and shall be

documented before the initiation of the

study. Any individual aryl phosphate

positional isomer, except tri-ortho-cresyl

phosphate (TOCP), or any other

substance present in a base stock, must

be identified and quantitated if present

at a concentration of I percent or

greater, quantitation is required to ±0.5

percent. TOCP shall be quantitated, at

±0.05 percent, unless present at less

than 0.10 percent.

(2) Reporting requirements. Chemical

analysis shall be completed and the

final report submitted to EPA no later

than 6 months after the effective date of

this test rule or, for new chemicals, with

the Premanufacture Notification under

TSCA section 5(a).

(3) EPA notification of manufacturers.

The Agency will notify manufacturers

by certified mail if their chemical is

equivalent to another manufacturer's

and costs may be shared, or if they are

required to begin additional testing

under this test rule without co-sponsors.

The notification will also include for

each manufacturer the level of testing

that should begin for the specific aryl

phosphate base stock substance and

will specify which of any equivalent

substances must be tested.

(f) Chemical fate-(1) Required

testing--i) Anaerobic biodegradation

testing shall be performed in accordance

with § 798.3140 of this chapter upon

receipt of EPA's written notification to

manufacturers, pursuant to paragraph

(e)(3) of this section, of a particular aryl

phosphate base stock substance that

EPA has determined that the aggregate

annual production volume of that

substance equals or exceeds 5 million

pounds.

(ii) Aerobic biodegradation testing

shall be conducted using clean

freshwater sediments in accordance

with the method described in an article

by Bourquin (1977) entitled "An

Artificial Microbial Ecosystem for

Determining Effects and Fate of

Toxicants in a Salt-Marsh

Environment", published in

Developments in Industrial

Microbiology, voL 18 Chapter 11, 1977,

which Is incorporated by reference. A

copy of this material incorporated by

reference is available in the TSCA

Public Reading Room, Rm. NF-G04, 401

M St., SW., Washington, DC 20460. This

material is also available for inspection

at the Office of the Federal Register, Rm.

8401, 1100 L St., NW., Washington, DC

20408. This incorporation by reference

was approved by the Director of the

Federal Register in accordance with 5

U.S.C. 552(a) and I CFR part 51. This

method is incorporated as it exists on

the effective date of this section and

notice of any change to the method will

2156
Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

be published in the Federal Register.

The aerobic biodegradation test is

required upon receipt of EPA's written

notification to manufacturers, pursuant

to paragraph (e)(3) of this section, of a

particular aryl phosphate base stock

substance that EPA has determined that

the aggregate annual production volume

of that substance equals or exceeds 10

million pounds.

(2) Reporting requirements. {i) Each

chemical fate test shall be completed and the final report submitted to EPA

within 12 months after receipt of EPA's

written notification that the anaerobic

biodegradation or the aerobic

biodegradation testing must be initiated.

(ii) Progress reports shall be submitted

to EPA at 6-month intervals, beginning 6

months after receipt of EPA's written

notification that testing must be initiated

until submission of the final report.

(g) Environmental effects-(1)

Required testing--(i Daphnid chronic

toxicity test. The chronic test for

Daphnia shall be performed according to

§ 797.1350 of this chapter upon receipt of

EPA's written notification to

manufacturers, pursuant to paragraph

(e)(3) of this section,of a particular aryl

phosphate base stock substance that

EPA has determined that the aggregate

annual production volume of that

substance equals or exceeds 5 million

pounds.

(ii) Fish ELS toxicity test. (A) The ELS

test for aquatic toxicity in the rainbow

trout shall be performed according to

§ 797.1600 of this chapter, except the

provisions of paragraph of

§ 797.1600(c)(1)(i), upon receipt of EPA's

written notification to manufacturers,

pursuant to paragraph (e)(3) of this

section, of a particular aryl phosphate

base stock substance that EPA has

determined that the aggregate annual

production volume of that substance

equals or exceeds 1 million pounds.

(B) For the purpose of this section, the

following provisions also apply:

(1) The test terminates following 120

days of post-hatch exposure (for an

approximate total exposure period of

150 days).

(2) [Reserved]

(iii) Generic freshwater microcosm

test. The generic freshwater microcosm

test shall be performed according to

proposed § 797.3050 (52 FR 36344,

September 28, 1987) upon receipt of

EPA's written notification to

manufacturers, pursuant to paragraph

(e)(3) of this section, of a particular aryl

phosphate base stock substance that

EPA has determined that the aggregate

annual production volume of that

substance equals or exceeds 10 million

pounds.

(2) Reporting requirements. (i) The

Daphnid chronic toxicity test shall be

completed and the final report submitted

to EPA within 12 months after receipt of

EPA's written notification that testing

must be initiated.

(ii) The fish ELS test in the rainbow

trout shall be completed and the final

report submitted to EPA 18 months after

receipt of EPA's written notification that

testing must be initiated.

(iii) The generic freshwater microcosm

test shall be completed and the final

report submitted to EPA 24 months after

receipt of EPA's written notification that

testing must be initiated.

(iv) Progress reports shall be

submitted to EPA at 6-month intervals,

beginning 6 months after receipt of

EPA's written notification that testing

must be initiated until submission of the

final report

(h) Health effects-(1) Subchronic

toxicity.-(i) Required testing. (A) Oral

toxicity testing in the Sprague-Dawley

rat shall be performed by gavage in

accordance with § 798.2650 of this

chapter, except the provisions of

§ 798.2650(e)(9)(i)(B), upon receipt of

EPA's written notification to

manufacturers, pursuant to paragraph

(e)(3) of this section, of a particular aryl

phosphate base stock substance that

EPA has determined that the aggregate

annual production volume of that

substance equals or exceeds 5 million

pounds.

(B) For the purpose of this section, the

following provisions also apply:

(1) Blood acetylcholinesterase activity

shall be determined pre-dosing, and

blood and brain acetylcholinesterase

activity at termination.

(2) [Reserved]

(ii) Reporting requirements-(A)

Subchronic toxicity testing shall be

completed and a final report submitted

to EPA within 18 months after receipt of

EPA's written notification that testing

must be initiated.

(B) Progress reports shall be submitted

to EPA at 6-month intervals, beginning 6

months after receipt of EPA's written

notification that testing must be initiated

until submission of the final report.

(2) Neurotoxicity-(i) Required

testing. (A) Gavage neurotoxicity testing

in the Sprague-Dawley rat shall be

performed according to § § 798.6050,

798.6200 and 798.0400 of this chapter

upon receipt of EPA's written

notification to manufacturers of a

particular aryl phosphate base stock

substance that EPA has determined that

the aggregate annual production volume

of that substance equals or exceeds 10

million pounds (see paragraph (e)(3) of

this section). Tests conducted according

to § 798.6050 and § 798.6200 of this

chapter shall be both acute and

subchronic. The test conducted

according to § 798.6400 of this chapter

shall be subchronic. The acute studies

according to § 798.6050 and § 798.6200 of

this chapter may be incorporated into

the subchronic neurotoxicity tests. The

subchronic neurotoxicity tests may be

combined with the testing required by

paragraph (h)(1)(i) of this section if the

test protocol allows. The cited

guidelines provide standard information

for these procedures.

(B) Gavage neurotoxicity testing in the

hen shall be performed according to

§ § 798.6450, 798.6540, and 798.6560 of

this chapter upon receipt of EPA's

written notification to manufacturers of

a particular aryl phosphate base stock

substance that EPA has determined that

the aggregate annual production volume

of that substance equals or exceeds 1

million pounds (see paragraph (e)(3) of

this section). Testing according to

§ 798.6450 of this chapter shall be

performed in conjunction with

§ 798.6540 of this chapter. However, if

results for a substance tested according

to § 798.6540 and § 798.6450 of this

chapter are negative, then testing

according to § 798.6560 of this chapter

need not be conducted on that

substance.

(ii) Reporting requirements-A) Rat

neurotoxicity studies shall be completed

and the final reports submitted to EPA

within 18 months after receipt of EPA's

written notification that testing must be

initiated until submission of the final

report.

(B) The hen neurotoxicity studies

pursuant to § 798.6450 and § 798.6540 of

this chapter shall be completed and final

reports submitted to EPA within 6

months after receipt of EPA's written

notification that testing must be

initiated. If the subchronic study,

§ 798.6560 of this chapter as specified in

paragraph (g)(2)(i)(B) of this section, is

necessary, the final reporting date will

be 18 months after receipt of EPA's

written notification that testing must be

initiated.

(iii) Progress reports shall be

submitted to EPA at 6-month intervals,

beginning 6 months after receipt of

EPA's written notification that testing

must be initiated until submission of the

final report.

(3) Reproduction and fertility-(i)

Required testing. (A) Reproduction and

fertility testing shall be performed by

gavage in the Sprague-Dawley rat

according to § 798.4700 of this chapter,

except the provisions of paragraphs

(c)(7)(i), (c)(8)(ii), (c)(9)(i) and (c)(9)(iii)

of § 798.4700, upon receipt of EPA's

written notification to manufacturers,

I I 2157 21S7
Federal Register / Vol. 57, No. 12 / Friday, January 17, 1992 / Proposed Rules

pursuant to paragraph (e)(3) of this

section, of a particular aryl phosphate

base stock substance that EPA has

determined that the aggregate annual

production volume of that substance

equals or exceeds I million pounds.

(13) For the purposes of this rule, the

following provisions apply: (1) Data on female cyclicity in P and

F, females over the last 3 weeks prior to

mating shall be described. The method

of Sadleir (1979], found under paragraph (i)(6) of this section, or an equivalent

method may be used. Data shall be

provided on whether the animal is

cycling and the cycle length. P and F,

females shall continue to be exposed to

the test substance through the 3 weeks

prior to mating. The ovary shall be

serially sectioned with a sufficient

number of sections examined to

adequately detail oocyte and follicular

morphology. The methods of Mattison

and Thorgierson (1979] found under

paragraph (i)(3) of this section and

Pederson and Peters (1988) found under

paragraph (i)(4) of this section or their

equivalent provide guidance. The

strategy for sectioning and evaluation is

left to the discretion of the investigator,

but shall be described in detail in the

test protocol and final report.

(2) Measurements of homogenizationresistant spermatid count, caudal

epididymal sperm density and motility

will be provided. Assessments of

motility include quantification of

progressively motile and immotile

sperm, and techniques that utilize video

recording of the samples, as well as

objective measurement of the motility

parameters. Guidance for assessing

motility is provided by Under et al.

(19806) found under paragraph (i)(2) of

this section, and Klinefelter et al. (1991)

found under paragraph (i)(1) of this

section, or their equivalent. (3] Weights of the testes, epididymes (total and cauda), pituitary, seminal

vesicles (with coagulating glands),

prostate, ovary and uterus shall be

recorded at the time of sacrifice of the P

and F animals. Histopathology of the

testes shall be conducted on the P and

F1 males at the time of sacrifice.

Particular attention shall be directed

toward achieving satisfactory quality

from fixation and embedding, and

preparations shall follow the

recommendations of Russell et al. (1990)

found under paragraph (i)(5) of this

section, or an equivalent. Histologic

analyses shall include evaluations of the

spermatogenic cycle, i.e.. the presence

and integrity of the 14 cell stages. These

evaluations follow the guidance

provided by Russell et al. (1990) found

under paragraph (i)(5) of this section, or

an equivalent.

(ii) Reporting requirements-(A) The

reproductive and fertility studies shall

be completed and final reports received

by the EPA 24 months after receipt of

EPA's written notification that testing

must be initiated.

(B) Progress reports shall be submitted

to EPA at 6-month intervals, beginning 6

months after receipt of EPA's written

notification that testing must be initiated

until submission of the final report.

(4) Developmental toxicity-(i)

Required testing. Developmental

toxicity studies shall be performed by

gavage in the rat and rabbit according to

§ 798.4900 of this chapter upon receipt of

EPA's written notification to

manufacturers, pursuant to paragraph

(e)(3) of this section, of a particular aryl

phosphate base stock substance that

EPA has determined that the aggregate

annual production volume of that

substance equals or exceeds 10 million

pounds.

(ii) Reporting requirements-(A) The

developmental toxicity studies shall be

completed and final reports submitted to

EPA within 12 months after receipt of

EPA's written notification that testing

must be initiated.

(B) Progress reports shall be submitted

to EPA at 6-month intervals, beginning 6

months after receipt of EPA's written

notification that testing must be initiated

until submission of the final report.

(i) References. For additional

background information, the following

references should be consulted.

(1) Klinefelter, G.R., Gray, L.E., Jr. and J.D.

Suarez. "The method of sperm collection

significantly influences sperm motion

parameters following ethane

dimethanesulfonate administration in the

rat." Reproductive Toxicology. 5:39-45 (1991).

(2) Linder. R.E.. Shrader, L.F. and W.K.

McElroy. "Measurement of epididymes sperm

motility as a test variable in the rat." Bulletin

of Environmental Contaminant Toxicology.

36:317-324 (1986).

(3) Mattison, D.R. and Thorgeirsson, S.S.

"Ovarian aryl hydrocarbon hydroxylase

activity end primordial oocyte toxicity of

polycyclic aromatic hydrocarbons in mice."

Cancer Research. 39-.3471-3475 (1979).

(4) Pederson. T. and Peters. H. "Proposal

for classification of oocytes and follicles in

the mouse ovary." Journal of Reproduction

and Fertility. 17:555-557 (1968).

(5) Russell. LD.. R.A. Ettlin. Sinha Hikim,

A.P. and E.D. Clegg. "Histological and

histopathologic evaluation of the testis."

Cache River Press: Clearwater, FL (1990).

(6) Sadleir, R.M.F.S. "Cycles and

seasons." In: Reproduction in Mommals:

I. Germ Cells and Fertilization, Austin,

C.R. and R.V. Short, eds. Cambridge

Press: New York, NY (1979).

(j) Effective date. (1) The effective

date of the final rule will be (insert date

44 days after date of publication of final

rule in the Federal Register).

(2) The guidelines cited in this section

are referenced here as they exist on

(insert effective date of the final rule).

(Information collection requirements have

been approved by the Office of Management

and Budget under control number 2070-0033.)

[FR Doc. 92-1200 Filed 1-16-92 8:45 am]

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