24596 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Parts 148, 261, 268, 271, and

302

[FRL–5999–9]

RIN 2050–AD79

Organobromine Production Wastes;

Identification and Listing of Hazardous

Waste; Land Disposal Restrictions;

Listing of CERCLA Hazardous

Substances, Reportable Quantities

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: The EPA is adding two new

hazardous waste codes to its current

lists of hazardous waste found in 40

CFR part 261. One waste type to be

added and designated by the hazardous

waste code K140 is floor sweepings, offspecification product and spent filter

media from the production of 2,4,6-

tribromophenol. The second waste is

2,4,6-tribromophenol and is being

added both to the list of commercial

chemical products, designated by the

hazardous waste code U408 and to the

list of hazardous constituents in

Appendix VIII of 40 CFR part 261. EPA

is also modifying the land disposal

treatment standards for hazardous waste

in 40 CFR part 268 by adding these new

wastes. The effect of listing this waste

will be to subject it to stringent

management and treatment standards

under RCRA, as well as to emergency

notification requirements for releases of

hazardous substances to the

environment. These notifications are

required under the Comprehensive

Environmental Response,

Compensation, and Liability Act

(CERCLA or Superfund) and the

Emergency Planning and Community

Right to Know Act (EPCRA). EPA is also

issuing Reportable Quantity (RQ)

requirements for these notifications.

EPA has made a final determination not

to list as hazardous ten waste streams

from the production of

bromochloromethane, ethyl bromide,

tetrabromobisphenol A, 2,4,6-

tribromophenol wastewaters,

octabromodiphenyl oxide, and

decabromodiphenyl oxide.

DATES: Effective Date: November 4,

1998.

ADDRESSES: The official record of this

action is identified by Docket number

F–98–OBLF–FFFFF and is located at the

following address: EPA Docket Clerk,

U.S. EPA, Crystal Gateway #1, 1st Floor,

1235 Jefferson Davis Highway,

Arlington, VA. The docket is open from

9 a.m. to 4 p.m., Monday through

Friday, excluding Federal holidays. The

public must make an appointment to

review docket materials by calling (703)

603–9230. The public may copy 100

pages from the docket at no charge;

additional copies are $0.15 per page.

FOR FURTHER INFORMATION CONTACT: The

RCRA/Superfund Hotline, at (800) 424–

9346 (toll-free) or (703) 412–9810, in the

Washington, DC metropolitan area. The

TDD Hotline number is (800) 553–7672,

or (703) 486–3323, locally. For technical

information on the final listing

determination, contact Anthony Carrell

at (703) 308–0458, or

carrell.anthony@epamail.epa.gov.

For technical information on the

CERCLA aspects of this rule, contact:

Elizabeth Zeller, Office of Emergency

and Remedial Response (5204G), U.S.

Environmental Protection Agency, 401

M Street, SW, Washington, DC 20460,

(703) 603–8744.

SUPPLEMENTARY INFORMATION:

This rule is available on the Internet.

Please follow these instructions to

access the rule electronically: From the

World Wide Web (WWW), type http://

www.epa.gov/epaoswer, then select

option for Rules and Regulations.

The official record for this action is

kept in a paper format, and is

maintained at the address in the

ADDRESSES section at the beginning of

this document.

I. Affected Entities

II. Legal Authority

III. Summary of the Proposed and Final Rules

A. Background Analysis

B. Summary of Proposed Rule

C. Additional Opportunity to Comment

D. Final Rule

IV. Response to Comments

A. Development of Structure-Activity

Relationship (SAR) Analyses

B. Why the SAR Analysis of 2,4,6-TCP and

2,4,6-TBP Constitutes a Scientific Study

That Shows Toxic Effects

C. Issues Regarding the Use of StructureActivity Relationship (SAR) Analysis

D. Addition of Constituent to Appendix

VIII

E. Plausible Mismanagement Scenario and

Other Issues in the Listing Determination

for Waste Solids From the Production of

2,4,6-Tribromophenol

F. Listing Determination for Wastes From

the Production of TetrabromobisphenolA

G. Other Issues

V. Conclusions

VI. Land Disposal Restrictions

A. Treatment Standards for Organobromine

Waters

B. Applicable Technology

C. Capacity Analysis Results Summary

VII. Waste Minimization Opportunities in the

Industry

VIII. State Program Implementation

A. Applicability of Rules in States

B. Effect on State Authorizations

IX. Compliance and Implementation

A. Section 3010 Notification

B. Compliance Dates for Facilities

X. Listing as CERCLA Hazardous Substances

and RQ Adjustment

XI. Regulatory Impact Analysis and

Compliance Costs

A. Regulatory Impact Analysis Pursuant to

Executive Order 12866

B. Regulatory Flexibility Analysis

XII. Paperwork Reduction Act

XIII. Unfunded Mandates Reform Act

XIV. National Technology Transfer and

Advancement Act

XV. Submission to Congress and the General

Accounting Office

I. Affected Entities

Entities potentially affected by this

action are those which handle either the

waste stream or the chemical being

added to EPA’s list of hazardous wastes

under RCRA, and to the CERCLA list of

hazardous substances, entities which

need to respond to releases of hazardous

substances, states that are required to

adopt RCRA hazardous waste programs.

Affected entities include:

Category Affected entities

Industry .......................................... Generators of the listed waste solids and filter cartridges from the production of 2,4,6-tribromophenol; or the

product 2,4,6-tribromophenol, or entities that treat, store, transport, or dispose of these wastes.

State, Local, Tribal Govt ............... State and Local Emergency Planning entities.

Federal Govt .................................. National Response Center, and any Federal Agency that handles the listed waste or chemical.

This table is not intended to be

exhaustive, but rather provides a guide

for readers regarding entities likely to be

affected by this action. This table lists

those entities that EPA now is aware

potentially could be affected by this

action. Other entities not listed in the

table also could be affected. To

determine whether your facility is

regulated by this action, you should

examine 40 CFR parts 260 and 261

carefully in concert with the amended
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24597

rules found at the end of this Federal

Register document. If you have

questions regarding the applicability of

this action to a particular entity, consult

the person listed in the preceding FOR

FURTHER INFORMATION CONTACT section.

II. Legal Authority

These regulations are promulgated

under the Solid Waste Disposal Act

(SWDA), as amended by various other

Acts over time. These statutes are

commonly referred to as the Resource

Conservation and Recovery Act (RCRA)

and are codified at Volume 42 of the

United States Code (U.S.C.), sections

6901 through 6992k (42 U.S.C. 6901–

6992k).

Section 3001(a) of RCRA, 42 U.S.C.

6921(a), requires EPA to promulgate

criteria for identifying characteristics of

hazardous wastes and for listing

hazardous wastes. Section 3001(b) of

RCRA requires EPA to promulgate

regulations, based on these criteria,

identifying and listing hazardous wastes

which shall be subject to the

requirements of RCRA Subtitle C.

Hazardous waste is defined at section

1004(5) of RCRA, 42 U.S.C. 6903(5).

There are two types of hazardous waste.

First, hazardous wastes are those solid

wastes which may cause or significantly

contribute to an increase in mortality,

serious irreversible illness, or

incapacitating reversible illness. In

addition, hazardous wastes are those

solid wastes which may pose a

substantial present or potential hazard

to human health or the environment

when improperly managed.

EPA’s regulations establishing criteria

for listing hazardous wastes are codified

at volume 40 of the Code of Federal

Regulations (CFR) at § 261.11 (40 CFR

261.11). Section 261.11 states three

criteria for identifying characteristics

and for listing wastes as hazardous.

First, wastes may be classified as

‘‘characteristic’’ wastes if they have the

properties described at 40 CFR 261.20

which would cause them to be classified

as having the characteristics of

ignitability, corrosivity, reactivity and

toxicity.

Second, wastes may be classified as

acute hazardous wastes if they are fatal

to humans at low doses, lethal in animal

studies at particular doses designated in

the regulation, or otherwise capable of

causing or significantly contributing to

an increase in serious illness.

Third, wastes may be listed as

hazardous if they contain hazardous

constituents identified in appendix VIII

of 40 CFR part 261 and the Agency

concludes, after considering eleven

factors enumerated in § 261.11(a)(3),

that the waste is capable of posing a

substantial present or potential hazard

to human health or the environment

when improperly managed. Under

§ 261.11(a)(3), a substance is listed in

appendix VIII if it has been ‘‘shown in

scientific studies’’ to have toxic effects

on life forms.

Wastes listed as hazardous are subject

to federal requirements under RCRA for

persons who generate, transport, treat,

store or dispose of such waste. Facilities

that must meet the hazard waste

treatment, storage and disposal

requirements, including the need to

obtain permits to operate, are commonly

referred to as RCRA Subtitle C or

‘‘Subtitle C’’ facilities. Subtitle C is

Congress’ original statutory designation

for that part of RCRA that directs EPA

to issue regulations for hazardous

wastes as may be necessary to protect

human health or the environment. Thus,

facilities like incinerators or landfills

that are required to comply with RCRA

requirements for hazardous waste are

referred to as Subtitle C incinerators or

landfills.

Subtitle C is codified as Subchapter III

of Chapter 82 (Solid Waste Disposal) of

Volume 42 of the United States Code, 42

U.S.C. 6921 thru 6939e. EPA standards

and procedural regulations

implementing subtitle C are found

generally at 40 CFR parts 260 through

272.

Section 3001(e)(2) of RCRA (42 U.S.C.

6921(e)(2)) requires EPA to determine

whether to list, as hazardous, wastes

generated by various chemical

production processes, including the

production of organobromines.

Solid wastes which are not hazardous

wastes may be disposed of at facilities

which are overseen by state and local

governments. These are the so-called

subtitle D facilities. Subtitle D is

Congress’ original statutory designation

for that part of RCRA which deals with

non-hazardous solid waste.

Subtitle D is codified as Subchapter

IV of Chapter 82 (Solid Waste Disposal)

of Volume 42 of the United States Code

(42 U.S.C. 6941 thru 6949a). EPA

regulations affecting subtitle D facilities

are found generally at 40 CFR parts 240

thru 247, and 255 thru 258.

In response to the mandate on

organobromine production wastes in

RCRA section 3001(e)(2), the Agency

undertook a two-year study of the

industry and, eventually, listed several

wastes from the production of ethylene

dibromide (EDB) and methyl bromide.

The final rule listing wastes from the

production of EDB was published in the

Federal Register on February 13, 1986

(51 FR 5327). These wastes are listed in

Title 40 of the Code of Federal

Regulations § 261.32 (40 CFR 261.32)

and are designated by EPA hazardous

waste numbers K117, K118, and K136.

The final rule listing wastes from

methyl bromide production was

published on October 6, 1989 (54 FR

41402). These wastes are listed at 40

CFR 261.32 and are designated by

hazardous waste codes K131 and K132.

Methyl bromide and ethylene dibromide

are also on the Appendix VIII list of

hazardous constituents.

In June of 1991, EPA entered into a

proposed consent decree in a lawsuit

filed by the Environmental Defense

Fund, et al. (EDF v. Reilly, Civ. No. 89–

0598 (D.D.C.)), in which the Agency

agreed, among other things, to publish

proposed and final determinations

whether to list wastes from the

production of the five other

organobromine chemicals evaluated in

this rulemaking.

Under a recently lodged proposed

consent order in that case, the Agency

is required to promulgate on or before

April 15, 1998 a final decision on

whether or not to list these wastes as

hazardous. The Agency reserves the

right to evaluate wastes from the

production of other organobromine

compounds in the future, if and when

such an evaluation is deemed necessary.

III. Summary of the Proposed and Final

Rules

A. Background Analysis

To provide a sound technical basis for

this listing determination, EPA

conducted a study of the organobromine

chemicals industry in 1991 and 1992.

Six firms were identified as currently

manufacturing organobromine

chemicals at eight facilities in the

United States. The majority of

organobromine chemicals are currently

sold as flame retardants. Most are solid

compounds that are incorporated into

polymers, which are then used in a

variety of products. Smaller volumes of

organobromine chemicals are used as

reagent chemicals and pharmaceutical

intermediates. Under the authority of

RCRA Section 3007, EPA sent

questionnaires to these firms and four of

them were selected for engineering site

visits. These four facilities account for

over 99 percent of total domestic

production. Samples of process

residuals were collected during the site

visits to familiarize the Agency with the

types of materials generated by the

industry. Later in the study, record

samples to be used as part of the

technical basis to decide whether a

listing rule is appropriate were collected

at facilities of the two largest domestic

producers. EPA published a proposed

rule on the listing of organobromine
24598 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

wastes in the Federal Register on May

11, 1994 (59 FR 24530). The Listing

Background Document for this proposed

listing determination contains a detailed

description of the Agency’s basis for

proposing to list this waste stream, and

for proposing not to list nine other

waste streams; EPA proposed to defer

action on one waste. The public version

of this document, which does not

contain confidential business

information, can be copied at the RCRA

public docket. See ADDRESSES section.

The third criterion described above

for listing hazardous wastes in 40 CFR

261.11, is applicable to the listing of

organobromine wastes. That is, wastes

may be listed if they contain hazardous

constituents identified in Appendix VIII

of 40 CFR Part 261 and the Agency

concludes the waste is capable of posing

a substantial present or potential hazard

to human health or the environment

when improperly managed.

With respect to the other two criteria,

the wastes under consideration here are

not acutely hazardous. Further,

‘‘characteristic’’ wastes, in general, are

not listed separately, since their

classification depends upon whether, on

a case-by-case basis, they qualify as

wastes based on various tests described

in the regulations. EPA notes that any of

the organobromine wastes could be

classified as ‘‘characteristic’’ wastes if

they ‘‘fail’’ the applicable tests.

B. Summary of Proposed Rule

Consistent with its regulations, EPA,

before proposing to list the

organobromine production wastes

determined whether there were present

any Appendix VIII constituents and

whether there was information on any

other constituents of the waste that

could lead to health or environmental

concerns. The health effects data, along

with other factors (generally related to

exposure) required to be considered

under 40 CFR 261.11(a)(3), were then

evaluated to decide whether the wastes

should be listed as hazardous wastes.

In this rulemaking EPA has

considered all relevant factors for each

waste stream. The critical factors, which

vary depending on the individual waste

stream, were identified in the

rulemaking record for the proposal and

are summarized at 59 FR 24536 to

24541. The record for this rule contains

responses to all comments submitted on

the relevant factors.

EPA proposed not to list as hazardous

nine waste streams from the production

of organobromine compounds. The

Agency also proposed to defer action on

the listing determination for one waste

stream from the manufacture of

tetrabromobisphenol A (TBBPA)

because of inadequate information on

the process. In the proposal the Agency

stated, ‘‘Based on comments received,

including any data, EPA may choose,

rather than deferring, to promulgate a

final determination either to list or not

to list tetrabromobisphenol A waste as

a hazardous waste under RCRA’’ (59 FR

24537).

EPA proposed to list as hazardous one

waste stream from the production of

2,4,6-tribromophenol (2,4,6-TBP). The

listing of this waste, as noted above,

required consideration of whether an

Appendix VIII constituent was present.

While none of the constituents had been

listed in Appendix VIII at the time of

proposal, EPA did consider that the

2,4,6-tribromophenol present in the

waste would likely qualify for Appendix

VIII listing. Accordingly, along with the

proposed hazardous waste listing, EPA

proposed to include 2,4,6-

tribromophenol in Appendix VIII.

The proposed addition to Appendix

VIII is discussed at 59 FR 24531 and

24538. While EPA did not have a

laboratory study directly showing that

2,4,6-tribromophenol has toxic effects

on life forms, the Agency explored the

use of structure-activity relationships to

determine whether, nevertheless, there

are other types of scientific studies that

could indirectly show that this

compound has toxic effects and,

thereby, qualify for listing on Appendix

VIII under 40 CFR 261.11(a)(3).

Structure-activity relationships involve

the use of health effects information for

a compound with a chemical structure

and properties very similar to those of

the chemical of concern. The Agency

determined that this technique could be

used for 2,4,6-tribromophenol because

the chemical behavior and mechanism

of action for this compound is expected

to be similar to its chlorinated analogue,

2,4,6-trichlorophenol.

After considering the data supporting

the Appendix VIII listing determination

and factors under 40 CFR 261.11(a)(3),

EPA proposed to list as hazardous waste

solids and filter cartridges from the

production of 2,4,6-tribromophenol and

designate it as K140. These waste solids

consisted of floor sweepings and offspecification product from the

production of 2,4,6-tribromophenol.

EPA also proposed to add 2,4,6-

tribromophenol to the list of commercial

chemical products (as U408) that are

hazardous wastes if discarded (40 CFR

261.33).

Under section 102(b) of CERCLA, all

hazardous wastes newly listed under

CERCLA have statutory reportable

quantities (RQs) of one pound unless

and until adjusted by regulation. Waste

U408 is 2,4,6-tribromophenol, an

individual hazardous substance. Based

on its evaluation, the Agency proposed

an adjusted RQ of 100 pounds for 2,4,6-

tribromophenol.

The only hazardous constituent

identified in the other waste proposed

for listing, K140, is 2,4,6-

tribromophenol. In accordance with the

RQ adjustment methodology for

hazardous waste streams, the RQ for

K140 is being adjusted to 100 pounds

based on the 100 pound RQ of its only

hazardous constituent, 2,4,6-

tribromophenol.

C. Additional Opportunities To

Comment

In the original listing determination,

EPA presumed that the plausible

management scenario for the 2,4,6-

tribromophenol waste solids was

disposal in an unlined landfill. This was

critical in the Agency’s determining that

the waste presented a substantial risk.

However, comments on the rule by the

only manufacturer of 2,4,6-

tribromophenol showed that these

wastes had been sent voluntarily, over

a period of more than fifteen years, to

a number of different Subtitle C

landfills. Accordingly, EPA reevaluated

the management scenario to comport

with the actual Subtitle C disposal

scenarios.

Since EPA’s reexamination evaluated

information not previously placed in the

record, the Agency provided notice of

this new information and its

reevaluation in a letter dated September

3, 1997. This letter, sent to three

commenters on the original proposal

who were expected to have a direct

interest in the listing of the particular

waste, added additional information to

the rulemaking record and explained

the Agency’s new rationale for listing

the 2,4,6-tribromophenol waste solids.

EPA received comments from the

three entities that received the notice

letter. One commenter supported the

decision to list 2,4,6-TBP production

wastes, and two opposed the listing.

The substance of the September 3 letter

and EPA’s response to the comments

appears below in Unit IV.E. The Unit

IV.E. deals with response to comments

on the plausible mismanagement

scenario for the 2,4,6-tribromophenol

waste solids.

The commenter supporting the listing

decision also argued that EPA

underestimated the risks posed by

disposal of the 2,4,6-TBP waste in a

Subtitle C landfill, because EPA had

ignored the presence of other toxic

contaminants in the waste. The Agency

reexamined the analytical data for the

waste samples from the 2,4,6-

tribromophenol production waste.
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24599

Based on that reexamination, EPA found

that the waste contained another toxic

constituent (ethylene dibromide) that

appeared to further support the listing.

EPA provided additional notice of this

additional constituent to the interested

party that is the sole generator of the

waste in a letter dated January 14, 1998.

The generator submitted comments on

this second notice letter, and Unit IV.E

also discusses the Agency’s responses to

these comments.

D. Final Rule

The final rule promulgated today is

based on consideration of all comments

submitted on the proposed rule,

including those submitted in response

to the reevaluation in the September 3

letter, and all relevant information

available in the rulemaking record.

Today’s rule issues the final listing for

2,4,6-tribromophenol as a hazardous

constituent in Appendix VIII of 40 CFR

part 261, promulgates the listing of floor

sweeping, off-specification product and

spent filter media from the production

of 2,4,6-tribromophenol as hazardous

waste K140 (40 CFR 261.32) and lists

the 2,4,6-tribromophenol commercial

chemical product as a hazardous waste

when discarded, with a waste code of

U408 (40 CFR 261.33 (f)). These listings

are based on the presence in the waste

of 2,4,6-tribromophenol. EPA also has

determined not to list any of the other

wastes described in the proposed rule,

including wastes from the production of

tetrabromobisphenol A, on which the

Agency had originally proposed to defer

a final decision.

Also included in today’s final rule,

the Agency is adding 2,4,6-

tribromophenol and K140 to the list of

CERCLA hazardous substances in Table

302.4 of 40 CFR 302.4. CERCLA defines

the term ‘‘hazardous substance’’ chiefly

by reference to various Federal

environmental statutes. For example,

the term includes ‘‘any hazardous waste

having the characteristics identified

under or listed pursuant to RCRA

Section 3001.’’ Thus, on the effective

date of today’s rulemaking, when 2,4,6-

tribromophenol and K140 are added as

RCRA hazardous wastes, these wastes

automatically become CERCLA

hazardous substances. In today’s final

rule, EPA also is adjusting the

reportable quantities (RQs) for 2,4,6-

tribromophenol (U408) and K140 to 100

pounds in Table 302.4 of 40 CFR part

302.

In the subsequent sections of today’s

notice, EPA responds to public

comments received on the proposal and

on the reevaluations and provides its

reasons for changing the final rule from

proposal or declining to make changes

suggested by commenters. Table 1

summarizes the basis for the listing

determinations.

TABLE 1.—BASIS FOR LISTING DETERMINATIONS

Product Waste stream Analysis Decision

Dibromomethane ............ Filters ................................................. Very small volume (less than 1 kkg/yr) One producer.No List.

Wastewaters ...................................... Deep-well injected at site with approved no-migration petition (only one producer).No List.

Ethyl Bromide ................. Filters ................................................. Very small volume stream (less than 1.5 kkg/yr) .. No List.

Wastewaters ...................................... Only constituent identified is ethanol at low concentration.No List.

Tetrabromobisphenol A .. Wastewaters ...................................... Stream is already listed as K131 for methyl bromide. Also contains 15,000 ppm tribromophenol.Already listed waste.

Octabromodiphenyl oxide Filter cake .......................................... Toluene and brominated dibenzofurans present at

levels below concern. Assuming worst case for

leachate, risk for the maximally exposed individual estimated to be below 10¥6 for

octabromodiphenyl oxide.

No list.

Wastewaters ...................................... Major constituent of concern, brominated

dibenzofurans, shows minimal risk; solubility of

octabromodiphenyl oxide is very low; modeling

of worst case for wastewaters showed risk

below 10¥6 for octabromodiphenyl oxide.

No list.

Decabromodiphenyl

oxide.

Filter cake .......................................... The major constituent in waste

(decabromodiphenyl oxide) could not be quantified. Assuming worst case for leachate, risk

below 10¥6 level because of very low solubility

for this chemical.

No list.

Wastewaters ...................................... The major constituent in waste

(decabromodiphenyl oxide) could not be quantified. Assuming worst case for leachate, risk

below 10¥6 level because of very low solubility.

No list.

Tetrabromobisphenol A .. Off-specification product .................... Tetrabromobisphenol A is of relatively low toxicity

and has limited mobility. Levels of

tribromophenol in leachate are below those for

concern.

No list.

Tribromophenol .............. Wastewaters ...................................... Used structure activity relationship analysis for

tribromophenol. Data collected indicate releases during deep-well injection are not likely

to occur or would be of low risk.

Tribromophenol not detected in groundwater at

site.

No list.
24600 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

1Waser J., N. Trueblood, and C. M. Knobler. 1976.

Chem One. New York, NY: McGraw-Hill pp. 25–29.

TABLE 1.—BASIS FOR LISTING DETERMINATIONS—Continued

Product Waste stream Analysis Decision

Floor sweepings, off-specification

product and spent filter media from

the production of 2,4,6-

tribromophenol; discarded commercial chemical product.

Used structure activity relationship analysis to

show carcinogenicity of tribromophenol. High

concentration of chemical in solids and TCLP

leachate. Mobile in leachate and would present

high risk if released from landfill, even a Subtitle C landfill.

List as hazardous waste

(K140) and commercial chemical product

(U408).

IV. Response to Comments

Seven parties submitted comments on

the proposed rulemaking. Comments

were received from two companies that

manufacture bromine products, one

trade association representing industrial

chemical producers, two manufacturers

of chemical products other than

bromines, one company involved in the

treatment and destruction of hazardous

and toxic wastes, and one

environmental interest group. The major

issue addressed by commenters to the

original proposal was the Agency’s use

of structure-activity relationship (SAR)

analysis to support a listing

determination. The major issue

addressed with respect to the September

3 reevaluation was on EPA’s use of

Subtitle C landfills as a mismanagement

scenario for modeling purposes and the

assessment of risk relating to Subtitle C

landfills. EPA also discusses the January

14, 1998 reevaluation of additional

constituents found in the 2,4,6-TBP

production wastes. More detailed

summaries of the comments and

complete Agency responses are

provided in the Public Comment

Summary & Response Document and

the Supplementary Comment Summary

& Response Document prepared for

comments on the September 3, 1997,

and January 14, 1998 letters. These

documents are included as appendices

to the Listing Background Document

supporting today’s rule (available in the

public docket—see ADDRESSES section).

Before addressing the public

comments in detail, some of the basic

concepts related to the use of SAR

analysis for this rulemaking are

addressed here.

A. Development of Structure-Activity

Relationship (SAR) Analyses

1. Principles Related to SAR Analyses

In the preamble to the proposed rule,

EPA briefly discussed the basis for using

SAR analyses for regulatory purposes.

The scientific process used in SAR

analysis also was presented in

Development of Provisional Human

Health Reference Value for 2,4,6-

Tribromophenol and the Listing

Background Document for the proposed

listing (henceforth collectively termed

‘‘the Listing Background Document.’’)

SAR analyses are based on the

observation that structurally similar

compounds have similar chemical

properties. Thus, they may be absorbed,

distributed, and metabolized in similar

ways, and may have similar

mechanisms of action and toxic

properties. If two compounds or a group

of compounds are chemically related,

toxicologic data for one or more

compounds in the group can be used to

predict the toxicologic effects of other

compounds in the group. The more

closely related two compounds are, the

more similar their toxic properties are

likely to be.

The validity of SAR analysis is related

to the degree of similarity of the

candidate (the compound for which

adequate toxicity information are

lacking) and the surrogate (the chemical

used as the basis for the analysis), and

the amount of information available on

how any differences between the two

chemicals affects their activity. Because

chemical similarity plays a critical role

in SAR analysis, this discussion begins

with a brief primer on chemical

structure.

The periodic table of the elements

arranges elements in order of increasing

atomic number, in a manner that shows

their chemical relatedness. Elements

that are in the same column on the

periodic table have the same number of

electrons in their outer shell, and are

chemically similar. Elements that lack

one electron in their outer shell are in

the same column, and are called

halogens. This group includes fluorine,

chlorine, bromine, and iodine, which

react in chemically similar ways.

Bromine and chlorine are the most

similar halogens; fluorine binds to

carbon much more strongly than do

chlorine or bromine, while the reactivity

of iodine is also influenced by its larger

size. When chemical groups replace the

hydrogen atoms in organic (carboncontaining) molecules, the molecules

are called ‘‘substituted.’’ The chemical

groups that do the substituting are

called ‘‘substituents,’’ and play a large

role in determining the chemical

reactivity of the compound.

Figure 1 compares the structures of

the two compounds studied in the SAR

analysis, and shows the structure of the

parent compound, phenol. 2,4,6-

Trichlorophenol (TCP) is phenol with

chlorine substitution at the 2-, 4-, and 6-

positions. Similarly, 2,4,6-

tribromophenol (TBP) is phenol with

bromine substitution at the 2-, 4-, and 6-

positions. Thus, the two compounds are

phenols substituted with closely related

halogens at the same positions. Note

that both the position and number of

substitutions are the same in the two

compounds. If the two compounds were

substituted by different numbers of

halogen atoms, or at different positions

from each other, they would be

expected to be less similar chemically

and physically. This is because both the

type and location of the substitution

contribute to the electronic, steric, and

other attributes of the molecule.1

BILLING CODE 6560–50–P
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24601

2Waser, J., K.N. Trueblood, and C.M. Knobler.

1976. Chem One. New York, NY: McGraw-Hill pp.

25–29.

3William, G.M. and J.H. Weisburger. 1991.

Chemical carcinogenesis. In: Amdur, M.O., J. Doull,

and C.D. Klaassen. Casarett and Doull’s Toxicology:

The Basic Science of Poisons, 4th ed. New York,

NY: Pergamon Press. pp. 127–200.

BILLING CODE 6560–50–C

2. Structure-Activity Relationship

Analysis

In the proposed rule, EPA developed

a Quantitative SAR (QSAR) analysis for

2,4,6-TBP using 2,4,6-TCP as the

surrogate, and attempting to adjust the

cancer slope factor based on the closelyrelated electronic properties of bromine

and chlorine. However, EPA received a

number of comments stating that this

analysis was too oversimplified to be

reliable. In particular, commenters

stated that additional parameters should

be used in such an analysis. It was

suggested that data on hydrophobicity (a

description of the degree to which a

compound repels water) and steric

effects be incorporated into the analysis.

Information on the hydrophobicity of a

molecule is relevant to understanding

how a molecule distributes in the body

(e.g., fatty tissues versus blood), whether

it accumulates in the fat, and the ease

or difficulty with which the molecule

may move across cell membranes to its

site of action. This attribute of a

molecule is often expressed as the

octanol-water partition coefficient,

which quantitatively indicates the

degree to which the compound

partitions to either water or lipid

materials. The water solubility of a

molecule, i.e., the amount that will

dissolve in pure water, also influences

the octanol-water partition coefficient.

Steric (spatial) effects, which are caused

by the different orientation of atoms in

space relative to each other, are

important because they provide

information on whether the molecule’s

size and shape allow it to interact with

receptors in biological systems, such as

enzymes, hormones, and genetic

material.

EPA has re-evaluated the SAR

analysis in light of these comments, and

agrees that additional parameters could

have been considered; however,

available data are insufficient to

adequately account for these additional

parameters. Despite the lack of adequate

information to evaluate all parameters

affecting the relative toxicity of 2,4,6-

TCP and 2,4,6-TBP, the Agency believes

that these compounds are so similar that

it is appropriate to use the 2,4,6-TCP

slope factor as an estimated slope factor

for 2,4,6-TBP. Many of the toxicological

similarities are discussed further in the

following sections. In addition, the very

factors suggested by comments for

consideration, as noted above, provide a

further basis for showing how these two

chemicals are closely related. For

example, when the Agency adjusted the

slope factor for electronic effects, the

change was less than 1%. Also, a key

measure of hydrophobicity, the log of

the octanol-water partition coefficients

(log Kow), is similar for these two

chemicals; the values of log Kow are 4.23

for 2,4,6-TBP and 3.69 for 2,4,6-TCP. All

of these factors lead the Agency to

conclude that 2,4,6–TCP can be used as

a direct surrogate for 2,4,6-TBP.

3. 2,4,6-TBP Slope Factor and Risk

Estimate

Although EPA is using the 2,4,6-TCP

cancer slope factor as a default for 2,4,6-

TBP, the Agency examined the impact

of modifying the cancer slope factor in

response to public and favorable peer

reviewer comment, to account for the

difference in molecular weight of 2,4,6-

TCP and 2,4,6-TBP.

The molecular weight of a compound

is the weight in grams of a specified

number (a mole) of molecules of that

compound, and is used to convert

between the weight of a sample of a

compound and a measure of the number

of molecules in that sample.2 Because a

bromine atom is heavier than a chlorine

atom, one gram of 2,4,6-TBP has fewer

molecules in it than does a gram of

2,4,6-TCP, and therefore a gram of 2,4,6-

TBP would be less potent than a gram

of 2,4,6-TCP, all other things being

equal. This is because chemicallyinduced cancer results from molecules

binding to DNA or to another molecule

in the body,3 and, therefore, a

compound’s cancer potency is related

most directly to the number of

molecules administered (rather than the

weight alone). As a result, the 2,4,6-TCP

slope factor may be multiplied by the
24602 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

4USEPA. 1992. Respiratory health effects of

passive smoking: Lung cancer and other disorders.

ORD, USEPA, Washington DC, 20460. EPA/600/6–

90/006F.

5Proposed Guidelines for Carcinogen Risk

Assessment. Federal Register 61(79): 17960–18011,

Tuesday, April 23, 1996.

ratio of the 2,4,6-TCP molecular weight

(197) to the 2,4,6-TBP molecular weight

(331). Adjusting for molecular weight

would result in a default value for the

2,4,6-TBP CSF of 6.5×10¥3 (mg/kg/

day)¥1, compared with 1.1×10¥2 (mg/

kg/day)¥1 for 2,4,6-TCP. If this slope

factor were applied in a risk analysis in

the preamble to the proposed rule, it

would have little effect on results. Using

the corrected cancer risk factor, the

estimated individual risk from exposure

to 2,4,6-TBP in groundwater would be

4.2×10¥4 and 1.2×10¥5 for the offspecification product and the filter

cartridges, respectively, compared with

risks of 7×10¥4 and 2×10¥5 calculated

without the correction in the proposed

rule. These changes are minor and

would not change the Agency’s

decision, i.e., the risks posed by these

wastes warrant control through listing.

4. Notice and Comment for the Use of

an SAR

To check its analysis, EPA subjected

it to both internal Agency review and

external peer review. External peer

review was solicited on a draft of the

Public Comment Summary & Response

Document. As background, the peer

reviewers were provided the risk

assessment section of the Listing

Background Document for the proposal

and the public comments on that part of

the proposal. Three individuals with

experience in SAR analyses were asked:

(1) Is the SAR presented for 2,4,6-TBP

sufficiently rigorous to be scientifically

defensible and could the reviewers

identify major areas of uncertainty with

the analysis? (2) Is it appropriate for the

Agency to conclude that 2,4,6-TCP and

2,4,6-TBP are similar and is 2,4,6-TCP

an appropriate surrogate for 2,4,6-TBP?

(3) Was all of the available information

about the mechanism of toxicity for

2,4,6-TBP considered? (4) Is there any

genetic toxicity data that could be

included in the analysis? and (5) Could

any additional information be provided

to strengthen the Agency’s conclusions?

All three peer reviewers agreed that a

SAR analysis was appropriate for this

rule. Additionally, the peer reviewers

agreed that 2,4,6-TCP is the most

appropriate surrogate for 2,4,6-TBP, and

that it is appropriate to use the cancer

potency factor for 2,4,6-TCP as a default

value for 2,4,6-TBP. (One commenter

also suggested that the potency factors

be adjusted for the differences in

molecular weight. This confirmed EPA’s

analysis. EPA has addressed the

substantive technical issues raised by

the commenters in a detailed

memorandum to the file, which is in the

docket.

B. Why the SAR Analysis of 2,4,6-TCP

and 2,4,6-TBP Constitutes a Scientific

Study That Shows Toxic Effects

1. Why This Is a Scientific Study

Although EPA usually uses controlled

animal studies or epidemiological

studies of human exposure as the basis

for its regulations, 40 CFR 261.11(a)(3)

does not preclude the use of other types

of scientific studies. Moreover, EPA’s

interpretation of its own regulations to

include SAR analysis as a scientific

study is entitled to substantial

deference.

SAR analysis is interpreted by EPA to

be a scientific study. The scientific

principles on which SAR analyses are

based were developed from many years

of chemical review and analysis and,

more recently, toxicity studies on

related compounds. For example, the

SAR analysis for 2,4,6-BP rests not only

on the chemical similarity of 2,4,6-TBP

and 2,4,6-TCP, but also on toxicity

studies showing structurally similar

brominated and chlorinated compounds

to be related in terms of whether they

are carcinogens. These studies are

discussed in more detail in Section

III.C.3. of this preamble.

EPA has, in the past, relied on

scientific studies in the form of

sophisticated statistical analyses that are

one step removed from a laboratory

study much in the same way SAR

analysis is. In addition, EPA has used

meta-analyses, a statistical tool for

combining the data from multiple

studies, in several risk assessments,

including the risk assessment for

environmental tobacco smoke.4

Furthermore, the controlled animal

studies performed on 2,4,6-TCP are

indisputably scientific studies and these

studies, with the aid of SAR analysis,

show that 2,4,6-TBP is a potential

carcinogen, as discussed below.

2. Does It ‘‘Show’’ Toxic Effects?

Section 40 CFR 260.11(a)(3) does not

specify that EPA must conduct

laboratory studies that directly

implicate the precise chemical. In this

case, the finding that 2,4,6-TCP is

carcinogenic in animal studies, together

with the SAR analysis demonstrating

the close chemical similarity of 2,4,6-

TCP and 2,4,6-TBP, shows that 2,4,6-

TBP is expected to be carcinogenic

because they provide a sound basis for

EPA to infer the toxic effects of 2, 4, 6–

TBP from the toxic effects demonstrated

for 2,4,6-TCP, as noted below.

It also is important to recognize that

all scientific studies that actually

measure toxic effects in a laboratory

have some level of uncertainty when

used as the basis for regulatory action.

Uncertainty is caused by:

a. Extrapolation from animal models

to humans;

b. Variable responses among animals

within a study;

c. Statistical variability of results

between different studies (i.e., if the

experiment were to be repeated, one

would not necessarily observe exactly

the same tumor incidences);

d. Extrapolation from high laboratory

doses to low actual human exposures;

and

e. Extrapolation to humans from

studies in animals that live for a fraction

of the human life span.

Uncertainty in carcinogen assessment

is discussed in detail in EPA’s Proposed

Guidelines for Carcinogen Risk

Assessment, and articles cited therein.5

From a scientific perspective it is

impossible to ‘‘show’’ anything without

some uncertainty. Therefore, EPA

interprets the language of the regulation

as a requirement to ‘‘show’’ with a

scientifically reasonable level of

uncertainty. In this case, the level of

uncertainty associated with this

particular SAR is reasonable for the two

chemicals being compared in this

rulemaking because:

• 2,4,6-TBP and 2,4,6-TCP are both

tri-halogenated phenols with

substitutions at the same positions;

• The physical and chemical

properties, such as the octanol-water

partition coefficient and the water

solubility, of the compounds are similar;

• Available genetic toxicity data show

consistent results for 2,4,6-TCP and

2,4,6-TBP; and

• Examples in the literature and in

Section C.3 of this preamble (e.g., 1,2-

dibromoethane and 1,2-dichloroethane)

support the idea that if a chlorinated

compound is a carcinogen, the

compound formed by substitution of a

chlorine with bromine will still be a

carcinogen.

Some commenters provided examples

of chemical pairs where SAR analysis

would be inappropriate, such as

benzene/toluene and methanol/ethanol

(see Figure 2 and the accompanying text

for a further discussion of these

chemicals). EPA agrees that for these

pairs, a SAR analysis should not be used

for regulatory purposes. However, the

data support a conclusion that the

structural and chemical similarities
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24603

between 2,4,6-TBP and 2,4,6-TCP are

much stronger than those in the pairs in

Figure 2, and thus the uncertainty for

the current rulemaking is much less

than the uncertainty/error would be for

a SAR analysis for any of the chemical

pairs in the counter example. EPA has

determined that these data support the

regulation of 2,4,6-TBP under RCRA,

because they reasonably support a

conclusion that 2,4,6-TBP has a level of

carcinogenicity comparable to that of

2,4,6-TCP, a known carcinogen.

C. Issues Regarding the Use of

Structure-Activity Relationship (SAR)

Analysis

1. Use of SARs to Support Listing

Constituents in Appendix VIII

All seven commenters addressed the

use of structure-activity relationships

(QSARs) in this rulemaking. Two

commenters stated that SAR analysis

cannot be used to support listing a

constituent in Appendix VIII, citing the

language of 40 CFR 261.11(a)(3), which

states that constituents may be listed in

Appendix VIII ‘‘only if they have been

shown in scientific studies to have

toxic, carcinogenic, mutagenic, or

teratogenic effects on humans or other

life forms.’’ The commenters stated that

SARs are not equivalent to empirical

data, do not represent ‘‘scientific

studies’’ and do not show that 2,4,6-

tribromophenol has toxic effects on life

forms. Therefore, the commenters stated

that information on structure-activity

relationships cannot be used to list

constituents in Appendix VIII and,

consequently, may not be used to list

hazardous wastes under EPA’s

regulation.

EPA disagrees with the commenters.

The commenters interpret ‘‘shown in

scientific studies’’ to mean directly

shown in laboratory studies that pertain

to the constituent in question. EPA does

not interpret the phrase so narrowly.

SAR analysis represents a valid

scientific approach for assessing

toxicity. As noted above, EPA has

concluded that there is sufficient

similarity between 2,4,6-TBP and 2,4,6-

TCP to justify using a SAR analysis for

this rulemaking.

EPA’s use of SAR analysis in

regulatory programs is not

unprecedented. EPA has used SAR

analysis for assessing the hazards of

chemicals to human health and the

environment for 15 years in the New

Chemicals Program under section 5 of

TSCA. The process of using SAR takes

into account the similarity of the

surrogate chemicals with regard not

only to chemical structure and

functional reactive groups, but physical/

chemical properties as well (e.g., water

solubility and octanol/water partition

coefficients). Physical/chemical

properties such as water solubility and

octanol/water partition coefficients are

important because they are related to

how a compound is absorbed and

distributed in the body. In particular,

the octanol/water partition coefficient is

a measure of a compound’s relative

solubility in octanol and water, and is

related to how well a compound

dissolves in fat versus the blood. The

octanol/water partition coefficient

describes a compound’s hydrophobicity,

which was mentioned in Section III.A.2.

of this preamble. In cases where direct

chemical-specific toxicity data are

lacking and where appropriate analogue

chemicals exist to allow valid

comparisons to be drawn, SAR analysis

represents a scientifically valid

approach for assessing the potential

toxicity of a chemical. As discussed in

Section III.B. of this preamble, EPA

regards SAR as ‘‘scientific studies’’ and

believes that the SAR analysis

conducted for this rulemaking does

‘‘show’’ toxic effects of 2,4,6-TBP

sufficiently to support its listing in

Appendix VIII.

2. Use of SARs Is a Departure From

Agency Policy

Two commenters stated that the use

of SAR analysis in this rulemaking

represents a departure from Agency

policy. The commenters added that the

use of SARs in making hazardous waste

determinations establishes a new

criterion for identifying hazardous

wastes and the public was not given

sufficient opportunity to comment on

this new criterion.

The Agency agrees that this listing

represents a new element in the

Agency’s hazardous waste listing

determination policy in that this is the

first listing to use SAR as a basis for

listing a waste stream as hazardous.

However, the SAR analysis is consistent

with 40 CFR 260.11(a)(3) of EPA’s

regulations, since EPA’s decision to list

a constituent in Appendix VIII makes

use of a scientific study that shows the

toxic effects of that constituent. There

has been adequate opportunity to

comment on this issue, since the

Agency explained in the proposal that it

was interpreting 40 CFR 260.11(a)(3) to

allow use of structure-activity

relationships. Indeed, the bulk of

comments on the proposed rule dealt

with the highly technical issue of

whether SAR could be used to list

hazardous wastes. This is a strong

indication that commenters understood

that they were being given the

opportunity to express their views on

this matter. EPA takes the position that,

depending on the strength of the

evidence, SAR-based listings are

appropriate to use for the hazardous

waste listings program. SAR is an

available tool that can solve a problem

the Agency faces in the case: Making

risk-based regulatory decisions (such as

listing determinations) in the absence of

Agency-verified or provisional health

benchmarks (e.g., reference dose (RfD),

reference concentration (RfC), or cancer

slope factor (CSF).

As described in further detail in other

places in this preamble, the evidence in

this case rests on four points: 2,4,6-TCP

is a close structural analogue to 2,4,6-

TBP; the physical and chemical

properties of the compounds are similar;

the available genetic toxicity data also

show consistent results for 2,4,6-TCP

and 2,4,6-TBP; and examples in the

literature support the idea that if a

chlorinated compound is a carcinogen,

the compound formed by substitution of

a chlorine with bromine will still be a

carcinogen.

SAR is one approach that was

designed specifically to address this

problem. The use of SAR is particularly

compelling in the organobromines

listing determination. The constituent

2,4,6-TBP has an extremely close

structural analogue (2,4,6-TCP) for

which direct toxicity data are available.

Because of this, the Agency specifically

solicited comment on the policy

implications of the use of QSAR/SAR in

the organobromines proposal.

The Agency has concluded that SAR

currently is a viable approach for

making a human health impact

determination for the waste stream of

concern. The strong technical argument

involved, that the principal toxicant of

concern, 2,4,6-TBP, is a highly similar

analogue of 2,4,6-TCP, makes this listing

the appropriate place to use SAR. It is

important to note, however, that the

determination to list 2,4,6-TBPcontaining residuals as hazardous

wastes is not based solely on the SAR

analysis for 2,4,6-TBP. Other factors

were included in the risk assessment,

including the concentrations of 2,4,6-

TBP in the waste, the volumes of waste

generated, the mobility of the 2,4,6-TBP

in leachate tests of the waste, plausible

mismanagement scenarios, and

potential receptors.

3. Validity of SAR Analysis in

Supporting the Hazardous Waste Listing

Determination for 2,4,6-TBP Production

Wastes

All seven commenters addressed the

general validity of the SAR analysis

employed in this rulemaking. One

commenter supported the Agency’s use
24604 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

6Zieger, E., B. Anderson, S. Halworth, T. Lawlor,

K. Mortelmans, and W. Speck. 1987. Salmonella

mutagenicity tests. III. Results from the testing of

225 chemicals. Environ Mutagen 9 (Suppl. 9) 1–

109. As cited in Docket #F–94–OBLP–S0013.

7Haworth, S., T. Lawlor, K. Mortelmans, W.

Speck, and E. Zeiger. 1983. Salmonella

mutagenicity test result for 250 chemicals. Environ

Mutagen Suppl 1:3–142.

Rasanen, L., M. L. Hattula, and A. U. Arstila.

1977. The mutagenicity of MCPA and its soil

metabolities, chlorinated phenols, catechols and

some widley used slimicides in Finland. Bull

Environ Contam Toxicol 18:565–571.

8NCI. 1978. Bioassay of 1,2-dichloroethane for

possible carcinogenicity. National Cancer Institute,

Bethesda Maryland. NCI–CG–TR No. 66; DHEW/

PUB/NIH–78–1361.

9NTP. 1982. Carcinogenesis bioassay of 1,2-

dibromoethane for possible carcinogenicity F344

rats and B6C3F1 mice. U.S. National Toxicology

Program, Research Triangle Park, North Carolina.

NTP–TR No. 210; NIH/PUB 87–1766.

of SARs and the inference that 2,4,6-

TBP and 2,4,6-TCP are similar, but the

other six commenters raised scientific

and procedural concerns related to the

use of SAR analysis to support a listing

determination. Some of the comments

were specific to the SAR analysis in the

proposed rule. Specifically, two

commenters objected to the analysis

being based on electronic effects alone,

instead of also considering hydrophobic

and steric effects. Other comments

addressed the general aspects of the

analysis, i.e., the appropriateness of

2,4,6-TCP as a surrogate for 2,4,6-TBP.

In light of the quantitative uncertainties

raised and other issues, the Agency

believes that a SAR analysis does show

that 2,4,6-TCP is an appropriate

surrogate for 2,4,6-TBP, based on their

high degree of structural similarity, i.e.,

both are tri-substituted phenols with the

closely-related halogens chlorine (2,4,6-

TCP) or bromine (2,4,6-TBP) located at

the 2-, 4-, 6-positions (see Section A1.

for a more detailed discussion of the

structural similarity between 2,4,6-TBP

and 2,4,6-TCP).

As mentioned in Section III.A.3., the

Agency is adopting one quantitative

manipulation suggested by both a

commenter and a peer reviewer. They

noted that the differing molecular

weights of the two compounds should

be taken into account in the slope factor

projection; this change has been

adopted. When making this adjustment,

however, the Agency found that the

change would not exert a significant

change in the risk results (i.e., a 40%

decrease in risk). Even if EPA made the

change, the risk would still warrant

listing.

As part of the support for SAR

analysis, this discussion summarizes the

available data related to the

carcinogenic activity of 2,4,6-TCP and

the genetic toxicity of 2,4,6-TCP and

2,4,6-TBP. 2,4,6-TCP carcinogenicity

was tested in mice and rats. Based on

the results of this study, 2,4,6-TCP is

classified as a probable human

carcinogen (B2), and the CSF for 2,4,6-

TCP was calculated based on leukemia

in male rats. No long-term animal

studies that could detect cancer have

been conducted with 2,4,6-TBP.

Results from short-term genetic

toxicity studies, such as those described

in the following paragraphs, provide

information on whether the compound

of interest interacts with DNA and

causes mutations or other DNA damage,

such as chromosome aberrations. These

data are used to predict whether a

compound is likely to be carcinogenic,

and to help interpret results of cancer

assays in animals. A variety of different

genetic toxicity tests commonly are

used. Because no single test can detect

all types of damage, a battery of tests is

necessary to assess completely a

compound’s potential to cause DNA

damage. Findings in mammalian cells

generally are considered more relevant

than findings in bacterial cells. For

2,4,6-TCP, genetic toxicity studies

appear to indicate that 2,4,6-TCP is

positive in mammalian cell gene

mutation assays, and negative in a

bacterial (Salmonella typhimurium)

mutation assay and in a mammalian cell

chromosome aberration assay. Genetic

toxicity data for 2,4,6-TBP are limited to

a negative result in a S. typhimurium

gene mutation assay.6 Although this

single negative result might appear to

predict that 2,4,6-TBP is not

carcinogenic, 2,4,6-TCP also produced

negative results in this bacterial assay,7

but is carcinogenic in rats. Therefore,

the S. typhimurium gene mutation assay

does not appear to accurately predict

whether this class of compounds is

carcinogenic.

One commenter believed that the

analysis should have compared 2,4,6-

TBP to an entire class of compounds

rather than to a single chemical

compound. The Agency believes that

comparison with a single compound is

acceptable for SAR analysis in cases

such as this, when the structural

similarities between the two compounds

are so strong. Comparisons across

multiple chemicals are needed for larger

structural differences. This commenter

also stated that the QSAR/SAR analysis

disregarded documented differences

between the carcinogenicity of

chlorinated and brominated analogues.

For example, the commenter noted

differences in the species and tissue

(e.g., kidney or liver) in which tumors

develop following administration of

trihalomethanes ranging from

chloroform (CHCl3) to bromoform

(CHBr3). The compounds in the series

represent a series of replacements of

chlorine atoms by bromine atoms (i.e.,

3 chlorines; 2 chlorines and 1 bromine;

etc.).

Because the trihalomethanes are such

small molecules, the three halogen

atoms constitute a relatively large

percentage of the total volume of the

molecule. Thus, substituting bromine

for chlorine would be expected to have

a larger effect than the same substitution

in the large 2,4,6-TCP/2,4,6-TBP

molecules. This difference in size may

explain the observed differences in

target organs among the

trihalomethanes. An important point to

note is that all four trihalomethanes are

carcinogens, regardless of the target

tissue.

Regarding the issue of the

appropriateness of SAR analyses based

on analogues in which a chlorine is

substituted by a bromine, the Agency

notes that there are additional wellstudied examples in which substitution

of a chlorine by a bromine has resulted

in retention of carcinogenic activity. For

example, both 1,2-dichloroethane

(ethylene dichloride) 8 and 1,2-

dibromoethane (ethylene dibromide) 9

are multi-target carcinogens, causing

tumors in the lung, the forestomach, the

circulatory system, and the mammary

gland. The Agency recognizes that

examples of bromine/chlorine

substitutions in which both the

chlorinated analogue and the

brominated analogue are carcinogens

are not sufficient to show that such

substitutions in general will not change

a carcinogen into a noncarcinogen.

However, based on these examples and

in light of the carcinogenicity of 2,4,6-

TCP in animal testing, it is plausible to

conclude that 2,4,6-TBP is a potential

carcinogen. (For a more detailed

discussion of many of the scientific

bases underlying SAR and the rationale

behind the selection of cancer as the

endpoint for human exposure, see the

Response to Public Comment Document

for this rulemaking, in the public

docket.)

One commenter expressed concerns

that the use of SAR analyses to make

predictions of the expected types of

toxicity produced by a compound can

result in erroneous predictions. The

commenter illustrated the point by

providing several cases (e.g., benzene/

toluene, methanol/ethanol, methyl nbutyl ketone/methyl isobutyl ketone

(MnBK/MIBK)) in which predictive

errors would occur based on SAR

analysis performed with structurally

similar chemicals. The Agency

recognizes the limitations to SAR
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24605

10Andrews, L.S. and R. Snyder. 1991. Toxic

effects of solvents and vapors. In: Amdur, M.O., J.

Doull, and C.D. Klaassen. Casarett and Doull’s

Toxicology: The Basic Science of Poisons, 4th ed.

New York, NY: Pergamon Press. pp. 681–722.

analysis and agrees that the choice of

surrogate needs to carefully take into

account the degree of similarity between

the chemical of interest (the

‘‘candidate’’) and the surrogate (from

which predictions are made). The

structural and chemical similarities

between 2,4,6-TCP and 2,4,6-TBP are

greater than those in the pairs cited by

the commenter. Both 2,4,6-TBP and

2,4,6-TCP consist of a phenol molecule

with halogen substitutions at the

2-, 4-, and 6-positions, and differ only

in the identity of the halogen. As shown

in Figure 2, the differences in the pairs

listed by the commenter are much

larger. The pairs cited by the commenter

differ in having/not having a substituent

group (benzene/toluene), or are

positional isomers (1-/2-

naphthylamine), homologues

(methanol/ethanol, n-hexane/nheptane), or structural isomers (MnBK/

MIBK). These differences in the cited

pairs have greater potential to change

the chemical properties of the molecule.

For example, the addition of the methyl

group in the benzene/toluene pair

changes the way that the molecule is

converted to other molecules and

removed from the body. Toluene is

converted (metabolized) to compounds

with low toxicity (e.g., benzoic acid)

that are dissolved easily in water and

removed from the body. Benzene’s

structure does not allow the use of this

pathway for removing the chemical.

Instead, benzene is converted and

removed via a pathway that creates

cancer-producing compounds.10

BILLING CODE 6560–50–P
24606 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24607

BILLING CODE 6560–50–C
24608 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

Thus, the structural similarities

between 2,4,6-TCP and 2,4,6-TBP are

greater than those between pairs of

chemicals cited by a commenter in a

counter-example. As described in the

Listing Background Document and the

Response to Public Comment

Document, the physical properties of

the compounds are also similar, with

similar octanol/water partition

coefficients and solubility in the same

solvents. The available genetic toxicity

data show consistent results for 2,4,6-

TCP and 2,4,6-TBP, although data for

the latter compound are quite limited.

Finally, examples in the literature

support the idea that if a chlorinated

compound is a carcinogen, the

compound formed by substitution of a

chlorine with bromine still will be a

carcinogen. Based on this line of

reasoning, the Agency believes that a

SAR is appropriate in this case, and the

very strong chemical similarities

between 2,4,6-TCP and 2,4,6-TBP justify

the use of the cancer slope factor for

2,4,6-TCP as a default value for 2,4,6-

TBP.

Two commenters expressed

reservations regarding the use of QSAR/

SAR analysis to support listing

determinations, but outlined conditions

under which the use of SARs may be

acceptable. Both of these commenters

recommended that the Agency require

some level of peer review of SAR results

as a standard procedure, including both

internal reviews by Agency senior

scientists and external peer reviews.

EPA is cognizant of the novelty of the

use of SAR analysis for this hazardous

waste determination and, therefore, has

subjected its analysis to both internal

Agency review and external peer

review, as described in Section III.A.4.

4. Types of Data Appropriate to Support

or Refute SAR Predictions

Five commenters responded to the

Agency’s request for information on the

types of data appropriate in supporting

or refuting SAR results. Three

commenters stated that actual data

should be used to confirm or refute SAR

predictions and that empirical evidence

should take precedence over modeling

predictions. One commenter added that

the Agency should simplify delisting

procedures for sole-constituent wastes

that were listed based on SAR analysis

such that if actual data become available

that refute the SAR conclusions, the

Agency could delist the waste. EPA

appreciates the commenters’ response to

its request for information on the types

of data appropriate for supporting or

refuting SAR analyses. If toxicity data

for 2,4,6-TBP become available at some

point in the future and these data refute

the results of the Agency’s SAR analysis

for this rulemaking, EPA could take

appropriate action at that time to revisit

the listing investigation for 2,4,6-TBP

production wastes.

D. Addition of Constituent to Appendix

VIII

Two commenters stated that EPA

cannot simultaneously propose to list a

constituent in Appendix VIII and

propose to list a waste as hazardous

because it contains that constituent. The

commenters contended that this

approach is illegal and violates the

procedures established in 40 CFR

261.11(a)(3), which require the Agency

to list a constituent in Appendix VIII

based on the results of ‘‘scientific

studies’’ demonstrating that the

substance has toxic or other adverse

effects. Following the listing of a

constituent in Appendix VIII, the

Agency may use that constituent to

justify a hazardous waste listing.

Therefore, they reasoned that EPA may

not proceed with listing the 2,4,6-

tribromophenol production wastes

because the hazardous constituent

(2,4,6-tribromophenol) was proposed for

inclusion in Appendix VIII

simultaneously with the proposed

hazardous waste listing.

EPA disagrees and finds no basis in

the regulation to support this

contention. Furthermore, this practice is

long-standing. Other simultaneous

listings are found at 59 FR 24530 (May

11, 1994), 59 FR 458 (Jan. 4, 1994), 54

FR 50968 (Dec. 11, 1989), and 51 FR

6537 (Feb. 25, 1986).

The plain language of 40 CFR

261.11(a)(3) provides that a waste shall

be listed if it contains an Appendix VIII

constituent and the Administrator

concludes it poses a hazard after

considering the eleven factors cited in

the regulation. Neither the August 1986

preamble text to which the commenter

makes reference nor the regulatory

language of 40 CFR 261.11(a)(3) suggest

that a sequential determination is

required. In the August 1986 rule, the

Agency stated that the significance of

placing a constituent in Appendix VIII

includes the fact that the constituent

then can be cited as a basis for listing

toxic wastes (51 FR 28296, August 6,

1986). Nothing in this statement

suggests that an Appendix VIII listing

must be proposed for public comment

and finalized separately from an

associated hazardous waste listing. The

public was given ample opportunity to

comment on all relevant issues

concerning both the hazardous waste

listing and the Appendix VIII listing on

which it is based.

Not only is there nothing in the

regulation that precludes EPA from

considering Appendix VIII and

hazardous waste listings in the same

proposal but, in many instances, to do

otherwise could lead to absurd and

futile results. In general, because listing

a substance in Appendix VIII and listing

a substance or a waste stream as a

hazardous waste under 40 CFR

261.11(a)(3) involve consideration of a

common factor, toxicity, simultaneous

listing is appropriate.

E. Plausible Mismanagement Scenario

and Other Issues in the Listing

Determination for Waste Solids From

the Production of 2,4,6-Tribromophenol.

1. Comments on the Proposed Rule

In comments on the proposed rule

published May 11, 1994 (59 FR 24530),

one commenter disputed the plausible

mismanagement scenario used by the

Agency to support the proposed listing

of 2,4,6-TBP production wastes

(disposal in unlined Subtitle D

landfills), and noted that the proposed

rule contained errors in the description

of 2,4,6-TBP waste quantities and

management practices. The commenter

stated that it was the sole generator of

TBP wastes covered by the proposed

listing and that all of its solid streams

containing TBP are shipped to a Subtitle

C disposal facility. The generator

subsequently submitted information

showing that it disposed of these wastes

in Subtitle C facilities for many years.

(See letter to Anthony Carrell, EPA,

from Stephen M. Wallace, Great Lakes

Chemical Corporation, dated April 23,

1997). The generator reported sending

the waste to various Subtitle C landfills

since 1981 (1981–1990, Chemical Waste

Management, Emelle, AL; 1991–1994,

Chemical Waste Management, Carliss,

LA; 1995–1996, American Ecology,

Winona, TX; 1997, Philips

Environmental, Avalon, TX). The

commenter noted that the only waste

from 2,4,6-TBP production disposed in

a Subtitle D landfill consists of 10 tons

of empty soda ash bags that do not

contain any TBP. The commenter stated

that the other combined waste solids

from TBP production (floor sweepings,

off-specification product and spent

carbon from filters) total approximately

34 tons annually. The commenter

argued that EPA’s selection of an

unlined Subtitle D landfill as a plausible

mismanagement scenario is erroneous

and, therefore, EPA’s risk analysis

significantly overstates the risk.

After considering these comments,

EPA issued the September 3, 1997,

letter, noted above, which evaluated

additional information to support the
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24609

Agency’s listing decision. The following

paragraphs in this section describe the

substance of the September 3 letter,

including the new risk analysis and the

new plausible mismanagement scenario

of voluntary disposal in a Subtitle C

landfill for this waste stream. Responses

to the additional comments received on

the September 3 letter are discussed in

the remaining sections of this Unit.

In the September 3 letter, EPA stated

that based on the information provided

by the commenter, the Agency agrees

that the quantity of waste solids from

2,4,6-TBP production that contain 2,4,6-

TBP levels of concern should be

approximately 34 tons, and should not

include the 10 tons of empty bags. The

Agency also acknowledges that the

generator apparently has a long record

of disposing the wastes with high 2,4,6-

TBP content in a lined Subtitle C

hazardous waste landfill. However, EPA

continues to believe that the waste

solids from production of 2,4,6-TBP

should be listed as hazardous, even if

the waste continues to be sent to

Subtitle C landfills. EPA considered

several critical factors in deciding to list

this waste stream.

First, Congress clearly expressed its

intent that the Agency is not to place

excessive reliance on confidence in

landfill design and liners for

problematic wastes. In the Hazardous

and Solid Waste Amendments (HSWA)

of 1984, Congress explicitly added as

one of the ‘‘findings’’ to RCRA that

‘‘land disposal facilities are not capable

of assuring long-term containment of

certain hazardous wastes’’ and that

‘‘reliance on land disposal should be

minimized or eliminated.’’ RCRA

section 1002(b)(7), 42 U.S.C. 6902(b)(7).

As a result of this finding, and others,

Congress added the land disposal

restriction (LDR) program to RCRA,

which significantly restricts land

disposal of hazardous wastes. Further, it

was made very clear in the Conference

Report for HSWA that the new findings

in RCRA were intended to House Report

No. 98–1133, 98th Cong., 2d Sess. at 80–

81 (Oct. 3, 1984). EPA views the statute

and legislative history as sufficient

justification to evaluate in a listing

determination all risks of land disposal,

including in appropriate cases risks

from voluntary disposal in permitted

Subtitle C facilities. This is particularly

true where risks presented by a waste

might be high if releases occur, and

treatment of the waste under Subtitle C

would significantly reduce these risks.

Accordingly, EPA added to the

rulemaking record additional data on

the effects of disposal in Subtitle C

landfills and reevaluated its analysis of

the factors contained in 40 CFR

261.11(a)(3) that are relevant to listing

the 2,4,6-tribromophenol waste solids.

The following analysis describes the

September 3 letter’s evaluation of, in

particular, the inherent toxicity of the

hazard constituent in the waste

(§ 261.11(a)(3)(i)), concentration of the

hazardous constituent in the waste

(§ 261.11(a)(3)(ii)), the potential of the

hazardous constituent to migrate into

the environment (§ 261.11(a)(iii)), the

relevance of the quantities of the waste

generated (§ 261.11(a)(3)(viii)) when

compared with these other factors, and

how these factors are weighed when

considered with the plausible

management scenario of voluntary

disposal of the waste in a Subtitle C

landfill (§ 261.11(a)(3)(vii)). EPA

concluded, after balancing these factors

in accordance with the Agency’s listing

determination policy described in its

December 22, 1994, proposed rule

listing certain wastes generated during

the production of dyes and pigments (59

FR 66073–78) that the 2,4,6-

tribromophenol waste solids are capable

of posing a substantial present or

potential hazard to human health or the

environment.

Review of the scientific data,

particularly sample analysis and

Structure Activity Relationships (SAR),

shows that evaluation of disposal in

subtitle C facilities is especially

appropriate for untreated 2,4,6-

tribromophenol waste solids. The waste

contains a highly toxic chemical, 2,4,6-

TBP, which may present significant

carcinogenic risk even at low

concentrations. This chemical was also

found to be present in the wastes of

concern at extremely high

concentrations. EPA’s analytical data

show levels up to 40% (equivalent to

400,000 ppm) in the waste solids. Thus,

while the volume of wastes generated

(approximately 34 tons annually) is not

very large, the extremely high levels of

2,4,6-TBP render this waste highly

toxic. As a general matter, when settings

its own priorities, EPA would not

ordinarily consider it a priority to make

a listing determination on a smallvolume waste from a single generator.

However, EPA has a set of statutory

obligations to make a prescribed set of

listing determinations and a

determination on this particular waste

stream is an obligation under the

consent decree governing EPA’s

completion of those obligations.

Furthermore, EPA’s data show that

2,4,6-TBP is relatively mobile and will

leach out of the waste at high

concentrations. In the proposal, EPA

used the TCLP method to estimate the

potential concentration of waste

constituents that could be in leachate

generated from disposal of the waste in

a landfill, and found up to 760 mg/L of

2,4,6-TBP in the TCLP leachate. This

level is 76,000 times the health-based

criteria of 0.01 mg/L that corresponds to

the 10–6 cancer risk level for ingestion.

The proposed rule estimated risks of 7

× 10–4 from migration to groundwater, if

this waste were placed in an unlined

landfill (see the proposed rule, 59 FR

24538). Although the generator has sent

this waste to a lined Subtitle C facility

in the past, EPA believes that the risks

estimated from migration from an

unlined landfill provide an indication of

the potential risks that could occur if

2,4,6-TBP is released from the lined

landfill due to failure of the unit to

contain the waste leachate. The Agency

agrees that the liner/leachate collection

system in a Subtitle C unit would serve

to contain the waste, and would

substantially lessen the risk even in the

case of liner failure. However, EPA

believes that the purpose of the RCRA

hazardous waste treatment requirements

(as expressed by Congress) is to reduce

the uncertainty inherent in engineered

containment approaches.

In past rulemakings EPA has assumed

that waste containment systems will

tend to degrade with time. In the

proposal for the Land Disposal

Restrictions (January 14, 1986, 51 FR

1641) EPA noted that in the long-term

(beyond the post-closure period) the

efficiency of cover and liner systems

will degrade. Eventually synthetic liners

will degrade and leachate collection

systems will cease operation. In the

proposed Liner and Leak Detection Rule

(May 29, 1987; 52 FR 20218) EPA also

stated that no liner can be expected to

remain impervious forever. As a result

of interactions with waste,

environmental effects, installation

problems, and operating practices,

liners eventually may degrade, tear, or

crack and allow liquids to migrate out

of the unit. In evaluating the benefits of

this rule (see 52 FR 20270), EPA noted

that a properly installed double liner

and leachate collection system, together

with a final cover placed at closure,

substantially reduces release during the

operating life and post-closure care

period. However, these technologies

may not effectively reduce the longerterm risk for landfills, especially for

persistent and mobile compounds,

because the containment system may

only delay leachate release from the

landfill until after the post-closure

period, when the cap and leachate

collection system begin to fail.

EPA has attempted to account for the

effect of Subtitle C containment (covers

and liners) in the Regulatory Impact

Analyses (RIA) completed for other
24610 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

recent rulemakings. (See the RIA for the

Land Disposal Restrictions—Phase II

rule, pages 5–10, in the docket for the

final Phase II rule, published September

19, 1994, 59 FR 47980; and the RIA for

the final rule on Corrective Action

Management Units, Appendix C, in the

docket for the rule published February

16, 1993, 58 FR 8658.) These documents

are incorporated by reference into the

docket for this rule. As EPA noted in the

source document used in these RIAs

(Technical Guidance Document,

‘‘Indexing of Long-Term Effectiveness of

Waste Containment Systems for a

Regulatory Impact Analysis,’’ Office of

Solid Waste, November 1992; this

document has been placed in the public

docket for today’s rule), the structural

integrity of waste containment systems

degrades over time due to stresses on

system components. EPA noted that

failures of multi-component liner

systems have been reported in the

literature, and that some liners fail

unpredictably with time. While

acknowledging the uncertainties in

predicting long-term effectiveness, EPA

estimated that the effectiveness of

Subtitle C composite liner systems may

decrease significantly with time.

Although it is difficult to quantify the

impact of the long-term degradation of

liner systems, the high level of risk

estimated from disposal of this waste in

an unlined landfill (7 × 10¥4) means

that even a modest reduction in longterm liner effectiveness would present

risks of concern. For example, if the

long-term effectiveness of the landfill

liner and containment system were on

the order of 95%, which would reduce

the potential risks from releases to

groundwater by 20-fold, the residual

risk would exceed 3 × 10¥5. In fact, the

containment systems would have to be

in excess of 98% effective for the

estimated risk to drop below 1 × 10¥5.

The risks for this particular untreated

waste, therefore, would remain above

EPA’s presumptive level of concern for

listing (>10¥5), whether they were sent

to an unlined landfill or a Subtitle C

landfill (for a discussion in risk levels

used in listing determination see

December 22, 1994, 59 FR 66075).

The Agency recognizes that a recent

court decision (Dithiocarbamate Task

Force v. EPA, 98 F.3d 1394 (D.C. Cir.

1996), raised questions as to what

constitutes ‘‘plausible’’ mismanagement

under the listing regulations

(§ 261.11(a)(3)). However, EPA has not

yet fully evaluated the recent court

decision to determine how to weigh

possible future changes in management

practices and is not relying on

projecting new management practices in

this listing decision. For the purposes of

the analysis in the September 3 letter,

EPA assumed that the current waste

management practices continue (i.e.,

disposal of the untreated waste in

Subtitle C landfills).

To respond to the commenter’s

concern related to waste solids that do

not contain 2,4,6-TBP, EPA is revising

the regulatory language to clarify that

the wastes covered in the listing are

those of concern, i.e., those containing

high levels of 2,4,6-TBP. This avoids

capturing the empty soda ash bags, and

possibly other waste solids downstream

from the production unit that EPA did

not intend to cover in the listing.

Therefore, the final listing reads as

follows:

K140—Floor sweepings, off-specification

product, and spent filter media from the

production of 2,4,6-tribromophenol.

Another commenter stated that the

high concentrations of TBP in the floor

sweepings sampled by EPA provide

singular justification for the listing of

these wastes. EPA agrees with the

commenter that the high concentration

of the toxic chemical, 2,4,6-TBP, is a

major concern. However, EPA did not

consider this factor in isolation, but also

considered the mobility of the waste

and its inherent toxicity as equally

important factors, and balanced all of

these factors in the risk assessment. As

noted above, the risk assessment

predicts TBP leaching from unlined and

lined landfills to receptor drinkingwater wells at concentrations well above

health-based levels of concern.

2. Comments on the September 3, 1997,

Notice Letter

As noted previously in today’s rule,

EPA provided an opportunity for further

comment on the Agency’s reevaluation,

described above, of the rationale for the

listing determination for the waste

solids from the production of 2,4,6-TBP.

EPA sent letters of notice to three

parties who commented on the

proposed rule and could be expected to

have an interest in the final decision

and the revised rationale for listing. EPA

received the comments noted below

from the three entities that received the

notice letter; one supported the decision

to list 2,4,6-TBP production wastes, and

two opposed the listing. EPA’s response

to these new comments are summarized

below and are described in more detail

in the docket. (See ‘‘Supplementary

Response To Public Comment’’, April

1998)

a. Procedural Comments. One

commenter challenged EPA’s approach

of sending notice letters to only three

commenters on procedural grounds, and

claimed that EPA was soliciting

comments through a ‘‘selective notice

procedure’’ that fails to give the general

public opportunity to be heard on

several issues. The commenter argued

that others should have a chance to

comment on the idea that placement of

waste in a Subtitle C landfill that is in

compliance with appropriate

regulations may be

‘‘mismanagement,’’because this may

have significant ramifications for

individuals who did not previously

comment and has ‘‘far-reaching effects

for those operating and using’’

hazardous waste facilities.

Another commenter argued that EPA

cannot list wastes based on the theory

that Subtitle C disposal constitutes

‘‘mismanagement’’ without amending

its listing criteria, stating that EPA must

first propose and seek comment on the

new theory of mismanagement before it

can redefine its basic approach to the

listing process.

EPA does not agree that notice was

inadequate, nor does the Agency agree

the listing criteria must be amended.

Due to the limited time EPA has for

completing this action, the Agency

decided that letters providing actual

notice to the parties who commented on

the proposed rule and could be

expected to have a direct interest in the

final rule decision was appropriate.

Those receiving the letter included the

only current generator of the waste, and

the industry group and environmental

group that commented on the proposed

rule. These are the parties EPA decided

were arguably affected by the

recharacterization of the rationale for

listing. EPA is not aware of any other

generators of this waste or any other

persons who would have a direct

interest in this decision. The actual

notice given in this case is sufficient.

No reasons offered by the commenters

indicate any need to go beyond the

actual notice EPA provided. The

decision in this case does not have

‘‘palpable effects upon a regulated

industry or the public in general.’’

Instead, it affects this wastestream,

alone, and those that can argue they

have an interest in the wastestream. To

the extent a similar analysis may be

used for other wastestreams EPA may

consider listing in the future, the

affected parties will have adequate

opportunity to comment then.

Moreover, today’s action does not

compromise their legal rights to

challenge such EPA listing decisions in

the future.

Also, there are no ramifications for

individuals who did not previously

comment. The fact of the matter is that

the revised rationale described in the

letter will not have ‘‘far-reaching
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24611

effects’’ for those operating and using

hazardous waste landfills. Rather, this

decision is being made on the basis of

risk for one specific waste with certain

properties and does not reflect any new

policy direction towards any other

operators or users of hazardous waste

landfills. No persons are expected to

change their habits, for example, in

changing the operations of their

landfills, as a result of this decision. No

persons who operate their landfills in

accordance with Agency regulations

will be affected by this decision. In any

future circumstances in which EPA

chooses to evaluate, as part of a listing

decision, the risk basis of voluntarily

putting a waste in a Subtitle C landfill

ample opportunity for comment will be

provided.

Further, the commenter’s concern that

disposal of untreated waste in a Subtitle

C landfill that complies with regulations

may be mismanagement is misleading.

Disposal of untreated waste in any type

of landfill could be considered

mismanagement, despite compliance

with all applicable landfill design and

operation regulations. No one would

want highly dangerous materials

voluntarily placed in a Subtitle C

landfill. Clearly, some untreated wastes

could pose a potential hazard of such

magnitude that merely voluntarily

placing them in a lined landfill would

not be sufficient. In this instance,

applying the factors in § 261.11(a)(3),

EPA has concluded that the disposal of

this highly toxic, untreated waste in a

Subtitle C landfill is improper

management within the meaning of that

subsection of the regulations. EPA is not

suggesting that the landfills in question

have been mismanaged. On the

contrary, the voluntary use of Subtitle C

landfills by the generator has been

laudable. However, for purposes of a

listing determination, the overall

practice is improper management in that

is does not adequately control risks to

human health and the environment.

EPA also does not agree that the

listing criteria have to be modified in

any way to allow the Agency to make

the listing determination for the

organobromine waste at issue. The

regulations (see § 261.11(a)(3)) clearly

permit EPA to render a listing decision

based on a variety of factors. These

factors were weighed when considered

with the plausible management scenario

of voluntary disposal of the waste in a

Subtitle C landfill without previous

treatment. After balancing these factors

EPA concluded that the 2,4,6-

tribromophenol waste solids are capable

of posing a substantial present or

potential hazard to human health or the

environment. It is consistent with the

regulations to reason that, if voluntary

Subtitle C landfilling (absent treatment)

presents a substantial present or

potential hazard, the practice

constitutes improper management under

§ 261.11(a)(3)(vii). Therefore, a

regulatory change is definitely not

needed prior to making this listing

determination.

b. Risks Related To Plausible

Mismanagement Scenario. One

commenter stated that EPA’s proposed

listing is based on a management

scenario that is unsupported and

implausible, and further noted that the

evaluation of future failure rates of

Subtitle C landfill containment systems

is not supported by evidence in the

docket. The commenter states that the

one study relied upon by EPA fails to

account for the multi-component nature

of liner systems and does not specify

how it accounts for these factors,

making it impossible to determine the

validity of the assigned failure rates.

The commenter claimed EPA’s sole

reliance on this study is arbitrary and

capricious. The commenter also stated

that EPA did not consider site-specific

factors (e.g, liner type, soil type, annual

precipitation) to determine if leachate

will reach groundwater. The commenter

claimed, therefore, that EPA has not

made a reasoned determination that the

long-term effectiveness evaluation is

valid at these specific facilities.

The commenter is wrong for a number

of reasons. The effectiveness-time

relationships given in the reference used

by EPA (Indexing of Long-Term

Effectiveness of Waste Containment

Systems for a Regulatory Impact

Analysis, USEPA, November 1992) was

based on an examination of the

technical literature on the subject, and

an evaluation of many technical factors.

The document evaluated the

effectiveness of various components of

the containment system, and identified

the likely degradation mechanisms. For

example, landfill containment systems

may leak due to improper installation,

and may be degrade by subsidence,

drying/cracking, freeze-thaw cycles,

burrowing of animals, leachate

incompatibility, and vehicle loads. This

analysis considered the composite clay/

geomembrane liners and caps required

under RCRA Subtitle C regulations. The

document also provided data and cited

references showing that even

configurations like RCRA Subtitle C

liners do, in some cases, leak over time.

Concerning the leachate collection

system, EPA notes that the regulations

require operation and maintenance of

these collection and leak detection

systems for 30 years after closure of the

landfill (see 40 CFR 264.117). Over the

long-term, therefore, EPA cannot rely on

leachate collection systems to prevent

the eventual release of leachate of

untreated waste from the landfill if the

liner system fails.

EPA agrees that the degradation of a

containment system depends to some

extent on the systems design and other

site-specific factors. However, the

commenter provided no specific data

indicating what site-specific factors

would prevent release of constituents

from the wastes disposed, or what the

long-term containment efficiencies

might exist for the landfills at the sites

in question. Therefore, EPA has no

reason to alter its analysis on this basis.

Furthermore, EPA does not believe that

such a site-specific analysis is

appropriate in this case, because the

generator may use many different

landfills for disposal. In fact, the history

of the generator’s disposal practices (See

letter from Great Lakes Chemical

Corporation to EPA dated April 23,

1997) shows that the generator changed

disposal sites quite often (e.g., the

generator sent the waste to three

different landfills between 1994 and

1997).

One commenter stated that EPA has

turned this inquiry from determining

whether dangerous ‘‘mismanagement’’

is plausible into an inquiry into whether

it can be ruled out completely, and cites

EPA’s admission that there is at least a

95% chance that C landfills will not

leak. The commenter claims EPA argues

that ‘‘nothing lasts forever,’’ and

therefore Subtitle C disposal can be

mismanagement. The commenter argues

that this type of logic was unacceptable

in the Dithiocarbamate case. The

commenter states that EPA effectively

writes the requirement of a ‘‘plausible

mismanagement scenario’’ out of the

listing rule, and that recent court

decisions do not allow EPA to evaluate

such a factor so as to drain it of all

content.

As a preliminary matter, EPA points

out that this listing is wholly consistent

with the Dithiocarbamate Task Force

case. The Agency has found that the

common practice of the only generator

of the waste over more than 15 years is

the plausible management scenario. The

assessment of all relevant factors under

§ 261.11(a)(3) led the Agency to

conclude that voluntary Subtitle C

landfill disposal is improper

management.

Furthermore, the Agency has not

turned this into an inquiry about

whether ‘‘mismanagement’’ can be ruled

out completely. Rather, the Agency has

evaluated this particular waste under

the conditions of plausible management

and reached a conclusion that there is
24612 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

a substantial present or potential risk.

The commenter is attempting to turn the

Agency’s risk analysis into a narrow

inquiry into plausible mismanagement.

This is simply incorrect.

With respect to the EPA’s analysis of

risk, the Agency did not state that there

is a 95% chance that C landfills will not

leak. Rather, EPA was indicating that

even if the containment system was

95% effective, the potential risks from

the waste in question are so high that it

would still present a risk at levels of

concern. Even if a Subtitle C landfill

was 98% effective in reducing risk

relative to risk in an unlined landfill

(e.g., the Subtitle C landfill’s

effectiveness decreased 2% from a

combination of cap failure and

abandonment of active landfill

management), the estimated risk would

still exceed 1 × 10¥5. The actual longterm efficiency is extremely difficult to

estimate, given the highly uncertain

long-term integrity of liners/leachate

collection systems and landfill caps.

The document cited by EPA that

attempts to evaluate the effectiveness of

liner systems estimated it would

degrade to an efficiency well below 95%

over the long term (e.g., one hundred

years). EPA is not attempting to

absolutely rule out certain management

scenarios, but rather to account for the

likely degradation of a Subtitle C

containment system over the long-term.

Certainly the available data (cited in the

document used by EPA) clearly show

that the materials that make up liners

and caps are expected to degrade over

time. Therefore, given this fact, in

conjunction with the available estimates

of long-term effectiveness, EPA believes

that the highly toxic waste in question

may present a significant risk when

placed in any landfill, even a Subtitle C

unit.

One commenter stated that EPA’s

legislative references do not support the

idea that disposal in Subtitle C landfills

constitutes mismanagement, but rather

relate to historic problems caused by

unregulated disposal, and expressed

support for minimizing the quantities

and toxicity of wastes that must be

disposed. The commenter states

Congress did not require all wastes to be

treated before land disposal, but only

wastes that are hazardous, and notes

that the fact that treatment might reduce

the hazardousness of a waste is not a

relevant factor in EPA’s listing criteria.

EPA disagrees with the claim that

Congress was concerned only with

unregulated land disposal. The statute

itself clearly states Congressional intent:

‘‘certain classes of land disposal

facilities are not capable of assuring

long-term containment of certain

hazardous wastes * * * and land

disposal, particularly landfill and

surface impoundment, should be the

least favored method for managing

hazardous wastes.’’ (See RCRA, section

1002(b)(7)). EPA agrees that Congress

did not require all wastes to be treated

prior to land disposal. However, in this

case EPA believes the waste in question

presents a substantial hazard when land

filled, even in a Subtitle C landfill, in

the form in which it is generated (i.e.,

untreated). Therefore, EPA believes the

waste is, in fact, hazardous and should

be subject to full regulation under

Subtitle C, including the land disposal

restrictions.

One commenter stated that, while

EPA is not relying on projecting new

management practices in this listing

decision, the Dithiocarbamates decision

is still controlling. The commenter

noted that when the court struck down

the K160 listing, it did not remand it to

allow EPA to reevaluate whether

disposal in a Subtitle C landfill

constitutes ‘‘plausible mismanagement,’’

as EPA is attempting to do here. The

commenter went on to say that, in

striking down 24 other waste listing (Ulistings) in the Dithiocarbamate

decision, the court refused to accept as

examples of mismanagement various

past or future accidents, and stated that

EPA assertions that ‘‘accidents will

happen’’ does not constitute ‘‘plausible

mismanagement.’’ The commenter

claimed this analysis is equally

applicable to EPA’s assumption that all

landfills will leak eventually, and the

fact that some unquantified uncertainty

exists regarding long-term risks from

Subtitle C disposal does not mean that

such disposal is mismanagement. The

commenter argued that the only change

listing the waste would cause would be

to require compliance with land

disposal treatment standards and it is

difficult to see how a listing would

substantially reduce risks. The

commenter stated that EPA did not

address the question of how much risk

reduction would result from treatment.

The commenter also noted that the fact

that treatment might reduce the

hazardousness of a waste is not a

relevant factor under § 261.11(a)(3) in

deciding whether to list a waste as

hazardous.

The commenter’s reference to ‘‘the

Dithiocarbamate case’’ is not relevant in

this context. In the Dithiocarbamate

case, the court did not address the issue

of Subtitle C management in any

substantive way. The court stated that it

was vacating the listing of K160

‘‘[b]ecause EPA failed to identify a

plausible mismanagement scenario

* * *’’ (98 F.3d at 1404) and did not

reach the issue of whether voluntary

disposal in a Subtitle C landfill (absent

treatment) would present a substantial

risk. The decision in no way limits the

Agency from considering potential risks

from Subtitle C management. EPA had

not raised the issue in rulemaking

because the Agency had determined that

the plausible management scenario was

an unlined landfill. The Agency did not

conduct a risk assessment on the

Subtitle C landfill because it did not

believe it had to.

The reference to consideration of the

U wastes in the Dithiocarbamate case is

also irrelevant in this context. The

commenter is confusing EPA’s

acknowledgment of the uncertainty in

quantitatively estimating the long-term

efficiency of Subtitle C containment

systems as being equivalent to

assertions that ‘‘accidents happen,’’

referenced by the Dithiocarbamate case.

As noted in response to other comments

in this proceeding, EPA’s evaluation

attempted to account for the likely

degradation of a Subtitle C containment

system over the long-term. Therefore,

EPA continues to believe that it is

logical and appropriate to assume that

the containment efficiency of landfills

will degrade sufficiently so that, for this

highly toxic waste, disposal of the

untreated material in a Subtitle C

landfill may present a substantial

present and potential hazard.

As noted in the commenter’s own

statements, unlike in the

Dithiocarbamate case, in which the

court did not see how U-listings would

avert accidents, a listing of the 2,4,6-

TBP waste solids would, in fact, prevent

the placement of untreated wastes in the

landfill. Further, the treatment

standards for this newly listed waste

(see the land disposal restrictions

section of today’s rule) require levels of

2,4,6-TBP for nonwastewaters to be no

greater than 7.4 mg/kg. This level

equates to a reduction of up to a 50,000-

fold reduction in the level of 2,4,6-TBP

in the waste. Such a reduction in 2,4,6-

TBP levels will likely result in

significant risk reduction—a clear

benefit of the listing. Furthermore, the

§ 261.11(a)(3) criteria, as noted by the

commenter, does not require the Agency

to consider risk reduction. Section

261.11 is promulgated under the

authority of section 3001 of RCRA,

which requires EPA to identify criteria

for listing. Once listed, the wastes

would become subject to the

management requirements of Subtitle C.

The regulations for management

requirements are promulgated under

other sections of RCRA, like sections

3002 (generator standards), 3003

(transportation standards), 3004
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24613

(standards for treatment, storage and

disposal facilities), and 3005 (permits

for treatment, storage or disposal). These

are the sections under which EPA

would consider risk reduction measures

that would be protective of human

health or the environment.

While one commenter supported

EPA’s decision to list the 2,4,6-TBP

solids and filter cartridges, the

commenter stated that EPA assumes in

its reevaluation that the wastes at issue

will always be landfilled in a Subtitle C

facility, even though the regulated

community is under no legal or

technical mandate to do so in the

absence of a hazardous waste listing.

The commenter claimed that EPA’s

proposed listing rationale based on

Subtitle C landfilling substantially

understates the risks, and argues that

EPA should not assume past disposal

practices represent the only plausible

mismanagement practice for at least four

reasons: (1) There is no technical or

other bar to additional companies

producing 2,4,6-TBP and generating the

wastes at issue, either at existing

organobromine chemical production

facilities or at new locations. Therefore

identification of plausible

mismanagement scenarios should

involve more than an analysis of one

company’s historic disposal practices;

(2) the wastes at issue (floor sweepings

and filter cartridges) are frequently

observed in the organobromine

chemical industry, and in many cases

are landfilled onsite in nonhazardous

units. Thus, EPA should consider how

similar wastes from other

organobromine production processes are

managed when identifying plausible

mismanagement scenarios; (3) the

company currently generating these

wastes has used three different landfills

since 1994, suggesting that cost is the

overriding factor in the company’s

disposal decision. It is not unreasonable

for EPA to assume the cost differential

between Subtitle C and D landfills may

cause the company to use a

nonhazardous waste landfill; and (4) the

production facility’s 1995 TRI report

reveals that half of the TRI chemicals

sent offsite for disposal were sent to a

nonhazardous landfill. Thus, even at

this one facility Subtitle C landfilling is

not uniformly practiced.

As a general response to these

comments, the Agency notes that these

arguments have no practical effect and

would not change EPA’s decision to list

the waste. In the original proposal to list

the 2,4,6-TBP production solids, EPA

estimated the risks from disposal in an

unlined landfill would warrant listing

the waste (see proposed rule, 59 FR

24530, May 11, 1994). As noted in the

September 3, 1997 notice letter, the

risks from such disposal would be

mitigated in a Subtitle C landfill, but

would still be at levels of concern.

Therefore, EPA does not need to rely on

projecting new management practices in

this listing decision. EPA intends to

address the more general issue of how

to weigh potential changes in

management practice in the future.

Two commenters argued that EPA did

not fully consider the impact of the

existing RCRA Subtitle C regulations in

its analysis of potential risks from

disposal in such a regulated landfill.

One argued that the proposed

mismanagement scenario presumes that

all landfill operators are in violation of

RCRA regulations, and noted that the

regulations require that liner/leachate

collection systems prevent migration

out of landfills during the active life

(including the closure period) of the

landfill. The commenter argues that the

resources spent on landfill design and

construction have resulted in more than

a 20-fold decrease in risk posed by the

waste disposed. The commenter stated

that if EPA is concerned with releases

from landfills, the proper place to

address this is through the regulations

governing land disposal units, and not

the listing process.

The other commenter stated that

comprehensive landfill regulations

prevent the release of hazardous

constituents from the waste into the

environment by: Double liners and

leachate collection systems,

groundwater monitoring, and corrective

action requirements in case of a release.

The commenter also noted that the

performance of Subtitle C landfills is

guaranteed by operating, closure, and

post-closure permits, but stated that

none of these safeguards were addressed

in EPA’s reevaluation.

EPA agrees that the regulations

governing Subtitle C landfills are

stringent and are designed to prevent

releases from the unit, to detect if such

leaks occur, and to take corrective

action if necessary. However, EPA is not

assuming that all landfill operators will

be in violation of RCRA. EPA is simply

recognizing that such standards are not

protective in perpetuity nor for every

possible waste. EPA is not saying that

voluntary Subtitle C landfilling is

always ‘‘improper’’, just that there are

wastes that should not go into them if

they are not treated. EPA agrees that

properly installed liner systems and

final covers substantially reduce the

potential for releases during the

operating life and post-closure period

(see 52 FR 20270, May 29, 1987). EPA

also agrees that permits for landfills

help to ensure the implementation of

stringent requirements for groundwater

monitoring and corrective action. The

RCRA regulations require a 30 year postclosure period, during which the unit is

maintained and monitored (see 40 CFR

264.117), but after the post-closure

monitoring ends releases may not be

detected or corrected. While extending

the post-closure period might be one

way to decrease potential risks from

Subtitle C landfills, EPA notes that

treatment under the land disposal

restrictions program is another way (and

perhaps a more direct way) of ensuring

long-term risks are minimized. Listing

the waste solids from the production of

2,4,6-TBP ensures that this highly toxic

waste will be treated prior to landfill

disposal.

c. Demonstration of a Substantial

Hazard. One commenter claimed that

EPA’s approach does not demonstrate

that the TBP wastes managed in Subtitle

C landfills pose a substantial hazard as

required by the statute and EPA’s rules

(§ 261.11(a)(3)). The commenter argued

that no human health or environmental

damage has ever occurred as a result of

improper management of TBP wastes,

and the quantity of the TBP waste (35

tons per year) is ‘‘inconsequential.’’ The

commenter also stated that the court in

the Dithiocarbamate case indicated that

EPA must balance the toxicity of the

chemicals with other factors specified in

EPA’s listing criteria. Finally, the

commenter noted that EPA’s estimate of

risks above 10¥5 from TBP wastes in

Subtitle C landfills is ‘‘based on

improper extrapolation from Subtitle D

risk modeling.’’

EPA disagrees with the commenter’s

assessment of the hazard posed by the

TBP wastes. First, the regulatory criteria

for listing wastes as hazardous is that

the wastes may * * * pose a substantial

present or potential hazard.’’ These

wastes certainly meet that criteria.

While EPA has not found damage cases

that document health or environmental

damage from disposal of this waste, this

is only one of the factors EPA considers

in its listing decisions. While EPA has

not identified any cases of actual

damages from this waste, EPA has

explained how it considered the other

factors under § 262.11(a)(3). The risk

assessment, after consideration of all of

these factors shows individual risk

numbers to be above EPA’s level of

concern. Furthermore, by listing a waste

as hazardous, EPA hopes to prevent

such damage from occurring, and the

Agency has often listed wastes in the

absence of definitive damage cases.

Contrary to the comment, EPA does not

concede that the volume of waste at

issue (34 tons annually) is necessarily

‘‘inconsequential.’’ The volume of waste
24614 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

must be examined in conjunction with

the concentration and properties of

toxic constituents present. In this case,

the relatively small quantity of waste

contains very high concentrations of a

highly toxic constituent, 2,4,6-TBP.

As noted elsewhere in today’s rule,

EPA continues to believe that the SAR

results demonstrate that 2,4,6-TBP is

highly toxic. Furthermore, EPA has

shown how this toxic chemical, in a

highly concentrated waste, may

potentially cause a substantial risk even

if managed in a Subtitle C landfill. The

waste in question is so toxic and

concentrated that release may occur at

levels of concern, even if the

containment system of a Subtitle C

landfill were very high (e.g., 95%).

Given this result, EPA believes that

listing is warranted.

d. Other Risk Issues. Two commenters

argued that the Agency’s toxicity

assumptions for 2,4,6-TBP are invalid.

One stated that EPA failed to address

comments on the use of Quantitative

Structure Activity Relationships (QSAR)

in its risk analysis, and incorporated its

previous comments by reference. The

commenter also noted that a proposal by

EPA to gather the data necessary to

evaluate 2,4,6-TBP was rejected by the

Interagency Testing Committee (ITC).

The commenter stated that, while the

ITC originally proposed to include

2,4,6-TBP on the priority testing list

under Section 4(e) of the Toxic

Substances Control Act (TSCA),

following receipt of exposure

information from an industry group and

the producer of 2,4,6-TBP, the ITC

revised its position and removed 2,4,6-

TBP from the priority list. The

commenter stated that the rationale for

removal of 2,4,6-TBP was based on the

ITC’s determination that

‘‘environmental and workplace

monitoring indicate that 2,4,6-

tribromophenol is not likely to result in

substantial environmental releases or

significant exposures to workers,

consumers or the general population.’’

EPA has not ignored the comments

received on the Agency’s use of

Structure Activity Relationships for

estimating the toxicity of 2,4,6-TBP.

EPA responds fully to all comments

related to this issue in a separate section

of today’s preamble. As the commenter

noted, the ITC’s 40th Report revised the

TSCA section 4(e) Priority Testing List

by removing 2,4,6,-TBP, which had

previously been recommended for

testing in its 39th report (62 FR 8578,

February 25, 1997). The ITC stated that

it removed 2,4,6-TBP after reviewing

data that demonstrated that: (1) It is

used as a chemical intermediate to

produce flame retardants; (2) greater

than 99% of 2,4,6-TBP used as an endproduct is shipped overseas to be used

as an intermediate in the production of

brominated flame retardants; and (3)

environmental and workplace

monitoring indicate that 2,4,6-TBP is

not likely to result in substantial

environmental releases or significant

exposures to workers, consumers, or the

general public. Exposure and release

information provided by industry and

the CMA include an industrial hygiene

survey from 1979, a historical

prospective mortality study of workers,

a pollution evaluation, and a

determination of brominated organic

compounds in environmental matrices

(secondary effluents). The available

exposure information pertains to

workers and the potential for general

population exposure from

manufacturing sites. In deciding to list

waste solids from the production of

2,4,6-TBP, however, EPA considered in

detail the potential exposure and risks

due to the disposal of wastes generated,

not product use. EPA notes that none of

the exposure studies used in the ITC

decision deal with RCRA issues, for

example, the presence of TBP in waste

streams, its subsequent disposal in a

landfill, and the potential hazards

associated with leakage from such a

landfill or with any mismanagement

scenario.

EPA further examined the rationale

for the removal of 2,4,6-TBP from the

Priority Testing List and does not agree

that this action in any way undermines

EPA’s use of SAR to estimate the

chemical’s toxicity. 2,4,6-TBP was not

removed from the ITC Priority Testing

List because the ITC had found that TBP

was not toxic. Indeed, the chemical was

originally included on the List because

the NIEHS needed chronic toxicity and

2-year carcinogenesis study data. The

availability of these data would obviate

the need for the use of a qualitative or

quantitative SAR by EPA, which would

prefer to use actual data on the

constituent in question whenever

possible. Among the studies cited by

CMA and GLCC as available for EPA

review are acute toxicity (oral,

inhalation, and dermal), dermal

sensitization, skin and eye irritation, 21-

day inhalation toxicity, 28-day subacute

dermal toxicity, clearance,

teratogenicity, genotoxicity, and

pharmacokinetics. None of these studies

are sufficient to judge the carcinogenic

potential of TBP, which is the primary

endpoint of concern for this chemical.

Therefore, EPA does not believe that the

ITC decision to remove TBP from the

Priority Testing List addresses EPA’s

determination that 2,4,6-TBP is highly

toxic as indicated by SAR and that

disposal of wastes containing high

levels of this toxic chemical in a landfill

(even a Subtitle C landfill) poses a

substantial hazard that requires listing

the waste as hazardous.

One commenter supported the

proposed decision to list waste solids

from the production of 2,4,6-

tribromophenol, but argued that EPA

underestimated the risks posed by

disposal of the waste in a Subtitle C

landfill for at least three reasons. The

reasons noted by the commenter were:

(1) The TCLP understates the leaching

potential of the waste in a Subtitle C

landfill by at least an order of

magnitude, because the waste may be

exposed to solvents and other chemicals

that encourage contaminant leaching,

and because the TCLP appears

‘‘uniquely ineffective’’ in leaching

contaminants from the waste; (2) EPA’s

risk estimates are based on the presence

of 2,4,6-TBP only and ignore the

presence of arsenic and other toxic

contaminants in the waste and TCLP

leachate; (3) EPA’s assumption of 95%

containment efficiency for a Subtitle C

landfill is unreasonable given that

owner/operator’s post-closure

responsibilities typically end after 30

years; containment efficiency would

drop to 60% at 100 years, and beyond

100 years additional declines can be

expected.

As a general response to the argument

that EPA underestimated the risks posed

by Subtitle C disposal for the wastes in

question, the Agency notes that these

arguments have no practical effect and

would not change EPA’s decision to list

the waste. However, EPA does not agree

with some of the arguments put forth by

the commenter, and is responding to

them for this reason. EPA does not agree

that the TCLP underestimates the

leaching potential of the waste in

question for reasons discussed below.

Absent any firm data to conclude

otherwise, EPA finds no reason to

conclude that the TCLP underestimates

the leaching potential of the 2,4,6-TBP

production wastes. As a preliminary

matter, EPA notes that the commenter

cites no basis for its quantified estimate

that the leaching is underestimated by

one order of magnitude. Moreover, there

is no indication that the TCLP is

‘‘uniquely ineffective’’ in leaching

contaminants from this waste, as the

commenter claims. The properties of

2,4,6-TBP indicate that the relatively

low leaching efficiency is not

unexpected. This chemical is not highly

soluble in water (70 ppm; see The

Merck Index, Ninth Edition, 1976) and

would not be expected to leach from the

organic waste matrix at very high levels.
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24615

The octanol-water partition coefficient

(Kow) for this substance is on the order

of 17,000 (or in log form, 4.23); this

coefficient is a measure of the tendency

of the chemical to partition into organic

phases compared to water, and this

value indicates the chemical is expected

to be at 17,000-fold higher concentration

in the organic phase compared to water.

It, therefore, would be expected to

remain bound in the organic phase and

would tend to be less mobile.

Furthermore, the lower leaching from

the spent filter material is also logical,

because the filter material is activated

carbon. Activated carbon is used

expressly to remove organic material

from a process stream, and the 2,4,6-

TBP is expected to be relatively tightly

adsorbed to this matrix. Therefore, EPA

has no reason to believe, despite the

commenters assertions, that the TCLP

results are not valid for this waste.

EPA’s decision to list this waste

focused on 2,4,6-TBP because this

chemical was found at levels that

greatly exceeded the other constituents

detected. While other constituents were

detected in the waste, many were also

found in blank laboratory QC samples

(e.g., methylene chloride) indicating

that the detection of these volatile

constituents in waste samples may have

been due to some sample

contamination, perhaps in the

laboratory. Concerning arsenic, the

analytical results are suspect due to

known problems with measuring some

metals in these type of waste matrices.

(See Method 6020, Test Methods for

Evaluating Solid Waste, Physical/

Chemical Methods, third edition, 1994;

OSW/USEPA). One of the waste

samples (spent carbon filter material,

number GL–08) showed the presence of

other brominated phenols, notably 2,4-

dibromophenol; however, EPA does not

have any health-based levels to

rigorously evaluate them.

Analysis of the other sample (floor

sweepings and off-specification product,

GL–09) showed the presence of several

volatile constituents that were found in

the blank samples. However, this

sample also contained significant levels

of 1,2-dibromoethane (also known as

ethylene dibromide, or EDB). As

evidenced by the very low drinking

water standard established for this

chemical (the maximum contaminant

level, or MCL, is 0.00005 mg/L; see 40

CFR 141.61), this substance is highly

toxic, and the level reported in the

TCLP analysis (36 mg/L) is 720,000

times the existing MCL. The Agency

believes that the relatively high levels of

this chemical in the waste (and the

corresponding TCLP sample) further

confirms that these production solids

contain high levels of highly toxic

chemicals and present a substantial

hazard, even if managed in a Subtitle C

landfill. There is further discussion of

the presence of EDB in the following

Unit IV.E.3.

In its reevaluation, EPA did not

conclude that the containment

efficiency for a Subtitle c landfill was

necessarily 95%. The Agency’s point

was, even if the efficiency was as high

as 95%, the potential release from 2,4,6-

TBP production solids in a landfill may

present risks at levels of concern. While

estimating the long-term efficiency of

containment is highly uncertain, EPA

agrees that it may be less than 95%,

thereby making the potential risk

higher.

e. Other Comments. The commenter

that supports EPA’s decision to list the

waste at issue noted that the disposal of

wastes with high concentrations of

organic contaminants is what Congress

sought to restrict through the Land

Disposal Restrictions program. The

commenter argued that a hazardous

waste listing for these wastes is

appropriate to ensure Congressional

objectives of the LDR program are

achieved. The commenter claims EPA

must consider these expressions of

‘‘proper’’ management when applying

its criteria for listing hazardous waste.

EPA agrees that in establishing the

Land Disposal Restrictions program,

Congress found land disposal to be

incapable of ensuring long-term

containment of hazardous waste.

However, EPA does not agree that the

high content of organic contaminants is,

by itself, sufficient to require listing.

The listing decision is based on the

highly toxic nature of the constituent in

question (2,4,6,-TBP), in conjunction

with potential risks associated with its

release, even if placed in a Subtitle C

landfill. Therefore, EPA agrees that

listing, and the associated treatment

required under the land disposal

restrictions program, are appropriate

because of the chemicals high toxicity

and potential mobility in groundwater.

EPA does not agree that listing is

appropriate merely to comply with

Congressional intent for treatment of

hazardous waste, because a waste must

first be determined to be hazardous

before the LDR program applies.

One commenter argued that EPA’s

reevaluation could be read as an

indictment of the Agency’s

comprehensive Subtitle C program for

managing hazardous wastes in landfills,

and indicated that if Subtitle C disposal

is not protective and constitutes

mismanagement, then EPA’s landfill

standards are inadequate. The

commenter does not believe this is the

case and claims the criticism of the

long-term integrity of landfills is an

effort to avoid the implications of the

Dithiocarbamate decision. The

commenter stated that, even is some

uncertain degree of risk is posed in the

long term by such disposal, this

uncertainty is not a sufficient basis for

listing these wastes.

As noted elsewhere in response to

other related comments, EPA believes

the extensive regulatory controls

provide management that reduces the

potential for releases to the

environments. EPA’s decision to list the

solids from the production of 2,4,6-TBP

is in not an indictment of the Agency’s

Subtitle C program, but is based on the

specific characteristics of this waste

(i.e., toxicity, mobility) and the potential

risks that would occur if these wastes

were disposed without prior treatment,

and the long-term containment systems

in a Subtitle C landfill degrade over

time, as expected.

3. Comments on the January 14, 1998

Notice Letter

As noted in the above section, a

reexamination of the analytical data of

the samples from the 2,4,6-TBP

production waste showed that 1,2-

dibromoethane (EDB) was found in both

the total and TCLP analyses of the

sample of floor sweepings and offspecification product. The EPA sent a

letter of notice to the interested parties

(i.e.,the sole generator of this waste and

the commenter that originated the

comment about additional constituents

being present in the waste). The letter

explains the new piece of information

and notes that the presence of this

highly toxic chemical appears to further

support the Agency’s contention that

the waste warrants listing. EPA received

comments from the generator, and the

Agency’s responses are summarized

below. The comments and responses are

described in more detail in the docket.

(See ‘‘Supplementary Response To

Public Comment,’’ April 1998).

The commenter challenged the

validity of the analytical results

showing the presence of EDB in the

waste, because of technical flaws in the

analytical procedure. The commenter

collected more samples of the floor

sweepings and product, and submitted

chemical analyses that did not show the

presence of EDB. The commenter went

on to note that EDB is not used as a raw

material, nor is it produced as a byproduct in the 2,4,6-TBP process. The

commenter argued that even if the EDB

was found in the floor sweepings, the

presence of EDB could not justify the

scope of the Agency’s proposed listing.

The commenter stated that, since EDB is
24616 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

not present in the 2,4,6-TBP process, its

presence would have to be the result of

a mixture of 2,4,6-TBP and EDB.

EPA disagrees with the contention

that the Agency’s analysis was flawed.

EPA reexamined the raw analytical data

for this sample and the data clearly

indicate that EDB was detected and

quantified as reported. EPA has

provided a full response in the docket

to these and other comments related to

the analysis of the wastes under study

(see the Supplementary Comment

Summary & Response Document in the

docket). EPA agrees that EDB does not

appear to be used in the 2,4,6-TBP

process, and that it is unlikely to form

as a by-product. However, EDB is used

as a raw material elsewhere in the

facility, and the raw analytical data

clearly support the finding of EDB in the

waste. Therefore its presence may be

due to the cross contamination of waste

streams, as the commenter suggested.

The lack of EDB in the recent samples

obtained by the commenter suggest that

EDB may not be present in all samples

of waste. Given the limited data, EPA

agrees that EDB is not the primary basis

of listing this waste, but that the

presence of the 2,4,6-TBP itself is the

major concern.

The commenter stated the Agency did

not provide public notice of its intent to

list 2,4,6-TBP production wastes based

on the presence of EDB, and that this is

in violation of the Administrative

Procedures Act. Furthermore, the

commenter contends that the EPA’s

‘‘new rationale’’ to list TBP as

hazardous would fail to take into

account the marked shift in emphasis

between the proposed and final rules.

As EPA noted in its response to

similar comments on the first notice

letter (see subsection 2.a above), due to

the limited time EPA has for completing

this action, the Agency decided that a

letter of actual notice to the

aforementioned interested parties was

appropriate. The generator of the 2,4,6-

tribromophenol production waste is the

only party EPA believes would be

affected by the recharacterization of the

rationale for listing and that would have

a direct interest in the final listing

decision. The Agency is not aware of

any other generators of this waste, or

any other persons who would have a

direct interest in this decision, thus the

actual notice given in this case is

sufficient.

Finally, the commenter stated that it

had not received any response to its

previous comments challenging the use

of QSAR as a basis for alleging that

2,4,6-TBP itself is toxic. The commenter

also stated that EPA does not have any

data indicating that 2,4,6-TBP is toxic,

and is instead relying on predictive

models that were never intended to be

used for this purpose. The commenter

submitted further comments on this

issue.

EPA was not seeking further

comments on the use of QSAR in this

listing determination. The Agency’s

responds to all comments concerning

QSAR submitted on the proposed rule

in Units IV.A, IV.B, and IV.C of today’s

final rule. These responses are also

given in the Public Comment Summary

and Response Document found in the

docket as an appendix to the

background document.

F. Listing Determination for Wastes

From the Production of

Tetrabromobisphenol-A

1. Solids

In the proposed rule, EPA deferred a

hazardous waste listing decision on

waste solids from the production of

tetrabromobisphenol-A (TBBPA), based

on a lack of information on waste

characterization and toxicity. In the

absence of data on the amount of

brominated phenols in TBBPA product,

the leachability of brominated phenols

from the product matrix and

toxicological data on TBBPA solids, the

EPA was unable to analyze the potential

risks associated with TBBPA migrating

to ground water if managed in unlined

landfills. The Agency, accordingly,

requested this information in the

proposal and also noted that if sufficient

information to support a listing

determination was received during the

public comment period, the Agency

may choose to promulgate a

determination rather than defer action

in the final rule.

One commenter provided

toxicological data on TBBPA that

support an assessment of the potential

for environmental risk from release of

TBBPA. (The toxicological data were

previously submitted to EPA under

Section 8(d) of the Toxic Substances

Control Act (TSCA) and as the result of

a TSCA Section 4 Test Rule.) The test

data on the toxicology of TBBPA

indicate that TBBPA product ‘‘does not

pose a health hazard to mammals.’’ One

reason appears to be that TBBPA is

poorly absorbed when ingested. In 1985,

the Interagency Testing Committee

reviewed TBBPA and found no need to

conduct further health effects testing. In

addition, the results of ecological testing

submitted to the Agency by the

Brominated Flame Retardant Industry

Panel do not indicate an unacceptable

level of hazard for aquatic organisms.

Ecological effects data submitted by

the commenter (and previously

collected by EPA under TSCA as noted

above) indicate that TBBPA is not

particularly toxic to aquatic test species

(e.g., fathead minnow, bluegill, daphia);

no long-term aquatic effects are

observed with tetrabromobisphenol-A in

water at levels below 0.22 mg/L. Using

the data on fish and assuming that the

waste was placed in an unlined landfill

close to a stream into which ground

water discharged, the Agency made a

worst-case assumption that leachate

from the landfill would be saturated

with tetrabromobisphenol-A at the

chemicals solubility level (4.16 mg/L).

This leachate would be diluted before

reaching any nearby stream (in the

proposed rule, EPA estimated a dilution

fraction on the order of 100 for leachate

exiting a landfill), and then diluted

further after discharge to such a stream.

Therefore, the diluted concentration in

the stream after such a scenario would

be well below the above-stated longterm aquatic effect level of 0.22 mg/L.

In determining potential risk from the

TBBPA waste, EPA also considered the

possible risk due to the presence of

traces of 2,4,6-TBP in the TBBPA waste.

The commenter provided the Agency

with data on concentrations of 2,4,6-

tribromophenol in the TBBPA product.

In considering whether to list spilled

product and floor sweepings from the

packaging of TBBPA due to the possible

presence of 2,4,6-TBP, EPA assumed

that the 2,4,6-TBP concentration in the

spilled product would be no greater

than the 2,4,6-TBP concentration in the

TBBPA product itself. (Note that this

appears to be a worst case assumption

because 2,4,6-TBP is not handled in the

packaging area, thus the spilled product

should not be contaminated with any

further 2,4,6-TBP; the commenter

confirmed that waste solids from

production of TBBPA are floor

sweepings generated from spills in the

packaging area, and not the production

area). The commenter reported that

commercial TBBPA has less than 1%

impurities, and the primary impurities

are isomers of tribromobisphenol A, not

2,4,6-TBP. The concentration of 2,4,6-

TBP in the TBBPA product reported by

the commenter is more than 100 times

less than the concentration of 2,4,6-TBP

EPA found in the off-specification 2,4,6-

TBP product.

The TCLP leaching data presented in

the proposed rule show a maximum

concentration of 760 mg/l of 2,4,6-TBP

in leachate extracts from the offspecification 2,4,6-TBP product. In the

absence of TCLP leaching data for the

TBBPA solids, EPA assumed the TCLP

leaching efficiency of 2,4,6-TBP from

the spilled TBBPA product and floor

sweepings would be comparable to the
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24617

leaching efficiency of 2,4,6-TBP

measured for the off-specification TBP

product. Thus, the TCLP level for 2,4,6-

TBP from the TBBPA solids was

assumed to be more than 100-fold less

than the TCLP level found in the TBP

off-specification product. As described

in the proposed rule, the level of

estimated individual risk from exposure

to 2,4,6-TBP in groundwater for disposal

of the off-specification 2,4,6-TBP

product in an unlined Subtitle D landfill

was 7×10¥4 (with the SAR-based health

number is corrected for molecular

weight differences of 2,4,6-TCP and

2,4,6-TBP as noted in today’s notice, the

risk would be 4.2×10¥4). Using this

analysis, any risk posed by TBBPA

solids under the same disposal scenario

would be more than a 100-fold less, or

less than 10–¥6. Therefore, this waste is

not a candidate for listing as hazardous

based on the presence of 2,4,6-TBP.

In addition, EPA has monitoring data

that also indicate TBBPA wastes do not

present a significant risk. As stated in

the proposed rule, record sampling of an

on-site landfill at one plant where

TBBPA solids formerly were disposed

for a number of years showed the

absence of TBBPA and any brominated

compounds in the landfill leachate.

Therefore, based on the data submitted

by the commenter, the available data on

the limited toxicity of TBBPA noted

above, and the monitoring data, the

Agency has decided not to list waste

solids from the production of TBBPA.

2. Wastewaters

As discussed in the proposed rule (59

FR 24537), wastewaters from the

manufacture of tetrabromobisphenol-A

already are listed and carry the

hazardous waste code of K131. Methyl

bromide and TBBPA are produced in

the same process. One commenter

objected to the language used in the

proposed rule to describe the process

step that generates wastewaters. The

proposal states ‘‘process wastewater

originates from the distillation step

where methyl bromide is recovered.’’

The commenter contended that the

wastewater originated from a distillation

step where methanol is recovered. The

commenter believed the language in the

proposed rule was inconsistent with the

existing listing description for K131 and

was concerned that EPA was attempting

to amend the K131 listing as part of this

rulemaking.

The Agency concedes that the

language used in the proposed rule was

misleading. Indeed, the distillation step

is where methanol, or both methanol

and methyl bromide, can be recovered,

as described in the Listing Background

Document. The Agency was not

referring to a specific process at any one

facility. It was simply attempting to

make the point that TBBPA and methyl

bromide are produced in the same

process and the wastewaters arising

from that process meet the existing

listing description for K131. As a result,

there is no need for further action on a

hazardous waste listing for wastewaters

from TBBPA production.

In response to a petition filed by the

Ethyl Corporation for judicial review of

the K131 listing, the Agency stayed the

K131 listing as it applies to the ‘‘liquid

material exiting the reactor producing

methyl bromide located at Ethyl

Corporation’s production facility.’’ This

facility currently recycles the

wastewaters, after solids removal, to the

bromine plant for recovery of bromine

values. As directed by the terms of the

stay, the Agency is in the process of

‘‘determining whether the wastewater

stream generated at this facility contains

a solid waste and, if so, whether it is

eligible for an exemption or variance.’’

EPA clarifies that today’s rulemaking

does not affect the Agency’s ongoing

effort to respond to this petition. EPA is

not attempting to reach a decision on

the applicability of the K131 listing to

Ethyl’s wastewater stream as part of the

listing determination for wastes from

organobromines production.

G. Other Issues

One commenter felt that the model

used by the Agency for assessing

migration of 2,4,6-tribromophenol

wastewaters from the deep formations

into which they were injected was very

conservative and over-estimated

potential risks. The commenter felt that

many of the assumptions of the model

describe physical conditions that are

known not to exist.

In response, the Agency notes that the

model was intended to represent a

conservative scenario in order to

identify any potential risk if leakage

were to occur. The Agency reexamined

the record and agrees that the existing

data collected for the site suggest that

the release scenario modeled is not

likely to exist. The information available

indicates that the only abandoned wells

found in the area of the injection wells

that are deep enough to penetrate the

injection zone are in fact known to be

plugged and should not serve as

potential conduits for release of waste

constituents from the injection zone to

the upper drinking water aquifer.

Furthermore, as noted in the proposed

rule, sampling of drinking water wells

on the plant site and in the vicinity of

the plant did not find any trace of

tribromophenol in the groundwater,

even though disposal has been

occurring for nearly twenty years. In any

case, the comment is moot, since EPA

has decided not to list wastewaters from

the production of 2,4,6-TBP.

One commenter requested that the

Agency provide a detailed definition of

the term ‘‘production’’ as used in the

proposed listing description for K140.

The commenter suggested that

production be defined to limit the reach

of the listing to wastes resulting from

the actual synthesis of 2,4,6-TBP (i.e.,

the listing should not encompass wastes

from processes that isolate an

intermediate or a product other than

2,4,6-TBP).

The Agency does not believe it is

necessary for this final rule to define

‘‘production’’ because the majority of

wastes listed in 40 CFR 261.37 include

the unambiguous term ‘‘production.’’

The fact that intermediates or coproducts may arise from the same

process that produces 2,4,6-TBP is

irrelevant to the basis for listing the

process wastes from the production of

2,4,6-TBP. If listings were constructed

so narrowly as to capture wastes from

the production of a given product only

when the process produced that product

alone, vast amounts of process waste

containing similarly hazardous

constituents would remain unregulated.

In this case, by manipulating the

process, a producer of tribromophenol

may co-produce di-, tetra-, or pentabrominated phenols along with

tribromophenol from the same process.

If the listing were crafted the way the

commenter suggests, the operator of

such a process would escape the intent

of this regulation, while still producing

2,4,6-TBP.

One commenter expressed concern

that the proposed rule may have the

unintended effect of increasing the land

disposal of wastes containing 2,4,6-TBP

by preventing their use as feedstocks to

bromine recovery units (BRUs). EPA

does not agree with this statement. The

listing of TBP production wastes should

not affect the current management of

these materials in BRUs. EPA clarifies

that BRUs are halogen acid furnaces,

which meet the definition of industrial

furnace in 40 CFR 260.10. As stated in

the proposed rule, the combustion of

hazardous waste in industrial furnaces

is regulated under 40 CFR part 266,

subpart H. The commenter noted that

EPA issued a correction notice on

August 27, 1991 that excluded from

regulation certain brominated materials

combusted in halogen acid furnaces (56

FR 42504). The Agency agrees that the

provision added by the correction notice

effectively excludes brominated

materials meeting the criteria in 40 CFR

261.2(d)(2)(i)–(iii) from designation as
24618 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

‘‘inherently waste-like’’ materials.

Accordingly, these materials are not

hazardous wastes; thus, furnaces

processing them are not processing

hazardous wastes and are not subject to

the BIF regulations. Listed and

characteristic brominated streams that

do not meet the criteria of 40 CFR

261.2(d)(2), i.e., that contain >1% of

Appendix VIII materials, are considered

inherently waste-like and should not be

burned in non-RCRA facilities. Today’s

listing of TBP wastes does not alter the

criteria of this exclusion nor subject the

commenter’s BRUs to any additional

requirements. If the commenter’s

brominated waste streams meet the

criteria for the exclusion, the BRUs to

which these streams are fed are not

subject to regulation under part 266,

subpart H.

Finally, the Agency notes that the sole

generator of the 2,4,6-tribromophenol

production solids did not attempt to use

this material as feedstock for the BRU,

even in the absence of a hazardous

waste listing.

One commenter questioned the

accuracy of early sampling and analysis

results obtained at one facility. This

commenter submitted a letter to the

Agency in 1993 detailing concerns over

the quality and accuracy of some of the

analytical results. The commenter

concluded in the 1993 letter, ‘‘There are

a great many non-credible and

questionable analyses in this study. We

believe that the analytical work will

simply not stand up to close scrutiny.

The analytical results are not of a

quality that lend themselves to making

a valid risk assessment or developing

regulations for the organo-bromine

industry. The validity and accuracy

simply aren’t there.’’ EPA prepared a

complete response to the issues

enumerated in that letter and has placed

it in the public docket for today’s

rulemaking. EPA notes that none of the

questioned data were used as a basis for

the decision to list wastes from the

production of 2,4,6-tribromophenol.

V. Conclusions

The Agency is listing, as EPA

Hazardous Waste No. K140, floor

sweepings, off-specification product,

and spent filter media from the

production of 2,4,6-tribromophenol.

EPA is also listing discarded 2,4,6-TBP

product as EPA Hazardous Waste No.

U408. EPA received no comments

objecting to the listing of U408, except

to the extent that issues relating to SAR

may be considered relevant to the U408

listing. (EPA notes, however, that the

analysis completed for the listing of

K140 also included an evaluation of the

risks posed by off-specification 2,4,6-

tribromophenol product. Such offspecification product should be very

similar to discarded material that might

carry the U408 listing and, as such, the

discarded U-waste may present

comparable risks and is even more

likely to be disposed of in an unlined

landfill). EPA responded above, and in

the separate Response to Public

Comment Document, to all comments

on the SAR analysis. These listing

determinations are based on the

projected toxicity of 2,4,6-TBP from

structural activity studies, and the

assessment of risk from potential

exposure to this chemical. EPA’s

decision to list these wastes as

hazardous represents a determination by

the Agency that the wastes identified in

this action meet the criteria for listing

hazardous wastes presented in 40 CFR

261.11. Specifically, based on available

evidence, the Agency concludes that

2,4,6-tribromophenol is similar in

toxicity to its chlorinated analogue

(2,4,6-trichlorophenol) and, therefore,

may pose a risk to human health and the

environment if improperly landdisposed.

Based on the data collected by the

Agency during the recent

organobromines industry study and the

unique conditions of the industry

regarding limitations to future

expansion, EPA believes there is ample

justification for a no-list determination

for wastes generated from production of

the other organobromine chemicals

identified in the proposed consent

decree (i.e., tetrabromobisphenol A,

bromochloromethane, ethyl bromide,

octabromodiphenyl oxide, and

decabromodiphenyl oxide) and for

wastewaters from 2,4,6-tribromophenol

production. After considering the

collected information and data from

toxicological, chemical,

hydrogeological, and engineering

viewpoints, EPA has concluded that the

disposal of any wastes from these

processes that are not currently listed in

40 CFR part 261, subpart D does not

pose a substantial present or future risk

to human health or the environment.

Therefore, EPA is not listing any

additional hazardous wastes generated

from the production of these chemicals.

The Agency received no comments

objecting to its decision not to list these

wastes.

VI. Land Disposal Restrictions

A. Treatment Standards for

Organobromine Wastes

In the land disposal restrictions Phase

III proposed rule (60 FR 11722, March

2, 1995), EPA proposed that the newly

identified K140 and U408 wastes

comply with numerical treatment

standards for 2,4,6-tribromophenol to be

promulgated in 40 CFR 268.40, and that

2,4,6-tribromophenol be added as a

underlying hazardous constituent

subject to the universal treatment

standards of 40 CFR 268.48.

Since treatment data currently are not

available for 2,4,6-TBP, the Agency

proposed to set the UTS for 2,4,6-TBP

based on analytical detection limit data

transferred from 2,4,6-trichlorophenol.

The structures of 2,4,6-tribromophenol

and 2,4,6-trichlorophenol are

sufficiently similar to be considered

halogenated congeners of phenol. Both

halogenated phenols contain three

symmetrically placed bromine or

chlorine substituents that are difficult to

remove by chemical substitution. The

chemical behavior and mechanisms of

action for 2,4,6-tribromophenol are

expected to be similar to its chlorinated

analogue, 2,4,6-trichlorophenol. Thus,

the Agency proposed the treatment

standards for 2,4,6-tribromophenol at

7.4 mg/kg for nonwastewaters and 0.035

mg/L for wastewaters for 2,4,6-

tribromophenol.

The Agency solicited comment

regarding the achievability of this

standard by demonstrated available

technologies and regarding the

analytical detection limit of 2,4,6-TBP

in treatment residual matrices. The

Agency also solicited any available data

on the concentrations 2,4,6-TBP in

treatment residuals from the recovery or

destruction of wastes containing 2,4,6-

TBP. The analytical method for 2,4,6-

TBP is SW–846 method 8270 (GC/MS

for semivolatiles, capillary column).

In response to the Agency’s request

for comment, Chemical Waste

Management, Inc. supported the

Agency’s proposed treatment standards

associated with organobromine wastes;

the Environmental Technology Council,

while objecting to setting treatment

standards on the sole basis of analytical

detection limits, noted that EPA can use

technology transfer to develop standards

from similar chlorinated organics.

Therefore, EPA is promulgating the

proposed UTS for 2,4,6-TBP at 7.4 mg/

kg for nonwastewaters and 0.035 mg/L

for wastewaters.

B. Applicable Technology

The single facility that produces 2,4,6-

TBP wastes uses a bromine recovery

unit (BRU) to recover bromine values

from organic liquid and vapor waste

streams. In this unit, the organics are

burned and the combustion products are

removed by a wet scrubber. The BRU is

a halogen acid furnace which meets the

regulatory definition of industrial

furnace in 40 CFR 260.10. The
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24619

combustion of hazardous waste in

industrial furnaces is regulated under 40

CFR part 266, subpart H, which

regulates air emissions from these units

and requires monitoring and analyses.

Treatment of 2,4,6-TBP wastes in the

BRU should be effective in destroying

the phenolic component of 2,4,6-

tribromophenol and providing for

recovery of bromine. Based on available

information, EPA proposed that the best

demonstrated available technology

(BDAT) for 2,4,6-tribromophenol wastes

is treatment by BRU. EPA solicited

comment on this assertion and on the

potential applicability of other

technologies which destroy 2,4,6-

tribromophenol and provide recovery of

bromine.

Great Lakes Chemical Corporation

(GLCC) commented that EPA’s

assumption that TBP waste generated by

GLCC currently is managed in a

bromine recovery unit (BRU) is

incorrect. GLCC maintains that

treatment of TBP in the existing BRU

would be very difficult, if not

impossible (both technically and

legally). Accordingly, GLCC concluded

that the proposed TBP treatment

standard is flawed. The Agency

disagrees. Because tribromophenol is

not refractory, EPA believes the BRU

technology clearly is applicable to waste

treatment of the K140 and U408 wastes

and, therefore, may form the basis of a

standard. There are various combustion

technologies capable of meeting the

numerical treatment standards, one of

which is BRU. The Agency stated in

error in the proposal that the existing

BRU already is subject to the

performance standards of part 266,

subpart H. However, in order to treat the

listed organobromine wastes, the subject

BRU would be subject to the part 266,

subpart H performance standards. EPA

has assessed the costs associated with

incineration of the newly identified

organobromine wastes as part of its

regulatory impact analysis. See the

regulatory impact analysis discussion in

Section X of this preamble. Because the

Agency has promulgated the universal

treatment standards for the

organobromine wastes, treaters are free

to use any technology capable of

achieving the numerical standard

promulgated today (so long as the

standard is not achieved by means of

impermissible dilution).

C. Capacity Analysis Results Summary

1. Introduction

This section summarizes the results of

the capacity analysis for the wastes

covered by today’s rule. For a detailed

discussion of capacity analysis-related

data sources, methodology, and detailed

response to comments for each group of

wastes covered in this rule, see the

following document: ‘‘Background

Document for Capacity Analysis for

Land Disposal Restrictions: Surfaceddisposed Organobromine Production

Wastes (Final Rule)’’ (i.e., the Capacity

Background Document).

When EPA establishes land disposal

restrictions (LDR) determinations, LDR

treatment standards become effective

when promulgated unless the Agency

grants a national capacity variance

delaying the effective date. RCRA

section 3004(h)(2), 42 U.S.C. 6924(h)(2)

authorizes EPA to grant a national

capacity variance for the waste and to

establish a different date (not to exceed

two years beyond the statutory

deadline) based on ‘‘* * * the earliest

date on which adequate alternative

treatment, recovery, or disposal capacity

which protects human health and the

environment will be available’’ if there

is inadequate alternative treatment/

recovery capacity.

In general, EPA’s capacity analysis

focuses on the amount of waste to be

restricted from land disposal that is

currently managed in land-based units

and will therefore require alternative

treatment as a result of the LDRs. The

quantity of wastes that are not managed

in land-based units (e.g., wastewater

managed only in RCRA exempt tanks,

with discharge to a Publicly Owned

Treatment Works (POTW)) is not

included in the quantities requiring

alternative treatment as a result of the

LDRs. Also, wastes that do not require

alternative treatment (e.g., those that are

currently treated using an appropriate

treatment technology) are not included

in these quantity estimates. Landdisposed wastes requiring alternative

treatment or recovery capacity that is

available on-site or within the same

company as the generator are also

omitted from the required commercial

capacity estimates.

EPA’s decisions on whether to grant

a national capacity variance are based

on the availability of alternative

treatment or recovery technologies.

Consequently, the methodology focuses

on deriving estimates of the quantities

of waste that will require either

commercial treatment or the

construction of new on-site treatment or

recovery unit as a result of the LDRs.

The resulting estimates of required

commercial capacity are then compared

to estimates of available commercial

capacity. If adequate commercial

capacity exists, the waste is restricted

from further land disposal before

meeting the LDR treatment standards. If

adequate capacity does not exist, RCRA

section 3004(h) authorizes EPA to grant

a national capacity variance for the

waste for up to two years or until

adequate alternative treatment or

recovery capacity becomes available.

2. Capacity Analysis Results Summary

A brief summary of the capacity

analysis performed to support this rule

is presented below. For additional

detailed information, please refer to the

‘‘Background Document for Capacity

Analysis for Land Disposal Restrictions:

Surfaced-disposed Organobromine

Production Wastes (Final Rule)’’.

For this capacity analysis, EPA

examined data on waste characteristics

and management practices that have

been gathered for the organobromine

production industry study in the 1992

RCRA Section 3007 survey. The Agency

analyzed the capacity-related

information from the survey responses,

reviewed the public comments received

in response to the proposed rule, and

identified the following annualized

quantities of newly listed hazardous

wastes requiring commercial treatment:

Less than 100 tons of organobromine

nonwastewater wastes (K140, U408) are

expected to require alternative treatment

capacity. The available data sources

indicate that there are no quantities of

K140 and U408 wastewaters that will

require alternative commercial

treatment, and therefore this volume is

assumed to be zero.

EPA is finalizing the rule to apply

UTS to these wastes. The treatment

standards for organobromine production

wastes are concentrations which in turn

are based on bromine recovery unit as

the BDAT. Additionally, EPA believes

that incineration and thermal

destruction technologies are applicable

technologies to meet these treatment

standards. The Agency estimated that

the commercially available sludge and

solid combustion capacity is

approximately 430,000 MT per year and

sufficient to treat these wastes when the

listing determinations for these wastes

become effective. Since EPA is

finalizing numerical standards for these

wastes, the Agency does not exclude the

use of other technologies capable of

meeting the final LDR treatment

standards. Sufficient commercial

capacity exists to treat theses wastes to

meet the LDR standards. Therefore, EPA

is not granting a national capacity

variance under LDR for these wastes.

The LDR standards for these wastes will

become effective when the listings

become effective.

For soil and debris contaminated with

the newly listed wastes, EPA proposed

to not grant a national capacity variance.

EPA received no comments regarding
24620 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

this issue. EPA believes that the

contaminated soil and debris can be

managed on-site or if necessary, off-site

commercial treatment capacity is

available. Therefore, EPA is not granting

a national capacity variance to

hazardous soil and debris contaminated

with the newly listed wastes covered

under this rule. Based on the

questionnaire, there were no data

showing the mixed radioactive wastes

with the newly listed wastes. There

were also no comments concerning the

radioactive wastes mixed with the

newly identified wastes. EPA is not

granting a national capacity variance for

mixed radioactive wastes or soil and

debris contaminated with these mixed

radioactive wastes.

VII. Waste Minimization Opportunities

in the Industry

During the industry study, the Agency

identified two potential opportunities

for waste minimization. The first

involves the recovery of tribromophenol

in the tetrabromobisphenol-A and

tribromophenol process. Commercial

tetrabromobisphenol-A is made by

condensation of phenol and acetone

and, hence, the feedstock contains some

unreacted phenol. Record sampling of

one wastewater stream, which leaves

the process hot, revealed that it

contained tribromophenol. The Agency

appreciates the effort that the

commenter has made to recover TBP

and understands the difficulty of

recovering pure product. The Agency

received some information from the two

manufacturers of TBBPA. One firm

claimed the idea was impractical. The

second has installed a process to recover

a low-grade material which is a mixture

containing underbrominated bisphenolA compounds. It is yet unknown if this

material can be marketed successfully as

a low-grade flame retardant formulation.

The facility has informed the Agency

that if the material cannot be marketed

it will be sent to Subtitle C facilities for

disposal. This plant also is recycling the

wastewater, after solids removal, to the

bromine plant for recovery of bromine

from the sodium bromide present.

Removal of the solids is necessary to

prevent problems in the bromine

recovery operation.

The second area where savings could

be achieved is in product packaging.

Materials spilled in the packaging areas

are drummed and shipped to Subtitle C

facilities. Presently, the two major

manufacturers of organobromine

chemicals generate over 300 tons per

year of various spilled solid products.

Improved housekeeping in the

packaging areas will reduce the volumes

of these wastes.

VIII. State Program Implementation

A. Applicability of Rules in States

Under section 3006 of RCRA, EPA

may authorize qualified States to

administer and enforce RCRA programs

within the State. (See 40 CFR part 271

for the standards and requirements for

authorization.) Following authorization

EPA retains enforcement authority

under sections 3008, 7003, and 3013 of

RCRA, although authorized States have

primary enforcement responsibility.

Prior to the Hazardous and Solid

Waste Amendments of 1984 (HSWA), a

State with final RCRA authorization

administered its authorized hazardous

waste program entirely in lieu of EPA.

The Federal requirements no longer

applied in the authorized State, and

EPA could not issue permits for any

facilities in the State which the State

was authorized to permit. When new,

more stringent Federal requirements

were promulgated or enacted, the State

was obliged to enact equivalent

authority within specified time frames.

New Federal requirements did not take

effect in an authorized State until the

State adopted the requirements as State

law.

In contrast, under section 3006(g) of

RCRA (42 U.S.C. 6926(g)), new

requirements and prohibitions imposed

by the HSWA take effect in authorized

States at the same time that they take

effect in unauthorized States. EPA is

directed to implement these

requirements and prohibitions in

authorized States, including the

issuance of permits, until the State

modifies its program to reflect the

Federal standards, and applies for and

is granted authorization. While EPA

initially implements HSWA-related

provisions in authorized States, States

still must adopt these provisions as

State law to retain final authorization.

Today’s rule for listing EPA

Hazardous Waste Nos. K140 and U408

is being promulgated pursuant to

section 3001(e)(2) of RCRA, a provision

added by the HSWA. With these rules

being promulgated today, EPA considers

its HSWA obligation to make a

determination regarding listing

organobromine wastes to be fulfilled.

Therefore, the Agency is adding these

requirements to Table 1 in 40 CFR

271.1(j), which identifies the Federal

program requirements that are

promulgated pursuant to the HSWA and

that take effect in all States, regardless

of their authorization status. The land

disposal restrictions and treatment

standards in today’s rule are being

promulgated pursuant to section 3004(g)

and (m) of RCRA, provisions also added

by HSWA. Table 2 in 40 CFR 271.1(j) is

modified to indicate that these

requirements are self-implementing.

States may apply for final authorization

for the HSWA provisions identified in

40 CFR 271.1(j), as discussed in the

following section of the preamble.

B. Effect on State Authorizations

As noted previously, today’s rule is

being promulgated pursuant to

provisions added by HSWA. The

additions of K140 to the list of

hazardous wastes from specific sources

and of U408 to the list of commercial

chemical products that are hazardous

when discarded are promulgated

pursuant to Section 3001(e)(2) of RCRA,

a provision added by the HSWA.

The land disposal restrictions and

treatment standards are promulgated

pursuant to Sections 3004 (g) and (m),

also HSWA provisions.

As noted above, EPA will implement

the HSWA portions of today’s rule in

authorized States until they modify

their programs to adopt these rules and

such modifications are approved by

EPA. Because this rule will be

promulgated pursuant to HSWA, a State

submitting a program modification may

apply to receive either interim

authorization under RCRA section

3006(g), if the State regulations are

substantially equivalent to EPA’s

regulations, or final authorization under

RCRA sections 3006(b), if the State

regulations are fully equivalent to EPA’s

regulations. The procedures and

schedule for State programs

modifications for either interim or final

authorization are described in 40 CFR

271.21. It should be noted that all

HSWA interim authorizations will

expire on January 1, 2003 (see 40 CFR

271.24(c), 52 FR 60129, December 18,

1992).

It should be noted that 40 CFR

271.21(e) requires that States having

final RCRA authorization must modify

their programs to reflect Federal

program changes and subsequently must

submit the modifications to EPA for

approval. The deadline by which States

must modify their programs to adopt

today’s rule will be determined by the

date of promulgation of the final rule in

accordance with 40 CFR 271.21(e)(2).

Once EPA approves the modification,

the State requirements become RCRA

Subtitle C requirements.

States with authorized RCRA

programs already may have regulations

similar to those in today’s rule. Such

State regulations have not been assessed

against the Federal regulations being

promulgated today to determine

whether they meet the tests for

authorization. Thus, these State

regulations will not be deemed as RCRA
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24621

requirements until the State program

modification is submitted to EPA and

approved. Of course, States with

existing regulations may continue to

administer and enforce those

regulations as a matter of State law. In

addition, in implementing the Federal

program, EPA will work with the States

under cooperative agreements to

minimize duplication of efforts; in many

cases, EPA will be able to defer to the

States in their efforts to implement their

programs, rather than take separate

actions under Federal authority.

States that submit their official

applications for final authorization less

than 12 months after the effective date

of EPA’s regulations are not required to

include regulations equivalent to the

EPA regulations in their application.

However, States must modify their

programs by the deadlines set forth in

40 CFR 271.21(e). States that submit

official applications for final

authorization 12 months after the

effective date of these standards must

include standards equivalent to these

standards in their application. The

requirements States must meet when

submitting final authorization

applications are set forth in 40 CFR

271.3.

IX. Compliance and Implementation

A. Section 3010 Notification

Generally, when new hazardous

wastes are listed, all persons who

generate, transport, treat, store, or

dispose of the newly listed wastes are

required to notify either EPA, or a State

authorized by EPA to operate the

hazardous waste program, of their

activities pursuant to section 3010 of

RCRA. However, under the Solid Waste

Disposal Amendments of 1980 (Pub. L.

96–482), EPA was given the option of

waiving the notification requirement for

persons who handle wastes that are

covered by today’s listing and already

have notified EPA that they manage

other hazardous wastes and have

received an EPA identification number.

This waiver is being promulgated

because of the likelihood that persons

managing today’s promulgated wastes

already are managing one or more

hazardous wastes that generally are

associated with the generation of EPA

Hazardous Waste Nos. K140 and U408

and, therefore, have previously notified

EPA and received an EPA identification

number. In the event that any person

who generates, transports, treats, stores,

or disposes these wastes and has not

previously notified and received an

identification number, that person must

obtain an identification number

pursuant to 40 CFR 262.12 before that

person can generate, transport, treat,

store, or dispose of these wastes.

B. Compliance Dates for Facilities

The effective date of today’s rule is

November 4, 1998. Today’s listings will

be promulgated pursuant to HSWA.

HSWA requirements are applicable in

authorized States at the same time as in

unauthorized States. Therefore, EPA

will regulate the wastes being

promulgated today until States are

authorized to regulate these wastes.

Once these regulations are promulgated

in a final rule by EPA, the Agency will

apply these Federal regulations to these

wastes and to their management in both

authorized and unauthorized States.

1. Facilities Newly Subject to RCRA

Permit Requirements

Facilities that treat, store, or dispose

of wastes that are subject to RCRA

regulation for the first time by this rule

(that is, facilities that have not

previously received a permit pursuant

to section 3005 of RCRA and are not

currently operating pursuant to interim

status), might be eligible for interim

status (see section 3005(e)(1)(A)(ii) of

RCRA). In order to obtain interim status

based on treatment, storage or disposal

of such newly identified wastes, eligible

facilities are required to comply with 40

CFR 270.70(a) and 270.10(e) by

providing notice under section 3010 and

submitting a Part A permit application

no later than November 4, 1998. Such

facilities are subject to regulation under

40 CFR part 265 until a permit is issued.

In addition, under section

3005(e)(3)and 40 CFR 270.73(d), not

later than November 4, 1998, land

disposal facilities newly qualifying for

interim status under section

3005(e)(1)(A)(ii) also must submit a Part

B permit application and certify that the

facility is in compliance with all

applicable groundwater monitoring and

financial responsibility requirements. If

the facility fails to submit these

certifications and a permit application,

interim status will terminate on that

date.

2. Existing Interim Status Facilities

Pursuant to 40 CFR 270.72(a)(1), all

existing hazardous waste management

facilities (as defined in 40 CFR 270.2)

that treat, store, or dispose of the newly

identified hazardous wastes and are

currently operating pursuant to interim

status under section 3005(e) of RCRA

must file an amended Part A permit

application with EPA no later than the

effective date of today’s rule, (i.e.,

November 4, 1998. By doing this, the

facility may continue managing the

newly listed wastes. If the facility fails

to file an amended Part A application by

that date, the facility will not receive

interim status for management of the

newly listed hazardous wastes, and may

not manage those wastes until the

facility receives either a permit or a

change in interim status allowing such

activity (40 CFR 270.10(g)).

3. Permitted Facilities

Facilities that already have RCRA

permits must request permit

modifications if they want to continue

managing newly listed wastes. See 40

CFR 270.42(g). This provision states that

a permittee may continue managing the

newly listed wastes by following certain

requirements, including submitting a

Class 1 permit modification request by

the date on which the waste or unit

becomes subject to the new regulatory

requirements (i.e., the effective date of

today’s rule), complying with the

applicable standards of 40 CFR parts

265 and 266, and submitting a Class 2

or 3 permit modification request within

180 days of the effective date.

Generally, a Class 2 modification is

appropriate if the newly listed wastes

will be managed in existing permitted

units or in newly regulated tank or

container units and will not require

additional or different management

practices than those authorized in the

permit. A Class 2 modification requires

the facility owner to provide public

notice of the modification request, a 60-

day public comment period, and an

informal meeting between the owner

and the public within the 60-day period.

The Class 2 process includes a ‘‘default

provision,’’ which provides that if the

Agency does not reach a decision within

120 days, the modification is

automatically authorized for 180 days. If

the Agency does not reach a decision by

the end of that period, the modification

is permanently authorized. See 40 CFR

270.42(b).

A Class 3 modification is generally

appropriate if management of the newly

listed wastes requires additional or

different management practices than

those authorized in the permit or if

newly regulated land-based units are

involved. The initial public notification

and public meeting requirements are the

same as for Class 2 modifications.

However, after the end of the 60-day

public comment period, the Agency will

grant or deny the permit modification

request according to the more extensive

procedures of 40 CFR part 124. There is

no default provision for Class 3

modifications. See 40 CFR 270.42(c).

Under 40 CFR 270.42(g)(1)(v), for

newly regulated land disposal units,

permitted facilities must certify that the

facility is in compliance with all
24622 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

11The toll free telephone number of the National

Response Center is 800–424–8802; in the

Washington, DC metropolitan area, the number is

202–267–2675.

12For more detailed information on this

methodology, see the preamble to an RQ adjustment

final rule published on August 14, 1989 (54 FR

33426). A different methodology is used to assign

adjusted RQs to radionuclides (see 54 FR 22524,

May 24, 1989).

13No RQ level increase based on BHP occurs if

the primary criteria RQ already is at its highest

possible level (100 pounds for potential carcinogens

and 5000 pounds for all other types of hazardous

substances except radionuclides). BHP is not

applied to radionuclides.

applicable 40 CFR part 265 groundwater monitoring and financial

responsibility requirements no later

than November 4, 1998. If the facility

fails to submit these certifications,

authority to manage the newly listed

wastes under 40 CFR 270.42(g) will

terminate on that date.

X. Listing as CERCLA Hazardous

Substances and RQ Adjustment

All hazardous wastes listed in 40 CFR

261.31 through 261.33, as well as any

solid waste that meets one or more of

the characteristics of a RCRA hazardous

waste (as defined at 40 CFR 261.21

through 261.24), are hazardous

substances under the Comprehensive

Environmental Response,

Compensation, and Liability Act of

1980, as amended (CERCLA), pursuant

to CERCLA section 101(14)(C), 42 U.S.C.

9601(14). CERCLA hazardous

substances and their reportable

quantities (RQs) are listed in Table

302.4 at 40 CFR 302.4. Therefore, in

addition to the K140 listing being

promulgated today for 40 CFR 261.32

and the U408 listing being promulgated

for 40 CFR 261.33, the Agency also is

adding K140 and 2,4,6-tribromophenol

to the list of CERCLA hazardous

substances at Table 302.4 of 40 CFR

302.4.

Reporting Requirements. Under

CERCLA section 103(a), the person in

charge of a vessel or facility from which

a hazardous substance has been released

in a quantity that equals or exceeds its

RQ must immediately notify the

National Response Center of the

release.11 In addition to this reporting

requirement under CERCLA, section 304

of the Emergency Planning and

Community Right-to-Know Act of 1986

(EPCRA), 42 U.S.C. 11004, requires

owners or operators of certain facilities

to report the release of a CERCLA

hazardous substance in a quantity that

equals or exceeds its RQ to State and

local authorities. EPCRA section 304

notification must be given to the

community emergency coordinator of

the local emergency planning committee

(LEPC) for each area likely to be affected

by the release, and to the State

emergency response commission (SERC)

of any State likely to be affected by the

release.

Adjustment of RQs. Under section

102(b) of CERCLA, all hazardous

substances under CERCLA have a

statutory RQ of one pound unless and

until adjusted by regulation. The

Agency’s methodology for adjusting RQs

of individual hazardous substances

begins with an evaluation of the

intrinsic physical, chemical, and

toxicological properties of each

hazardous substance.12 The intrinsic

properties examined—called ‘‘primary

criteria’’—are aquatic toxicity, acute

mammalian toxicity (oral, dermal, and

inhalation), ignitability, reactivity,

chronic toxicity, and potential

carcinogenicity. Generally, for each

intrinsic property, the Agency ranks

hazardous substances on a scale,

associating a specific range of values on

each scale with an RQ of 1, 10, 100,

1000, or 5000 pounds. Each hazardous

substance may receive several tentative

RQ values based on the primary criteria.

The lowest of the tentative RQs becomes

the ‘‘primary criteria RQ’’ for that

substance.

After the primary criteria RQs are

assigned, substances are evaluated

further for their susceptibility to certain

degradative processes, which are used

as secondary RQ adjustment criteria.

These natural degradative processes are

biodegradation, hydrolysis, and

photolysis (BHP). If a hazardous

substance, when released into the

environment, degrades relatively

rapidly to a less hazardous form by one

or more of the BHP processes, its RQ (as

determined by the primary RQ

adjustment criteria) generally is raised

one level.13 This adjustment is made

because the relative potential for harm

to public health or welfare or the

environment posed by the release of

such a substance is reduced by these

degradative processes. Conversely, if a

hazardous substance degrades to a more

hazardous product after its release, the

original substance is assigned an RQ

equal to the RQ for the more hazardous

substance, which may be one or more

levels lower than the RQ (as determined

by the primary RQ adjustment criteria)

for the original substance. The

downward adjustment is appropriate

because the potential for harm posed by

the release of the original substance is

increased as a result of degradative

processes.

The methodology summarized above

is applied to adjust the RQs of

individual hazardous substances. An

additional process applies to RCRA

listed wastestreams, which contain

individual hazardous constituents. As

the Agency has stated (54 FR 33440,

August 14, 1989), to assign an RQ to a

RCRA wastestream, the Agency

determines the RQ for each constituent

within the wastestream and establishes

the lowest RQ value of these

constituents as the adjusted RQ for the

wastestream.

Adjusted RQs for 2,4,6-

tribromophenol and K140. Waste U408

is 2,4,6-tribromophenol, an individual

hazardous substance. It has been

evaluated for the six primary RQ

adjustment criteria—aquatic toxicity,

acute mammalian toxicity, ignitability,

reactivity, chronic toxicity, and

potential carcinogenicity—and the

secondary adjustment criteria of BHP.

Available studies of aquatic toxicity

have measured an LC50 of 6.54 mg/L for

the fathead minnow, resulting in a

primary criterion RQ of 100 pounds for

the substance.

In addition, based on an analysis of

the structural and chemical similarities

of 2,4,6-tribromophenol and 2,4,6-

trichlorophenol and an evaluation of the

potential carcinogenicity of the latter of

the two substances, EPA has estimated

a low hazard ranking for the potential

carcinogenicity of 2,4,6-tribromophenol.

This low hazard ranking results in a

primary criterion RQ of 100 pounds.

Based on this evaluation and the

absence of relevant BHP data, the

Agency today is finalizing an adjusted

RQ of 100 pounds for 2,4,6-

tribromophenol.

The EPA is adjusting the RQ of waste

K140 in accordance with the

methodology for adjusting RQs of

hazardous wastestreams by assigning

them RQs equal to that of the

wastestream constituent with the lowest

RQ.

XI. Regulatory Impact Analysis and

Compliance Costs

A. Regulatory Impact Analysis Pursuant

to Executive Order 12866

Executive Order 12866 requires that a

regulatory agency determine whether a

new regulation will have ‘‘significant

regulatory action’’ and, if so, that a costbenefit analysis be conducted. This

analysis is a quantification of the

potential benefits, costs, and economic

impacts of a rule. A significant

regulatory action is defined as a

regulation that has an annual cost to the

economy of $100 million or more that

adversely affects in a material way the

economy, a sector of the economy,

productivity, competition, jobs, the

environment, public health or safety, or
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24623

14 In the proposal, this analysis considered waste

volumes as CBI, however, in the docket comments received by the Agency from Great Lakes Chemical Company publicly state the generation of 34 tons

of waste per year.

state, local, or tribal governments or

communities; creates a serious

inconsistency with actions taken or

planned by another agency; materially

alters the budgetary impact of

entitlements, grants, user fees, or loan

programs or the rights and obligations or

recipients thereof; or raises novel legal

or policy issues arising out of legal

mandates, the President’s priorities, or

the principles set forth in the Executive

Order.

The Agency estimated the costs of

today’s rule to determine if it is a

significant regulation as defined by

Executive Order 12866. Today’s rule is

estimated to have an annualized

incremental cost of well below

$100,000. Based on this compliance cost

estimate, today’s rule is not considered

to be an economically significant

regulatory action. However, the Agency

believes that this action is significant for

novel policy reasons. The following

section discusses the results of the

economic analyses used to support the

Agency’s determination.

Approach

To estimate the costs, economic

impacts, and benefits of today’s rule, the

Agency compared post-regulatory costs,

benefits, and economic impacts with

those resulting under baseline

conditions. Benefits are addressed in the

risk assessment section of this preamble.

The baseline management practice for

this waste is disposal in a Subtitle D

landfill, because this would the least

expensive disposal option.

Results

The facility generating this waste is

already in the Subtitle C universe

because it generates other listed

hazardous wastes. Therefore, costs

associated with entering the RCRA

hazardous waste system are not

attributable to this listing. The owner/

operator of the affected facility currently

manage wastes off-site, and it is

assumed for purposes of this analysis

that off-site management would

continue under Subtitle C.

At the time of the proposed listing

there were two available options for

handling the waste—land filling and

incineration. The initial costs were

based on the cost of management in a

Subtitle C landfill. During the time

between the proposal and final

promulgation of this listing, Land

Disposal Restrictions (LDRs), requiring

incineration, were proposed for this

waste. Using costs from the Assessment

of the Potential Costs and Benefits of the

Hazardous Waste Identification Rule for

Industrial Process Wastes, Volume One:

Chapter 3, May 25, 1995, incineration of

low volumes of hazardous waste are

assumed to be $1,428/ton. Additionally,

costs of $130/ton are needed to handle

the residual which is assumed to be

one-quarter of the original tonnage, by

weight. For disposal of the 34 tons 14 of

waste and residual generated by the

affected facility, the marginal

compliance cost of this listing would be‘

would less than $48,000 per year. The

transportation costs are assumed to

equivalent to the Subtitle D handling

because there is a hazardous waste

incinerator in El Dorado, Arkansas.

Disposal method Cost/year Marginal difference

Hazardous

Incineration ....................................................................... $48,552 ....................

Residual-Sub C ................................................................ 1,105 ....................

Land filling ........................................................................ .................... ....................

Total post-rule .................................................................. 49,657

Baseline ............................................................................. Subtitle D landfilling ......................................................... 1,700 47,957

B. Regulatory Flexibility Analysis

Pursuant to the Regulatory Flexibility

Act of 1980, 5 U.S.C. 601 et seq., when

an agency publishes a notice of

rulemaking, for a rule that will have a

significant effect on a substantial

number of small entities, the agency

must prepare and make available for

public comment a regulatory flexibility

analysis that considers the effect of the

rule on small entities (i.e., small

businesses, small organizations, and

small governmental jurisdictions).

With respect to organobromine

producing facilities that are small

entities, the Agency does not believe

that today’s final rulemaking will have

a significant impact. The organobromine

chemical-producing industry in the U.S.

is geographically limited by the location

of underground bromide-bearing brine

deposits. EPA identified two firms in

southern Arkansas that account for 95%

of the organobromine chemicals

produced in the U.S. EPA evaluated the

economic effect of the rule as discussed

in the cost and economic impact section

of this rulemaking, and determined that

no facilities would be significantly

affected.

For the reasons discussed above in the

cost and economic impact section, EPA

has determined that today’s final rule

will not have a significant impact to a

substantial number of these small

entities. Based on the foregoing

discussion, I hereby certify that this rule

will not have a significant adverse

economic impact on a substantial

number of small entities. This rule,

therefore, does not require a regulatory

flexibility analysis.

XII. Paperwork Reduction Act

This rule does not contain any new

information collection requirements

subject to OMB review under the

Paperwork Reduction Act of 1995, 44

U.S.C. 3501 et seq. Facilities will have

to comply with the existing Subtitle C

recordkeeping and reporting

requirements for the newly listed

wastestreams.

To the extent that this rule imposes

any information collection requirements

under existing RCRA regulations

promulgated in previous rulemakings,

those requirements have been approved

by the Office of Management and

Budget (OMB) under the Paperwork

Reduction Act, 44 U.S.C. 3501 et seq.,

and have been assigned OMB control

numbers 2050–0009 (ICR 1573, Part B

Permit Application, Permit

Modifications, and Special Permits);

2050–0120 (ICR 1571, General Facility

Hazardous Waste Standards); 2050–

0028 (ICR 261, Notification of

Hazardous Waste Activity); 2050–0034

(ICR 262, RCRA Hazardous Waste

Permit Application and Modification,

Part A); 2050–0039 (ICR 801,

Requirements for Generators,

Transporters, and Waste Management

Facilities under the Hazardous Waste

Manifest System); 2050–0035 (ICR 820,

Hazardous Waste Generator Standards);
24624 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

and 2050-0024 (ICR 976, 1997

Hazardous Waste Report).

Release reporting required as a result

of listing wastes as hazardous

substances under CERCLA and

adjusting the reportable quantities (RQs)

has been approved under the provisions

of the Paperwork Reduction Act, 44

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

assigned OMB control number 2050–

0046 (ICR 1049, Notification of Episodic

Release of Oil and Hazardous

Substances).

XIII. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates

Reform Act of 1995 (UMRA), Public

Law 104–4, establishes requirements for

Federal agencies to assess the effects of

their regulatory actions on state, local,

and tribal governments, and on the

private sector. Under section 202 of the

UMRA, EPA generally must prepare a

written statement, including a costbenefit analysis, for proposed and final

rules with ‘‘Federal mandates’’ that may

result in expenditures to state, local,

and tribal governments, in the aggregate,

or to the private sector, of $100 million

or more in any one year. Before

promulgating an EPA rule for which a

written statement is needed, section 205

of the UMRA generally requires EPA to

identify and consider a reasonable

number of regulatory alternatives and

adopt the least costly, most costeffective or least burdensome alternative

that achieves the objectives of the rule.

The provisions of section 205 do not

apply when they are inconsistent with

applicable law. Moreover, section 205

allows EPA to adopt an alternative other

than the least costly, most cost-effective

or least burdensome alternative if the

Administrator publishes with the final

rule an explanation why that alternative

was not adopted. Before EPA establishes

any regulatory requirements that may

significantly or uniquely affect small

governments, including tribal

governments, it must have developed

under section 203 of the UMRA a small

government agency plan. The plan must

provide for notifying potentially

affected small governments, enabling

officials of affected small governments

to have meaningful and timely input in

the development of EPA regulatory

proposals with significant Federal

intergovernmental mandates, and

informing, educating, and advising

small governments on compliance with

the regulatory requirements.

EPA has determined that this rule

does not include a Federal mandate that

may result in estimated costs of $100

million or more to either State, local, or

tribal governments in the aggregate

because this rule imposes no

enforceable duty on any State, local, or

tribal governments. The rule would not

impose any federal intergovernmental

mandate because it imposes no

enforceable duty upon State, tribal or

local governments. States, tribes and

local governments would have no

compliance costs under this rule, which

applies only to facilities managing the

listed organobromine production wastes

and the discarded product waste. It is

expected that states will adopt similar

rules, and submit those rules for

inclusion in their authorized RCRA

programs, but they have no legally

enforceable duty to do so.

For the same reasons, EPA also has

determined that this rule contains no

regulatory requirements that might

significantly or uniquely affect small

governments. In addition, as discussed

above, the private sector is not expected

to incur costs exceeding $100 million.

EPA has fulfilled the requirement for

analysis under the Unfunded Mandates

Reform Act.

XIV. National Technology Transfer and

Advancement Act

Under section 12(d) of the National

Technology Transfer and Advancement

Act (‘‘NTTAA’’), the Agency is required

to use voluntary consensus standards in

its regulatory activities unless to do so

would be inconsistent with applicable

law or otherwise impractical. Voluntary

consensus standards are technical

standards (e.g., materials specifications,

test methods, sampling procedures,

business practice, etc.) which are

developed or adopted by voluntary

consensus standard bodies. Where

available and potentially applicable

voluntary consensus standards are not

used by EPA, the Act requires the

Agency to provide Congress, through

the Office of Management and Budget,

an explanation of the reasons for not

using such standards. EPA identified no

potentially applicable voluntary

consensus standards for today’s final

rule.

XV. Submission to Congress and the

General Accounting Office

Under 5 U.S.C. 801(A)(1)(a) as added

by the Small Business Regulatory

Enforcement Act of 1996, EPA

submitted a report containing this rule

and other required information to the

U.S. Senate, the U.S. House of

Representatives and the Comptroller

General of the General Accounting

Office prior to publication of the rule in

today’s Federal Register. This rule is

not a ‘‘major rule’’ as defined by 5

U.S.C. 804(2).

List of Subjects

40 CFR Part 148

Administrative practice and

procedure, Hazardous waste, Reporting

and recordkeeping requirements, Water

supply.

40 CFR Part 261

Environmental protection, Hazardous

wastes, Recycling, Reporting and

recordkeeping requirements.

40 CFR Part 268

Hazardous waste, Reporting and

recordkeeping requirements.

40 CFR Part 271

Environmental protection,

Administrative practice and procedure,

Confidential business information,

Hazardous materials transportation,

Hazardous waste, Indian lands,

Intergovernmental relations, Penalties,

Reporting and recordkeeping

requirements, Water pollution control,

Water supply.

40 CFR Part 302

Air pollution control, Chemicals,

Emergency Planning and Community

Right-To-Know Act, Extremely

hazardous substances, Hazardous

chemicals, Hazardous materials,

Hazardous materials transportation,

Hazardous substances, Hazardous

wastes, Intergovernmental relations,

Natural resources, Pesticides and pests,

Reporting and recordkeeping

requirements, Superfund, Waste

treatment and disposal, Water pollution

control, Water supply.

Dated: April 15, 1998.

Carol M. Browner,

Administrator.

For the reasons set out in the

preamble, title 40 of the Code of Federal

Regulations is amended as follows:

PART 148—HAZARDOUS WASTE

INJECTION RESTRICTIONS

1. The authority citation for part 148

continues to read as follows:

Authority: Secs. 3004, Resource

Conservation and Recovery Act, 42 U.S.C.

6901 et seq.

2. Section 148.18 is amended by

adding paragraph (f) to read as follows:

§ 148.18 Waste specific prohibitions-newly

listed and identified wastes.

* * * * *

(f) Effective August 3, 1998, the

wastes specified in 40 CFR 261.32 as

EPA Hazardous Waste number K140,

and in 40 CFR 261.33(f) as EPA

Hazardous Waste number U408 are

prohibited from underground injection.
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24625

PART 261—IDENTIFICATION AND

LISTING OF HAZARDOUS WASTE

3. The authority citation for Part 261

continues to read as follows:

Authority: 42 U.S.C. 6905, 6912(a), 6921,

6922, 6924(y) and 6938.

4. In § 261.32 the table is amended by

adding in numerical order the following

waste stream to the subgroup ‘Organic

chemicals’:

§ 261.32 Hazardous wastes from specific

sources.

* * * * *

Industry and

EPA hazardous

waste No.

Hazardous waste Hazard

code

* * * * *

K140 .......... Floor sweepings,

off-specification

product and

spent filter media

from the production of 2,4,6-

tribromophenol.

(T)

Industry and

EPA hazardous

waste No.

Hazardous waste Hazard

code

* * * * *

5. In § 261.33(f) the table is amended

by adding in numerical order the

following substance to read as follows:

§ 261.33 Discarded commercial chemical

products, off-specification species,

container residues, and spill residues

thereof.

* * * * *

(f) * * *

Hazardous

waste No.

Chemical

abstracts

No.

Substance

* * * * *

U408 .......... 118–79–6 2,4,6-

Tribromophenol.

* * * * *

6. Appendix VII to Part 261 is

amended by adding the following waste

stream in alphanumeric order.

Appendix VII to Part 261—Basis for

Listing Hazardous Waste

EPA hazardous

waste No.

Hazardous constituents for which

listed

* * * * *

K140 ........ 2,4,6-Tribromophenol.

* * * * *

7. Appendix VIII to Part 261 is

amended by adding the following

hazardous constituent in alphabetical

order:

Appendix—VIII to Part 261—

Hazardous Constituents

Common name Chemical abstracts name

Chemical

abstracts

No.

Hazardous

waste No.

* * * * * * *

2,4,6-Tribromophenol ......................................................... Tribromophenol, 2,4,6– ..................................................... 118–79–6 U408

* * * * * * *

PART 268—LAND DISPOSAL

RESTRICTIONS

8. The authority citation for Part 268

continues to read as follows:

Subpart C—Prohibitions on Land

Disposal

Authority: 42 U.S.C. 6905, 6912(a), 6921,

and 6924.

9. Section 268.33 is added to read as

follows:

§ 268.33 Waste-specific prohibitions—

organobromine wastes.

(a) Effective November 4, 1998, the

waste specified in 40 CFR 261.32 as

EPA Hazardous Wastes Numbers K140,

and in 40 CFR 261.33 as EPA Hazardous

waste number U408 are prohibited from

land disposal. In addition, soils and

debris contaminated with these wastes,

radioactive wastes mixed with these

hazardous wastes, and soils and debris

contaminated with these radioactive

mixed wastes, are prohibited from land

disposal.

(b) Between May 4, 1998 and

November 4, 1998, the wastes included

in the paragraph (a) of this section may

be disposed in a landfill or surface

impoundment only if such unit is in

compliance with the requirements

specified in § 268.5(h)(2).

(c) The requirements of paragraphs (a)

and (b) of this section do not apply if:

(1) The wastes meet the applicable

treatment standards specified in subpart

D of this part;

(2) Persons have been granted an

exemption from a prohibition pursuant

to a petition under § 268.6, with respect

to those wastes and units covered by the

petition;

(3) The wastes meet the applicable

treatment standards established

pursuant to a petition granted under

§ 268.44;

(4) Hazardous debris that has met

treatment standards in § 268.40 or in the

alternative treatment standards in

§ 268.45; or

(5) Persons have been granted an

extension to the effective date of a

prohibition pursuant to § 268.5, with

respect to these wastes covered by the

extension.

(d) To determine whether a hazardous

waste identified in this section exceeds

the applicable treatment standards

specified in § 268.40, the initial

generator must test a sample of the

waste extract or the entire waste,

depending on whether the treatment

standards are expressed as

concentrations in the waste extract or

the waste, or the generator may use

knowledge of the waste. If the waste

contains constituents (including

underlying hazardous constituents in

characteristic wastes that have been

diluted to remove the characteristic) in

excess of the applicable Universal

Treatment Standard levels of § 268.48,

the waste is prohibited from land

disposal, and all requirements of this

part 268 are applicable, except as

otherwise specified.

Subpart D—Treatment Standards

10. In § 268.40 the table is amended

by adding in alphanumeric order the

following new entries. The appropriate

footnotes are republished without

change.

§ 268.40 Applicability of treatment

standards.

* * * * *
24626 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

TREATMENT STANDARDS FOR HAZARDOUS WASTES

[Note: NA means not applicable]

Waste Code Waste Description and Treatment/Regulatory Subcategory 1

Regulated Hazardous Constituent Wastewaters Nonwastewaters

Common Name CAS2 number

Concentration in mg/

L 3; or Technology

Code4

Concentration in mg/

kg 5 unless

noted as

‘‘mg/L

TCLP’’; or

Technology

Code

* * * * * *

K140 ............. Floor sweepings, off-specification product, and spent

filter media from the production of 2,4,6-

tribromophenol.

2,4,6-Tribromophenol ......... 118–79–6 0.35 7.4

* * * * * *

U408 ............ 2,4,6-Tribromophenol ................................................... 2,4,6-Tribromophenol ......... 118–79–6 0.035 7.4

* * * * * *

1The waste descriptions provided in this table do not replace waste descriptions in 40 CFR 261. Descriptions of Treatment/Regulatory Subcategories are provided, as needed, to distinguish between applicability of different standards. 2 CAS means Chemical Abstract Services. When the waste code and/or regulated constituents are described as a combination of a chemical

with it’s salts and/or esters, the CAS number is given for the parent compound only. 3 Concentration standards for wastewaters are expressed in mg/l are based on analysis of composite samples.

4All treatment standards expressed as a Technology Code or combination of Technology Codes are explained in detail in 40 CFR 268.42

Table 1—Technology Codes and Descriptions of Technology-Based Standards. 5Except for Metals (EP or TCLP) and Cyanides (Total and Amenable) the nonwastewater treatment standards expressed as a concentration

were established, in part, based upon incineration in units operated in accordance with the technical requirements of 40 CFR Part 264 Subpart O

or Part 265 Subpart O, or based upon combustion in fuel substitution units operating in accordance with applicable technical requirements. A facility may comply with these treatment standards according to provisions in 40 CFR 268.40(d). All concentration standards for nonwastewaters

are based on analysis of grab samples.

* * * * *

11. In § 268.48(a), the table is amended by adding in alphabetical order the following new entry as follows: The

appropriate footnotes are republished without change.

§ 268.48 Universal treatment standards.

(a) * * *

UNIVERSAL TREATMENT STANDARDS

[Note: NA means not applicable]

Regulated constituent/common name CAS1 Number

Wastewater

standard

Nonwastewater

standard

Concentration in mg/

L 2

Concentration in mg/

kg 3 unless

noted as

‘‘mg/L

TCLP’’

* * * * * * *

2,4,6-Tribromophenol ................................................................................................................................ 118–79–6 0.035 7.4

* * * * * * *

1 CAS means Chemical Abstract Services. When the waste code and/or regulated constituents are described as a combination of a chemical

with it’s salts and/or esters, the CAS number is given for the parent compound only. 2 Concentration standards for wastewaters are expressed in mg/l are based on analysis of composite samples.

3Except for Metals (EP or TCLP) and Cyanides (Total and Amenable) the nonwastewater treatment standards expressed as a concentration

were established, in part, based upon incineration in units operated in accordance with the technical requirements of 40 CFR part 264, subpart O

or 40 CFR part 265, subpart O, or based upon combustion in fuel substitution units operating in accordance with applicable technical requirements. A facility may comply with these treatment standards according to provisions in 40 CFR 268.40(d). All concentration standards for

nonwastewaters are based on analysis of grab samples.

* * * * * *
Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations 24627

PART 271—REQUIREMENTS FOR

AUTHORIZATION OF STATE

HAZARDOUS WASTE PROGRAMS

12. The authority citation for Part 271

continues to read as follows:

Authority: 42 U.S.C. 6905, 6912(a), and

6926.

13. Section 271.1(j) is amended by

adding the following entries to Tables 1

and 2 in chronological order by date of

publication to read as follows.

§ 271.1 Purpose and scope.

* * * * *

(j) * * *

TABLE 1.—REGULATIONS IMPLEMENTING THE HAZARDOUS AND SOLID WASTE AMENDMENTS OF 1984

Promulgation date Title of regulation Federal Register reference Effective date

* * * * * * *

May 4, 1998 .................................. Listing of Organobromine Production Wastes.[Insert Federal Register reference

page cite from publication date]..

November 4, 1998

* * * * * * *

* * * * *

TABLE 2.—SELF-IMPLEMENTING PROVISIONS OF THE SOLID WASTE AMENDMENTS OF 1984

Effective date Self-implementing provision RCRA citation Federal Register reference

* * * * * * *

August 3, 1998 .............................. Prohibition on land disposal of

newly listed and identified

wastes.

3004(g)(4)(C) and 3004(m) .......... [Insert date of publication; FR

page numbers]

May 4, 2000 .................................. Prohibition on land disposal of radioactive waste mixed with the

newly listed and identified

wastes, including soil and debris.

3004(m) .........................................

3004(g)(4)(C) and .........................

3004(m) .........................................

Do.

Do.

Do.

* * * * * * *

* * * * *

Part 302—DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION

14. The authority citation for Part 302 continues to read as follows:

Authority: 42 U.S.C. 9602, 9603, and 9604; 33 U.S.C. 1321 and 1361.

15. Section 302.4 is amended by adding the following entries to Table 302.4 and its Appendix A as set forth

below. The appropriate footnotes to Table 302.4 are republished without change.

TABLE 302.4.—LIST OF HAZARDOUS SUBSTANCES AND REPORTABLE QUANTITIES

Hazardous substance CASRN Regulatory

synonyms

Statutory Final RQ

RQ Code +

RCRA

Waste

Number

Category Pounds

(Kg)

2,4,6-tribromophenol ...................................... 118796 .................... 100 4 U408 B 100 (45.4)

* * * * * * *

K140 Floor sweepings, off-specification product and spent filter media from the production of 2,4,6-tribromophenol...................... .................... 1* 4 K140 B ##

100 (45.4)

* * * * * * *

* * * * * * *

4—indicates that the statutory source for designation of this hazardous substance under CERCLA is RCRA Section 3001.

1*—indicates that the 1-pound RQ is a CERCLA statutory RQ.

* * * * * * *
24628 Federal Register / Vol. 63, No. 85 / Monday, May 4, 1998 /Rules and Regulations

APPENDIX A TO § 302.4—SEQUENTIAL CAS REGISTRY NUMBER LIST OF CERCLA HAZARDOUS SUBSTANCES

CAIRN Hazardous substance

* * * * * * *

118796 ......... 2,4,6-Tribromophenol

* * * * * * *

[FR Doc. 98–11259 Filed 5–1–98; 8:45 am]

BILLING CODE 6560–50–P