[Federal Register Volume 63, Number 85 (Monday, May 4, 1998)]
[Rules and Regulations]
[Pages 24596-24628]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11259]



[[Page 24595]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 148, et al.



Organobromine Production Wastes; Identification and Listing of 
Hazardous Waste; Land Disposal Restrictions; Listing of CERCLA 
Hazardous Substances, Reportable Quantities; Final Rule

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

[[Page 24596]]



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, off-specification 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 
<a href="/cdn-cgi/l/email-protection#d3b0b2a1a1b6bfbffdb2bda7bbbcbdaa93b6a3b2beb2babffdb6a3b2fdb4bca5"><span class="__cf_email__" data-cfemail="0f6c6e7d7d6a6363216e617b676061764f6a7f6e626e6663216a7f6e21686079">[email protected]</span></a>.
    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 Structure-Activity 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 
Tetrabromobisphenol-A
    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

[[Page 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 Sec. 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 
Sec. 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 Sec. 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 
Sec. 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

[[Page 24598]]

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 off-specification 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.

[[Page 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      No List.              
                                                              than 1 kkg/yr) One                                
                                                              producer.                                         
                                     Wastewaters...........  Deep-well injected at site   No List.              
                                                              with approved no-migration                        
                                                              petition (only one                                
                                                              producer).                                        
Ethyl Bromide......................  Filters...............  Very small volume stream     No List.              
                                                              (less than 1.5 kkg/yr).                           
                                     Wastewaters...........  Only constituent identified  No List.              
                                                              is ethanol at low                                 
                                                              concentration.                                    
Tetrabromobisphenol A..............  Wastewaters...........  Stream is already listed as  Already listed waste. 
                                                              K131 for methyl bromide.                          
                                                              Also contains 15,000 ppm                          
                                                              tribromophenol.                                   
Octabromodiphenyl oxide............  Filter cake...........  Toluene and brominated       No list.              
                                                              dibenzofurans present at                          
                                                              levels below concern.                             
                                                              Assuming worst case for                           
                                                              leachate, risk for the                            
                                                              maximally exposed                                 
                                                              individual estimated to be                        
                                                              below 10<SUP>-6 for                                    
                                                              octabromodiphenyl oxide.                          
                                     Wastewaters...........  Major constituent of         No list.              
                                                              concern, brominated                               
                                                              dibenzofurans, shows                              
                                                              minimal risk; solubility                          
                                                              of octabromodiphenyl oxide                        
                                                              is very low; modeling of                          
                                                              worst case for wastewaters                        
                                                              showed risk below 10<SUP>-6 for                        
                                                              octabromodiphenyl oxide.                          
Decabromodiphenyl oxide............  Filter cake...........  The major constituent in     No list.              
                                                              waste (decabromodiphenyl                          
                                                              oxide) could not be                               
                                                              quantified. Assuming worst                        
                                                              case for leachate, risk                           
                                                              below 10<SUP>-6 level because                          
                                                              of very low solubility for                        
                                                              this chemical.                                    
                                     Wastewaters...........  The major constituent in     No list.              
                                                              waste (decabromodiphenyl                          
                                                              oxide) could not be                               
                                                              quantified. Assuming worst                        
                                                              case for leachate, risk                           
                                                              below 10<SUP>-6 level because                          
                                                              of very low solubility.                           
Tetrabromobisphenol A..............  Off-specification       Tetrabromobisphenol A is of  No list.              
                                      product.                relatively low toxicity                           
                                                              and has limited mobility.                         
                                                              Levels of tribromophenol                          
                                                              in leachate are below                             
                                                              those for concern.                                
Tribromophenol.....................  Wastewaters...........  Used structure activity      No list.              
                                                              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.                              

[[Page 24600]]

                                                                                                                
                                     Floor sweepings, off-   Used structure activity      List as hazardous     
                                      specification product   relationship analysis to     waste (K140) and     
                                      and spent filter        show carcinogenicity of      commercial chemical  
                                      media from the          tribromophenol. High         product (U408).      
                                      production of 2,4,6-    concentration of chemical                         
                                      tribromophenol;         in solids and TCLP                                
                                      discarded commercial    leachate. Mobile in                               
                                      chemical product.       leachate and would present                        
                                                              high risk if released from                        
                                                              landfill, even a Subtitle                         
                                                              C landfill.                                       
----------------------------------------------------------------------------------------------------------------

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 
(carbon-containing) 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.<SUP>1</SUP>
---------------------------------------------------------------------------

    \1\ Waser J., N. Trueblood, and C. M. Knobler. 1976. Chem One. 
New York, NY: McGraw-Hill pp. 25-29.

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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 closely-related 
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 K<INF>ow</INF>), is similar for these two 
chemicals; the values of log K<INF>ow</INF> 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.<SUP>2</SUP> 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 chemically-induced cancer results 
from molecules binding to DNA or to another molecule in the 
body,<SUP>3</SUP> 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

[[Page 24602]]

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 x 10<SUP>-3</SUP> (mg/kg/
day)<SUP>-1</SUP>, compared with 1.1 x 10<SUP>-2</SUP> (mg/kg/
day)<SUP>-1</SUP> 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 x 10<SUP>-4</SUP> and 1.2 x 10<SUP>-5</SUP> for the off-
specification product and the filter cartridges, respectively, compared 
with risks of 7 x 10<SUP>-4</SUP> and 2 x 10<SUP>-5</SUP> 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.
---------------------------------------------------------------------------

    \2\ Waser, J., K.N. Trueblood, and C.M. Knobler. 1976. Chem One. 
New York, NY: McGraw-Hill pp. 25-29.
    \3\ William, 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.
---------------------------------------------------------------------------

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.<SUP>4</SUP>
---------------------------------------------------------------------------

    \4\ USEPA. 1992. Respiratory health effects of passive smoking: 
Lung cancer and other disorders. ORD, USEPA, Washington DC, 20460. 
EPA/600/6-90/006F.
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    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.<SUP>5</SUP>
---------------------------------------------------------------------------

    \5\ Proposed Guidelines for Carcinogen Risk Assessment. Federal 
Register 61(79): 17960-18011, Tuesday, April 23, 1996.
---------------------------------------------------------------------------

    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:
    <bullet> 2,4,6-TBP and 2,4,6-TCP are both tri-halogenated phenols 
with substitutions at the same positions;
    <bullet> The physical and chemical properties, such as the octanol-
water partition coefficient and the water solubility, of the compounds 
are similar;
    <bullet> Available genetic toxicity data show consistent results 
for 2,4,6-TCP and 2,4,6-TBP; and
    <bullet> 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

[[Page 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-TBP-
containing 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

[[Page 24604]]

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.<SUP>6</SUP> 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,<SUP>7</SUP> 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.
---------------------------------------------------------------------------

    \6\ Zieger, 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.
    \7\ Haworth, 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.
---------------------------------------------------------------------------

    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 (CHCl<INF>3</INF>) to bromoform (CHBr<INF>3</INF>). 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 well-studied 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) <SUP>8</SUP> and 1,2-dibromoethane (ethylene dibromide) 
<SUP>9</SUP> 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.)
---------------------------------------------------------------------------

    \8\ NCI. 1978. Bioassay of 1,2-dichloroethane for possible 
carcinogenicity. National Cancer Institute, Bethesda Maryland. NCI-
CG-TR No. 66; DHEW/PUB/NIH-78-1361.
    \9\ NTP. 1982. Carcinogenesis bioassay of 1,2-dibromoethane for 
possible carcinogenicity F344 rats and B6C3F<INF>1</INF> mice. U.S. 
National Toxicology Program, Research Triangle Park, North Carolina. 
NTP-TR No. 210; NIH/PUB 87-1766.
---------------------------------------------------------------------------

    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 n-butyl 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

[[Page 24605]]

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/n-heptane), 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.<SUP>10</SUP>
---------------------------------------------------------------------------

    \10\ Andrews, 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.

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    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

[[Page 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 (Sec. 261.11(a)(3)(i)), concentration of the hazardous 
constituent in the waste (Sec. 261.11(a)(3)(ii)), the potential of the 
hazardous constituent to migrate into the environment 
(Sec. 261.11(a)(iii)), the relevance of the quantities of the waste 
generated (Sec. 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 (Sec. 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 
small-volume 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<SUP>-6</SUP> 
cancer risk level for ingestion. The proposed rule estimated risks of 7 
 x  10<SUP>-4</SUP> 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 longer-term 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

[[Page 24610]]

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  x  10<SUP>-4</SUP>) 
means that even a modest reduction in long-term 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  x  
10<SUP>-5</SUP>. In fact, the containment systems would have to be in 
excess of 98% effective for the estimated risk to drop below 1  x  
10-<SUP>5</SUP>. The risks for this particular untreated waste, 
therefore, would remain above EPA's presumptive level of concern for 
listing (>10-<SUP>5</SUP>), 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 (Sec. 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 drinking-water 
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

[[Page 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 
Sec. 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 Sec. 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 Sec. 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 Sec. 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

[[Page 24612]]

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 
x  10-5. The actual long-term 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 
(U-listings) 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 Sec. 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 Sec. 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

[[Page 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 post-closure 
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 (Sec. 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<SUP>-5</SUP> 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 Sec. 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

[[Page 24614]]

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 end-product 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.

[[Page 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 off-specification 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 by-product 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

[[Page 24616]]

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 long-term 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 off-specification 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

[[Page 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 x 10<SUP>-4</SUP> (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 x 10<SUP>-4</SUP>). 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-<SUP>-6</SUP>. 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 co-products 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 penta-brominated 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

[[Page 24618]]

``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 off-specification 
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 land-disposed.
    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

[[Page 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: Surfaced-disposed 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. Land-disposed 
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

[[Page 24620]]

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 bisphenol-A 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

[[Page 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

[[Page 24622]]

applicable 40 CFR part 265 ground-water 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.<SUP>11</SUP> 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.
---------------------------------------------------------------------------

    \11\ The 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.
---------------------------------------------------------------------------

    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.<SUP>12</SUP> 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.
---------------------------------------------------------------------------

    \12\ For 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).
---------------------------------------------------------------------------

    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.<SUP>13</SUP> 
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.
---------------------------------------------------------------------------

    \13\ No 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.
---------------------------------------------------------------------------

    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 cost-benefit 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

[[Page 24623]]

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 <SUP>14</SUP> 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.
---------------------------------------------------------------------------

    \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.

----------------------------------------------------------------------------------------------------------------
                                                                                                       Marginal 
                Disposal method                                                          Cost/year    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);

[[Page 24624]]

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 cost-
benefit 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 cost-effective 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:


Sec. 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.

[[Page 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 Sec. 261.32 the table is amended by adding in numerical order 
the following waste stream to the subgroup `Organic chemicals':


Sec. 261.32  Hazardous wastes from specific sources.

* * * * *

------------------------------------------------------------------------
    Industry and EPA                                                    
   hazardous waste No.         Hazardous waste           Hazard code    
------------------------------------------------------------------------
                                                                        
                  *        *        *        *        *                 
K140....................  Floor sweepings, off-     (T)                 
                           specification product                        
                           and spent filter media                       
                           from the production of                       
                           2,4,6-tribromophenol.                        
                                                                        
                  *        *        *        *        *                 
------------------------------------------------------------------------

    5. In Sec. 261.33(f) the table is amended by adding in numerical 
order the following substance to read as follows:


Sec. 261.33  Discarded commercial chemical products, off-specification 
species, container residues, and spill residues thereof.

* * * * *
    (f) * * *

------------------------------------------------------------------------
                                 Chemical                               
     Hazardous waste No.        abstracts             Substance         
                                   No.                                  
------------------------------------------------------------------------
                                                                        
                  *        *        *        *        *                 
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

------------------------------------------------------------------------
                                      Hazardous constituents for which  
      EPA hazardous waste No.                      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

----------------------------------------------------------------------------------------------------------------
                                                                             Chemical                           
               Common name                    Chemical abstracts name       abstracts      Hazardous waste No.  
                                                                               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:


Sec. 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 Sec. 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 Sec. 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 Sec. 268.44;
    (4) Hazardous debris that has met treatment standards in 
Sec. 268.40 or in the alternative treatment standards in Sec. 268.45; 
or
    (5) Persons have been granted an extension to the effective date of 
a prohibition pursuant to Sec. 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 
Sec. 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 Sec. 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 Sec. 268.40 the table is amended by adding in alphanumeric 
order the following new entries. The appropriate footnotes are 
republished without change.


Sec. 268.40  Applicability of treatment standards.

* * * * *

[[Page 24626]]



                                    Treatment Standards for Hazardous Wastes                                    
                                         [Note: NA means not applicable]                                        
----------------------------------------------------------------------------------------------------------------
                                            Regulated Hazardous Constituent          Wastewaters        Non-    
                                   ---------------------------------------------------------------  wastewaters 
                                                                                                  --------------
                        Waste                                                                      Concentration
                   Description and                                                  Concentration   in mg/kg \5\
    Waste Code        Treatment/                                         CAS \2\     in mg/L \3\;   unless noted
                      Regulatory               Common Name                number    or Technology    as ``mg/L  
                   Subcategory \1\                                                     Code\4\       TCLP''; or 
                                                                                                     Technology 
                                                                                                        Code    
----------------------------------------------------------------------------------------------------------------
                                                                                                                
        *                  *                  *                  *                  *                  *        
K140.............  Floor            2,4,6-Tribromophenol.............     118-79-6          0.35            7.4 
                    sweepings, off-                                                                             
                    specification                                                                               
                    product, and                                                                                
                    spent filter                                                                                
                    media from the                                                                              
                    production of                                                                               
                    2,4,6-                                                                                      
                    tribromophenol.                                                                             
                                                                                                                
        *                  *                  *                  *                  *                  *        
U408.............  2,4,6-           2,4,6-Tribromophenol.............     118-79-6          0.035           7.4 
                    Tribromophenol.                                                                             
                                                                                                                
        *                  *                  *                  *                  *                  *        
----------------------------------------------------------------------------------------------------------------
\1\ The 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.   
\4\ All 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.             
\5\ Except 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 Sec. 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.


Sec. 268.48  Universal treatment standards.

    (a) * * *

                                          Universal Treatment Standards                                         
                                         [Note: NA means not applicable]                                        
----------------------------------------------------------------------------------------------------------------
                                                                                      Wastewater   Nonwastewater
                                                                                       standard       standard  
                                                                                   -----------------------------
                                                                         CAS \1\                   Concentration
                  Regulated constituent/common name                      Number                     in mg/kg \3\
                                                                                    Concentration   unless noted
                                                                                     in mg/L \2\     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.   
\3\ Except 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.              

* * * * * *

[[Page 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.


Sec. 271.1  Purpose and scope.

* * * * *
    (j) * * *

               Table 1.--Regulations Implementing the Hazardous and Solid Waste Amendments of 1984              
----------------------------------------------------------------------------------------------------------------
                                                                    Federal Register                            
          Promulgation date              Title of regulation           reference              Effective date    
----------------------------------------------------------------------------------------------------------------
                                                                                                                
*                  *                  *                  *                  *                  *                
May 4, 1998..........................  Listing of               [Insert Federal          November 4, 1998       
                                        Organobromine            Register reference                             
                                        Production Wastes.       page cite from                                 
                                                                 publication date]..                            
                                                                                                                
*                  *                  *                  *                  *                  *                
                                                        *                                                       
----------------------------------------------------------------------------------------------------------------

* * * * *

                  Table 2.--Self-Implementing Provisions of the Solid Waste Amendments of 1984                  
----------------------------------------------------------------------------------------------------------------
                                          Self-implementing                                  Federal Register   
            Effective date                    provision              RCRA citation              reference       
----------------------------------------------------------------------------------------------------------------
                                                                                                                
*                  *                  *                  *                  *                  *                
August 3, 1998.......................  Prohibition on land      3004(g)(4)(C) and        [Insert date of        
                                        disposal of newly        3004(m).                 publication; FR page  
                                        listed and identified                             numbers]              
                                        wastes.                                                                 
May 4, 2000..........................  Prohibition on land      3004(m)................      Do.                
                                        disposal of             3004(g)(4)(C) and......      Do.                
                                        radioactive waste       3004(m)................      Do.                
                                        mixed with the newly                                                    
                                        listed and identified                                                   
                                        wastes, including soil                                                  
                                        and debris.                                                             
                                                                                                                
*                  *                  *                  *                  *                  *                
                                                        *                                                       
----------------------------------------------------------------------------------------------------------------

* * * * *


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                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Statutory                                    Final RQ             
          Hazardous substance              CASRN      Regulatory ---------------------------------------------------------------------------------------
                                                       synonyms        RQ         Code +       RCRA Waste Number            Category         Pounds (Kg)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2,4,6-tribromophenol..................       118796  ...........          100            4  U408                     B                        100 (45.4)
                                                                                                                                                        
                   *                  *                  *                  *                  *                  *                  *                  
K140 Floor sweepings, off-              ...........  ...........           1*            4  K140                     B                            ##    
 specification product and spent                                                                                                              100 (45.4)
 filter media from the production of                                                                                                                    
 2,4,6-tribromophenol..                                                                                                                                 
                                                                                                                                                        
                  *                  *                  *                  *                  *                  *                  *                   
--------------------------------------------------------------------------------------------------------------------------------------------------------
*                  *                  *                  *                  *                  *                  *                                     
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.                                                                                             
*                  *                  *                  *                  *                  *                  *                                     


[[Page 24628]]

APPENDIX A TO Sec. 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


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