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Reviewing New Chemicals under the Toxic Substances Control Act (TSCA)

Exposure-based Policy Letter to Chemical Manufacturers Association 1988

The following letter from EPA to the Chemical Manufacturers Association explains EPA’s exposure-based policy in the New Chemicals Program.

Geraldine V. Cox, Ph.D.
Vice President - Technical Director
Chemical Manufacturers Association
2501 M Street, NW
Washington, DC 20037

Dear Dr. Cox:

I am writing in response to the Chemical Manufacturers Association's (CMA's) letters to Wendy Cleland-Hamnett dated June 2, 1988, (from Mr. William Royce) and your letter dated July 15, 1988. I have chosen to write to you because I feel it is important that you understand my position on future discussions between CMA members and staff of the new chemicals program in the Office of Toxic Substances (OTS). As I have stated before, I am always interested in a constructive dialogue about the policies which direct our implementation of the program. Such discussions can contribute to better compliance with program requirements on the part of your member companies, and can lead to the development of better data and, hence, better decisions on the part of OTS.

However, I am sure you are aware that the workload of the new chemicals program has continued to increase while the staff resources devoted to the program have been limited. Thus, I must be protective of staff time, in order to insure that it is devoted to those activities which are most effective in carrying out our mandate to protect human health and the environment. In order for a continued dialogue between our organizations to warrant the investment of additional staff resources, it must be mutually beneficial. That is, I must be convinced that it will serve not only the interests of CMA member companies, but those of EPA and of the general public as well.

Below is my response to the specific questions which you and Mr. Royce raised in your letters.

(1). Categories of Chemicals. Many of your questions revolved around the Agency's approach to reviewing certain groups of similar new chemical substances. As part of the answer to your questions, I would first like to explain the background for EPA's approach to the review and regulation of new chemical substances under TSCA.

Since the beginning of the program, we have made constant efforts to build on our past experience to improve the quality and efficiency of our review process. The recent delegation of some decision-making authority for certain groups of chemicals is just another step in this continuing effort. As you know, few of the Premanufacture Notice (PMN) submissions the Agency receives contain any data regarding the health or environmental effects of the substance. Consequently, EPA must often rely on structural analogues for reference. Among the substances frequently reviewed by EPA are certain classes of chemicals with structural analogues in common. PMNs in these classes had been regularly scheduled for our "standard" review process, meaning that we did not reach a regulatory decision until Day 82, despite the fact that very little additional technical work was required to assess the potential health or environmental concerns presented by the specific PMN substances (in light of the previous assessments of risks presented by the analogous substances in that class). By identifying chemical substances in these classes early in the 90 day review process, the Agency saves valuable resources and time which can be devoted to negotiating appropriate 5(e) consent orders or testing with PMN submitters.

We expect that the list of chemical groups distributed during the April meeting will change over time as we gain additional experience. New information (including data developed by PMN submitters) will allow us to remove some groups, while others will be added.

In response to your questions, these classes or categories of chemicals are not related to the "risk list" which can be created under the authority of section 5(b) (4) of TSCA. The term "category" has not been specifically defined for the PMN process,, nor do we believe that this is necessary, since it involves only our internal process for managing the New Chemicals program.

Your letter (and Mr. Royce's earlier correspondence) contained a request that the Agency prepare extensive information describing each category and the Agency's concerns for those substances in greater detail. Such a project would be very resource intensive, and I do not believe that it is necessary at this time. However, I do believe that it is important to apprise the chemical industry of those classes of chemical substances which the Agency considers to be of concern and which we have seen submitted frequently in PMNS. This will enable notice submitters to plan accordingly when preparing PMNs for-such chemicals. Also, the Agency would like to encourage companies to test these chemicals for effects of concern prior to submitting their notices. Therefore, we have provided information (see attachment A) that 1) describes the chemical groups and provides examples of members of each group, 2) identifies the health or environmental concerns, and 3) identifies the boundaries and typical testing requirements for each group. This document is a working document and is subject to change as I've discussed above. I do believe the attachment will be most useful to your constituents if they use it to develop data on substances within these categories which address EPA's concerns prior to the submission of a PMN.

You also expressed interest in establishing a mechanism for EPA to solicit public comment on its selection of categories of concern. I do not see the need for formally soliciting public comment on the procedures we use to conduct PMN reviews. Chemical manufacturers are always welcome to approach the Agency with information on categories or any other subject that may improve the analysis on which our decisions are based. One subject of future discussions that I believe would be mutually beneficial is the development of testing schemes which could be useful in defining the boundaries of concern for groups of chemicals. We believe that through such an approach, EPA and the affected industry can successfully identify a limited body of testing on the group which, if undertaken by the industry segment, could greatly improve understanding of the category and its toxicity or risk boundaries.

Please keep in mind that the structure activity relationship database, on which the chemical categories are based, is a fluid one which changes as new data are received. Given the case-by-case nature of PMN review, and our experience to date with testing under section 5, it is likely that data focused on more effectively defining category boundaries is a long-term solution to resolving uncertainties. Therefore, OTS remains very interested in identifying (with the aid of industry) limited series of tests which could help in redefining category boundaries. The parameters for such a dialogue must be flexible and focused on improving the quality of data on new chemical substances and our understanding of category boundaries rather than revisiting past debate. However, I would welcome any attempt to improve the Agency's decision making capabilities should CMA member companies choose to "form consortiums to cooperate in addressing generic testing and control issues for specific categories."

You asked if the Agency is working on category issues with industry groups other than with CMA and the Specialty Acrylates and Methacrylates Panel (SAM). There are two such groups. First, the Cationic Flocculant Producers Association is working with EPA on strategies for testing of cationic polymers. Also, the Ecological and Toxicological Association of the Dyestuffs Manufacturing Industry is working with the Agency to develop information on azo, anthraquinone, and triphenylmethane dyes. You may also be aware that a few years ago, companies frequently submitting notices for propylene glycol ethers tested several members of this chemical class because of Agency concerns based on the known toxicity of the related ethylene glycol ethers. Based on the data developed on the P-series glycol ethers, the Agency dropped its concerns for the propylene glycol ethers and as a result discontinued use of its section 5(e) authority for these PMNS. Constructive discussions of potential testing strategies for other chemicals of concern are welcomed.

(2). Normal Versus "Fast Track" 5(e) Order Negotiations. In your letter you expressed concern that the Agency's categories approach and order negotiation process would deny submitters an opportunity to fully express their concerns about the Agency's regulatory strategy as it relates to their own submission. I believe that you misunderstand our intent in introducing this approach. We have developed this approach in response to companies who complained that it took too long to issue "standard" 5(e) orders. The "fast track" is offered as an alternative to those submitters who prefer to accept our standard provisions in return for the ability to get their substances on the market sooner. The normal approach is available to companies that wish to negotiate unique provisions.

Under the "fast track" process, OTS prepares the order, sends it through the Agency review process, and sends the submitter the final order for signature after it has been signed by the Assistant Administrator. The order becomes effective once the signed order is returned by the submitter to the Agency. If the PMN chemical were a member of a group for which a regulatory decision is reached early in the review process, the whole process could take place within a few months.

The "fast track" process refers to the development of the requirements of a 5(e) order, not to the discussion of the technical analysis which supports our regulatory approach. We are always willing to engage in a technical dialogue when it is mutually beneficial. However, protracted discussions which do not provide additional relevant data do not serve the interests of the Agency or the public.

For your reference, I have attached schedules (attachment B) for the development of a typical 5(e) consent order and for a "fast track" or expedited order.

(3). Schedule For Consent Order Development. Your letter reiterates your interest in having the Agency provide an "up-front" explanation of its regulatory approach to a substance prior to order development. I agree with this recommendation. Submitters are encouraged to request such an explanation from the Program Manager assigned to their case once that decision point has been reached in the review process.

You should understand, however, that the decision to enter a negotiated order development process cannot start prior to day 80-85 of the review process for chemicals for which there may be concerns but which do not belong to one of the well characterized groups. This is because these chemicals are entered into a more detailed review process (standard review) than are chemicals in one of the categories. Submitters, however, are contacted after an initial decisional meeting on these types of cases and are presented with the possible regulatory outcomes so that they have an understanding of our initial concerns throughout the standard review process. In such cases, EPA's letter describing its concerns must, of course, await the conclusion of the full standard review process.

In response to your encouraging words concerning our prenotice consultation activities, the Agency has always encouraged potential submitters to communicate with EPA's Prenotice Communications Coordinator on any issues pertaining to the submission of section 5 notices. Typically, demand for this service often exceeds our resources for this activity. Therefore, we urge you to encourage your members to first call the TSCA Hotline for routine questions (202) 554-1404). This will allow the Prenotice Coordinators time to answer the more complex questions appropriate to their expertise (e.g., questions on consent order issues, chemical categories, and regulatory interpretation).

(4). Exposure-based Testing Requirements. Your letter questioned EPA's authority to pursue 5(e) orders with submitters on the basis of exposure-based concerns. Over the last year, EPA has implemented a policy designed to routinely seek data on substances which may present widespread human or environmental exposures. Section 5(e) of TSCA provides EPA with the authority to regulate new chemicals and to require health and environmental effects testing of new chemicals based on either the potential risk presented by the substance (section 5(e)(1)(A)(ii)(I)) or the potential for substantial production volume and substantial or significant human exposure or substantial environmental releases (section 5(e)(1)(A)(ii)(II)). EPA, in the past, has predominantly used the potential risk of a new chemical identified through the use of structure-activity analysis, as the basis for selecting new chemicals for regulation and testing under section 5. However, experience has shown that very little data are submitted with PMNS. Therefore, one of the objectives for the exposure-based policy is to obtain more test data on new chemicals, encourage fair and consistent decisions across numerous chemical categories and uses, and carry out Congress's intent that a greater priority for testing be placed on high exposure chemicals.

In initiating this policy, EPA developed criteria to define the terms in the exposure-based finding. These criteria are illustrated in Attachment C and serve as general guidelines used for entering chemicals into EPA's exposure-based review. our determination as to whether a PMN chemical meets these criteria is based not only on the PMN submission, but on our knowledge of the markets for these products and the processes for producing and using them. Thus, we attempt to identify production volume and exposure estimates which we believe have been over- or understated in the PMN submissions. However, commencement of an exposure-based review for a premanufacture notice (PMN) submission does not automatically result in section 5(e) regulation. Only those PMNs which fully meet the statutory criteria will become subject to 5(e) orders. During this initial period of implementing the exposure-based authority, these internal guidelines will remain flexible. As the Agency gains more experience in conducting such reviews, the guidelines may be modified.

EPA has established core testing requirements for chemicals regulated under this finding. For your information, they are also contained in Attachment C. Test requirements may be modified due to the physical/chemical properties of a chemical. The route of administration may also change to reflect specific (anticipated) exposures. Tests within the core set will not be requested if they are submitted with the PMN.

(5). Model Consent order Provisions. Your letter expressed your interest in meeting with OTS staff to comment further on the Agency's model consent order provisions. I do not believe this is an appropriate time for such a discussion.

It is my understanding that CMA provided EPA with its complete comments on the model consent order in response to EPA's formal solicitation of public comments in the Federal Register announcement of March 6, 1988. Based on all comments received, we have proceeded to complete the process of preparing final Significant New Use Rule (SNUR) language for the expedited SNUR procedural rule. This rule is now in Agency review.

I do, however, welcome the opportunity to fully brief you and member companies on both the final expedited SNUR rule and model 5(e) provisions once the rule and order language are in place. As always, CMA's comments (and those of all commenters) have been carefully considered in the rule and model language development processes. I am enclosing, as attachment D, an outline of the expedited SNUR rule. The rule is expected to be promulgated near the conclusion of this calendar year.

Finally, in your letter you also repeated the chemical industry's desire for flexibility in selecting control strategies in 5(e) orders. Consistent with that concern, EPA presently has a workgroup discussing potential "performance based" standards for 5(e) orders. In the future, these standards might allow PMN submitters the flexibility of selecting the appropriate control strategies based on performance standards set by EPA rather than being limited to specific control measures, as now required in 5(e) orders.

I hope I have answered your questions. If you have any further questions, please feel free to contact Wendy Cleland-Hamnett, Deputy Director, Chemical Control Division.

Charles L. Elkins
Office of Toxic Substances

cc: Wendy Cleland-Hamnett
William J. Royce 
OTS Division Directors


The 1988 Attachments have not been included with this text because they are not current. Current information which replaces these attachments is available:

A. Attachment A was the 1988 version of the Categories document, current version is available or through the TSCA Hotline on (202) 554-1404.

B. Attachment B was a schedule for the development of a typical 5(e) consent order and for a "fast track" or expedited order. The current estimates for development of a "fast track" or expedited section 5(e) consent order and for a non-expedited section 5(e) order are:

C. Attachment C was the then-current version of the Exposure-based Policy Criteria. Current policy and criteria are:

TSCA section 5(e) provides EPA with the authority to regulate new substances pending development of health and environmental effects data based on either the potential risk presented by the substance ("risk-based") or the potential for substantial production volume and substantial or significant human exposure or substantial environmental release ("exposure-based").

Action under section 5(e) for a new chemical substance is taken based under either or both of these authorities. Limited test data are submitted or otherwise available on new chemical substances and as a result EPA often relies on Structure Activity Relationship (SAR) predictions to evaluate potential effects associated with these substances. In 1988, EPA developed internal guidelines to assist in identifying new chemical substances received as PNms which would meet the "exposure-based" finding. Data obtained using the exposure-based finding can better characterize the tested chemical tested, confirm or refute a "negative" prediction of no risk or low risk, and supplement and validate the use of SAR in the review of PMNs. Expanded use of this finding was warranted for these reasons and because Congress intended that a greater priority for testing exist for high exposure chemicals. These "exposure-based" guidelines capture all PMN chemicals with estimated production volumes greater than or equal to 100,000 kilograms per year, and include specific exposure/release criteria shown below. The objectives of this approach were: to encourage fair and consistent decisions across numerous chemical categories and uses, to provide clear guidance to the public and industry about EPA's policy and expectations, and to implement the policy in the simplest, least resource-intensive way.

The Criteria are:

Exposure Parameter - TSCA 5(e) Exposure-Based Policy Criterion

1. Production Volume - 100,000 kg/yr or greater

2. Significant or Substantial Human Exposure: High Number of Workers Exposed - 1,000 workers or more exposed

3. Significant or Substantial Human Exposure: Acute Worker Exposure - 100 or more workers exposed to 10 mg/day or more

4. Significant or Substantial Human Exposure: Chronic Worker Exposure, Inhalation - 100 or more workers exposed to 1-10 mg/day for 100 days/yr or more

5. Significant or Substantial Human Exposure: Chronic Worker Exposure, Dermal - 250 or more workers exposed by routine dermal contact for 100 days/yr or more

6. Significant or Substantial Human Exposure: Consumer - Presence in consumer product where exposures are likely

7. Significant Human Exposure: Ambient General Population - 70 mg/yr exposure or more via drinking water, air, or groundwater

8. Substantial Human Exposure: Ambient General Population - 10,000 kg/yr or more release to environmental media

9. Substantial Environmental Release - 1000 kg/yr or more total release to surface water calculated after wastewater treatment

D. Attachment D was a draft for the expedited SNUR rule, now promulgated at 40 CFR section 721, subpart D.