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Master Testing List - Executive Summary

Note: EPA no longer updates this information, but it may be useful as a reference or resource.


As stated in Section 2 of the Toxic Substances Control Act (TSCA), "It is the policy of the United States that adequate data should be developed with respect to the effect of chemical substances and mixtures on health and the environment and development of such data be the responsibility of those who manufacture and those who process such chemicals and mixtures."

Section 4 of TSCA gives EPA the authority to require chemical manufacturers and processors to test existing chemicals. Under Section 4, EPA can by rule require testing after finding that (1) a chemical may present an unreasonable risk of injury to human health or the environment, and/or the chemical is produced in substantial quantities that could result in significant or substantial human or environmental exposure, (2) the available data to evaluate the chemical are inadequate, and (3) testing is needed to develop the needed data. The Chemical Testing Program in EPA's Office of Pollution Prevention and Toxics (OPPT) also works with members of the U.S. chemical industry to develop needed data via TSCA Section 4 Enforceable Consent Agreements (ECAs) and Voluntary Testing Agreements (VTAs). ECAs and VTAs are usually less resource intensive than formal TSCA rule-making and allow EPA to consider agreed-upon pollution prevention and other types of product stewardship initiatives by the chemical industry as a possible substitute for or adjunct to certain types of needed testing.

OPPT has been using a "Master Testing List" (MTL) since 1990 to establish its TSCA Existing Chemical Testing Program agenda. The MTL presents a consolidated listing of OPPT's Existing Chemical Testing Program priorities as well as those brought forward to OPPT by other EPA Program Offices, other Federal agencies, the TSCA Interagency Testing Committee, and international organizations such as the Organization for Economic Cooperation and Development (OECD).

The main purposes of the MTL are to (1) identify chemical testing needs of the Federal Government (including EPA) and relevant international organizations (e.g., OECD), (2) focus limited EPA resources on the highest priority chemical testing needs, (3) publicize the testing priorities for industrial chemicals, (4) obtain broad public input on OPPT's TSCA Chemical Testing Program and its priorities, and (5) encourage voluntary initiatives by the U.S. chemical industry to fill the priority data needs that are identified on the MTL.

EPA believes that companies with product stewardship programs will recognize the importance of promptly filling the data needs identified via the MTL because they know a database that is inadequate to support risk assessment deprives people who are exposed to a chemical of their right to know about the hazards/risks that may be posed by that chemical substance. The identification of testing needs on the MTL provides an opportunity for responsible companies to initiate voluntary activities to develop the needed data for their own MTL-listed chemicals. In those instances in which companies decline to take this opportunity, EPA is put in a position of having to initiate formal, resource intensive, regulatory actions such as promulgating TSCA Section 4 Test Rules. Issuance of such rules can be viewed as "forcing" chemical companies to adhere to their own professed standards of product stewardship and corporate responsibility.

The MTL contains over 500 individual existing chemicals and more than 10 existing chemical categories and presents EPA's TSCA Chemical Testing Program priorities for 1996-1998. Testing actions are currently being developed on more than 200 chemicals listed on the MTL while testing is currently underway on almost 300 chemicals identified on the MTL. In addition, more than 100 chemicals are being removed from the MTL at this time, over 70 of those because their testing programs have been completed.

It is also important to note that the Chemical Testing Program and the MTL are integral components of OPPT's TSCA Existing and New Chemicals Programs. These programs are responsible for assessing and managing health and environmental risks that may be posed by existing and new chemicals covered by TSCA. The "universe" of existing chemicals on the TSCA Chemical Substances Inventory that may present the greatest potential health and/or environmental concerns have been and continue to be identified and refined through various existing chemical screening activities within OPPT.


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