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April 14, 2011

EPA Announces Chemical Action Plans for MDI, TDI, and Related Diisocyanate Compounds

The ACTA Group

The U.S. Environmental Protection Agency (EPA) released on April 13, 2011, chemical action plans for methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and related compounds. According to EPA, Americans may be exposed to these chemicals when they are used in certain applications, such as spray foam insulation, sealing concrete, or finishing floors. EPA states that diisocyanates are used to make polyurethane polymers. Most polyurethane products, such as foam mattresses or bowling balls, are fully reacted or “cured,” and are not of concern. EPA notes that some products, however, such as adhesives, coatings, and spray foam, continue to react while in use, and may contain “uncured” diisocyanates to which people may be exposed. EPA states that there has been an increase in the consumer availability of or incidental bystander exposure to polyurethane products containing uncured diisocyanates. The chemical action plan for MDI and related compounds is available online, and the chemical action plan for TDI and related compounds is available online.

According to the action plan summaries, EPA is concerned about these chemicals because diisocyanates are well known dermal and inhalation sensitizers in the workplace and have been documented to cause asthma, lung damage, and in severe cases, fatal reactions. While worker exposures are already subject to protective controls in occupational settings, EPA states that it is concerned about potential health effects that may result from exposures to the consumer or self-employed worker while using products containing uncured MDI or TDI, and their related polyisocyanates or incidental exposures to the general population while such products are used in or around buildings, including homes or schools. Citing information in the 2006 Inventory Update Reporting (IUR) database, EPA states that these diisocyanates are used in consumer/commercial categories, including the following: adhesives and sealants, paints and coatings, transportation products, rubber and plastic products, wood and wood furniture (TDI), electrical and electronic products (TDI), and lubricants, greases, and fuel additives (MDI).

To address concerns associated with MDI, TDI, and related compounds, EPA intends to:

  • Based on statements by some in industry that uncured TDI is not used in consumer products, initiate rulemaking under Section 5(a)(2) of the Toxic Substances Control Act (TSCA) for a significant new use rule (SNUR) designating the use of uncured TDI and its related polyisocyanates in a consumer product as a new use requiring prior notice to EPA;
    • If, however, public comments on the proposed SNUR indicate ongoing uses of uncured TDI in consumer products, EPA intends to consider working with industry to develop a voluntary phase-out of such uses within one year, to be followed by a SNUR; and
    • If voluntary phase-out is not agreed upon, or is not completed as agreed upon, EPA intends to consider initiating rulemaking under TSCA Section 4 to require exposure monitoring studies on TDI and its related polyisocyanates in consumer products.
  • Issue rules under TSCA Section 8(c) to call in data on any past allegations of significant adverse effects due to MDI or TDI;
  • Obtain one-time reporting of unpublished health and safety data on MDI and TDI from industry through a TSCA Section 8(d) rulemaking;
  • Consider initiating a TSCA Section 4 test rule to require exposure monitoring studies on uncured MDI and its related polyisocyanates in consumer products, and exposure monitoring studies in representative locations where commercial products with uncured MDI, TDI, and related polyisocyanates would be used;
  • Consider initiating a TSCA Section 6 rule for: (a) consumer products containing uncured MDI; and (b) commercial uses of uncured MDI and TDI products in locations where the general population could be exposed; and
  • Consider identifying additional diisocyanates and their related polyisocyanates that may be present in an uncured form in consumer products that should be evaluated for regulatory and/or voluntary action.

EPA states that it “will continue to work with other federal agencies, the polyurethanes industry, and others to ensure improved labeling and provide comprehensive product safety information for polyurethane products containing uncured compounds, especially in consumer products.”


The action plan proposes a generally measured approach to the diisocyanates which is focused on consumer and potential bystander exposures. In preparing two separate action plans, EPA is careful to distinguish TDI from MDI and to focus particular attention on a sequence of possible actions to better understand and control consumer uses of the former, while taking a more general approach to MDI. The action plan is the first to suggest a call-in of “allegations” under TSCA Section 8(c), which is interesting in that EPA previously required such submissions on diisocyanates under Section 8(c) over 20 years ago and it is not clear that that step resulted in further EPA action at that time. Interestingly, the action plan does not tee MDI and TDI up for inclusion in the TSCA Section 5(b)(4) “Chemicals of Concern” list, a step which was identified in most of the earlier action plans.