The U.S. Environmental Protection Agency has announced steps allowing it to limit the use of toluene diisocyanate, a common chemical in commercial products which the agency said can cause asthma and lung damage.
The EPA's move would require manufacturers and importers to notify the agency at least 90 days prior to starting or resuming use of TDI at levels above 0.1 percent by weight. The EPA would then evaluate the use of the chemicals and potentially limit or prohibit the proposed activity.
The agency called toluene diisocyanates "well-known dermal and inhalation sensitizers in the workplace" that can cause death in severe cases. They are used in residual amounts in the production of polyurethanes and in consumer products such as adhesives, coatings, elastomers and sealants.
Many other products also contain toluene diisocyanates, but are considered non-toxic after they fully react with other compounds to form polyurethane polymers. Domestic demand for TDI was 425.2 million pounds as of 2008, according to the EPA proposal.
Diisocyanates are already subject to worker protection regulations in occupational settings, but EPA officials are concerned about exposure by consumers or self-employed workers using spray-applied coatings, as well as incidental exposure by the public in or around buildings where products containing TDI may be used.
The EPA has also issued an action plan for methylene diphenyl diisocyanate, a similar chemical used in different products but presenting comparable health concerns.