- 05 January 2007 -
EPA Eyes Controversial Method for Testing HCN

The EPA's proposal to require industry to use a complicated detection model that has produced uncertain results to test a common Superfund and air pollutant is forcing industry to launch a new effort to organize producers of the chemical to conduct extensive tests.

EPA granted Dec. 18 the industry officials' request for an extension to comment on a proposal that could require industry to conduct extensive testing on hydrogen cyanide (HCN) under section 4(a) of the Toxic Substances Control Act. (HCN is found in soil and water as a result of discharges from metal mining, electroplating, iron and steel manufacturing, and wastewater treatment facilities, according to the Agency for Toxic Substances & Disease Registry.)

The proposal is seeking comment on model agreements that would call on industry to conduct tests on the pollutant using emerging toxicology tools known as physiologically based pharmacokinetic (PBPK) models.

Industry officials say that no single trade association exists for producers of HCN—which is regulated as a hazardous air pollutant under section 112 of the Clean Air Act—and that time is needed to organize the producers in order to comment on the EPA proposal.

PBPK models allow scientists to analyze toxicological data, producing highly specific extrapolations by using extensive data sets that can be difficult to obtain. But the models have come under criticism lately when testing another common Superfund contaminant, trichlorethylene (TCE), because the PBPK models create a great deal of uncertainty.

Relevant documents are available on InsideEPA.com.

Source: Risk Policy Report