MMT is blended with motor gasoline to boost octane. The EPA said standards for health effects testing, required under the Clean Air Act for fuels and fuel additives were finalised in 1994 establishing three testing tiers. The regulation permits the agency to modify the Tier 2 requirements which address health and welfare effects.
The EPA said because of continuing uncertainties regarding the public health effects of MMT and the potential of widespread public exposure to its emission products, it is proposing a testing program under the Alternative Tier 2 provisions to address specific research needs that will allow the agency to perform a more definitive risk evaluation.
Comments on proposed health effects testing requirements will be accepted until March 30, l999.