Forthcoming requirements of Ihe Clean Air Act Amendments of 1990 will inventory many more specific chemicais considered hazardous. From acetaldehyde lo xylenes, the list regulated under the air toxics program includes 189 hazardous air pollutants (HAPs). That number may grow. The Environmental Protection Agency (EPA) intends to add another 100 of more chemicais under the “prevention of accidental releases” prograrn dealing with releases of extremely hazardous air p01- lutants (EHAPs). A preliminary list of EHAP chernicais is given in Table 1. Any company producing, using or handling more than threshold quantities of one of these substances wiIl be mandated to have an approved release prevention and control program.
While EPA has yet to establish threshold quantities, the fact that these limits will be based on toxicity, flammability and amount of the substances known to cause serious adverse effects to human health implies thaI the thresholds will be low. Remediation measures probably wilI be required for most producers and users of EHAPs.
In the past, local jurisdictions were left to decide whether certain chemicais were emitted in sufficient quantity to need treatment. New regulations, however, give EPA the final word. Relatively small sources — lO tons per \ear of any HAP wilI come under designation as “major sources,” while Iower eveis otemissions will be addressed as “area