Validation attempts of a generic approach for regulating air toxics.

The validity of deriving ambient air quality standards or levels via threshold level values (TLVs) is assessed via two methodologies: (1) using current U.S. standards for ambient air standards and occupational standards where the data base is very robust and (2) using Soviet occupational and community air standards where the standards are based on experimentally derived toxicological endpoints. The analysis indicates that the TLV-derived approach using TLV/420 and the appropriate averaging time is in wide disagreement with both validating methodologies.