How chemical firms regulated by EPA respond when their products are designated as suspect toxic hazards (as distinguished from being formally regulated) was the subject of a pilot study to: (1) determine the types of public data and methodological approaches available to study the problem; and (2) assess and measure actual impact based on (1). Ten chemicals were selected for initial study, based on: (1) their presence on NIOSH and EPA or OSHA lists of potential carcinogenic substances; (2) availability of sufficient public data for analysis (3) reasonable diversity and representativeness. A total of 28 categories of production or use were studied for these ten chemicals. They were supplemented by eight uses for three additional chemicals in some of the analyses conducted. Economic case history studies and formal econometric statistical models were the investigation tools used. It was concluded that although important data gaps and limitations in economic methodology existed in this pilot study, sufficient public data were available for a number of high-profile chemicals to conduct a meaningful pilot assessment of the impact of suspect hazard designation on their production/use, and that for these chemicals suspect hazard designation frequently had a significant impact on production/consumption.