151 



This test of reasonableness has been very difficult for EPA because of the com- 

 plexity and amount of evidence required to demonstrate that the benefits to human 

 health and the environment outweigh the economic and social costs of controlling 

 or banning the use of a chemical. According to EPA, the nature of scientific assess- 

 ment is such that it must make extrapolations to determine both human and envi- 

 ronmental risks, and uncertainties always exist. However, the introduction of doubt 

 means that EPA may fall short of TSCA's threshold of sufficient proof to substan- 

 tiate claims of unreasonable risk. Because of TSCA's legal standards, EPA has is- 

 sued regulations under TSCA to regulate only nine chemicals. 



EPA's 1989 regvilation to phase out almost all products containing asbestos illus- 

 trates the difficulty of demonstrating unreasonable risk. In that case, EPA had con- 

 siderable scientific evidence of serious health risks and spent several years develop- 

 ing the regulation. Nevertheless, the Fifth Circuit Court of Appeals decided in 1991 

 that the agency had issued the regulation on the basis of insufficient evidence. 



In contrast to TSCA, the Canadian Environmental protection Act separates the 

 process of deciding whether to control a chemical from the process of determining 

 what appropriate control action to take. The act authorizes the government to con- 

 trol chemicals that are toxic, which are defined as those entering the environment 

 in a quantity or concentration, or under a condition, having a harmful effect on the 

 environment or human health. Determining whether a chemical is toxic and should 

 be controlled is based on an assessment of the chemical's risks. Costs and benefits 

 are then considered as factors in deciding what control actions to take, rather than 

 in deciding whether chemical risks should be addressed. 



A similar two-step process could be established in TSCA. For example, EPA could 

 be required to determine whether a chemical presents a significant risk on the basis 

 of several factors, including the chemical's toxicity, production volume, releases to 

 the environment, and exposures. For those chemicals found to pose a significant 

 risk, EPA would determine the most cost-effective actions to take to adequately re- 

 duce the risks. The agency would have the flexibility to select actions — whether 

 under TSCA, other laws, or voluntary agreements — by considering their cost effec- 

 tiveness in reducing risks. In effect, costs and benefits would not be factors in decid- 

 ing whether to reduce risks; they would be considerations in selecting a course of 

 action to deal with the risks. 



Improve EPA's Review of New Chemicals 



TSCA does not require routine chemical testing, and industry performs only lim- 

 ited testing on new chemicals. Because sufficient test data are generally not avail- 

 able, EPA uses a method known as structure activity relationships analysis to pre- 

 dict new chemicals' health and environmental effects. This method, which relies on 

 test data from chemicals with similsir molecular structures, is highly accurate in 

 predicting some chemical characteristics but is often inaccurate for other important 

 characteristics. 



To provide better data, TSCA could require manufacturers to perform basic tests 

 for new chemicals and additional tests when production for the chemicals reach cer- 

 tain levels. This would increase the burden on both the manufacturers and on EPA, 

 which would have to review the test results and related information to determine 

 the chemicals' risks. These burdens could be reduced if TSCA were revised to allow 

 EPA to review chemicals before they enter the marketplace, rather than before they 

 are manufactured. Many chemicals at the premanufacture stage are never mar- 

 keted. 



Require Basic Testing of New Chemicals 



A 1993 study comparing EPA's predictions using structure activity relationships 

 analysis and actual test results for new chemicals in the European Union ^ showed 

 that EPA performed poorly in predicting some characteristics, such as physical 

 chemical properties. For example, EPA had only a 63-percent accuracy rate in pre- 

 dicting vapor pressure, an important factor in determining the amount of potential 



2 Formerly the European Community. 



