Establishing standards for human exposure to carcinogens at low concentrations raises mixed questions of science and law.Delegation of congressional authority to administrative agencies and exercise of that authority by them to protect the public health and welfare are subject to judicial review.The Supreme Court in 1980 overturned a decision to adopt a new standard set by OSHA that would reduce the allowable concentration of benzene in ambient air in the workplace from 10 ppm to 1 ppm.The relationships between law and science in the .benzene case. exemplify the multi-disciplinary issues that must be faced in increasing numbers under great scientific uncertainty.