Regulations were promulgated by OSHA to protect healthcare workers from AIDS, and Hepatitis B. Most groups adopted the regulations the minute they were released. Some groups disputed the adoption of the regulations. The precautions against infections for workers by the two viruses were very similar except that there was a vaccine for HBV and dirty laundry could spread HBV. There is no vaccine for HIV, and dirty laundry cannot spread that virus. The regulations prescribed various precautions to be taken and required employers to make available vaccination for HBV at employer expense. Under the statute, OSHA was not authorized to compare the benefits with the costs and impose the restrictions on finding that the former exceeded the latter. OSHA was directed to determine if the regulations would materially reduce a significant workplace risk to human health without imperiling the existence of or threatening massive dislocation to the healthcare industry. OSHA relied upon the expertise of the Centers for Disease Control to determine that its rules would save almost 200 lives per year with respect to deaths from HBV. The agency did not focus on HIV because of the minute number of healthcare workers who had been infected by that virus. OSHA estimated the total cost of compliance to be $813 million per year. Petitioners (P) attacked the regulations in that OSHA ignored time costs associated with daily compliance of the regulations, they treated all parts of the profession the same even though parties like surgeons were the ones most exposed to blood pathogens, they exaggerated the number of lives to be saved by the rules by the lives likely to sacrificed because of the increased cost of medical care and that the likely net contribution to the safety of health care workers would be trivial.