The purpose of the research program and resulting manual have been to improve and update EPA's safety capability which involve underwater hazardous chemical cleanup responses. The manual includes the assessment, testing, evaluation, and demonstration of commercial underwater protective suits, clothing, support equipment, and breathing apparatus in water contaminated with hazardous substances that may be injurious to a diver's health. The manual also identifies specific types of 'in-water' hazards, their location and effects upon divers, their equipment and considerations for protection surface support personnel. The major participates and beneficiaries of the program sponsored by the EPA and NOAA are the U.S. Coast Guard, U.S. Army Corps of Engineers, Department of Energy, Association of Diving Contractors, and the many local underwater search and recovery units. The helmets which were successfully evaluated for chemical exclusion were the Draeger Helmet System, the Desco 'Pot' Diving Hat, Diving Systems International Superlite-17B Helmet, Morse Engineering MK-12 Navy Deep Water Helmet System, and Safety Sea Systems SS-20 Helmax Helmet. Seven different suit configurations were evaluated along with the above stated helmets. One diving dress was from Draeger with the remaining six supplied by Viking Diving Systems.