In conventional machining, metal exposure from the cutting tool is insignificant. Stainless steel machining may expose the operator to chromium, nickel, and cobalt. Machining of beryllium alloys is hazardous. Besides the conventional method, other types of metal machining include electrochemical, electrical discharge, hard metal, laser, and waterjet cutting. [Burgess, p. 146] Ethanolamines are used in metalworking fluids to stabilize pH and prevent corrosion. Biocides are used to inhibit bacterial and fungal growth in metalworking fluid reservoirs. Nitrosamines have been found in metalworking fluids. Hypersensitivity pneumonitis (HP) may develop in workers exposed to microbially contaminated, water-based metalworking fluids. [Occupational Exposure to Metalworking Fluids. DHHS (NIOSH) Publication No. 98-102, 1998] See the agent "Oil mist, mineral."