Pigments containing lead, cadmium, and chromium are hazards for spray painters. Spray painters who use isocyanates in polyurethane coatings or aliphatic amines in epoxy paint systems have a high risk for occupational asthma. Biocides are commonly added to paints. [Burgess, p. 247-75] The ingredients in paints can be classified into pigments, solvents, and vehicles. Vehicles are the binders that hold the paint together and include the following types: epoxy, alkyd, urethane, vinyl, and phenolic. In the shipyard industry, copper is common in anti-fouling paints and zinc is used in "preconstruction primers." [ILO Encyclo: Ship and Boat Construction and Repair] Powdered paints, used increasingly in the transportation equipment industry, contain epoxy formulations. Manual spray painting is still necessary in the production of commercial trucks, buses, construction equipment, and farm machinery. Lead and chromate-based paints are still used in this segment of the transportation equipment industry. [ILO Encyclo, 3:91.1-91.8] In the aerospace industry, zinc chromate is used in primer paints. [ILO Encyclo, 3:90.1-90.13] See "Painting (Solvents)."