The presence of chemicals, oils (e.g. diesel) or solvents in the water or in the air may shorten the life of the materiel. If the equipment is operated in a chemically contaminated environment, clean it thoroughly as instructed in chapter 7, Preventive maintenance. Equipment that may have been affected by chemicals should be examined separately for abnormal impacts such as burns or other changes to the surfaces. If there are signs of chemical attack, the equipment must be submitted to qualified maintenance staff for inspection and possible action.