While almost half of automotive service technicians work a standard 40-hour week, over 30 percent work more than 40 hours a week. Many of the latter are self-employed. Some shops offer evening and weekend service. Generally, these workers work indoors in well-ventilated and well-lit repair shops, although some are drafty and noisy. They frequently work with dirty and greasy parts and in awkward positions. They often lift heavy parts and tools. Minor cuts, burns and bruises are common, but serious accidents are usually avoided when the shop is clean and orderly and proper safety practices are observed.