Cleanroom protective clothing is made of low-shedding materials to limit contamination. They also limit contamination caused by worker's clothing, hair, and skin. Coveralls provide a continuous coverage from neck to ankle and also cover arms. Bouffants keep hair in place and veils cover the nose and mouth. They are often worn with hoods that cover the head and neck. Sleeves are worn over other clothing to provide supplemental protection when handling samples. Shoe and boot covers prevent contaminants from footwear from dirtying surfaces and protect footwear from incidental contact with substances.