Protective clothing is worn over personal clothes to protect workers from environmental hazards. Aluminized clothing reflects heat when working near fire or in forges. Arc flash and flame-resistant clothing protects workers from flames or electrical hazards. Chemical protective clothing includes encapsulated suits, coveralls, and sleeves to keep workers clean and protected from harsh chemicals found in chemical manufacturing and sanitation work. Cleanroom clothing is low-shedding and worn over a worker's clothing to keep areas clean. Hairnets, bouffants and beard nets prevent hair from falling into food, pharmaceuticals, and other substances to ensure a clean and hygienic work area. High-visibility vests are made of bright colors and reflective materials to make workers more visible. Liquid and particulate clothing protects workers from hazardous and non-hazardous powders, aerosols, and liquid splash and spray. Welding clothing protects against heat and sparks.