Cleanroom coveralls are low-shedding garments that protect workers from hazards and prevent particles on the worker's clothes from contaminating the environment. Coveralls are worn over personal clothing and provide continuous coverage from ankle to neck to cover the worker's front, back, arms, and legs. The continuous coverage prevents particles and aerosols from entering or exiting at the waist as compared to pants and shirt, so they're often used in settings with more stringent regulations. Cleanroom garments are assigned a cleanroom class to indicate which cleanrooms they can be used in. Lower classes (ISO 1) indicate a cleaner garment than higher classes (ISO 9).