A cleanroom is designed to control particulate debris—things like dust, lint, dandruff, hair, ash, and powder. The cleanroom is not necessarily sterile and often contains numerous chemical contaminants and hazards. In fact, much of the protection worn in a microfabrication cleanroom is for your safety against the hazards present in the environment—gloves, face shields, full skin coverage suits, and more provide you protection from exposure. One of the hardest habits for many to overcome is their desire to shake hands with others while in the cleanroom. This is simply not done, as it can transfer toxic chemicals from one person to another. There are no doorknobs for the same reason.