No. Using PPE is often essential, but it is generally the last line of defense, after engineering controls, work practices and administrative controls. Engineering controls involve physically changing a machine or work environment (e.g. use of a chemical hood or biosafety cabinet). Administrative controls involve changing how or when employees do their jobs, such as scheduling work and rotating employees to reduce exposures. Work practices involve training workers how to perform tasks in ways that reduce their exposure to workplace hazards.