Currently, workplaces in the United States function under the Hazard Communication Standard 1910.1200 as published in the Code of Federal Regulations on March 11, 1994 - also referred to as HCS 1994.
The first step in the process of developing a RPP is to conduct an industrial
hygiene audit of the workplace to assess the presence of any atmospheric contaminants.
Respiratory hazards can take the form of harmful dust, fogs, fumes, mists,
gases, smoke, sprays or vapors.