Engineering controls in the context of Ventilation (architecture)

Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemical, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. Protective clothing is applied to traditional categories of clothing, and protective gear applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit.

The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering controls and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it does not eliminate the hazard at the source and may result in employees being exposed to the hazard if the equipment fails.

Administrative controls are modifications or changes to work practices or behaviors in order to reduce the severity of impact from hazards or hazardous operations. This category of control relies more on worker compliance (e.g., factory floor workers) and often does not offer permanent solutions to control hazards in workplaces.

In the hierarchy of hazard controls, administrative controls lies 4th below engineering controls and above personal protective equipment in terms of the effectiveness and efficiency of hazard controls ranking. They should be used after elimination, substitution and engineering controls have already been implemented / considered or as an extra layer of protection from hazards. Some agencies add isolation as a step to their hierarchy of controls, with that level also needing consideration prior to administrative controls. The reasoning for lower effectiveness is that success in reducing hazards relies on individuals following rules, procedures, and/or training, all of which are still susceptible to human error, while levels above it reduce the impact of human error.

A physical hazard is an agent, factor or circumstance that can cause harm with contact. They can be classified as type of occupational hazard or environmental hazard. Physical hazards include ergonomic hazards, radiation, heat and cold stress, vibration hazards, and noise hazards. Engineering controls are often used to mitigate physical hazards.

Physical hazards are a common source of injuries in many industries. They are perhaps unavoidable in certain industries, such as construction and mining, but over time people have developed safety methods and procedures to manage the risks of physical danger in the workplace. Employment of children may pose special problems.