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600 Introduction to Occupational Safety and Health
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Enclosure of Hazards

When you cannot remove a hazard or replace it with a less hazardous alternative, the next best control is enclose the hazard. Enclosing a hazard is an effective method to prevent exposure to noise, dust, and excessive heat during normal production operations.

Machine guards enclose hazardous moving parts.

There may be potential exposure to workers during maintenance operations or if the enclosure system breaks down. For those situations, additional controls such as safe work practices or personal protective equipment (PPE) may be necessary to control exposure.

Some examples of enclosure designs are:

  • complete enclosure of moving parts of machinery with machine guards;
  • complete containment of toxic liquids or gases from the beginning to end of a process;
  • glove box operations to enclose work with dangerous microorganisms, radioisotopes, or toxic substances; or
  • complete containment of noise, heat, or pressure producing processes with materials designed for those purposes.

Knowledge Check Choose the best answer for the question.

3-5. What is the purpose of enclosing a hazard in the workplace?