Respiratory Protection
The purpose of a respirator is to prevent the inhalation of harmful airborne substances and/or an oxygen-deficient atmosphere.
The Weird History of the Respirator
A respirator is designed as an enclosure that covers the nose and mouth or the entire face or head.
Respirators are available in many types, models, and sizes from several manufacturers for a variety of applications. Different types of respirators are designed to provide different levels of protection and to protect against different hazards.
The type of respirator to be used depends on several considerations:
- professional judgment,
- the type of airborne contaminant, its concentration, and potential to cause a health effect in exposed personnel, and
- applicable regulations.
When information regarding the exposure is limited, the decision should rely more heavily on professional judgment and more protective respirators may be selected for use.
Each facility's written policies and training programs should specify whom to contact for questions or additional information.
Examples of Respiratory Hazards
Particulates
These are airborne particles such as dust, fibers, fumes, mists, soot, and smoke. Some are so small they can only be seen with an electron microscope. The diameter of a particulate is usually measured in micrometers (one micrometer equals 1/1,000 millimeter or 1/25,400 inch). Particles with diameters under 10 micrometers are more likely to enter the respiratory system.
Gas and Vapors
Gases can spread freely in the air. Vapors are the gaseous states of substances that are liquids or solids at room temperature. Gases and vapors are classified by their chemical forms.
Biological Organisms
These include bacteria, viruses, fungi, and other living organisms that can cause respiratory infections.
Oxygen-deficient Atmosphere
Normal air has an oxygen concentration of 20.8 percent by volume. When the concentration drops below 19.5 percent, the air is oxygen deficient and considered immediately dangerous to life and health (IDLH). The harmful effects of oxygen deficiency include impaired thinking and coordination, unconsciousness, and death.
Knowledge Check Choose the best answer for the question.
2-1. At what concentration of oxygen is air considered oxygen deficient?
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