The OSHA Respiratory Protection Standard lists seven key
elements that every respiratory protection program should contain. These include:

A written plan detailing how the program will be administered;

A complete assessment and knowledge of respiratory hazards that will be encountered in the work place;

Procedures and equipment to control respiratory hazards,  including the use of engineering controls and work practices designed to limit or reduce employee exposures to such hazards;

Guidelines for the proper selection of appropriate  respiratory protective equipment;

An employee training program covering hazard recognition, the dangers associated with respiratory hazards, proper care and use of respiratory protective equipment;

Inspection, maintenance and repair of respiratory protective equipment;

Medical surveillance of employees.

The responsibility for administration of these procedures should be assigned to one individual who may, and probably will, have assistance. The necessity for a central authority is to ensure consistent coordination and direction. The actual respiratory protection program will vary widely depending upon many factors and may require input from specialists such as safety personnel, industrial hygienists, health physicists and physicians. But program responsibility should reside with a single individual if the program is to achieve optimum results.

Finally, there should also be regular inspection and evaluation of the program itself to ensure its continued effectiveness.

Respiratory Hazards

Of the three normally recognized ways toxic materials can enter the body - (1) through the gastrointestinal tract, (2) skin and (3) lungs - the respiratory system presents the quickest and most direct avenue of entry. This is because of the respiratory system's direct relationship with the circulatory system and the constant need to oxygenate tissue cells to sustain life.

OXYGEN DEFICIENCY

Normal ambient air contains an oxygen concentration of 20.8 percent by volume.  When the oxygen level dips below 19.5 percent, the air is considered oxygen-deficient.  Oxygen concentrations below 16 percent are considered unsafe for human exposure because of harmful effects on bodily functions, mental processes and coordination.

PARTICULATE CONTAMINANTS

Particulate contaminants can be classified according to their physical and chemical characteristics and their physiological effect on the body.  The particle diameter in microns (1 micron = 1/25,400 inch) is of utmost importance.  Particulates below 10 microns in diameter have a greater chance to enter the respiratory system, and particles below 5 microns in diameter are more apt to reach the deep lung or alveolar spaces.

The various types of airborne particulate contaminants can be classified as follows:

Fumes - An aerosol created when solid material is vaporized at high temperatures and then cooled. As it cools, it condenses into extremely small particles - generally less than 1 micron in diameter.  Fumes can result from operations such as welding, cutting, smelting or casting molten metals.

GAS AND VAPOR CONTAMINANTS

Gas and vapor contaminants can be classified according to their chemical characteristics. True gaseous contaminants are similar to air in that they possess the same ability to diffuse freely within an area or container.  Nitrogen, chlorine, carbon monoxide, carbon dioxide and sulfur dioxide are examples.

In terms of chemical characteristics, gaseous contaminants may be classified as follows:

Inert Gases - These include such true gases as helium, argon, neon, etc.  Although they do not metabolize in the body, these gases represent a hazard because they can produce an oxygen deficiency by displacement of air.

In terms of chemical characteristics, vaporous contaminants may be classified as follows:

Organic Compounds - Contaminants in this category can exist as true gases or vapors produced from organic liquids. Gasoline, solvents and paint thinners are examples.