PURPOSE
The purpose of this program is to set forth uniform policies and procedures concerning the use of respirators at Calvin College by its employees and students. The requirements for this program are detailed in the Occupational Safety and Health Administration (OSHA) Respiratory Protection Standard (29 CFR 1910.134).
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 workplace;
- 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 most effective means to control air contaminants is to have appropriate equipment design, efficient ventilation, and careful consideration of how specific materials are used. EHSO will determine if there are options other than respirators to protect the employee/student against air contaminants. The other options include:
- · eliminating the hazard
- · replacing the product with a less hazardous one
- · shifting the operation to a well-ventilated or enclosed area
- · installing a ventilation system
- · changing work practices to reduce exposure.
In the event that effective engineering and administrative methods may fail to control air contaminants or to provide an added level of protection, respirators may be used to ensure that employees are not exposed to hazardous levels of air contaminants.
The Environmental Health & Safety Officer (EHSO), or an identified representative, is responsible for administering the program. Supervisors will be responsible for enforcing the respirator program in the work areas. Employees are responsible for using, maintaining, and storing their respirators as instructed through the training and fit testing provided at EHSO.
Before initiating a respiratory protection program, it is important to first understand the types of respiratory hazards inherent to your industry. 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.
There are three basic classifications of respiratory hazards: oxygen-deficient air; particulate contaminants; and gas and vapor contaminants.
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.
It is important to note that life-supporting oxygen can be further displaced by other gases, such as carbon dioxide. When this occurs, the result is often an atmosphere that can be dangerous or fatal when inhaled. Oxygen deficiency also can be caused by rust, corrosion, fermentation or other forms of oxidation which consume oxygen. The impact of oxygen-deficiency can be gradual or sudden.
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.
In the healthy lungs, particles from 5 to 10 microns in diameter are generally removed by the respiratory system by a constant cleansing action that takes place in the upper respiratory tract. However, with excessive "dust" exposures or a diseased respiratory system, the efficiency of the cleansing action can be significantly reduced.
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.
- Dusts—An aerosol consisting of mechanically produced solid particles derived from the breaking up of larger particles. Dusts generally have a larger particle size when compared to fumes. Operations such as sanding, grinding, crushing, drilling, machining or sand blasting are the worst dust producers. Dust particles are often found in the harmful size range of 0.5 to 10 microns.
- Mists— An aerosol formed by liquids, which are atomized and/or condensed. Mists can be created by such operations as spraying, plating or boiling, and by mixing or cleaning jobs. Particles are usually found in the size range of 5 to 100 microns.
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.
Vapors are the gaseous state of substances that are liquids or solids at room temperature. They are formed when the solid or liquid evaporates. Gasoline, solvents and paint thinners are examples of liquids that evaporate easily, producing vapors.
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.
- Acidic Gases —Often highly toxic, acidic gases exist as acids or produce acids by reaction with water. Sulfur dioxide, hydrogen sulfide and hydrogen chloride are examples.
- Alkaline Gases —These gases exist as alkalis or produce alkalis by reaction with water. Ammonia and phosphine are two examples.
- 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.
- Organometallic Compounds —These are generally comprised of metals attached to organic groups. Tetraethyllead and organic phosphates are examples.
Proper assessment of the hazard is the first important step to protection. This requires a thorough knowledge of processes, equipment, raw materials, end-products and by-products that can create an exposure hazard.
To determine an atmosphere's oxygen content or concentration levels of particulate and/or gaseous contaminants, air samples must be taken with proper sampling instruments during all conditions of operation. The sampling device and the type and frequency of sampling (spot testing or continuous monitoring) will be dictated by the exposure and operating conditions. Breathing zone samples are recommended and sampling frequency should be sufficient to assess the average exposure under the variable operating and exposure conditions. Should contaminant concentrations exceed exposure limits recommended by the American Conference of Governmental Industrial Hygienists (ACGIH), OSHA or NIOSH, hazard control procedures must be implemented promptly.
Exposure monitoring plays a critical role in the respirator selection process. The results from such tests will help you determine whether respiratory protection is needed and, if it is, the type of respirator required. Generally, respirator selection is based on three factors:
- The results of your atmospheric monitoring or sampling program;
- The accepted ACGIH, OSHA or NIOSH exposure limits for the substance(s) present;
- And the maximum use concentration (of a substance) for which a respirator can be used.
Exposure limits include ACGIH Threshold Limit Values (TLVs), OSHA Permissible Exposure Limits (PELs), NIOSH Recommended Exposure Levels (RELs) and AIHA Workplace Environmental Exposure Levels (WEELs). These values are guides for exposure concentrations that healthy individuals can normally tolerate for eight hours a day, five days a week without harmful effects. Unless otherwise noted, exposure limits are eight-hour, time-weighted-average (TWA) concentrations.
In general, gas and vapor exposure limits are expressed in ppm by volume (parts of contaminant per million parts of air), while particulate concentrations are expressed as mg/m3 (milligrams of concentrations per cubic meter of air). For substances that can exist in more than one form (particulate or gaseous), concentrations are expressed in both values. It is important to note that exposure limits and other exposure standards are constantly changing as more data is gathered about specific chemicals and substances. As such, you must be certain that you are using the most recent data when determining allowable exposure levels for employees.
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