October 23, 2003
Welders are among the millions of workers who face respiratory hazards every day in the workplace. Confined spaces, solvents, and gas emissions, as well as welding, grinding, and soldering, may expose workers to airborne hazards.
Often invisible to the human eyes, airborne contaminants can have serious consequences for your health. Be familiar with the potential hazards and the effects they can have on your respiratory system.
The Occupational Safety and Health Administration (OSHA) standard 1910.134 (c) (k) details the requirements for an effective respiratory training program and workplace safety plan.
Effective safety training can help to eliminate incidents and accidents associated with airborne hazards in the workplace. The effort spent on proper safety training can pay for itself if it helps to reduce costly accidents.
Following a respiratory safety plan not only can help you comply with OSHA standards, but it also can increase your company's productivity and morale and decrease costs of incidents and injuries.
But not all respiratory safety programs are created equal. An effective, high-quality respiratory safety program should include basic information about airborne hazards, the potential for respiratory hazards in the workplace, and the use of respiratory personal protective equipment (PPE), usually a respirator.
Most airborne hazards aren't always visible to the eye. Common respiratory hazards can be broken down into three categories:
Oxygen Deficiency. You can survive weeks without food and days without water but only minutes without oxygen and other vital gases that comprise our atmosphere. Because your body's need to take in oxygen is immediate, constant, and essential, respiratory safety often can be a matter of life or death.
Normal air contains approximately 78 percent nitrogen, 20.9 percent oxygen, and 1.1 percent other gases. When the oxygen content in air drops below 19.5 percent, the atmosphere is considered to be oxygen-deficient and can affect your mental and physical capabilities negatively.
An oxygen-deficient environment is considered an immediate threat to life. Such an environment typically occurs in confined spaces, such as manholes, sewers, ship holds, silos, and storage tanks.
One of the greatest dangers of an oxygen-deficient atmosphere is that you aren't aware of it immediately. This is why you always should use monitoring devices to measure the oxygen level in an unknown environment.
In a matter of minutes your judgment and muscular coordination are affected by the lack of oxygen, including your sense of balance and direction, mental awareness, hearing, and touch. Long-term exposure to an oxygen-deficient atmosphere will lead to unconsciousness and eventually death.
Gas and Vapors. Gases are substances that become airborne at room temperature and often are invisible. Vapors act like gases, except that they're formed when a liquid, such as a solvent, evaporates. Common hazardous gases found in the workplace include chlorine, hydrogen sulfide, and carbon monoxide.
Substances that enter the lungs are absorbed into the bloodstream quickly. Once in your bloodstream, gases and vapors can cause blood disorders, heart disease, forms of cancer, birth defects, and damage to internal organs—all of which can result in disability or death.
Particulate Matter. Particulate contaminants typically include dust, mist, fog, fumes, and smoke. Dust comprises solid particles that can range greatly in size, from particles that can be seen with the naked eye to those that are invisible under normal conditions. Some common operations that produce dust include grinding, mixing, sanding, and cleaning operations such as blowing and sweeping—all common activities associated with welding.
Mist is made up of tiny droplets of moisture formed when you spray or mix liquids. Some common mist-producing operations are dipping, machining, and spray-painting.
Fumes are tiny metallic or metal oxide particles given off when metals are heated, such as in casting, galvanizing, soldering, and welding. Smoke consists of gases, vapors, particles, and liquid aerosols generated by burning or chemical reaction and often is concentrated enough to obscure vision.
Larger particulate matter passes through the respiratory system, and although it isn't absorbed into the bloodstream, it can embed itself in the lungs. There it can form scar tissues, which can make breathing more difficult and lead to respiratory illnesses.
The first line of defense for respiratory safety is engineering controls. These include screens, machine guards, vents, and filters. Also important in many respiratory protection programs are air quality monitors that can detect the presence of hazardous gases and also warn of oxygen deficiency.
Welders face unique respiratory hazards and safety issues. Many welders, for example, are tempted to stand directly over their work, placing their face as close as possible to the materials being worked on. This places the worker directly in the path of fumes, dust, smoke, and other airborne hazards emitted from the welding activity. Welders should stand at an angle from their work, allowing fumes and emissions to dissipate away from their face.
However, no system is foolproof. Therefore, individual respiratory protection often is required to ensure your safety. A primary part of any respiratory protection plan is respirator use. You should use a respirator for protection only when engineering controls are too impractical to use or during the interim period when engineering controls are being installed.
Respirators are divided into two basic categories:
Air-purifying respirators clean contaminated air by removing hazards when air passes through an air-purifying element.
Air-supplying respirators supply breathable air from a source that is different than the contaminated air.
Basic respirator configurations include tight-fitting respirator pieces, such as half-masks and full facepieces, as well as loose-fitting respirator pieces, such as hoods and helmets. The type of respirator used is determined by the specific hazards you may encounter, as well as your task. Beyond using the proper respirator for the task at hand, establishing a proper fit for the respirator also is essential for worker safety.
Fit testing helps you find the style and size of respirator that provides the proper seal and is comfortable to wear. Two types of fit testing are qualitative and quantitative.
During a qualitative fit test, you are exposed to a test agent, such as an odorous chemical or an irritant smoke. If you smell the odor or your nose or throat becomes irritated, that particular respirator fails the test.
During a quantitative fit test, the respirator is fitted with a special probe. A tube connects it to an instrument that measures the air outside the facepiece versus inside. If leakage exceeds specifications, the respirator fails the test.
During both the quantitative and the qualitative fit tests, you should perform a number of exercises, including talking, to simulate all possible situations that you may encounter on the job. A correct fit is essential to prevent airborne hazards from entering your respiratory system.
Facial hair, such as beards, sideburns, and even one day's growth of razor stubble for a heavy-bearded man, can prevent a proper fit. Facial scars, glasses, goggles, and hats also can interfere with an effective seal.
Most important, you always should perform a fit check before wearing a respirator on the job to check for a proper seal. Without a proper seal, a respirator won't function correctly, exposing you to airborne hazards. Check with your supervisor for details on how to conduct a proper fit check for the specific respirators used at your facility.
OSHA requires your employer to develop and implement a written respiratory protection program with required worksite-specific procedures and elements for required respirator use. A suitably trained program administrator must manage the program.
Developing a written respirator program entails significant planning before it can be used. Such preparation includes respiratory protection selection, medical fitness, maintenance, training, fit testing, use, and ongoing program evaluation.
The first step toward a successful respiratory protection program is understanding and respecting potential workplace hazards. By understanding and respecting potential airborne hazards and following safe work practices, you can take control of your own health and safety.
Occupational Safety and Health Administration, 200 Constitution Ave. N.W., Washington, DC 20210, 800-321-6742, www.osha.gov.