Respirator Clearance

Respirator hazards and where to find them

Nowadays, the use of respirators and its regulation is widespread in industry in the USA. Although wearing respirators has been a common practice for several hundreds of years, their performance is still based on two main principles: purifying the air before it reaches the breathing space, or providing clean air from an uncontaminated source.

In general, the purpose of a respirator is to avoid, to the extent possible, the exposure of a person to harmful airborne contaminants or to an atmosphere with a deficiency of oxygen. This is achieved by covering the nose and mouth of the user, or the entire face or head of the person in some cases.

The most common use of respirators in industry, especially in manufacturing, maintenance and construction companies, is to avoid airborne contaminants, also named respiratory hazards. However, it is important to mention that not every respirator is adequate for all types of respiratory hazards, and that each of them has a specific purpose or usage scope. This is why you should be aware of the possible contaminants you will be exposed to before actually working. In fact, all employees have to be medically evaluated through a respirator clearance test.

If you want to learn more about respirator medical evaluations and why they are important for your health and safety, please check out our article on respirator clearance tests.

Now, respiratory hazards may be present in many forms in the workplace. Some of them can make you sick or even kill you if inhaled. However, the time necessary for them to harm you varies across respiratory hazards. Some substances like asbestos can cause lung cancer even several years or decades after you breathe it in. But some like carbon monoxide can make you unconscious or kill you in minutes.

Respiratory Hazards Categories

According to the Occupational Safety and Health Administration (OSHA), respirator clearance tests have to consider the presence of the next basic categories of respiratory hazards:

a) Dusts, which are particles formed by reducing the size of solid materials through processes like grinding, drilling, crushing, abrading or blasting. Examples are wood particles and dry substances like cement or alimentary powders.

b) Fumes are particles formed when volatilized solids condense in cool air, which process is commonly accompanied by a chemical reaction. Examples are fumes produced while smelting, welding, cutting or burning metals.

c) Gases are fluid substances that can change to liquid or solid state only by combining a decrease in temperature and an increase of pressure. Examples are welding gases such as helium, nitrogen, acetylene, and other gases like carbon monoxide or hydrogen sulfide.

d) Mists are finely divided liquids suspended in the air. Mists can be generated by condensation of gases to the liquid state or by dispersing a liquid into the air by atomizing, foaming or splashing it. Examples are oil mist produced during cutting and grinding operations, acid mists produced during electroplating, paint mists formed during spraying operations, and the condensation of water vapor.

e) Oxygen deficiency is the lack of oxygen in the environment or its presence in the air in concentrations below 19.5%. Oxygen deficiency might be found in confined spaces that can include storage tanks, bins, tunnels, pits, process vessels and other semi-closed environments.

f) Smokes are carbon or soot particles formed by the incomplete combustion of carbon-based fuels like wood, coal, oil, fossil-fuels, and natural gas.

g) Vapors are gases, formed by evaporating substances that are normally found in solid or liquid state at room temperature and at atmospheric pressure. Some examples are solvent vapors from spay coatings, adhesives, and cleaning solvents.

Final thought

Remember that selecting a respirator is your employer’s responsibility and it must be selected based on the respiratory hazards you will be exposed to at work. OSHA requires companies to be compliant with a series of regulations and standards, such as the respirator medical clearance, in order to assure employee’s safety and health. Therefore, knowing the types of respirators hazards that might be present in your workplace is vital for you to perform your job correctly.