Safety Articles

Choosing the Right Respirator for the Job

Take a breath through your nose. When you take that breath, feel the air passing through hairs that filter and attempt to clean your air. Next, your air is warmed by blood vessels and is moisturized by your mucous membranes (as well as your sinuses) in order to adapt the air to the existing conditions in your lungs. In addition to customizing the air, your nose contains the olfactory organ, a dime-sized organ of additional tiny hairs, chemical receptors, and mucus, that allows you to smell. Tiny bundles of nerves take the information from this organ to the brain, while the air passes through the throat to the lower respiratory areas — all in a split second without you even thinking about it. Those small hairs at the front of your nose have a big job as they attempt to clean large air particles (not to mention that we often trim these hairs away). The hairs loose the battle entirely when you work in the dusty or vaporous conditions commonly found on coatings job sites. This is why you need to wear a mask — to help your nose do its job in providing you with clean, healthy air.

Who Is That Particulate-Masked Man?

Let’s talk about “Do’s and Don’ts” of the two most common types of respiratory protection: particulate masks and vapor masks.

A particulate mask is the half-face paper mask with elastic straps, often called a dust mask. When you use a dust mask, you inhale, pulling particles up against the mask material. Single-use dust masks are considered by OSHA to be air-purifying particulate respirators.

Here are some guidelines to consider when working with dust masks:

  1. Dust masks provide protection for only 10 times the permissible exposure limit (PEL).
  2. Dust masks should not be used for heavy amounts of dust-like particles.
  3. Dust masks also do not provide protection against exposure to gases, chemicals, or situations where you need oxygen provided.
  4. A medical-type mask is not a dust mask. Medical masks are designed to keep particulates (germs) IN the mask, not filter them from the outside of the mask.
  5. Use only NIOSH-approved masks, which are usually clearly marked on the front of the mask.
  6. Dust masks come in a variety of styles and models and with different levels of protection. The coding on the masks makes it easy to determine which mask you should use for your particular PEL — generally the higher the number the higher the filtration and the smaller the particles that it filters. The most common levels of protection for these masks are:
    • N95/R95/P95 — filter out 95% of particles
    • N99/R99/P99 — filter out 99% of particles
    • N100/R100/P100 — filter out 100% of particles
  7. Your mask should be fit-tested to make sure that you have a proper seal. You should not notice any odors or dust inside the mask. If you do, leave the area immediately and replace the mask. If you have not been previously fit-tested, ask your employer if there is an onsite Occupational Nurse or any trained personnel who are capable of completing a fit-testing for you.
  8. Beards are never a good idea, as they prevent a proper fit of any mask.
  9. Most particulate masks have a metal strip over the nose that you need to squeeze for a proper fit. Stan Studzka of California Poison Control System explained, “The proper fit should feel like a pair of sunglasses on your nose.” 10. Do not attempt to repair or clean a used mask. Replace the mask often if you are having trouble breathing. Always throw away your mask at the end of the work day.

A Rose By Any Name Would Smell As Sweet

Your sense of smell is even more advanced than your sense of taste. Olfactory cells are chemical receptors that are stimulated by a chemical process on the surface of the tiny hairs (cilia). Exactly how the molecular reaction creates a definition of literally hundreds of smells is still unclear. Gaseous substances are easier to smell than other odors. Hence any use of solvents, epoxies, enamels, and other coatings should probably call for a vapor mask to help prevent harmful gases and vapor from entering the lungs. A common vapor mask looks like a particulate mask with a small canister positioned horizontally underneath it. These type masks are also called respirators. Air purifying vapor respirators do not supply oxygen and thus should not be used in oxygen deficient areas. Air-supplying respirators are designed to provide a clean air source in an otherwise contaminated and unbreathable work space.

If your job calls for a vapor mask, here are some general rules for choosing the right one:

  1. All vapor masks need to be fit-tested. This is usually done by spraying a harmless, but easily identifiable, spray (commonly a banana scent) around the masked individual. If you can smell the odor through your mask, it has an improper fit.
  2. In addition, an Effective Protection Factor (EPF) test may also be done. An EPF is a test conducted in the workplace environment on a properly fitted (fit tested) mask that is worn intermittently. This test includes samples from both the time the individual spends with the mask on and samples from the time the individual spends with the mask off, while in the same working conditions. This test is more common when respirators are in use.
  3. A good vapor mask will have four to six straps on it to help keep an even fit of the mask to your head and to prevent “gapping” between the straps.
  4. Always check the MSDS of the material you are applying for the type of canister you should have in your vapor mask. There is no “universal” canister for all materials, except scuba gear.
  5. If you are using paint, enamels, or varnishes, it is a good idea to apply a thin layer of petroleum jelly to your face to help aid in cleanup after the job is complete for the day and to maintain the seal between your face and the mask itself. Do not get the petroleum jelly on the canister or the any fittings.
  6. Selection of the general type of respirator to use should be based on the type of contaminant present: the concentration of the contaminant, and the hazardous quality of the contaminant. Other factors to be considered include:
    • The comfort of the user in relation to heat, humidity, and other conditions is also a determinate in respirator selection, as well as compatibility with other heavy equipment and protective clothing.
    • The availability of replacement supplies, such as cartridges and repair parts.
    • Once the general type of respirator is determined, refer to the NIOSH guidelines for the correct make, model, and size for your job.
  7. Each canister or cartridge used on an air-purifying respirator should come with an End-of-Service-Life-Indicator (ESLI) certified by NIOSH for the contaminant in use on the job site. If no ESLI has been established, the canisters or cartridges should be changed according to manufacturer’s guidelines.
  8. A medical evaluation is required by OSHA’s Respiratory Protection Standard (29 CFR 1910.134) for employees who wear respirators. This evaluation usually consists of a licensed medical provider reviewing the employee-completed Respiratory Medical Evaluation Questionnaire.
  9. An EPF is a test conducted in the workplace environment on a properly fitted (fit tested) respirator that is worn intermittently. This test include samples from both the time the individual spends with the respirator on and samples from the time the individual spends with the respirator off, while in the same working conditions.
  10. A Workplace Protection Factor (WPF) test is conducted with a properly fitted respirator used under normal conditions in the actual workplace environment. No data is included from when the respirator isn’t being worn. The higher the protection, the higher the WPF rating.

Carbon Monoxide: The Silent Killer

Once you inhale particles, your body commonly expels the particles by coughing, sneezing, or swallowing the particles. Rick Clark, Medical Director of California Poison Control System, explains, “Small particles and vapors, however, get into the lungs and may get absorbed into the bloodstream.”

Some of the most dangerous vapors are odorless — carbon monoxide will not be filtered out by a non-approved carbon monoxide mask. Any equipment that runs on fossil fuel emits carbon monoxide. “Electrical generators are the cause of the most common inhalation accidents from worksites,” says Rick Clark, “For example, workers may go into an enclosed space or room for hours to clean or prep a floor with generator-powered equipment in the room with them. While the generator is running it is usually emitting carbon monoxide. Their vapor mask cartridges are rated for the chemicals and coatings that they are using, but may not filter the carbon monoxide produced by the generator. They end up in our emergency department with carbon monoxide poisoning.”

Be safe. Make sure that you and your crew are properly fitted — and properly using — respiratory protection. On a coatings job site, every breath you take could depend upon the right gear.

If you have any questions regarding a possible inhalation event, call the Poison Control Hotline at (800) 222-1222.

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