Clear Breaths, Clear Choice: Find Your Ideal Respirator

By: Ray Chishti, Contributor

One of the most challenging aspects of respiratory protection is respirator selection. There are myriad requirements that employers often misunderstand. Unfortunately, these misunderstandings can lead to overexposure and illness. Selecting the proper respirator for the job is essential to protecting
employees’ health.

Identify the Contaminants

Respiratory protection is only appropriate after you have determined and implemented feasible administrative or engineering controls. Respirators should be the last defense from harmful exposures to air contaminants. © Summit Art Creations – stock.adobe.com

Before employees can be protected, air contaminants have to be identified. Employers must determine whether the airborne contaminant is a:

• Particulate (dust, fume, vapor or mist);
• Chemical; or
• Biological agent (mold, spore, fungus, virus or bacteria).

Closely observe work practices to complete the picture of how employees are exposed. How do your operations generate these contaminants? Pin down the sources of exposure; the length of time workers are exposed; the amount of physical exertion and movement required during the job; and other factors that influence respirator selection.

Remember, as noted in both OSHA’s air contaminants and respiratory protection standards, respiratory protection is only appropriate after you have determined and implemented feasible administrative or engineering controls. Respirators should be the last defense from harmful exposures to air contaminants.

Review Exposure Limits

Once you know the identities of the contaminants to which employees are exposed, you can review information on exposure limits. Meeting OSHA’s permissible exposure limits (PELs) outlined in the air contaminants standard (29 CFR 1910.1000) is mandatory. However, there are other sources of exposure recommendations to consider, such as those developed by the National Institute for Occupational Safety and Health (NIOSH) and published in the NIOSH Pocket Guide To Chemical Hazards.

The American Conference of Governmental Industrial Hygienists (ACGIH®) publishes Threshold Limit Values (TLVs) for Chemical Substances and Physical Agents and Biological Exposure Indices (BEIs). ACGIH formulates a conclusion on what level of exposure the typical worker can experience without adverse health effects. TLVs and BEIs are guidelines to be used by professionals trained in the practice of industrial hygiene.

You must meet OSHA’s PELs. However, other exposure recommendations may be more stringent. You may decide to meet these stricter exposure recommendations as good practice.

If OSHA hasn’t set a PEL for a contaminant, you still have to meet the OSH Act’s Section 5(a)(1) (the “General Duty Clause”) requirements to provide a safe workplace. These other exposure recommendations, along with the OSHA PELs, can help guide you in meeting your General Duty Clause obligations.

Respirator selection involves matching a careful assessment of the hazards to the capabilities and limitations of the respirator. © littlewolf1989 – stock.adobe.com

Measure Employee Exposures

Don’t rely on a novice to measure employee exposure. OSHA’s air contaminants standard states, at 1910.1000(e), that “a competent industrial hygienist or other technically qualified person” must approve administrative or engineering controls, or protective equipment to meet exposure limit requirements.

Work with the person conducting your exposure monitoring to ensure you get the most reliable results and best recommendations. Exposure monitoring should be done to capture information on employees’ greatest exposures. Employee protection is most assured when control measures are implemented to address the highest anticipated levels of exposure.

Review APFs and MUCs

Employers must use the assigned protection factors (APFs) and maximum use concentrations (MUCs) to select respirators that meet or exceed the required level of employee protection.

OSHA states at 1910.134(b), “Assigned protection factor means the workplace level of respiratory protection that a respirator or class of respirators is expected to provide to employees when the employer implements a continuing, effective respiratory protection program.”

Use APFs to select the appropriate type of respirator based on the exposure limit of a contaminant and the contaminant level in the workplace. Select respirators by comparing the exposure level found in the workplace to the maximum concentration of the contaminant in which a particular type of respirator can be used (the MUC). You can determine the MUC by multiplying the respirator’s APF by the contaminant’s exposure limit. If the workplace level of the contaminant is expected to exceed the respirator’s MUC, you must choose a respirator with a higher APF.

For example, a full-facepiece air-purifying respirator has an APF equal to 50. The chemical dimethylformamide has a PEL of 10 parts per million (ppm) as an 8-hour, time-weighted average (TWA). Multiplying the APF by the PEL gives a MUC equal to 500ppm for this application. The workplace level of dimethylformamide is expected to reach 30ppm. In this example, the respirator is expected to offer enough protection—30ppm is less than the MUC of 500ppm.

Note NIOSH Approvals

OSHA requires employers to select NIOSH-certified respirators (see 1910.134(d)(1)(ii)). NIOSH evaluates and approves respirators per the requirements of 42 CFR part 84. The manufacturer of a NIOSH-certified respirator provides a copy of the NIOSH approval for the respirator. The NIOSH approval indicates those contaminants and airborne concentrations for which the respirator is approved. Only use a respirator approved for the contaminants and exposures in your workplace.

Suppose the calculated MUC exceeds the NIOSH-approval performance limits of a respirator’s cartridge or canister. In that case, the MUC must be recognized as the lower limit, based on the approved performance limits. For example, an employee will wear a full-facepiece air-purifying respirator with an APF equal to 50 while exposed to methyl ethyl ketone vapor. The PEL for methyl ethyl ketone is 200ppm as an 8-hour TWA. The MUC would calculate to 10,000. However, since NIOSH approved the respirator’s cartridge for a maximum of 1,000ppm of organic vapor, the MUC must be recognized as the lower 1,000ppm.

Examples of OSHA’s Assigned Protection Factors (APFs)

Type of Respirator APF

Filtering facepiece 10

Half-mask air-purifying respirator with elastomeric facepiece 10

Full-facepiece air-purifying respirator with elastomeric facepiece 50

Powered air-purifying respirator with tight-fitting half-mask facepiece 50

Powered air-purifying respirator with tight-fitting full-facepiece 1,000

Powered air-purifying respirator with a loose-fitting facepiece 25

Beware of Improper Respirator Replacement Parts

OSHA requires respirators approved by NIOSH. Are all of the parts of the respirators in use at your company NIOSH-approved? If not, you could be at risk for OSHA citations.

NIOSH issues certificates of approval for specific and complete respirator assemblies. The approval is granted after the respirator has been evaluated and found to comply with all of the requirements of the NIOSH regulations in Title 42, Code of Federal Regulations, Part 84. The requirements include a viable quality assurance program that controls the important aspects of the components and their assemblies in a configuration to ensure that produced units continue to meet the requirements.

NIOSH is aware of a dangerous practice where respirator users are swapping the original hose provided to supplied-air respirators with different-sized hoses. The danger of using non-original equipment manufacturer hoses that are sized differently is that they can result in too little breathing air being delivered to the facepiece or too much air being delivered. In addition, because these hoses haven’t been subjected to the rigors of the OEM’s NIOSH-approved quality assurance program, they may have other performance features that aren’t compatible with the respirator’s proper performance.

Although respirators are comprised of various component parts, they’re approved as a single unit. Replacing NIOSH-approved respirator parts, components and accessories with non-NIOSH approved parts manufactured by another company voids the NIOSH approval. The performance level required and demonstrated to obtain the NIOSH approval label can no longer be expected. Therefore, the modified configuration puts the user at risk. Using a modified configuration may also void the manufacturer’s product warranty.

Conclusion

When OSHA finalized the respiratory protection standard in 1998, the Agency’s best estimates were that the rule would avert over 4,000 work-related injuries and illnesses and over 900 deaths each year. This goal can be achieved when respirator selection involves matching a careful assessment of the hazards to the capabilities and limitations of the respirator. IHW

About the Author:

Ray Chishti is a dedicated EHS Editor at J. J. Keller & Associates, Inc. Prior to joining the team in 2017, Ray held prominent roles in EH&S, executing audits, steering management strategies and spearheading executive leadership endeavors, all while overseeing multimillion-dollar projects. Ray’s extensive expertise spans over 20 years and diverse sectors, including fossil fuel power plants, utilities, retail establishments, warehousing and college campus construction.

Holding a Juris Doctor with a concentration in Occupational Safety and Health, Ray is also an authorized OSHA trainer for both general industry and construction. He also holds first aid, AED and CPR certifications, signifying a steadfast commitment to a comprehensive safety landscape.