OHS Canada Magazine

Comfort a key factor in revised respiratory-protection standards

March 16, 2019
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By Jean Lian

The latest edition of the CSA Standard Z94.4-18 Selection, Use and Care of Respirators, published last fall, saw the introduction of several significant changes. One of them is making user comfort a key factor when selecting respirators.

“While attention to comfort as a part of respirator selection is certainly not a new concept, this edition of the standard now introduces mandatory comfort assessment conditions and criteria,” says Stacey Blundell, senior health and safety application specialist with 3M’s personal safety division in Montreal. “If a worker is more comfortable while wearing a respirator, they are more likely to wear it,” she says, resulting in increased compliance.

The 2018 standard also clarified several aspects in the workplace respiratory-protection program relating to the following: the supervisor’s role in a respiratory-protection program; the process of using hazard and risk assessments as the basis for selecting respirators; requirements for initial and subsequent periodic training; the handling of respiratory-interference concerns like facial hair, dentures, eyeglasses and facial jewelry that can disrupt a proper seal on a respirator; and the timing of health assessments needed prior to fit testing. Scenarios for bioaerosol-exposure have also been expanded significantly, including several new annexes to provide guidance on measuring bioaerosols and determining exposure limits.

“We put a lot of emphasis on this biohazard aerosols, which was not well covered in the previous standard,” says Sylvain Lefebvre, respiratory product manager with DSI Safety Inc. in Laval, Quebec. Lefebvre sits on the CSA board that rewrote standards for the fifth edition of CAN/CSA-Z94.4: Selection, Use and Care of Respirators, which sets out requirements for administering an effective respiratory-protection program in the workplace. Some of the changes focused on fit testing.

“A lot of people are doing fit-testing, but the standard was not giving the right information to everybody to perform a fit-test properly,” Lefebvre says. A proper fit test is critical as that forms the basis for choosing a respirator that suits an individual’s unique facial structure and orientation of features.

“No one has the same shape of nose or cheek,” Lefebvre says. “We try to tweak that section to be more informative to people and make sure the person or fit-tester understands his role and what he is supposed to do to meet the CSA standard.”

There are two types of respirator fit tests accepted under CSA Z94.4: Qualitative fit tests are a pass/fail test method which rely on the subject’s ability to detect a challenge agent. Accepted methods make use of bitter or sweet aerosols, irritant smoke, or banana oil. If the respirator wearer detects an odour, irritation, or taste while they are wearing the respirator, the test has failed.

Quantitative fit tests use an instrument to assess the amount of leakage into the respirator and calculate a numeric fit factor. Both types of tests, which has to be conducted by a competent instructor, must be repeated periodically as required by the provincial or federal authority.

“As a best practice, it should be [done] annually,” Blundell says. Other conditions that would require a fit test include a change in the work environment or the type of respirator used, weight loss or gain on the user’s part and when the user experiences significant discomfort or inability to successfully complete a seal check.

It is not uncommon to see individuals skip their fit-testing appointments, or see supervisors refuse to let their employees attend fit-testing appointments because they are “too busy”, says Dr. Ken Jenkins, national medical director of Horizon Occupational Health Solutions in St. John’s, Newfoundland. “Respirators are like cars — they break down if they are not maintained well,” Dr. Jenkins says. “I can’t urge you enough to make sure that those who work for or with you maintain respirators appropriately and get fit testing done on a scheduled basis.”

If weight fluctuates or facial or dental alterations occur, a fit test should be done again to ensure the respirator remains effective, he adds. Otherwise, fit testing should be completed at least annually to ensure continued adequate fit. “Be your own health advocate, perform a user seal check to ensure that an adequate seal is achieved each time the respirator is put on.”

As it is important to strike a balance between comfort and protection, respirators today offer a wide degree of adjustability, features, styles and sizes. But if the workers are not trained on how to use them properly, “they won’t be able to take advantage of those additional features, many of which focus on comfort,” Blundell says.

For example, 3M’s reusable respirator lineup includes comfort features on both its half and full facepiece models. The 3M™ Rugged Comfort Quick Latch Half Facepiece Reusable Respirator is designed with a texturized silicone faceseal for a soft, but secure fit, as well as the 3M™ Cool FlowTM Exhalation Valve, which makes breathing easier.

In addition, the quick latch mechanism makes it easy to drop down the respirator from the user’s face without moving the headstraps, which is a popular feature for those who wear hard hats, faceshields or eyewear. For a full facepiece option, the 3M™ Ultimate FX Full Facepiece Reusable Respirator was designed with many comfort features, including a wide lens incorporated with ScotchgardTM Paint and Stain Protector, which provide excellent visibility, a silicone faceseal, 6-point strap harness with head cradle, Cool FlowTM Valve for easy breathing and lastly, a passive speaking diagram for improved communication.

Comfort is key, but so is choosing a respirator that fits a large number of people. Lefebvre advises that it is ideal to standardize respirators to the same brand, as using a repertoire of respirators by different manufacturers would give rise to the challenge of keeping an inventory comprising different types of cartridges and parts. The United States’ National Institute of Occupational Safety and Health (NIOSH) requires manufacturers to make cartridges that fit only their brand of respirators to prevent misuse.

“Imagine the poor buyer who has to carry three types of cartridges and inventory and a bunch of parts. It is very difficult for the safety officer to maintain the inventory level of the product to support the people wearing respirators,” Lefebvre says.

DSI Safety is launching a new line of NIOSH-approved disposable respirators, which it started developing last year. The line offers enhanced comfort through straps that can be adjusted to alleviate tension around the head and neck to meet the proper comfort zone. The disposable respirators come in various designs, including an original cup-style design and a flat-fold-panel design that is easy to carry and individually wrapped.

Some model comes with a layer of charcoal bed to absorb organic vapour, acid gas or ozone when used in welding applications. “Our clear cover valve is also pretty unique,” Lefebvre adds. “A user can inspect and make sure the butterfly valve is in good condition before use.”

DSI also offers the NIOSH-approved Deluxe P95 Disposable Respirators for use in environments that contain oil-based aerosols. The respirator’s adjustable straps and closed cell foam facepiece seal offer maximum fit and comfort, in addition to providing odour relief from of organic vapours, acid gases and ozone. The exhalation valve also directs exhaled breath downward and lessens the buildup of carbon dioxide.

Lefebvre says the company is finalizing the design of its half-mask cartridge, which will be sent to NIOSH for approval. “We hope to be ready to launch our half-mask cartridge and full face in September or October this year.”

3M also offers disposable respirators, one of which is the 3M™ Aura™ Particulate Respirator, 9211+. This three-panel disposable flatfold respirator featuring soft inner material that controls airflow to reduce eyewear fogging. The proprietary Cool Flow™ Valve reduces heat build-up inside the respirator to help keep the wearer cool, making it suited for hot or dusty work settings that require long periods of wear. Braided headbands keep the respirator securely in place and minimize the pulling of hair, while the curved, low-profile design conforms well to nose and eye contours, allowing more room for eyewear.

Lefebvre points out that air-purifying respirators and disposable masks remain a big part of the market. “A half-mask with cartridge and a disposable is less expensive than buying a powered air-purifying respirator at $1,000 apiece,” he says.

As with any personal protective equipment, some user attitudes die hard. Common misconceptions include not needing to wear a respirator when advised to do so, disliking the look or feel of a respirator and a one-size-fits-all assumption with respirators, Dr. Jenkins notes. “I still see patients in my occupational medicine practice who are suffering from entirely preventable work-related lung disease.”

Jean Lian is editor of OHS Canada.