December 7, 2020 By danny.carvalho@ymail.com Off

COVID-19 medical masks and respirators: Information for health professionals

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N95 respirators for medical use

N95 respirators for medical use (or particulate filtering face-piece respirators):

  • are Class I medical devices
  • are manufactured, imported and distributed by companies that hold a Medical Device Establishment Licence (MDEL) or
  • are authorized by Health Canada under the Interim Orders for COVID-19 medical devices

N95 respirators:

  • achieve a minimum filtration efficiency of 95% when worn properly
    • the edges of the mask form a seal around the nose and mouth
  • are designed to reduce the risk of inhaling hazardous airborne particles and aerosols
  • are produced in many different styles, such as:
    • flatfold
    • duckbill
    • cup-style
  • may or may not have an exhalation valve
  • provide 95% protection around the nose and mouth against exposure to respiratory viruses and bacteria (non-oil based particles) in a health care setting when fit appropriately to the user’s face

image of cup-style N95 respirator

The U.S. National Institute for Occupational Safety and Health (NIOSH) evaluates, tests, and certifies N95 respirators. Certified respirators must:

  • pass minimum performance requirements, such as:
    • fit testing
    • filter efficiency
    • breathing resistance
  • have an approval number stamped on the mask, represented as TC-84A-####n.

Health Canada, the regulator for medical devices in Canada, accepts the NIOSH certification as an appropriate quality standard for N95 respirators. For a depiction of the NIOSH symbol, refer to the NIOSH website. Equivalent respirators approved under standards used in other countries are also acceptable such as medical KN95 respirators and FFP2 respirators, if the manufacturer can provide the evidence demonstrating testing to the appropriate standards.

The N95 respirator is the U.S./NIOSH standard for respirators and KN95 is the Chinese standard. Commercial-grade (non-medical) and medical-grade N95 and KN95 respirators are similar with respect to design, filtration, performance and material standards. In Canada, it is the labelling, indications for use and claims that contribute to the classification of a product as a medical device.

There is also a subset of medical N95 respirators labelled as surgical respirators. These devices are sold sterile and are tested for fluid resistance (penetration by synthetic blood) under ASTM F1862. Because COVID-19 may be transmitted by respiratory droplets, the use of surgical N95 respirators in most instances is not considered essential.

Medical masks (surgical and procedural masks)

Medical masks are worn by operating room personnel during surgical procedures (see image). They protect both the patient and operating room staff from the transfer of:

  • bodily fluids
  • micro-organisms
  • particulate material

There are 3 classifications under ASTM International standards:

  • Level 1 (low) – venous pressure splash
  • Level 2 (moderate) – arterial pressure splash
  • Level 3 (high) – high-velocity procedures, orthopedic surgery

image of medical mask

Unlike N95 respirators, medical masks are looser in fit. As a result, they do not provide the same level of filtration.

Strategies to address shortages

Due to critical shortages during the COVID-19 response, we are implementing and/or proposing a range of strategies to respond to the increased demand for medical masks and respirators.

Use of N95 and equivalent respirators beyond their shelf life

Most respirators have a limited shelf life, after which they should normally be thrown out. The length of time a respirator is stored beyond its shelf life or recommended conditions of storage may affect its performance. This includes the filter media, the headbands and the nose foam components, which may affect the seal that is created.

N95 and equivalent respirators that are past their designated shelf life are no longer NIOSH-certified, as they must meet all manufacturer-designated conditions of use to maintain the NIOSH approval. However, in times of increased demand and decreased supply, health care providers may consider using expired respirators. An expired respirator can still be effective at protecting health care providers if:

  • it can be fit-tested
  • the straps are intact
  • there are no visible signs of damage

Health care providers should inspect the respirator and perform a seal check.

It is unknown how long after the expiry date the respirator would be considered suitable for use.

Use of medical masks beyond their shelf life

Medical masks can be used beyond their shelf life to protect health care providers. Health care providers should check that the straps are intact and there are no visible signs of damage.

It is unknown how long after the expiry date the mask would be considered suitable for use.

Use of non-medical (commercial-grade) N95 and equivalent respirators

During the COVID-19 outbreak when medical-grade N95 or equivalent respirators aren’t available, health care institutions may, at their discretion, purchase and use:

  • commercial-grade N95 (or P95 and similar) respirators
  • equivalents such as commercial-grade KN95 (or KP95) respirators
  • other alternative, equivalent commercial-grade filtering facepiece respirators that are at least as protective as the commercial-grade N95, such as the N99, N100, P95, P99, P100, R95, R99, and R100 respirators.
    • P100 respirators are filtering, oil-resistant industrial respirators. These are similar to the N95 respirators, but their filter performance of airborne particles is greater than 95% (99.97%).
    • N100 respirators have the same filtration performance as the P100 but are not oil resistant (similar to the N95).
    • R respirators protect against oils but have a limited lifespan of about 8 hours.

Respirators with exhaust valves

Some commercially available respirators have exhaust valves which are intended to make the respirator more comfortable for the person wearing it, but also allow infectious respiratory droplets to be released outside the respirator.

Use of respirators with exhaust valves will not protect others from COVID-19. Please do not use respirators with exhalation valves to prevent the spread COVID-19.

Use of respirators approved under standards used in other countries

To expand the availability of medical and non-medical N95 respirators during the pandemic, equivalent alternate standards may also be acceptable. This includes respirators that are approved or certified under standards used in other countries that are similar to NIOSH-approved N95 respirators. Note that different countries may regulate medical and commercial respirators differently than in North America.

For example, this includes both medical and commercial (non-medical) KN95 or medical FFP2 respirators (including those with head straps or ear loops) that meet standards:

  • EN 149-2001 (Medical FFP2)
  • GB 2626-2006* (Commercial KN95) *(standard to be replaced with GB2626-2019 on July 1, 2020)
  • GB 19083-2010 (Medical KN95)

Important information about KN95 medical respirators

In relation to respirators, the United States Food and Drug Administration (FDA) issued a revised guidance on May 7, 2020, indicating that certain filtering face-piece respirators from China may not provide adequate respiratory protection. The FDA will still consider KN95 respirators medical devices equivalent to N95s (as the FDA and U.S. Centers for Disease Control and Prevention (CDC) consider GB2626-2006 to be equivalent to NIOSH N95) but authorization for KN95 respirators will require additional validation and review by the FDA.

Recent testing performed by the CDC/NIOSH resulted in concerns with some KN95 respirators (specifically those with ear loop design) that pose a difficulty in achieving a proper fit, which is essential for use. This is in contrast to N95s that use a head band design (not ear loops), which appears easier to achieve a proper fit and seal. In addition, several models of respirators, including some KN95 respirators, failed to meet the filtration criteria of 95%.

In response to these findings, Health Canada has asked manufacturers and importers to stop the sale of any products that do not meet the filtration criteria of 95% and re-label them as non-medical use face masks, as they could be used in settings where 95% filtration is not needed. Authorized KN95s that meet the filtration criteria may continue to be sold and used as respirators.

Manufacturers wishing to sell KN95s as medical respirators in Canada are encouraged to submit an application for authorization under Health Canada’s Interim Order for the Importation and Sale of Medical Devices.

Health Canada will continue to authorize KN95 medical respirators in Canada through the Interim Order pathway. As of May 7, 2020, Health Canada will request test results from accredited testing facilities to validate the effectiveness of these respirators.

The Government of Canada has developed detailed specifications for personal protective equipment such as disposable N95 respirators.

Use of reprocessed N95 respirators

N95 respirators are considered single-use medical devices. However, given the current crisis, extending the usability of these respirators through reprocessing and reuse can be considered to ensure the continued availability of these devices. Health Canada is assessing the acceptability of various decontamination methods for the reprocessing of single-use N95 respirators. Visit Health Canada’s reprocessing of single-use respirators page for information on:

  • specific guidance for industry
  • decontamination done in hospitals
  • Health Canada’s evidence requirements and basis for the approach

What you should do before wearing your respirator

In addition to the application of routine practices and additional precautions (RPAP) based on a point-of-care risk assessment (PCRA), you can protect your own health by checking your respirator prior to use. This includes checking:

  • the straps are intact
  • it forms a proper seal
  • there are no visible signs of damage

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