Levitt-Safety Blog

Respiratory Protection 101: Respirators, cartridges and filters

Michael DouglasNational Manager, Market SegmentsJuly 10, 2020

This year has shone a spotlight on the importance of respiratory protection. It was a steep learning curve for a lot of people.

To help people along, we hosted two webinars (links below) to answer FAQs about respirators and fit testing.

A lot more people are aware of what an N95 is and how a fit test works because of COVID-19. There is still a lot to learn when it comes to choosing the right respirator, filter or cartridge. 70% of all occupational disease deaths are respiratory-related according to NIOSH.

We created the Respiratory Protection 101 to help you better understand the world of respirators, filters and cartridges. We’ll also provide recommendations for further readings if you want to learn more.

    respiratory protection 101, cartoon of diverse population wearing masks

    Create a respiratory protection program:

    A respiratory protection program ensures everyone in your workplace is aware of their roles and responsibilities related to respirator use. The program should outline the rationale, scope and guidelines to meet necessary compliance requirements.

    The written program should address all 10 CAN/CSA-Z94.4 standard components. The program should also provide an overview of best practices for using a respirator.

    For example, it should include that respirator users must be clean shaven and outline duties that require a respirator and list the correct filter or cartridge. The program also establishes a change-out schedule for replacing respirator filters and cartridges. This should be before the filter or cartridge reaches its end of service life.

    To read the full CSA-Z94.4 standard, visit www.csagroup.org.

    Need help creating your respiratory program?

    Levitt-Safety can help! We will work with you to build your respiratory protection program from the ground up. Contact us today to get started.

    Conduct a hazard assessment:

    You’ll often find many respiratory hazards in a workplace and some exposures are unknown. You need to conduct a hazard assessment to identify the contaminants in a workplace, which could be defined as:

    • Threshold limit value (TLV)
    • Permissible exposure limit (PEL)
    • Time-weighted average (TWA)
    • Immediately dangerous to life and health (IDLH), and
    • Any other available exposure limit information.

    Where you can find this information:

    • Provincial occupational health and safety legislation
    • The Federal Labour Code
    • TLVs and Biological Exposure Indices published by the American Conference of Governmental Industrial Hygienists (ACGIH)
    • Workplace Environmental Exposure Level (WEEL) guide series published by the American Industrial Hygiene Association (AIHA)
    • NIOSH recommended exposure limits, and
    • Supplier recommendations on SDS.

    You will also need to check:

    • If the work environment is oxygen deficient.
    • Whether the contaminant is dust, mist fume, gas, vapour or combination.
    • The concentration of contaminants by measuring time-weighted averages (TWA) and peak exposures.
    • Routes of entry besides respiratory, like skin absorption. See if other health effects like sensitization, irritation and corrosion to the skin exist.
    • If gas or vapour contaminants: Determine if there are warnings of odour, taste or irritation.

    Types of respiratory protection:

    There are four respirator types:

    1. Air-purifying respirators:

    Air-purifying respirators (APR) are available in powered and non-powered styles.

    APRs include disposable respirators like N95s. Since this is Respiratory Protection 101, we're focusing on high-level information.

    APRs provide respiratory protection from:

    • dusts
    • mists
    • aerosols
    • fumes, and
    • fibres.

    APRs can also remove gases and vapours if you attach the right chemical cartridge.

    APRs come in two common styles:

    1. Half-mask respirators.
    2. Full facepiece respirators.

    Air-Purifying Half-Mask Respirators:

    Half-mask APRs are relatively lightweight and offer good protection from many airborne contaminants. These respirators provide comfort and safety for the user.

    However, air-purifying respirators do have some limitations:

    1. They cannot be used for all types of airborne contaminants and are limited by the type and capacity of the filters or cartridges used.
    2. Protection factors are not as good as those provided by a full facepiece APRs
    3. They do not provide any eye or face protection.
    4. They cannot be used in oxygen-deficient atmospheres or in atmospheres that have high concentrations of contaminants.

    Proper fit is essential and many factors may affect the face-to-facepiece seal. For instance, people with facial hair cannot use APRs if the hair comes between the respirator seal and their skin.

      Air-Purifying Full Facepiece Respirators

      Air-purifying full facepiece respirators work on the same principle as half-mask respirators. The facepiece extends around the entire face to cover the eyes, nose, chin and mouth.

      Some advantages of full facepiece respirators include the superior seal they provide, therefore offering more protection than half-mask air-purifying respirators.

      They also protect the eyes and face from irritating vapours, mists and splashed chemicals.

      Full facepiece respirators are heavier than half-masks and are often less comfortable for the user to wear.

      Full facepiece air-purifying respirators cannot be used for all types of air contaminants and are limited by the type and capacity of the filters and cartridges used.

      Eyeglass wearers must also ensure that temple bars do not interrupt their face-to-facepiece seal. If required, prescription eyewear inserts are available for most brands.

      Full facepiece air-purifying respirators cannot be used in oxygen-deficient atmospheres or in atmospheres that have high concentrations of contaminants.

      Breathing may become difficult because of the additional effort required to draw air through the purifying media.

      Similar to that of the half-mask, full facepiece air-purifying respirators cannot be used by personnel with facial hair which comes between the respirator seal and the skin.Full facepiece respirators are used when a greater degree of respiratory protection is needed or when eye and face protection is desirable

      2. Gas masks:

      Gas masks filter out chemicals and gases and are not found in typical workplaces.

      3. Airline respirators:

      Within airline respirators, there are several sub-types.

      Supplied-air respirators:

      Supplied-air respirators are respirators attached to an air source like a cylinder or air compressor. These respirators may have an auxiliary self-contained air supply which can be used if the primary supply fails. The self-contained supply can be small as it needs to supply enough air to escape.

      Atmosphere-supplying respirators:

      Atmosphere-supplying respirators supply breathable air directly to the user from a source other than the air surrounding the user. The air supply could be from a low pressure or high pressure source.

      • Low pressure source: This could be an ambient pump that is located in or draws air from a clean environment.
      • High pressure source: This could be supplied from a breathing air cylinder or an air compressor.

      Combination respirators:

      Combination respirators are airline respirators combined with air-purifying cartridges or filters.

      These respirators have a cartridge/filter which can be used to exit the area safely if the primary air supply fails.

      4. Self-contained breathing apparatus (SCBA):

      A self-contained breathing apparatus is a standalone system, like a firefighter would use, that carries the air into the hazard with the wearer. SCBAs have limited duration — typically 30 minutes, 45 minutes or 60 minutes.

      Want a deeper dive into respiratory protection?

      Download our Essential Guide to Respirator Protection.

      thumbnail for the essential guide to respiratory protection

      What you'll learn from the Essential Guide to Respirator Protection:

      • an overview of CSA respiratory standards
      • contaminants and occupational exposure limits (OELs), and
      • calculating assigned protection factors, hazard ratio, maximum use concentration (MUC) for choosing the right respirator

      Respiratory filters and cartridges:

      Using the right respirator filter and cartridge is just as important as using the right respirator.

      • Respirator filters are made of materials designed to trap particulate as you breathe.
      • Respirator cartridges contain material that absorbs gases and vapours.

      It is critical that you choose the right filter or cartridge for the chemicals or substances present in your workplace.

      Choosing the right respiratory filter:

      Filters come in three classes:

      • N for non-oil applications only
      • R for oil resistance for 8 hours
      • P for oil proof

      choosing the right filter for a respirator, N class, R class and P class

      Each of those classes will offer a filtering efficiency of 95%, 99% and 99.97% (rounded up to 100%)

      Your respiratory protection program or appointed administrator will explain which option is correct depending on the job hazard analysis.

      Choosing the right respiratory cartridges

      There are a variety of cartridge options available on the market. You must choose the right cartridge for the gas or vapour hazards you are facing.

      NIOSH has a helpful tool called the Pocket Guide to Chemical Hazards. You can search applicable chemicals and the Guide will give you suggestions for cartridges based on the chemical concentration.

      To make choosing the right cartridge for your application easier, NIOSH created a colour coding system.

      colour coding system for choosing the right type of filter

      What's up next?

      This post just scratches the surface of respiratory protection. If you want to learn more about respirators, take our online respiratory course now.

      In the 60-minute course you will learn:

      • The importance of proper respiratory protection
      • Respirator selection
      • The medical evaluation
      • The fit test
      • How to inspect the respirator
      • How to conduct a proper seal check
      • Cleaning and storage methods
      • Respirator limitations