Respiratory Protection 101: Respirators, cartridges and filters

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.

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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.

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.