How often to fit test?

RSST 45.1 points to CSA Z94.4; it does not say “annual fit test.” Use the standard and your program — not an invented rule.

Can you wear an RPE with a beard?

No—beards prevent negative-pressure masks from sealing. Bearded workers must use positive-pressure units (supplied air or PAPR) or shave.

How to add RPE checks in OK Sécurité?

Tasks with respiratory risk (asbestos, welding, painting) already include PPE items. You can also create a custom list for your respiratory program.

Guides

Respiratory protection on construction sites

Written by the OK Sécurité team · Updated September 9, 2026

Silica dust, welding fumes, asbestos, and VOCs threaten construction workers' lungs. The right respirator, properly fitted and maintained, makes the difference.

When is an RPE needed?

On a construction site, CSTC 3.25.6 requires a respirator for sawing, grinding, sanding, bush-hammering, jackhammers, confined drilling, and piercing — unless isolation/confinement or a demonstration under the RSST Annex I OELs. In an establishment, RSST 45–45.1 governs supplying a respirator and a CSA Z94.4 program.

In construction, common situations include: concrete or ceramic sawing (silica), welding and cutting (metal fumes), spray painting (VOCs, isocyanates), asbestos removal, and drywall sanding.

Choosing the right type

Disposable N95/P100 masks suit dust and particulates. Half-mask cartridge respirators protect against organic vapors and some gases. Supplied-air units are needed for high-risk asbestos work and hazardous-atmosphere confined spaces.

Selection must consider contaminant type, concentration, and working conditions. A written CSA Z94.4 program is required by RSST 45.1 when the employer supplies a respirator in an establishment. Do not present that as an annual “RSST” rule.

Fit and seal check

A poorly fitted RPE provides no protection. Fit testing must occur before first use and periodically after. Beards, scars, and some glasses can compromise the seal.

Before each use, the worker should perform a quick seal check (positive and negative pressure) to verify proper positioning.

Maintenance and replacement

Filter cartridges have limited service life depending on contaminant concentration and humidity. Follow manufacturer guidance and replace when the worker detects odor or taste through the filter.

Store RPE in a clean, dry place. Inspect straps, valves, and seals before each use. OK Sécurité helps integrate these checks into your daily lists.

This guide is informational. RPE selection must be based on site-specific risk assessment. Consult an industrial hygienist for complex situations. For information only — this is not legal advice. OK Sécurité is an independent company with no affiliation to the CNESST: we are not mandated, endorsed or certified by it. Where there is any discrepancy, the official text published by Légis Québec or the CNESST prevails.

Sources

Informational only. Confirm obligations with your prevention program and:

CNESST — Mesures spécifiques pour les chantiers de construction
Safety Code for the construction industry (CSTC) and Regulation respecting occupational health and safety (RSST)

Official rules

Related checklists

Checklists for respiratory-risk tasks:

Browse all checklists View plans

Common questions

Is an N95 enough for concrete sawing?: CSTC 3.25.6 requires a respirator for sawing unless isolation/confinement or a demonstration under the OELs. An N95 is not “enough by default” for concrete.
How often to fit test?: RSST 45.1 points to CSA Z94.4; it does not say “annual fit test.” Use the standard and your program — not an invented rule.
Can you wear an RPE with a beard?: No—beards prevent negative-pressure masks from sealing. Bearded workers must use positive-pressure units (supplied air or PAPR) or shave.
How to add RPE checks in OK Sécurité?: Tasks with respiratory risk (asbestos, welding, painting) already include PPE items. You can also create a custom list for your respiratory program.