How many first aiders does the CNESST require?

The question comes up the moment an employer opens the regulation: exactly how many first aiders are needed? The answer is a short calculation rule. The whole difficulty is counting the right thing.

Who is covered

The Regulation respecting minimum standards for first aid and first aid kits (RNMPSPS) applies to every establishment, and to any construction site employing at least 10 workers simultaneously at a given point in the work. Health and social services establishments that already have qualified medical or nursing staff are excluded.

In other words: if you operate an establishment, you are covered, whatever its size. What varies is the number of first aiders, not the obligation to have one.

The calculation rule, in an establishment

The employer must ensure the presence, at all times during working hours, of at least one first aider when 50 workers or fewer are present simultaneously — then one additional first aider per additional hundred or part of a hundred workers.

And so on: a hundred begun counts as a hundred.

“Present simultaneously”, not “on the payroll”

This is where most calculations go wrong. The regulation does not count your headcount: it counts the people present at the same time, and it requires coverage at all times during working hours.

A 30-person company running two shifts does not need two first aiders because it has 30 employees. It needs a first aider present during each shift, at every hour worked. Three trained first aiders whose schedules all fall on the same day cover nothing for the rest of the week.

Two practical consequences:

• think in terms of moments in the day, not the org chart;
• keep a margin above the minimum — vacations, illness, departures. Coverage has to hold at all times, not on average.

Who counts, and who does not

Since February 12, 2026, two clarifications change the count:

• Less than 30 minutes on site: workers present for less than 30 minutes are excluded from the calculation.
• Remote work: only people physically present in the establishment enter the calculation.

A third clarification works in your favour: a nurse or a licensed practical nurse whom the employer designates to act as first aider counts as a first aider — with no additional first aid certificate.

On a construction site

The obligation falls on the prime contractor, and it starts at 10 workers present simultaneously: at least one first aider from 10 to 50 workers, then one more per additional hundred or part of a hundred. Kits must be reachable within about 5 minutes for every worker.

In forestry work

Since 2026 the regulation sets a distinct and noticeably tighter scale here — the distance from emergency services justifies it.

Which training, and for how long

The first aid certificate is issued by an organization recognized by the Commission, on completion of training that confers the competencies of the intermediate level of the CSA Z1210 standard. The training must include a practical demonstration of the skills, lasting at least as long as the standard provides for that level.

In practice, that level corresponds to workplace first aid courses of about 16 hours. Several providers offer a blended version: online theory, then a shorter in-room session. The practical demonstration itself cannot be skipped.

The certificate is valid for a maximum of 3 years from issuance. It is issued in the person’s name: it leaves with the employee who leaves.

What the employer bears

The costs of setting up and maintaining the first aid service are borne by the employer — or by the prime contractor on a construction site. There is also an often-forgotten obligation: every intervention is the subject of a report stating the injured worker’s name, the date, the time, a description of the injury and the first aid given. That report is kept in a register, and the worker concerned must be able to access it.

A worked example

A company of 23 people, split across two shifts of 12 and 11, three of whom work remotely. The calculation is based neither on 23 nor on 26: it is based on the people physically present at the same time, so 12 at most. That stays under 50, so one first aider present per shift.

That means at least two trained people — one per shift — and in practice one or two more so that vacations and absences do not bring coverage down.

Before training anyone

The above reflects the text of the regulation, current as of September 2026. Your situation may involve particulars this article does not cover: category of establishment, a required nurse’s room, vehicles used to transport workers. The regulatory text governs — if in doubt, confirm with the CNESST before committing to training.

See workplace first aid courses and their dates, or check the prices charged in Quebec.

Source: Regulation respecting minimum standards for first aid and first aid kits (CQLR, chapter A-3.001, r. 10), sections 2, 2.1, 3, 6.1, 7, 15 and 18.