Bill 27: why CoSS professionals should follow the debate

The term “Law 27” often comes up in occupational health and safety discussions. Let us clarify what it means.

What are we talking about?

“Law 27” refers to the chapter designation of the Act to modernize the occupational health and safety regime (arising from Bill 59), assented to in October 2021. It is Quebec’s most significant OHS reform in decades. Important permanent-regime provisions, including psychosocial risk prevention requirements, came into force in October 2025.

What this means for prevention

The reform extends prevention and participation requirements to all workplaces, using tools such as a prevention program or action plan depending on the establishment’s size.

Issues specific to construction

Construction has its own mechanisms (CoSS, RSS and worksite committee). Recent developments could change the thresholds triggering these mechanisms; because the rules may change, we recommend checking the law currently in force with the CNESST before making any decision. See also the requirements governing the CoSS.

Why this matters for CoSS professionals

Any threshold change affects when prevention mechanisms become mandatory, and therefore the CoSS role on site.

Frequently asked questions

Does Law 27 apply to construction?

The psychosocial risk provisions primarily concern establishments; construction retains its own mechanisms. Consult the CNESST for current details.

Official sources

CNESST — measures for construction sites. Legislation: see LégisQuébec (reference to be confirmed).

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This article is part of ACSSQ’s series on the CoSS profession. See the association’s page.