Occupational health and safety priority categories

At the CNESST, we regularly analyze the causes of occupational injuries, which include occupational accidents and diseases. This analysis allows us to establish occupational health and safety priority categories to act on in order to reduce the number of injuries.

The priority categories that we have identified in the Planification pluriannuelle en prévention‑inspection 2024‑2027 (in French only) are as follows:

• Zero tolerance
• Predominant hazards
• Emerging, proven or known hazards

Take note of the relevant information to apply all the necessary preventive measures depending on the sector of activity in your workplace.

Zero tolerance

Some hazards are considered intolerable, as they can have serious consequences, or even be fatal, for workers. To avoid them, we have identified 10 zero tolerance targets that apply to all workplaces and for which you must put immediate preventive and corrective measures in place before a worker is exposed to these hazards. Otherwise, a CNESST inspector may order the work to be stopped. You may also be subject to legal proceedings (statements of offence).

10 zero tolerance targets

1. Falls of more than 3 m
2. Lader falls
3. Collapse of a scaffolding
4. Collapse of the walls of an unsupported excavation
5. Exposure to asbestos dust
6. Exposure to silica dust
7. Exposure to carbon monoxide
8. Exposure to the hazardous areas of a machine in the event of:
   • moving parts
   • uncontrolled energy
9. Electric shock due to:
   • a contact with a live overhead line
   • an exposure to an uncontrolled electric energy
10. Unstable rocks

See all the zero tolerance sheets.

Predominant hazards

We have identified 5 occupational health and safety hazards to prioritize, as they are the most recurrent. They account for about 70% of all the injuries we treat.

5 predominant hazards

1. Ergonomic hazards
   • Excessive effort
   • Awkward postures
2. Work-related psychosocial hazards
   • Violence
   • Harassment
   • Exposure to a potentially traumatic event
3. Exposure to noise
4. Falls from the same height
5. Risk of getting hit, stuck or crushed by an object or equipment

Consult the predominant hazard prevention sheets.

Note that this section does not reproduce all the information disseminated in French, unless this is required and an authorization has been obtained for this purpose, in accordance with the Directive institutionnelle en matière de langue de la CNESST (in French only).

Emerging, proven or known hazards

We have implemented a mechanism for identifying, monitoring and managing emerging, proven or known hazards to better anticipate hazards and promote more sustainable and effective prevention.

Emerging hazards are hazards whose effects on worker health and safety are not yet very well known, but which we are monitoring closely.

Proven hazards are known, but specific preventive measures for them have yet to be defined. They can be different depending on the workplace.

Known hazards are understood and preventive measures exist, such as engineering controls, standards and regulations. However, some situations may increase the frequency of and threat posed by a known hazard. This is why we pay special attention to them.

Our role is to support you in managing these hazards.

Hazards identified

• Safety hazards
  • Lithium‑ion batteries, including those in electric vehicles
• Climate change hazards
  • Outdoor air quality index: feux de forêt et panache de fumée (in French only)
  • Heatwave: coup de chaleur (in French only)
• Biological hazards
  • Exposure to tick bites – Lyme disease: maladies transmises par les animaux (in French only)
• Hazards associated with the organization of work
  • Télétravail (in French only)