Yves Tardif

Following a collision between two Canadian National Railway trains in Quebec, an inspector from the provincial Commission de la santé et de la sécurité du travail initiated an investigation under the provincial Act respecting occupational health and safety.

The railway company challenged the investigation, arguing the provincial statute could not constitutionally apply to a federal undertaking.

The Supreme Court of Canada held that the provincial occupational health and safety legislation, because of its preventive nature, directly regulates the working conditions and management of the undertaking.

Consequently, the investigative powers under the Act are wholly inapplicable to an interprovincial railway undertaking.

A constitutional appeal concerning whether Quebec occupational health and safety provisions governing protective re-assignment of a pregnant worker applied to a federal telecommunications undertaking.

The Court held that the provincial scheme, though aimed at worker health and safety, in pith and substance regulated working conditions, labour relations, and the management and operation of undertakings.

As applied to federal undertakings, those matters fell within Parliament's exclusive jurisdiction, rendering the provincial provisions constitutionally inapplicable.

The Court rejected reliance on the double aspect theory and held it unnecessary to decide the operational conflict issue.