Generally, in Canada, fall protection is required when working at heights where there's a potential to fall 3 metres (approximately 10 feet) or more 1, 3, 6, 14. However, this height can be less than 3 meters if the surface below presents a greater risk of injury than a solid, flat surface 4, 7, 9, 10, 11, 15. Examples of such risks include working near machinery, risk of drowning, or open tanks containing hazardous materials [1].

It's important to remember that specific requirements can vary by jurisdiction, so always consult the relevant local legislation for complete information [1].