A roof hatch is an opening in the walking surface, and the area around an open hatch is a fall exposure. Canadian OH&S regulations require employers to protect workers from falls at unguarded edges and openings, and a guardrail or comparable protection is the standard control for the exposure created when the hatch is open and a worker is alongside it. A self-closing gate or a fixed guardrail around the hatch opening keeps the protection in place without depending on the cover being shut. Because the specific requirement depends on the province and the type of workplace, a qualified person should evaluate the hatch and confirm the governing regulation.

Fall protection is usually grouped by the hierarchy of controls: elimination (remove the hazard or the need to work at height), passive prevention (guardrails, covers, and other physical barriers that need no worker action), active fall restraint or fall arrest (harness-and-anchor systems that prevent or stop a fall), and administrative controls (warning lines, training, and procedures). A freestanding guardrail is a passive prevention control, which is why it sits above harness-based systems in the order an employer should consider. The CSA Z259 series covers the equipment used across these categories.

The height that triggers fall protection is set by each province or territory, so there is no single national figure. A common trigger across Canadian jurisdictions is a fall of 3 metres (about 10 feet), but several jurisdictions require protection at lower heights for specific work or near particular hazards, and the federal regime under the Canada Labour Code applies to federally regulated workplaces. Confirm the governing regulation for the site. Where a guardrail is the chosen control, its height and strength must meet the requirements of the applicable regulation and CSA standard.