What must an Ontario employer do after a critical workplace injury?

Get emergency help, protect people from further harm and immediately notify the required Ontario health-and-safety parties when a person is killed or critically injured at a workplace. Under section 51 of Ontario's Occupational Health and Safety Act, the employer and any constructor must notify an inspector and the joint health and safety committee, health and safety representative and trade union, if any, immediately by telephone or another direct means. The employer must then send the prescribed written report to a director and those workplace representatives within 48 hours after the occurrence. The scene generally must not be disturbed except for the limited statutory purposes in section 51(2).

The Ontario ministry's current reporting guide is the practical filing entry point. It explains that this duty can apply when a person, not only an employee, is killed or critically injured where workers were working or could reasonably be expected to work and the relevant hazard has a reasonable connection to worker health and safety. Do not wait for a workers' compensation claim number before making the OHSA notification. The event-specific OHSA duty and any WSIB claim duty are separate.

This guide is limited to Ontario workplaces subject to the OHSA. It does not import the US OSHA eight-hour fatality deadline, the federal Canada Labour Code process or another province's rule. It also does not say every first-aid case or injury requiring medical attention is a “critical injury.” The reporting category matters because immediate section 51 notice and the 48-hour report are more urgent than some other Ontario written-notice routes.

Stabilise the scene, then make the immediate calls

The first response is human: summon emergency services, provide safe first aid and prevent a second exposure. Assign someone to secure an unsafe machine, area or process without creating another casualty. At the same time, have a designated person begin the required direct notifications. The legal word is immediately. A draft incident form, a queue in a software system or a message to a manager who may read it later is not a substitute for notifying the inspector and applicable workplace representatives by direct means.

Write down who was contacted, by which number or direct channel, the time, the person spoken to and what was said. If a contact is not reached, follow the ministry's current contact instructions and record the attempts and next steps. Do not invent a notification time after the fact. A large multi-site employer should maintain current after-hours contacts for the inspector route, JHSC or representative, union and any constructor. A construction project may have both an employer and constructor with statutory notice obligations; the site plan must not assume one phone call made by one party silently satisfies the other party's duty.

The ministry's incident-reporting page identifies the ministry Health and Safety Contact Centre and the current submission paths. Use the live page at the time of the event. This article intentionally does not hard-code a telephone number that could change, and the responsible person should have the regulator's route in the site's emergency plan before an incident occurs.

Is the injury “critical” under the current definition?

Ontario Regulation 420/21 defines critical injury for the section 51 process. The ministry's current summary describes a serious injury that places life in jeopardy, causes unconsciousness or substantial blood loss, involves specified fractures or amputations, causes burns to a major portion of the body or loss of sight in an eye. The exact legal definition must be read in the current regulation against the actual medical facts; an old copy of repealed Regulation 834 is not the source to use.

A supervisor may not know the full diagnosis in the first minutes. Do not delay emergency care or all notification while trying to conduct a legal classification from a photograph. Escalate a potentially critical event to the employer's safety lead and the ministry promptly, explain the facts currently known and update them as reliable information arrives. Calling an incident “minor” because the worker is conscious, or calling it “critical” solely because an ambulance attended, both substitute a casual impression for the legal criteria. Record what was known when the decision was made and when new facts changed it.

For example, a worker falls from height and is taken to hospital. The site initially knows the person lost consciousness but does not yet know the fracture pattern. Unconsciousness is itself in the ministry's critical-injury summary, so the team should make the direct notifications without waiting for imaging. Conversely, a superficial hand injury may require medical treatment but not meet the critical definition; it can still trigger other written-notice or WSIB duties. The employer should not use uncertainty as a reason to ignore all reporting pathways.

Preserve the scene without blocking rescue

Section 51(2) generally prohibits disturbing the scene of a death or critical injury unless needed for specified purposes, including saving life or relieving human suffering, maintaining essential services, or preventing unnecessary damage to equipment or other property. The Ontario OHSA guide to Part VII explains the preservation rule. Check the current Act for the full exceptions and for any inspector permission before moving items for an investigation or production restart.

Establish a safe perimeter, stop the relevant work and control ongoing hazards. Keep people from altering machine settings, deleting footage, clearing debris or replacing a failed component simply to make the area look normal. Rescue and hazard control can require movement; document what was moved, by whom, when and why, then protect the remaining evidence. If emergency services move equipment to reach a casualty, that is very different from a supervisor tidying the site before an inspector arrives.

Assign a person to maintain an evidence log. Preserve photos taken safely, equipment identity and configuration, permits, training and maintenance records, relevant CCTV, witness names and the initial timeline. Do not let evidence collection distract from medical care or immediate notification. The worker side of a JHSC may have statutory investigation rights; coordinate that safely and without prejudging what happened. An internal investigation can proceed, but it does not authorise disregard of the scene-preservation rule.

Complete the written report within 48 hours

Section 51(1) places the written report duty on the employer. The current Act requires the report to go to a director and the committee, health and safety representative and trade union, if any, within 48 hours after the occurrence. Ontario Regulation 420/21 prescribes content, and the ministry provides a reporting form and guidance. Check the current form's fields before submission; do not rely on a generic internal incident template that omits prescribed particulars.

Build the report from verified facts available within the deadline: workplace and employer/constructor identities, affected person and contacts as the form requires, date, time, location, circumstances, known injury, equipment and witnesses, plus required notification information. Identify what remains under investigation rather than filling a gap with speculation. The 48-hour clock is not permission to wait until hour 47 to start. A site with several shifts or remote headquarters should decide in advance who can gather and approve the report on a weekend.

Give copies to the applicable representatives as required. Keep the submitted version, proof of sending and any subsequent correction or supplemental information. A draft saved in the incident system is not evidence that the ministry received it. If more facts emerge after the 48-hour submission, update the record through the appropriate ministry channel rather than quietly replacing the original file and losing the timeline.

The regulator's form is a reporting route, not an incident-investigation conclusion. Do not promise that submitting it closes the file or prevents an inspection. The employer should continue to identify immediate controls, investigate causes and prevent recurrence while respecting the scene, worker privacy and inspector instructions.

Distinguish the other Ontario notice clocks

The ministry's incident-reporting guide describes other pathways. If a person is injured and unable to do usual work or requires medical attention because of an accident, explosion, fire or workplace violence, section 52(1) can require a written notice within four days to the JHSC or representative and union, with ministry delivery if an inspector requires it. The ministry explains what “medical attention” means for this purpose. An occupational illness can trigger a separate four-day notice to the ministry and workplace representatives after the employer is advised. Certain construction, mining, diving or X-ray incidents can require a two-day written notice even where nobody is injured. The exact statutory trigger and recipient differ.

These other clocks do not replace section 51 when there is a death or critical injury. Nor does a section 51 report automatically satisfy a WSIB claim, an insurer notice or a police investigation. Use a short event decision tree with separate lines for immediate OHSA notification, 48-hour written report, other OHSA notices, WSIB and sector-specific reporting. Mark “not applicable” only after the responsible person has checked the actual trigger. A single “incident submitted” status hides too many distinct duties.

Example: non-critical injury requiring medical attention

A worker cuts a hand and a nurse practitioner treats it; the person is not critically injured. The employer should assess the section 52 written-notice condition, the ministry's definition of medical attention, WSIB obligations and the incident's underlying hazard. It should not make a false section 51 critical-injury report just to be safe, but neither should it skip all notice because the injury is not critical. A later medical update could change the assessment; keep a process to revisit it.

Example: near miss at a construction project

An unexpected equipment failure on a construction project could have endangered workers, but no one is hurt. The section 51 death/critical-injury route may not apply. Ontario's reporting guide identifies specified construction incidents that may require a written notice within two days. The constructor should check Regulation 420/21 against the actual event, notify the appropriate parties and investigate the hazard. Do not treat “no injury” as “no possible statutory notice.”

Build a response record that holds together

Before any incident, assign an emergency caller, an alternate, a scene lead, a report writer and a reviewer. Keep current after-hours contacts and form links. Make the site's incident intake capture the time and location, people affected, immediate hazard controls, medical response, direct notifications, scene changes, known evidence, reporting-category decision and follow-up owner. The record should preserve chronology; it should not permit one late edited timestamp to overwrite the original sequence.

After the immediate period, tie corrective actions to the actual hazard. Record the interim control, the permanent fix, who verified effectiveness and when work could safely resume. If an inspector gives a direction, record it separately with the responsible person and evidence of completion. A neatly filed report with no action on a known hazard is poor safety management. Share appropriate learning with workers without disclosing more personal medical information than necessary.

The Complys Ontario OHSA overview explains the broader provincial duty framework. This page owns the critical-injury notification task. The verified Complys Canada OHS page is a potential tool for organising relevant safety records; the Canada site describes incident and document records. This article does not claim Complys automatically identifies a critical injury, places a call to the inspector, files the statutory report, preserves a physical scene or replaces professional judgement. Check the deployed product and the employer's access controls before using it for sensitive incident information.

If a person has just been killed or may be critically injured, act on the emergency and direct-notification duties now using Ontario's current official guidance. Preserve the scene within the Act's exceptions, and start the 48-hour report with verified facts. Do not wait for software, a perfect investigation or a compensation decision before meeting the section 51 timetable.

For the related Complys product, see Ohs Compliance Software. This guide is general information, not legal advice; verify current requirements against the official sources linked above.