Overview: Safety obligations in Ontario’s mining sector
Workplaces in the mining sector – surface mines, underground mines, processing plants, quarries and related operations – present a wide spectrum of hazards: explosives, haulage equipment, hoisting systems, electrical and mechanical systems, ventilation, dust and gases, and more.
The Occupational Health and Safety Act (OHSA) provides the legal framework, and Ontario Regulation 854/90 sets out specific requirements for mines and mining plants to protect workers across these hazards.
This guide simplifies the key aspects of the regulation, helping mine operators, EHS professionals and site leaders understand their responsibilities and maintain safer, compliant operations.
What Ontario Regulation 854/90 Covers
Ontario Regulation 854/90 applies to all “mines and mining plants” as defined in the regulation – including underground and surface mines, ore processing plants, quarries and associated facilities.
The regulation is extensive, covering:
- General definitions and application (Part I)
- Fire protection (Part II)
- Access to workplaces (Part III)
- Protection of workers (Part IV)
- Haulage equipment and systems (Part V)
- Explosives (Part VI)
- Electrical systems (Part VII)
- Mechanical systems (Part VIII)
- Railroads onsite (Part IX)
- Mine hoisting plant (Part X)
- Working environment (Part XI)
Key focus areas for mining operations
- Risk assessment & management of change: The regulation requires employers to conduct workplace risk assessments and develop measures to eliminate or control identified hazards, and to implement formal processes such as management-of-change when significant operational changes occur.
- Key mining systems such as hoisting installations, electrical systems and structural designs must be prepared or reviewed by a professional engineer and documented at the mine site.
- Explosives, blasting and storage: Mines must follow specific requirements inculding approval for underground use and proper storage in designated magazines.
- Working environment controls: Dust, gases, noise, ventilation, and access/egress all appear in the “Working Environment” sectionairborne hazard management programs, ventilation systems, diesel equipment emissions, dust control and environmental monitoring.
Why This Regulation Matters
For mining companies and operations, the implications of non-compliance are significant. By understanding and applying Regulation 854/90, you:
- Uphold legal duty and demonstrate due diligence under the OHSA
- Reduce risk of serious accidents, equipment failures or exposure to hazardous conditions
- Support safer, reliable operations and help protect mobile and stationary workers
- Mitigate regulatory scrutiny, stoppages, fines and reputational damage
Embedding a compliance mindset aligned with the regulation is therefore both a safety imperative and a strategic asset.
Simplified Compliance Checklist
Use this high-level checklist to gauge your current alignment with Regulation 854/90:
| Area | Compliance Focus | Status |
| Risk Assessment & Management of Change | Written procedures, reviews when major changes occur | ☐ |
| Hoisting & Shaft Systems | Rope testing, safe conveyances, standard maintenance | ☐ |
| Mobile Equipment & Haulage | Trained operators, safe vehicles, maintenance records | ☐ |
| Explosives & Blasting | Magazines, storage, blasting procedures in line with regulation | ☐ |
| Mechanical/Electrical Systems | Inspections, guarding, safety systems in place | ☐ |
| Working Environment | Ventilation, dust/gas controls, access/egress, noise monitoring | ☐ |
| Fire Protection & Emergency Systems | Fire-suppression, alarms, emergency response procedures | ☐ |
If items are unchecked, you may need to review those areas and consult with specialized expertise.
Next Steps for Mine Operators and Safety Professionals
Even though the regulatory landscape for mines is complex, approaching compliance proactively makes it manageable. Start by:
- Reviewing your site operations against the requirements of Regulation 854/90.
- Conducting or updating a formal risk assessment and management-of-change procedure.
- Auditing key systems such as hoisting, ventilation, explosives, mobile equipment and fire protection.
- Employers must ensure workers complete approved mining training programs (e.g., Common Core training modules) appropriate to their role before performing certain tasks.
- Ensuring staff are supervised and competent for their tasks under this regulation.
- Documenting your compliance program, keeping records accessible, and reviewing periodically.
If you’re unsure where to begin or want support in interpreting how the regulation applies to your site, consider reaching out for expert advice.
Have questions about how Ontario Regulation 854/90 affects your mine or mining plant?
Contact T. Harris Environmental Management Inc. →