Alert: Equipment blocking
Learn about the necessary precautions for blocking hazardous energy to prevent injury or death from workplace machinery.
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Anyone who operates, cleans, services, adjusts or repairs machinery or equipment must be aware of the hazards associated with that machinery. Every year workers die or are critically injured because the equipment they are working on does not have adequate blocking installed. In addition to properly locking out control mechanisms, it is critical to block all forms of hazardous energy including: potential energy due to gravity, hydraulic pressure, or any stored energy that may cause equipment to move or drift, such as electrical or mechanical energy. The lack of blocking allows equipment to move or drop, striking workers, which could lead to fatal and critical injuries.
These events involve:
- raised blades of bulldozers
- raised buckets of backhoes
- raised boxes of dump trucks
- raised forks of forklifts
- punch presses
- hoisting equipment
This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations, and should not be used as or considered legal advice. Health and safety inspectors apply the law based on the facts in the workplace.
Hazard location and sectors
All sectors: construction, healthcare, industrial, and mining.
Legal requirements and recommendations
Construction – Section 108 of Ontario Regulation 213/91 (Regulations for Construction Projects) under Ontario's Occupational Health and Safety Act (OHSA) requires that blocking be installed to prevent the collapse or movement of part or all of a piece of equipment that is being dismantled, altered or repaired if its collapse or movement may endanger a worker.
Section 37 of Ontario Regulation 213/91 requires that materials or equipment at a project be stored and moved in a manner that does not endanger a worker.
Section 38 of Ontario Regulation 213/91 requires specifically that blocking, support chains, metal bands, wire ropes and rigging components be removed from material or equipment in a manner that does not endanger a worker.
Healthcare – Section 53 of Ontario Regulation 67/93 (Regulations for Healthcare and Residential Facilities) under the OHSA requires that “If machinery or equipment is being dismantled, serviced or repaired and the collapse of any part of it may injure a worker, blocking shall be installed to prevent its collapse.”
Section 54 of Ontario Regulation 67/93 requires “If a worker may pass or work under machinery, equipment or material that is temporarily elevated, it shall be securely and solidly blocked to prevent it from falling or moving.”
Industrial – Section 74 of Regulation 851 (Regulations for Industrial Establishments) under the OHSA requires that, “Machinery, equipment or material that is temporarily elevated and under which a worker may pass or work shall be securely and solidly blocked to prevent the machinery, equipment or material from falling or moving.”
Section 75 of Regulation 851 requires that a part of a machine, transmission machinery, device or thing that has been stopped and that may subsequently move and endanger a worker must be blocked to prevent its movement before maintenance or repair work is conducted on the equipment.
Section 58 of Regulation 851 requires that no powered equipment be left unattended unless forks, buckets, blades or similar parts are in the lowered position or solidly supported.
Mining – Section 108(2) of Regulation 854 (Regulations for Mines and Mining Plants) under the OHSA requires that any part of a motor vehicle or other equipment, including the blade or bucket or dump box of a truck, must be blocked so as to prevent it from being lowered accidentally if the lowering could endanger a worker.
In addition to the regulations referenced above, clauses 25(2)(h) and 25(2)(a) of the Occupational Health and Safety Act require that all Ontario employers, regardless of the type of work, take every precaution reasonable in the circumstances and provide information, instruction and supervision to a worker to protect the worker’s health and safety.
Given the seriousness of this hazard, it is advisable to have in place an additional control such as connecting the blocking to a mechanical, electrical or other type of device (interlock) that causes the power to be shut off until the block is removed and the power reactivated manually.
It is also important that safety-blocking devices are rated to support the total weight of the equipment components they are used to support. They should also display the permitted tonnage for workers to reference and must be able to bridge the entire vertical space they are blocking to prevent any hazardous movement.