Mechanical Safety

Did you know?

Some of the most common hazards associated with machinery are crushing, rotating parts, pinch-points, entanglement, hazardous substance exposure, flying debris, sharp edges, and being struck by equipment. 

Summary

Effective mechanical safety starts with understanding how each machine operates. Some machines perform fixed, repetitive tasks, while others run continuously. Some perform multiple functions on command. Proactively identifying the machine’s operating modes, energy sources, and potential equipment failures is critical to hazard assessment and risk control.

Employer duties

Employers must make sure all machinery is operated according to the manufacturer's instructions or the direction provided by the supplier. Additionally, they must make sure that employees have received adequate information, instruction, and training to safely use the equipment as intended.

As an employer, you must:

  • Make sure that a machine is erected, installed, assembled, started, operated, used, handled, stored, stopped, serviced, cleaned, tested, adjusted, repaired and dismantled according to the manufacturer's specifications. [Reg. 91-191, S.235(1)]
  • Make sure the rated capacity or other machine operational limitations for all or part of a machine set out by the manufacturer or any relevant specifications certified by an engineer are not exceeded. [Reg. 91-191, S.235(2)]
  • Make sure machine operators do not exceed these specifications. [Reg. 91-191, S.235(3)]
  • Make sure all machinery is routinely checked for defects that could harm employees, and take any defective equipment out of operation until it has been properly repaired. [Reg. 91-191, S.236]  

Starting and Stopping Machinery 

As an employer, you must: [Reg. 91-191, S.237] 

  • Make sure that operating controls are clearly marked and located so they are protected against unintentional activation. Pedals must also be safeguarded to prevent the machine from activating due to unintentional contact.
  • Make sure that both active and idler pulleys have a permanent belt shifter installed. This shifter must include a mechanical device that stops the belt from unintentionally sliding from the idler pulley onto the active pulley and starting the machine.
  • Make sure that if an operator cannot clearly see the machine or certain parts of it from the control panel, and starting the machine could put a worker in danger, an alarm system must be installed. The alarm system must sound before the machine starts so workers know it is about to start-up.
  • Make sure that the machine operator can easily access the controls to stop the machine in their immediate work area, without any obstructions.   
  • Make sure that any machine not powered by its own motor or prime mover has a clutch, idler pulley, or another device that allows for the disconnection of the power source.  

As an employee, you must:

  • Make sure that starting, stopping, or running the machine does not endanger any individual. [Reg. 91-191, S.238]  

Abrasive Wheels and Grinders

As an employer, you must: [Reg. 91-191, S.244]  

  • Make sure that the maximum revolutions per minute is clearly marked on both the abrasive wheel according to the manufacturer’s instructions, and on the grinder’s output shaft.
  • Make sure that abrasive wheels are:  
    • Checked for flaws before installation,
    • Fitted with protective hoods that have sufficient strength to hold fragments or ruptured wheels, and
    • Mounted in accordance with the manufacturer's specifications.
  • Make sure that the tool rests on a bench grinder as close to the abrasive wheel as safely possible. 

As an employee, you must: [Reg. 91-191, S.244(4)(5)]  

  • Make sure to run an abrasive wheel at full speed, as specified by the manufacturer, before using it for any work.
  • Not operate abrasive and grinding wheels at speeds over those recommended by the manufacturer.
  • Not grind on the side of an abrasive wheel unless the wheel has been designed for that purpose.
  • Not adjust a tool rest while the abrasive wheel is in motion.

Cutting or Shaping Machines

The employer must make sure that an employee uses a push block, push stick, or other adequate protective device when there is a risk of hand injury while using cutting or shaping machinery. [Reg. 91-191, S.245(2)]

Saws 

As an employer, you must: [Reg. 91-191, S.246]

  • Make sure stands used for lead sawyers on sawmills are protected by shields that are:  
    • At least 1.2 m (4 ft.) in height, and
    • Constructed of iron or steel at least 6 mm thick, wooden planks not less than 50 mm thick, or other material of equal strength.
  • Make sure wheels on wood-working band saws and the return portion of the blades between the upper and lower wheels are guarded by sheet metal at least 1 mm in thickness or other equally strong materials.
  • Make sure the wheels on sawmill band saws and the return portion of the blades between the upper and lower wheels are guarded by sheet metal at least 3 mm in thickness or other equally strong materials.
  • Make sure circular saws are fitted with hood guards that cover as much of the exposed blade as possible, and at a minimum extend down to the depth of the teeth. 

Tumbler Drums 

As an employer, you must make sure that any access doors on guards or enclosures around tumbler drums are equipped with interlocks that: [Reg. 91-191, S.247] 

  • Prevent the doors from opening while the drums are turning, or
  • Automatically disconnect the power and stop the drums when the doors open.

Agitator

As an employer, you must install guardrails on all exposed sides when the top of an open agitator, beater or paddle tank is less than 1m above the floor, walkway or work area. [Reg. 91-191, S.248] 

Gears and Sprockets

As an employer, you must make sure that all gears and chain drive sprockets are: [Reg. 91-191, S.249]

  • Fully enclosed, or
    • Where full enclosure is not practical,
      • Have band-type guards with flanges extending inward beyond the root of the teeth, and
      • Are enclosed on exposed sides if there is a hazard from exposed spokes. 

Drive Shafts and Pulleys 

As an employer, you must:

  • Make sure that exposed parts of permanently installed horizontal shafts that are within 2.1 meters of the floor, a walkway, or a work area are properly guarded with: [Reg. 91-191, S.250(1)]
    • Casings completely enclosing the shafting,
    • Casings in the form of a trough enclosing either the top and both sides or the bottom and both sides of the shafting, as the location requires, or
    • Railings that are placed not less than 300 mm or more than 500 mm from any moving part.
  • Make sure that any exposed parts of permanently installed vertical shafts within 2.1 meters of the floor, walkway, or work area are guarded with stationary casings. [Reg. 91-191, S.250(2)]
  • Make sure that any shaft ends that project more than half their diameter are guarded with non-rotating caps or safety sleeves. [Reg. 91-191, S.250(3)]
  • Make sure that any exposed pulley within 2.1 meters of the floor, walkway, or work area is properly guarded with:
    • A complete enclosure when the belt or rope is completely exposed, or
    • A partial enclosure that goes from the bottom to at least the top of the pulley on all open sides when part of the belt or rope is partially exposed. [Reg. 91-191, S.251(1)]
  • Make sure that any horizontal belt on a pulley or drive shaft above a floor, walkway, or work area is completely guarded to prevent contact with an employee or any object that is being carried or moved. [Reg. 91-191, S.251(2)]
  • Make sure that when the bottom part of a horizontal belt on a pulley or drive shaft is 2.1 meters or less above the floor, walkway, or work area, the guards must cover up to at least 380 mm above the top of the belt, or up to 2.1 meters, whichever is less. [Reg. 91-191, S.251(3)]
  • Make sure that guarding for an overhead belt, pulley or drive shaft: [Reg. 91-191, S.252(1)]
    • Is at least 1.25 (1 ¼) times as wide as the belt that it protects,
    • Does not extend more than 150 mm on either side of the belt, and
    • Is strong enough to contain the belt if it breaks.
  • Make sure that vertical or inclined belt, rope, and link drive on a pulley or drive shaft are covered up to the top pulley, sleeve, or sprocket, reaching at least 2.1 meters above the floor, walkway, or work area, or are protected with guardrails. [Reg. 91-191, S.252(2)]

Hoses and Pipes 

As an employer, you must:

  • Make sure that any hose or pipe containing a hazardous substance is: [Reg. 91-191, S.253(1)]
    • Shielded to prevent contact with an employee,
    • Protected from damage from falling objects and from chafing,
    • Placed where no materials or equipment can come in contact with it,
    • Adequately secured, and
    • Marked to indicate the direction of the flow of the product or material.
  • Make sure that when a pressure hose is hung in a loop, the weight of the hose is supported by ropes anchored to hold its weight. [Reg. 91-191, S.253(2)]
  • Make sure compressed air used to clean any surface has: [Reg. 91-191, S.254(1)]
    • A blowpipe installed on the end of the hose,
    • A control valve as part of the blowpipe, and
    • Appropriate protective equipment is worn by employees using the compressed air.
  • Make sure appropriate eye protection is worn by employees if compressed air is used to blow dust or other substances off of an employee’s clothing, and [Reg. 91-191, S.254(2)]
    • The compressed air supply is limited to 69 kPa, or
    • Safety nozzles are used that have the same pressure limiting effect. 

Legislation

General Regulation - Occupational Health and Safety Act

N.B. Reg. 91-191

Part XVI MECHANICAL SAFETY

Section 235
  • 235. (1) An employer shall ensure that a machine is erected, installed, assembled, started, operated, used, handled, stored, stopped, serviced, tested, cleaned, adjusted, maintained, repaired and dismantled in accordance with the manufacturer's specifications.
  • (2) An employer shall ensure that the manufacturer's rated capacity or other limitations on the operation of a machine or any part of it, as set out in the manufacturer's specifications or in any relevant specifications certified by an engineer, are not exceeded.
  • (3) An operator of a machine shall not exceed the manufacturer's rated capacity or other limitations referred to in subsection (2).
Section 236

236. An employer shall ensure that a machine is regularly inspected for defects and that a defective machine that may cause injury to an employee is removed from service until repaired.

Section 237 Starting and Stopping Machines
  • 237. (1) An employer shall ensure that the operational controls on a machine are
    • (a) located and protected in such a manner as to prevent unintentional activation, and
    • (b) suitably identified so as to indicate the nature of each control mechanism.
  • (2) Where a pedal is used to activate a control device on a machine, an employer shall ensure that the pedal is guarded so that it cannot be struck accidentally and activate the machinery.
  • (3) An employer shall ensure that each pair of active and idler pulleys on a machine is equipped with a permanent belt shifter that has a mechanical means of preventing the belt from creeping from the idler pulley to the active pulley.
  • (4) Where there is not a clear view of a machine or parts of it from the control panel or operator's station and moving parts of the machine may endanger an employee when the machine is started, an employer shall ensure that
    • (a) an alarm system is installed, and
    • (b) the alarm system gives an effective warning before start-up of the machine so that an employee is made aware of the imminent start-up.
  • (5) An employer shall ensure that an operator of a machine has unimpeded access in the operator's immediate work area to the means of stopping the machine.
  • (6) An employer shall ensure that a machine not driven by an individual motor or prime mover is equipped with a clutch, idler pulley or other means of quickly disengaging the power source.
Section 238

238. An operator of a machine shall ensure that the start-up, stopping or operation of the machine does not endanger any person.

Section 244 Abrasive Wheels and Grinders
  • 244. (1) An employer shall ensure that the maximum number of revolutions per minute
    • (a) of an abrasive wheel, as recommended for safe use in the manufacturer's specifications, is identified on the wheel, and
    • (b) of a grinder output shaft is identified on the grinder.
  • (2) An employer shall ensure that an abrasive wheel is
    • (a) checked for flaws before installation,
    • (b) fitted with a protective hood of sufficient strength to contain fragments of ruptured wheels, and
    • (c) mounted in accordance with the manufacturer's specifications.
  • (3) An employer shall ensure that a tool rest is mounted on a bench grinder as close as is safely possible to the abrasive wheel.
  • (4) Before applying any work to an abrasive wheel, an employee shall run the wheel at full operating speed in accordance with the manufacturer's specifications.
  • (5) An employee shall not
    • (a) operate an abrasive wheel at a speed in excess of the speed set out in the manufacturer's specifications,
    • (b) do grinding on the side of an abrasive wheel unless the wheel has been designed for that purpose, or
    • (c) adjust a tool rest while the abrasive wheel is in motion.
Section 245 Cutting or Shaping Machines
  • 245. (1) In this section
  • "push block" means a block of wood with a handle similar to that of a hand plane and with a shoulder at the rear, that is used to feed material into a machine and is of sufficient length to protect an employee from coming into contact with the machine;
  • "push stick" means a narrow strip of wood or other soft material with a notch cut into one end that is used to feed material into a machine and is of sufficient length to protect an employee from coming into contact with the machine.
  • (2) Where there may be a danger of injury to an employee's hand from a cutting or shaping machine, an employer shall provide and the employee shall use a push block, push stick or other adequate protective device.
Section 246 Saws
  • 246. (1) An employer shall ensure that stands for lead sawyers in sawmills are protected by shields that are
    • (a) at least 1.2 m in height, and
    • (b) constructed of iron or steel at least 6 mm thick, wooden planks not less than 50 mm thick or other material of equivalent strength.
  • (2) An employer shall ensure that wheels on wood-working band saws and the return portion of the blades between the upper and lower wheels are enclosed with guards of sheet metal at least 1 mm thick or other material of equivalent strength.
  • (3) An employer shall ensure that wheels on sawmill band saws and the return portion of the blades between the upper and lower wheels are enclosed with guards of metal plate at least 3 mm thick or other material of equivalent strength.
  • (4) An employer shall ensure that a circular saw is provided with a hood guard that covers as much as possible of the exposed part of the saw at least to the depth of the teeth.
Section 247 Tumbler Drums

247. An employer shall ensure that the access doors in the guards or enclosures to tumbler drums are, if there is a potential hazard to an employee, fitted with interlocks that will

  • (a) prevent the access doors from opening while the drums are rotating, or
  • (b) disconnect the power from the driving mechanism causing the drums to stop if the doors are opened.
Section 248 Agitators

248. Where the top of an open agitator, beater or paddle tank is less than 1 m above a floor, walkway or work area, an employer shall ensure that guardrails are installed on all exposed sides.

Section 249 Gears and Sprockets

249. An employer shall ensure that all gears and chain-drive sprockets

  • (a) are completely enclosed, or
  • (b) where complete enclosure is not practicable,
    • (i) have band-type guards with flanges extending inward beyond the root of the teeth, and
    • (ii) are enclosed on exposed sides if there is a hazard from exposed spokes.
Section 250 Drive Shafts and Pulleys
  • 250. (1) An employer shall ensure that exposed parts of permanently installed horizontal shafting within 2.1 m of a floor, walkway or work area are guarded with
    • (a) casings completely enclosing the shafting,
    • (b) casings in the form of a trough enclosing either the top and both sides or the bottom and both sides of the shafting as the location requires, or
    • (c) railings that are placed not less than 300 mm nor more than 500 mm from any moving part.
  • (2) An employer shall ensure that exposed parts of permanently installed vertical shafting within 2.1 m of a floor, walkway or work area are enclosed with stationary casings.
  • (3) An employer shall ensure that the ends of shafts which project more than half the diameter of the shaft are guarded by non-rotating caps or safety sleeves.
Section 251
  • 251. (1) An employer shall ensure that an exposed pulley, any part of which is located within 2.1 m of a floor, walkway or work area, is guarded with
    • (a) a complete enclosure when the belt or rope is completely exposed, or
    • (b) a partial enclosure extending from the bottom to at least the top of the pulley on all unprotected sides when the belt or rope is partially exposed.
  • (2) An employer shall ensure that a horizontal belt of a pulley or drive shaft that runs over a floor, walkway or work area is guarded the full length of the belt so as to prevent contact with an employee or an object being carried or moved by an employee.
  • (3) Where the lower run of a horizontal belt of a pulley or drive shaft is 2.1 m or less above a floor, walkway or work area, an employer shall ensure that the guard extends to at least 380 mm above the top run of the belt or to a height of 2.1 m, whichever is the lesser.
Section 252
  • 252. (1) An employer shall ensure that an overhead belt guard for a pulley or drive shaft
    • (a) is at least 1 1/4 times as wide as the belt that it protects,
    • (b) does not extend more than 150 mm on each side of the belt, and
    • (c) is sufficiently strong to contain the belt in the event of breakage.
  • (2) An employer shall ensure that vertical or inclined belt, rope and link drives for a pulley or drive shaft are enclosed to the upper pulley, sleeve or sprocket guard to a height of at least 2.1 m above a floor, walkway or work area or are guarded with guardrails.
Section 253 Hoses and Pipes
  • 253. (1) An employer shall ensure that a hose or pipe containing a hazardous substance is
    • (a) shielded to prevent contact with an employee,
    • (b) protected from damage from falling objects and from chafing,
    • (c) located so as not to be struck by any material or equipment,
    • (d) adequately secured, and
    • (e) marked to indicate the direction of the flow of the product or material.
  • (2) Where a pressure hose is hung in a bight, an employer shall ensure that the weight of the bight is relieved by ropes that are anchored so as to support the weight.
Section 254
  • 254. (1) Where compressed air is used to clean any surface, an employer shall ensure that
    • (a) a blowpipe is installed on the end of the hose,
    • (b) a control valve is part of the blowpipe, and
    • (c) appropriate protective equipment is worn by an employee using the compressed air.
  • (2) Where compressed air is used for blowing dust and other substances from clothing worn by an employee, an employer shall ensure that appropriate protective equipment for eyes is used by an employee and
    • (a) the compressed air supply is limited to 69 kPa, or
    • (b) safety nozzles are used that have the same pressure limiting effect.