Canada–Nova Scotia Offshore Area Occupational Health and Safety Regulations — 140
Requirements 140 (1) Every employer must ensure that no hot work is carried out at a workplace under its control unless (a) the atmosphere in the work area and any adjacent area that may be affected by the hot work is continuously monitored for flammable, explosive or combustible substances, if there is a risk of them being present in those areas, and all persons in those areas are alerted if there is a risk of any of those substances being present in concentrations exceeding the values referred to in paragraphs (b) and (c); (b) the atmospheric concentration of oxygen is less than 22.5%; (c) the atmospheric concentration of any other flammable, explosive or combustible substance is less than 5% of its lower explosive limit; (d) all potential sources of flammable, explosive or combustible substances have been identified, isolated and locked out; (e) the work area and any adjacent area that may be affected by the hot work are free of all materials that could produce a toxic, flammable, explosive or combustible vapour when heated; (f) a competent person maintains a fire watch patrol; and (g) firefighting equipment appropriate to all fire hazards that may arise is readily accessible. Welding, cutting and allied processes (2) The employer must ensure that welding, cutting and allied processes are carried out, to the extent feasible, in accordance with the requirements set out in CSA Group standard W117.2, Safety in welding, cutting, and allied processes . Use of gas (3) The employer must ensure that, if gas is used in the carrying out of hot work, (a) all hose lines or pipes that convey gases to the burner, and all couplings, are clearly identified to ensure they are not interchanged; (b) only standard fittings are used and those fittings, as well as any regulator or automatic reducing valve on the equipment being used, are designed for the gas being used; (c) safety devices that prevent the reverse flow of fuel, gas, oxygen or air from the torch end of the equipment being used to the supply lines and that prevent a flame from burning back from the torch end into the supply lines are used; (d) all gas cylinders, piping and fittings are located to prevent them from being damaged or are otherwise protected against damage; (e) all regulators and associated flexible connecting hoses are tested for leaks, using a substance that is not oil-, fat- or grease-based, immediately after being connected to a gas cylinder or other gas supply; (f) while the hot work is being carried out, a person is stationed in a location that allows them to immediately cut off the gas supply in an emergency; (g) the gas supply is immediately cut off if a leak is detected during the test referred to in paragraph (e) or during the hot work and no further work is carried out until the leak has been repaired and another test has been carried out to verify the success of the repair; (h) all parts of the equipment being used are free from defects, leaks, oil and grease; (i) the torch is ignited only with a device that is designed for that purpose; and (j) hot metal parts and electrode stubs are disposed of or otherwise dealt with when not in use in a manner that dissipates heat and minimizes the potential for ignition and fire.