Write a toolbox talk on trench safety

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## OCCUPATIONAL HEALTH AND SAFETY, 2020 S-15.1 REG 10 - (6) If a worker is required to enter a trench, an employer or contractor shall: - (a) install ladders, stairways or ramps to provide a safe means of entrance to and exit from the trench; and - (b) ensure that the ladder, stairway or ramp is located not more than 8 metres from a worker working in the trench. - (7) An employer or contractor shall ensure that workers are instructed in and comply with the requirements of this section. 31 Dec 2020 c S-15.1 Reg 10 s17-7. ## Excavated shafts and tunnels - 17-8 (1) An employer or contractor shall ensure that: - (a) during excavating, the walls of an excavated shaft or tunnel are retained by temporary protective structures that are adequate: - (i) for the type of soil; and - (ii) to prevent collapse or cave-in of the walls of the excavated shaft or tunnel; - (b) during the excavating of an excavated shaft that is 3 metres or more deep or of a tunnel, the walls of the shaft or tunnel are retained by temporary protective structures designed and certified by a professional engineer to be adequate for the protection of workers in the shaft or tunnel and constructed, installed, used, maintained and dismantled in accordance with that design; - (c) a solid or wire mesh fence at least 1 metre high, or other equally effective means of preventing material from falling into an excavated shaft or the surface opening of a tunnel, is provided around that shaft or opening; and - (d) substantial gates that are not less than 1 metre high are installed in every opening in a fence provided pursuant to clause (c) and the gates are kept closed except when being used. - (2) A worker who opens a gate mentioned in clause (1) (d) shall close the gate after the worker no longer has a need to keep the gate open. - (3) An employer or contractor shall provide suitable equipment to keep a tunnel or excavated shaft free from any accumulation of water. 31 Dec 2020 c S-15.1 Reg 10 s17-8. ## Bor…

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- (b) where a trench cage is used, within the trench cage. - 168 An employer shall ensure that excavated material is - (a) kept at least 1 m away from the edge of an excavation or trench, unless an engineer certifies a shorter distance as adequate; and - (b) located a sufficient distance from the edge of the excavation or trench to ensure the excavated material does not re-enter the excavation or trench. Clause 168(b) amended: O.I.C. 2000-130, N.S. Reg. 52/2000. - 169 (1) An employer shall ensure that an excavation or trench in which a person works is kept reasonably free of water. - (2) Where a person may be exposed to a hazardous substance or to an oxygen rich atmosphere in an excavation or trench, an employer shall ensure that, before the person enters the excavation or trench, - (a) testing is performed to - (I) determine the concentration of any hazardous gas, vapour or dust, flammables, the concentration of oxygen and oxygen deficiency in the atmosphere in the immediate area of the excavation or trench where the work is to be performed, - (ii) ensure that the concentration of a chemical substance or a mixture of chemical substances in the excavation or trench does not exceed its occupational exposure limit under Part 2: Occupational Health of the Workplace Health and Safety Regulations made under the Act or 50% of its lower explosive limit, and - (iii) ensure that the level of oxygen in the atmosphere in the excavation or trench is not less than 19.5 % and not more than 22.5 %, unless the employer can demonstrate that an unsafe oxygen level is not possible in the circumstances; and Clause 169(2)(a) replaced: O.I.C. 2013-65, N.S. Reg. 53/2013. - (b) adequate precautions are taken to reduce the risk of injury to a person. Subsection 169(2) replaced: O.I.C. 2000-130, N.S. Reg. 52/2000. - (3 ) No person shall store hazardous substances in an excavation or trench. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\…

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## OCCUPATIONAL HEALTH AND SAFETY, 2020 - (3) An employer or contractor shall ensure that a temporary protective structure in an excavation more than 3 metres deep is designed and certified as safe by a professional engineer and installed, used, maintained and dismantled in accordance with that design. 31 Dec 2020 c S-15.1 Reg 10 s17-6. ## Protection against cave-in of trenches - 17-7 (1) If a worker is present in a trench that is more than 1.2 metres deep, an employer or contractor shall ensure that the worker is protected from cave-ins or sliding material by: - (a) cutting back the upper portion of the walls of the trench in accordance with subsection 17-4(2); - (b) installing a temporary protective structure; or - (c) a combination of cutting back the walls to the slope specified in subsection 17-4(2) and installing a temporary protective structure that extends at least 300 millimetres above the base of the cut-back. - (2) An employer or contractor shall ensure that a temporary protective structure required by clause (1) (b) or (c) is: - (a) designed and installed using shoring made of number 1 structural grade spruce lumber having the dimensions set out in Table 14 of the Appendix for the type of soil and the depth of the trench or made of material of equivalent or greater strength; or - (b) designed by a professional engineer and constructed, installed, used, maintained and dismantled in accordance with that design. - (3) An employer or contractor shall ensure that a temporary protective structure in a trench more than 6 metres deep in type 1, type 2 or type 3 soil or in a trench more than 4 metres deep in type 4 soil is designed and certified as safe by a professional engineer and installed, used, maintained and dismantled in accordance with that design. - (4) An employer or contractor shall ensure that: - (a) shoring is installed and removed in a manner that protects workers from cave-ins and structural collapses and from being struck …

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- (c) Access and egress -(1) Structural ramps. (i) Structural ramps that are used solely by employees as a means of access or egress from excavations shall be designed by a competent person. Structural ramps used for access or egress of equipment shall be designed by a competent person qualified in structural design, and shall be constructed in accordance with the design. - (ii) Ramps and runways constructed of two or more structural members shall have the structural members connected together to prevent displacement. - (iii) Structural members used for ramps and runways shall be of uniform thickness. - (iv) Cleats or other appropriate means used to connect runway structural members shall be attached to the bottom of the runway or shall be attached in a manner to prevent tripping. - (v) Structural ramps used in lieu of steps shall be provided with cleats or other surface treatments on the top surface to prevent slipping. - (2) Means of egress from trench excavations. A stairway, ladder, ramp or other safe means of egress shall be located in trench excavations that are 4 feet (1.22 m) or more in depth so as to require no more than 25 feet (7.62 m) of lateral travel for employees. - (d) Exposure to vehicular traffic. Employees exposed to public vehicular traffic shall be provided with, and shall wear, warning vests or other suitable garments marked with or made of reflectorized or high-visibility material. - (e) Exposure to falling loads. No employee shall be permitted underneath loads handled by lifting or digging equipment. Employees shall be required to stand away from any vehicle being loaded or unloaded to avoid being struck by any spillage or falling materials. Operators may remain in the cabs of vehicles being loaded or unloaded when the vehicles are equipped, in accordance with §1926.601(b)(6), to provide adequate protection for the operator during loading and unloading operations. - (f) Warning system for mobile equipment. When mobile equipment is operated ad…

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455 (2) An employer must ensure that if a worker is in a trench that is more than 1.5 metres deep, the trench is supported or sloped so that the worker can reach the safe point in order to enter and leave. ## Temporary protective structures - 456 (1) An employer must ensure that temporary protective structures in an excavation - (a) 3 metres deep or less are of sufficient strength to prevent the walls of the excavation from caving in or otherwise moving into the excavation, and - (b) more than 3 metres deep are designed, constructed and installed in accordance with the specifications of a professional engineer. - 456 (2) The specifications of a professional engineer for subsection (1)(b) must include - (a) the size and specifications of the structure, including the type and grade of materials used in its construction, and - (b) the loads for which the structure is designed. 456 (3) An employer must ensure that, before beginning an excavation, a foundation that may be affected by the excavation is supported by a temporary protective structure designed, constructed and installed in accordance with the specifications of a professional engineer. ## Alternatives to temporary protective structures 457 (1) Despite section 456, an employer may install the following as temporary protective structures in trenches: - (a) if the trenches vary in depth from 1.5 metres to 6 metres, shoring, stringers and bracing constructed of lumber that complies with Schedule 9, or a material that has equal or greater properties to those of the lumber; - (b) exterior grade plywood as a substitute for 38 millimetre shoring elements if - (i) the plywood meets the requirements of CSA Standard O121-08, Douglas Fir Plywood or CSA Standard O151-04, Canadian Softwood Plywood , - (ii) the plywood is at least 19 millimetres thick, - (iii) the trench is not more than 2.7 metres deep, - (iv) uprights are installed at intervals of not more than 600 millimetres centre-to-centre, - (v) cross braces do …