LEARNING TASK 4 : Describe general safety precautions and procedures
Confined space work
Confined space describes any enclosed temporary working area that has limited access and egress and is not made for continuous human occupancy. Systematic procedures must be followed for any worker to enter a confined space.
If entering a confined space is unavoidable, supervisors are given the responsibility to ensure that all the necessary precautions are taken; to check safety at each stage; to follow all written procedures; and to ensure that all workers are suited for the work and properly trained before they enter the confined space.
Mechanical and electrical isolation of equipment is essential if it could otherwise inadvertently operate or be operated. If gas, fumes, or vapours could enter the confined space, supply piping needs to physically isolate airborne hazards. In all cases, a check should be made to ensure isolation is effective. Check on the provision for ventilation.
You may be able to increase the number of openings and therefore improve ventilation. Mechanical ventilation may be necessary to ensure an adequate supply of fresh air. This is essential where portable gas cylinders and diesel-fuelled equipment are used inside the space because of the dangers from buildup of engine exhaust. Provision must be made for breathing apparatus to be made available if it is not possible to maintain adequate oxygen levels for confined space entry.
Air testing of the environment is necessary to ensure that it is free from both toxic and flammable vapours and that it is fit to breathe.
A competent person should carry out testing using a suitable gas detector that is correctly calibrated. Where the risk assessment indicates that conditions may change—or as a further precaution—continue monitoring the air to detect any changes.
The provision for non-sparking tools and specially protected lighting is essential where flammable or potentially explosive atmospheres are likely. In certain confined spaces (e.g., inside metal tanks), suitable precautions to prevent electric shock include use of extra-low- voltage equipment (typically less than 30 V) and, where necessary, residual current devices such as ground fault circuit interrupters (GFCIs).
Immediate means of communication must be made available for workers in confined spaces to call the standby person, and the standby person must have a means to call rescue personnel.
A rescue team with properly trained personnel and a rescue plan must be in place before any worker is allowed to enter a confined space. all lifelines, harnesses and lifting equipment must be approved for the application, and the standby person must be able to use the equipment to lift the person from the confined space.