It is essential that the atmosphere in any confined space is tested and passed fit before entry. An atmosphere fit for working in is one that is breathable (i.e. has about 21% oxygen) and there are no toxic, flammable, or explosive gases or vapours present. It is also important that there is no enrichment of the atmosphere with inert gases or oxygen.
Evaluation of confined space atmospheres must include measurements for oxygen plus any other relevant gas.
Falls and Entrapment
Precautions to avoid trips and falls are basically common sense, vigilance and good housekeeping. Keep floors inside the space as dry, grease-free and free from obstructions as far as possible.
To reduce the risk of electric shock, it is recommended to locate electric welding power sources outside and ensure all cables entering the area are properly insulated.
Welders and others should make sure that they are insulated from the workpiece and grounded by dry insulation.
Radiation and Heat
Wherever possible use radiation and heat shields to prevent burns.
Take plenty of replacement fluid when working for lengthy periods in hot conditions to avoid dehydration and possible heat exhaustion.
Fire and Explosion
When using fuel gas processes extra care should be taken to ensure that the equipment is not leaking, as this can result in build-up of gas and possible explosion.
Oxygen should never be used to enrich the atmosphere in a confined space. It is a severe fire and explosion hazard.