Easier breathing

Re: Easier breathing

in the HSE publication INDG 258 Safe Work in Confined Spaces, the risk of lack of oxygen in confined spaces can be caused by a reaction between some soils and atmospheric oxygen following the action of groundwater on chalk and limestone, producing CO2.

The CO2 displaces normal air in spaces such as ship holds, freight containers and lorries as a result of the cargo reacting with oxygen. Oxygen deficiency also occurs inside steel tans and vessels when rust forms.

The Irish COP for Safe Working in Confined Spaces states an oxygen-deficient atmosphere forms as a result of the displacement of air by another gas, various biological processes or chemical reactions.

The presence of dust in high concentrations (eg grain and flour dust in silos) poses a different risk - respiratory sensitiser, flammable atmosphere, engulfment hazard, etc. Solids can flow into the confined space drowning or suffocating the occupant and in powder form may be disturbed resulting in an asphyxiating atmosphere.

Asphyxiants cause a hazard by reducing the amount of oxygen available to breathe. The airborne concentration of a particulate needs to be quantified in order to select the appropriate protection factor. For example, a filtering face mask will clog with a high concentration of dust.

In an oxygen-deficient atmosphere (< 19 per cent) requiring a self contained breathing apparatus, quantifying the level of oxygen within the confined space rather than just the level of dust is also important.>

Anonymous | 14:42 07.09.2007| Report this answer as unsuitable