By providing effective training in the selection and use of gas detection equipment, such as that carried out at Draeger's purpose built sewer and crawl galleries at Blyth, employees can be shown how to assess, understand and control the hazards involved.

Defining the Hazards
The seriousness of the hazard is obviously dependent upon the nature of the substance and/or the application concerned. The dangers can be dramatically increased, however, if a combination of hazards exists.

Toxic gases or vapours, for instance, can poison or suffocate personnel and work in progress, such as cleaning, welding and painting can produce dangerous fumes. It is also possible that the toxic gases and vapours that are created during previous work might still be present upon re-entry at a later date.

A build up of flammable gases or vapours can also burn or explode. Formed by scale or residue inside the confined space or by cleaning methods and decomposition of organic materials, etc., these substances can ignite or explode upon exposure to an open flame or a spark. In addition, some applications, such as oxy-propane cutting, may create an excess of oxygen which would increase the danger of spontaneous combustion.

An atmosphere containing less than 21 per cent oxygen is known as being oxygen deficient and can be life-threatening. Caused by oxidation, rusting, fire, growth of bacteria, or displacement of the oxygen by another gas, oxygen deficiency can cause drowsiness. It can also lead to euphoria, a 'happy' state which prevents the worker from realising the dangers in time to escape.

Ensuring Safety through Training
The most frequent causes of serious accidents are that people do not always recognise a confined space hazard when they see one. Instead, they tend to rely on their senses and do not seem to realise that it is impossible to see, hear, touch, taste or smell most dangerous atmospheres.

To ensure absolute safety, employees should always assume that hazards are present until they are sure that they are not. It is obviously essential that workers first test and then continue to monitor the confined space before entering the area and whilst working within it. For this reason, the Draeger course highlights the need to use appropriate equipment in each area, i.e. at the bottom of the space and in corners and explains why areas should be tested, cleaned and tested again. It also covers the use of breathing apparatus and respiratory protection equipment as well as general safety procedures.

Further information is available from

Gary Turnbull,
Draeger Safety UK Limited,
Ullswater Close,
Blyth Riverside Business Park,
Blyth,
Northumberland, NE24 4RG.

Tel: 01670 352891.
Fax: 01670 356266

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