In recent years, employers have become increasingly more aware of their responsibility to comply with breathing air standards and regulations. The most commonly specified standard for the prescription of breathable air is BS 4275:1997 ‘Guide to implementing an effective respiratory protective device programme’ which was withdrawn on 22 November 2005.

This was then replaced on that date by BS EN 529:2005 respiratory protective devices. Recommendations for selection, use, care and maintenance. Unlike BS 4275 the new standard BS EN 529 does not identify an air purity specification but indicates in annexe A, clause 4.5 that reference be made to BS EN 12021.

BS EN 12021 ‘Respiratory protective devices – Compressed air for breathing apparatus’ is now the only standard to indicate contaminant levels for breathing air both in the UK and in the EU.

Breathing Air Filtration

There are many different types of products available to provide clean and safe air for breathing apparatus.

A complete 5 stage filtration system is recommended to provide clean and safe compressed air that can be used for breathing apparatus. You can purchase each stage of filtration separately or most commonly available are all in one filtration systems.

Air Quality Testing

If your compressed air system is being used for breathing air, you have a legal responsibility as an employer to have regular Air Quality Testing carried out and the correct maintenance plan in place. Compressed air should be tested for the following:

SubstanceExtract from BS EN 12021 – Clause 6.
Contaminants – Compressed air for breathing apparatus shall not contain any contaminants at a concentration, which can cause toxic or harmful effects. In any event, all contaminants shall be kept to as low a level as possible and shall be far below the national exposure limit. (WEL – See EH40)
Oxygen(21 ± 1) % by volume (dry air)
Carbon monoxideAs low as possible but not to exceed 15ml/m3
(formerly BS 4275 specified 5ml/m3)
Carbon dioxide500ml/m3
Oil mistLubricants (droplets or mist) 0.5 mg/m3
Odour / TasteWithout significant odour or taste.
Water (Liquid)There should be no free liquid water.

We can carry out complete Breathing Air Quality tests to meet these standards.

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