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How often do I need to test my compressed air to ensure it is suitable for breathing?

How often do I need to test my compressed air to ensure it is suitable for breathing?

All employers have a duty of care to ensure that the quality of breathing air from a compressed air system is constantly to the correct level.

BS EN 12021 is the compressed breathing air standard that details the required quality of compressed air for breathing air and how often it should be tested.

See link for an extract of this standard.

The required air quality for breathing air from compressed air systems is as set out below:

SubstanceExtract from BS EN 12021:2014 - Clause 6.
Contaminants – Compressed gas for breathing shall not contain 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 less than one tenth of a national 8 h exposure limit. For breathing air only the limit shall be less than one sixth of a national 8 h exposure limit. (WEL – See EH40)
Oxygen(21 ± 1) % by volume (dry air)
Carbon monoxide≤ 5ml/m3 (now at the same level as was formerly indicated in BS 4275)
Carbon dioxide500ml/m3
Oil0,5 mg/m3 (previously identified as lubricants [droplets or mist])
Odour/tasteShall be free from unsatisfactory odour or taste
WaterSee Note 1 and 2 - (Previously stated as "There shall be no free liquid water")
Note 1 – Compressed breathing air shall have a dew point sufficiently low to prevent condensation and freezing. Where the apparatus is used and stored at a known temperature the pressure dew point shall be at least 5 °C below the likely lowest temperature.

Note 2 – Where the conditions of usage and storage of any compressed air supply is not known the pressure dew point shall not exceed −11 °C.

Clause 180, Frequency of Examination and Tests of BS EN 12021, states the following:

“The frequency of examinations or tests should also be linked to the type of engineering control in use, the extent of any risk in the event of its failure or deterioration, and the likelihood that failure or deterioration will occur.”

Therefore a risk assessment needs to be completed to analyse how often testing should be completed to ensure the safety of the user.  The assessment will need to consider the air quality at the intake to the compressor, location of system, filtration equipment, maintenance and servicing schedule, age and reliability of the system, ambient temperature fluctuations, usage, user training and awareness and other site and equipment factors.

As a result of their Risk Assessment, most companies have tests completed every 3 months but assessments could determine this to be a more regular requirement.  Our specialist team are happy to assist in offering guidance in completing this assessment.  We also have the latest monitoring equipment to test your compressed air to see if it meets the required levels.

Contact us today on 01359 272828 for further guidance.

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