Oil-free compressor benefits explained

 Under the Department of Health’s Health Technical Memorandum, HTM 02-01, this is not the case, although ‘oil-free’ is an option. Mark Allen, vice-president of Medical Marketing at Atlas Copco/BeaconMedæs, who is involved with the National Fire Protection Association (NFPA) in the US, the Canadian Standards Association (CSA) in Canada, and the ISO SC-6 (a technical committee on indoor air), discusses how harnessing such technology impacts on production of medical air under the pharmacopeia, and the potential opportunities to reduce maintenance and system problems

On page 71 of HTM 02-01 there is a quiet statement that ‘oil-free compressors may be beneficial in reducing filter requirements’. This little statement, delivered, as it were, sotto voce, means what, exactly? Perhaps a good place to start would be to compare other world standards where this comment is not made quietly at all, but is central to the ethos of producing medical air. Examples include the NFPA for the US, the AS standard in Australia, the JIS in Japan, and the CSA in Canada.

The CSA may be the most relevant, since, like the HTM, it is a ‘flavour’ of the ISO 7396-1, deriving from (and sharing the number of) the parent ISO document. Under the CSA, the only permitted compressors are oil-free and oil-less. Three particular differences with the HTM immediately appear: there is no requirement to remove the oil from the air; the filtration required is less complicated, but the air must be taken from the best available outdoor source. These requirements recognise an important point: for most of the world, most of the time, clean outdoor air already meets the pharmacopeia. Most of the filtration we add to air systems is not there because the air was ‘bad’ to begin with – after all, we breathe it every minute of every day. All that filtration is there because the compressor contaminates the air, and we naturally cannot allow that ‘mess’ to reach the patient.