The pharmaceutical handbook leaves no doubt: by all means, compressed air used for pharmaceutical must be sterile in case it is used for artificial respiration. This regulation will only astonish compressed air experts at first sight, because the patient under anaesthetic requires breathing air corresponding to highest quality requirements and is guaranteed free from harmful impurities.
The pharmaceutical handbook takes this into consideration. In a supplement from the year 2000 it is specified: medical compressed air may maximally contain 500 ppm carbon dioxide, 5 ppm carbon monoxide and 67 ppm water vapour – which corresponds to an atmospheric dew point of -46°C. Also for other substances of content of the air e.g. for residual oil content and nitrogen oxides strict critical values apply.
With conventional refrigerant and adsorptions dryers designed for industrial applications these critical values are not achievable: here systems are used, which were developed particularly for sensitive applications "processing and supply of breathing air" as for example the breathing air units of the series ultrapure 2000, medipac 2000 and ALGs of the product brand Donaldson Ultrafilter.
These units prepare compressed air produced by the central compressor of the hospital in several stages. With the ultrapure 2000 and medipac 2000, filters, adsorptions dryers and an activated carbon absorber retain particles, dampness, oil vapour and odours; a downstream catalyst stage converts carbon monoxide into innocuous carbon dioxide. As last stage a high efficiency filter of the product brand Donaldson Ultrafilter with highly effective depth filtering medium is used, which frees the air from even the smallest particles and also removes possible abrasion particles caused by the desiccant. The five preparation stages are exactly aligned; the optional central control system offers additional safety and monitoring functions. For example during a decrease of pressure the system can automatically switch to a second processing line.
With the ALGs breathing air units an adsorption dryer is followed by a two-stage filter combination, which actually bind the vapour particles, and a three-stage processing system removes CO, CO2, SO2 and NOX as well as oil vapour and odours from the compressed air. Also here a downstream filter retains abrasion of the desiccant.
The series ultrapure 2000, medipac 2000 and ALGs supply compressed air, which fulfil to all requirements of medical compressed air and have accordingly been validated: the Fraunhofer institute for environment -, safety and energy engineering (CIRCUMSPECTION) in Germany has examined the processing systems in detail and stated that without exception the critical values comply to the values specified in the pharmaceutical handbook. Thus compressed air prepared by these systems can be used as "pharmaceutical" for the artificial respiration of patients.
Donaldson Filtration Asia Pacific is headquartered in Singapore. Donaldson Company, Inc., headquartered in Minneapolis, Minn., is a leading worldwide provider of filtration systems and replacement parts. Founded in 1915, Donaldson is a technology-driven company committed to satisfying customer needs for filtration solutions through innovative research and development. Donaldson serves customers in the industrial and engine markets including in-plant air cleaning, compressed air and gas purification, power generation, specialty filtration, off-road equipment and trucks. Our 10,000 employees contribute to the company’s success at over 30 manufacturing locations around the world. In fiscal year 2004, Donaldson reported sales of more than $1.4 billion and grew earnings for the 15th consecutive year. Donaldson is a member of the S&P MidCap 400 Index and Donaldson shares are traded on the New York Stock Exchange under the symbol DCI. Additional company information is available at www.donaldson.com.