FEATURE HAZARDOUS AREAS & SAFETY HOW TO AVOID CONTAMINATED BREATHING AIR


Andy Lill, business development manager for Quality Air at Atlas Copco, highlights the hazards of contaminated workplace breathing air, and the role of compressed air purification as a safe alternative


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n some work areas, particularly in industrial sectors such as oil and gas,


chemical, pharmaceutical and manufacturing, the ambient atmospheric air is too contaminated for operatives to breathe without risk to health. In these cases, it is common practice, and an essential duty of care, for employers to provide a safe compressed air system as an alternative source of breathing air. But the emphasis must be on ‘safe’ and


it is important that the risks are understood. Standard compressed air is probably insufficient to ensure consistent breathing air quality and it is vital to realise that untreated compressed air is not clean. The compression of ambient air concentrates the normal contaminants already present in the air and can also introduce other constituents such as oil vapours, condensed water and bacteria that can effect operator well-being and long-term health. The solution to the problem is the


addition of breathing air purification equipment to the compressed air supply, controlled and monitored in accordance with compressed air for breathing quality standards such as EN 12021:2014 'Respiratory equipment - Compressed gases for breathing apparatus’. In selecting the appropriate purification


equipment, it must be remembered that contaminates will be in one of three states of matter: solid, liquid or gaseous. The corresponding contaminant limits within EN 12021:2014 requirements are as follows: Odour: The gas shall be free from


unsatisfactory odour and taste Oxygen: Content shall be 21% +/- 1% Carbon Dioxide: Content shall be less


than 500 ppm Carbon Monoxide: Content shall be less


than 5 ppm Oil: Content shall be less than 0.5mg/m3 Water (for airlines less than 40 BarG):


Where the apparatus is used and stored at a known temperature the compressed breathing air shall have a dew point sufficiently low to prevent condensation and freezing and be at least 5°C below the likely lowest temperature. Where the conditions of usage and storage of any compressed air supply is not known, the pressure dewpoint shall not exceed -11°C In order to limit health risk and to


comply fully with regulatory requirements 32 MAY 2020 | PROCESS & CONTROL


it is essential that assured purity levels are achieved by the purification unit within the compressed air network. Breathing air purifiers should have the capacity to take air from any type of compressor and convert it into ultra-clean breathing quality air. It needs to combine the functions of water separation, contaminant filtration and desiccant drying of the air output. One such unit, Atlas Copco’s BAP


(breathing air purifier) range, features seven vital functions: a water separator that removes any liquid water, a bulk aerosol filter to eliminate oil and water content, a fine coalescing filter to remove even smaller particles of oil and water from the supply, plus a desiccant dryer to take out any remaining water and CO2. An activated carbon filter is included to remove gaseous impurities and a catalyst takes care of CO oxidation. Finally, a bacteria filter eliminates micro-organisms and fine particles. This level of capability ensures the


breathing air purifier complies with a wide range of standards and regulations, such as OSHA Grade D, NFPA-99, CSA Z180.1- 00, CGA G7.1-1997, EN 12021, BS 4275, ISO 14971, OHSAS 18001, European Pharmacopeia and other International Breathing Standards. Such compliance guarantees a safe working environment in applications ranging from shot-blasting, tank cleaning, tunnelling, pharmaceutical manufacturing, spray painting, offshore/ marine processes, asbestos removal, to high-pressure cylinder filling and many others. Within a purified compressed air supply


network, it is essential to carry out air quality tests to ensure that the control


Compliance with standards and


regulations guarantees a safer working environment


measures put in place are delivering the air quality required. In the UK, EN12021 advises that samples should be taken and analysed at least every three months or more frequently if there has been a change in, or any concerns relating to, the production process. In the HSE guideline document


Employers should get to know the details of the following regulations as they apply to a variety of industry requirements:


Management of Health and Safety at Work Regulations 1999 (SI 1999/3242)


The Personal Protective Equipment Regulations 2002 (SI 2002/1144) Schedule


The Work in Compressed Air Regulations 1996 (SI 1996/1656)


Control of Substances Hazardous to Health (COSHH) Regulations 2002 (SI 2002/2677 − also as amended by S.I. 2004 No. 3386 in respect of the term "workplace exposure limit")


Respiratory Equipment at Work (HSG53) it states the frequency of such tests should be based on a risk assessment, should take place at least every three months and more often when the quality of air cannot be assured to these levels. For mobile breathing-air compressors in


the UK, COSHH stipulates that the employer should ensure that, wherever a compressor is located, the quality of air it supplies is not compromised by nearby contaminants. It strongly recommends that for mobile compressors the air quality is tested whenever the unit is first moved into a new position or if prevailing wind conditions change. The final decision on frequency of tests


is the responsibility of the employer and should reflect local legislation and also the task and frequency of use. It should be incorporated into risk assessments and updated regularly to reflect results from ongoing breathing air tests. EN12021:2014 is now the standard to


indicate contaminant levels for breathing air both in the UK and in the EU expressed as “in any event all contaminants shall be kept to as low a level as possible and shall be below the national exposure limit”. It goes without saying that only


Atlas Copco’s BAP (breathing air purifier) range features seven vital functions


competent personnel should be involved in designing breathing air systems and preparing risk assessments. To assist employers in this complex area, it is recommended that management seek the assistance of compressed air system suppliers with specific breathing air capabilities and product ranges, such as Atlas Copco, who will have competent persons trained in providing and maintaining breathing air systems.


Atlas Copco www.atlascopco.com


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