Seal testing for air handling equipment.
To guarantee the correct filtration effect for construction vacuums, air filters and negative air pressure machines, their filtration effect should be regularly tested, especially before use.
According to law the responsibility for machine safety falls not only on the employer, but also partially on the manufacturer, importer, seller, or other actor who introduces the machine to Finnish markets or use. The law also covers the sale and rental of machines already in use.
Machines already in use in Finland that meet the safety requirements may be resold and taken into use in Finland as long as they are kept in a condition that meets the standards.
The use of aftermarket filters for negative air pressure machines and vacuums in asbestos work should be carefully considered, as the manufacturer has specified their own filters for the machines’ specification guarantees. Aftermarket filter retailers may not necessarily have ensured the compatibility of the filter with the machine in question.
Government Decree on the Safety of Asbestos Work 798/2015
Paragraph §14 states the following:
“The employer shall ensure that the capacity of the filters on the air handling equipment is good enough and no more than 0.01 fibres per cubic centimetre of asbestos dust can be spread from the working equipment to the clean areas of the site” In practice this means the device should be tested before being taken into use and when changing filters. ASTQ Rental House uses DOP/POA testing here, which is the method commonly used in Central Europe.
“Separate provisions are laid down on how to select and use work equipment and ensure their working condition.” According to law the responsibility for machine safety falls not only on the employer, but also partially on the manufacturer, importer, seller, or other actor who introduces the machine to Finnish markets or use. The law also covers the sale and rental of machines already in use.
Equipment testing
Measuring the device’s separation ratio is done with a photometer (EN1822). A measuring system consisting of a particle generator and meter can be used.
eparation ratio E=100·(1-N2/N1) (%), where N1 is the particle density before filtration and N2 the particle density after filtration. Separation ratio is always measured after changing the HEPA filter, to ensure the device is safe to use (image to the right)**
**source: image and text ASBTEST 2019. Malliratkaisu asbestipurkutöihin
Test particles are fed into the device’s intake and density is measured before and after filtration. The particles used in the test are so few in number and small in size that they do not affect the functioning of the device.
The devices being tested must be clean and equipped with new HEPA filters which the manufacturer has guaranteed as class H13. If the test fails, we do not write a report for failures. We charge 50% of the testing price for fails.
Limits
The employer must ensure that the air processor’s filter’s separation ratio is sufficient and that tools do not release over 0,01 asbestos particles per cubic centimetre of air in clean spaces. Tools must be kept safe to use by regular care and maintenance. Maintenance and other actions taken to ensure functionality must be recorded in the device’s logbook.
A new device’s air filtration must be measured before it is used in asbestos removal
The exhaust air’s particle density may not exceed 0,01 particles. If the particle density exceeds 0,01 the machine must be maintained/repaired and followed up with a test. Repairs and tests are to be done until the exhaust air’s particle density no longer exceeds 0,01 particles per cubic centimetre
Studies
Limits will not be exceeded if the device’s filtration level is at least class H13 according to EN 1822:2009. An negative air pressure machine’s separation ratio is measured with a DOP test, where the device’s filtration ability with the MPPS* method should be at least 99,95% with 0,3 µm particles. I.e. the result should be under 0,05%
*(most penetrating particle size)
Testing Equipment
ATI Aerosol Photometer 2i s/n: 32756 calibration valid until 15.5.2020
ATI I probe
ATI Aerosol Generator 5D s/n: 32792
Manufacturer: ATI Techniques International
DECONTA Air/particle mixing chamber
Testo 510 pressure difference meter, VTT metering cone
