Page 3 - Westbury Filtermation Catalogue

ISO 16890 Overview

The provision of clean air to breathe is one of life’s essentials. For many years this has been
overlooked to the point where currently over 73% of airborne particulate matter is manmade –
from combustion, emissions and industrial processes.
Generally the air quality in a building will reflect the air quality outside the building unless
conditioned air is provided. Local authorities and Government are now legislating for the quality
of air within a building to be to an acceptable standard and the occupants to be protected from
particulate contamination.

To simplify the classification of air the airborne particulates are indexed under four headings
these are:-

PM Course - Particles with a diameter greater than 10 μm
PM10 - Particles with a diameter of less than 10 μm

PM2.5 - Particles with a diameter below 2.5 μm

PM1 - Particles with a diameter below 1 μm
th
Note: 1 μm (micron) is 1 millionth of a metre or 1/25,400 of an inch.

As the particle sizes become smaller they become more

dangerous the human respiratory system, with PM1
(sub-micron) particles able to deeply penetrate the

capillary vessel walls within the lungs, with long term

exposure causing serious adverse health conditions

including; arteriosclerosis, adverse birth outcomes and
respiratory diseases in children.

Testing Air filters

The European test standard (EN 779), based on a test procedure around 40 years old, the test is
based on measuring the efficiency of filters based on exposure to a synthetic test aerosol with a
uniform particle size of 0.4 μm and classifying filters to a range of efficiencies ratings from M5 to
F9, however, these results are not indicative of a filters performance in a real life environment.
To rectify this the air filtration industry has now adopted a new testing method whereby filters can
be selected based on the air quality demands of each and every specific area.
Where Outdoor Air quality (OAQ) is poor and Indoor Air Quality (IAQ) needs to be good, the filters
can be selected to accomplish this.
Here’s how: -
ISO 16890

The new international ISO 16890 standard defines four new filter groups based on dust particle
size.
■ ISO Coarse
■ ISO PM10 particle size ≤ 10 μm
■ ISO PM2.5 particle size ≤ 2.5 μm
■ ISO PM1 particle size ≤ 1 μm
If this looks familiar, it’s because it follows the same format as the way Governments and Local
Authorities index them - as previously mentioned above.