ISO 16890 has been the internationally valid test standard for the classification of air filters since 2018. It completely replaced the previous industry standard EN 779. The introduction of ISO 16890 marked a paradigm shift. Filter collection efficiencies are now determined with regard to the fine dust fractions PM1, PM2.5 and PM10, which are also included as evaluation variables by the World Health Organization (WHO) and environmental authorities. In contrast to the EN 779 standard, the test procedure according to ISO 16890 is far more differentiated and is based on the local air quality of the respective process location. Air filters are evaluated in the test according to a broad particle spectrum of 0.3-10 µm, which is based on the typical mass distribution densities of urban and rural regions. The advantage of this is that the filter test takes into account the particle sizes actually prevailing in the air, so that the characteristic data determined are close to reality.
1. Who is the ISO 16890 standard relevant for?
2. Content and advantages of ISO 16890
3. Legal significance of the ISO 16890 standard
4. ISO 16890 has replaced EN 779
5. Why is EN 779 no longer up to date?
6. Can the EN 779 filter classes be transferred to ISO filter groups?
7. Separating capacity and filter classification according to ISO 16890
8. What is particulate matter?
9. Particulate matter and its health hazards
The ISO 16890 standard is relevant for manufacturers and distributors of air filters, as they are responsible for the performance and reliability of their products. However, the standard is also relevant for planners, plant engineers and operators of ventilation and air-conditioning systems. This is especially true for employers, who have a duty of care to their staff with regard protecting them from particulate matter and improving indoor air quality. This applies to ventilation systems in office buildings, cultural facilities, laboratories and hospitals, but also to the ventilation of factory and production halls. In terms of relevant industries, the ISO 16890 standard is significant for, among others, general air-conditioning technology, process air filtration in the pharmaceutical and food industries, the supply air of gas turbines and compressors, or exhaust and recirculating air filtration in painting technology.
According to the ISO standard, filters are divided into four fine dust groups according to their filter collection efficiency: PM1, PM2,5, PM10 and coarse dust (ISO coarse). These are the same rating parameters used by the WHO and the German Federal Environment Agency for measuring particulate matter (PM) pollution in the air. Filters meet the classification according to ISO 16890 if they achieve an effectiveness of at least 50% for the respective PM group.
Taking into account the actual particle sizes prevailing in the air during filter testing enables transparent and realistic performance evaluation. This makes it much easier and more reliable to select the best possible filters to meet specific individual requirements. You can view local particulate loads on the website of the German Federal Environmental Agency as well as the European (EEA) and American environmental authorities (EPA). This usually provides a sounds basis for characterizing the actual dust exposure on site. This is because the ambient air and, as a result, the most efficient filtration solution for your plants and processes differ significantly, depending on the location and the climatic conditions.
Until EN 779:2012 was finally withdrawn, ISO 16890 was initially a non-binding standard. During a transition period of 18 months, both EN 779 and ISO 16890 were valid. Since 2018, ISO 16890 has replaced EN 779 and has been established as the current binding international standard. How legally binding is a standard now? The German Institute for Standardization has stated: “The application of DIN standards is basically voluntary. Standards only become binding when they become the content of contracts or when the legislator makes compliance with them mandatory. In addition, they help in the event of potential liability: anyone who applies DIN standards – as recognized rules of technology – can more easily prove proper conduct.” (Source: © 2021 DIN Deutsches Institut für Normung e. V. )
For a long time, EN 779 was used as the most commonly applied method for classifying air filters, thus simplifying filter selection. EN 779 was last revised in 2012. The test method behind it was conceived some 40 years ago and tests the collection efficiency of air filters based on a uniform particle size of 0.4 µm using ASHRAE dust. Since the introduction of the EN 779 standard, air quality in Germany and other industrialized nations has improved. Coarse production dusts and industrial exhaust gases have decreased significantly as a result of compliance with emission limits. However, nitrogen dioxide and particulate matter in the atmosphere exceed the specified EU limits. Because minute particles in the air can affect human health, new target values for air pollution control have been defined. Therefore, filter systems in room air conditioning (HVAC) systems should ensure effective separation of fine dust. The replacement of the previous industry standard EN 779 by ISO 16890 has led to a radical change in the assessment of air filters.
Since the test and evaluation procedures of EN 779 and ISO standard 16890 differ greatly, it is not possible to make a like-for-like transfer. Existing conversion tables only serve as a rough guide to how filters of the old classes could be mapped onto the new system. In selecting suitable air filters, the critical particle size range for the application is the most decisive factor.
The table published by the EUROVENT Association in January 2022 serves as a guide for comparing filter classifications (Guideline 4/23). A 1:1 comparison between filter class according to EN 779 and filter class according to ISO 16890 is not possible.
EN ISO 16890 – Range of currently measured average separation efficiencies
|M 5||5 – 35 %||10 – 45 %||40 – 70 %|
|M 6||10 – 40 %||20 – 50 %||60 – 80 %|
|F 7||40 – 65 %||65 – 75 %||80 – 90 %|
|F 8||65 – 90 %||75 – 95 %||90 – 100 %|
|F 9||80 – 90 %||85 – 95 %||90 – 100 %|
The new ISO standard no longer divides filters into classes, but into four groups. The basis for evaluating the performance of a filter is its collection efficiency against a particle size spectrum of 0.3 - 10 micrometers. The prerequisite for the respective group is that a filter separates at least 50% of the corresponding particle size range. For example, if a filter separates more than 50% PM1 particulate matter, it is categorized as an ISO ePM1 filter. For this purpose, the respective collection efficiency is reported, rounded off in 5-percent increments. The new ISO standard evaluates not only particulate filters, but also coarse dust filters.
|ISO 16890||Group classification|
|ISO ePM1||ePM1, min ≥ 50 %|
|ISO ePM2,5||ePM2,5, min ≥ 50 %|
|ISO ePM10||ePM10 ≥ 50 %|
|ISO coarse||ePM10 < 50 %|
Particulate Matter(PM) is the term used to describe small to very small particles in the air that remain suspended in the atmosphere for some time; i.e., do not sink immediately. The definition goes back to the “National Ambient Air Quality Standards for Particulate Matter” of the US Environmental Protection Agency (EPA). The mass concentrations PM1, PM2.5 and PM10 are commonly used as the unit of measurement for particulate matter. Dust particles with an aerodynamic diameter of 10 micrometers or less (1 µm = one-thousandth of a mm) belong to the PM10 fraction. PM2.5 stands for particles with a diameter of 2.5 micrometers or less. Ultrafine particles with a diameter of less than or equal to 1 micrometer are assigned to the PM1 category. For these ultra-small particulate matter particles of the PM₁ category, which are dangerous to the human lung tract, there are as yet no standardized measurement methods and no statutory limit values. In contrast, organizations such as the WHO (World Health Organization) or the German Federal Environment Agency have set limits and annual averages for PM10 and PM2.5 dust concentrations. By way of comparison, a human hair has an average diameter of between 60 and 80 micrometers.
Natural sources of fine dust include pollen, fungal spores and dust from erosion processes. These can usually be seen with the naked eye due to their large particle diameter of around 10 µm. Far more dangerous are the small fine dust particles around 0.3 µm, typically produced by motor vehicle traffic, industrial emissions, building heating systems and agriculture. Particulate matter occurs not only in the outdoor air, but also indoors.
Particulate matter air pollution can affect our health and is a worldwide problem. Natural protective mechanisms of the human body keep out fine dust with a size of more than 10 μm. However, the smallest fine dust particles can enter the organism through respiration. Excessive concentrations of fine dust in the air increase the risk of stroke, heart disease, diabetes, asthma and lung cancer. Particulate matter can be especially dangerous in the case of immune deficiency, respiratory diseases or cardiovascular problems. Young children and senior citizens are also part of the risk group. Researchers even assume that people in areas with high air pollution levels are more sensitive to infection with SARS-CoV-2 viruses. In the case of infection – which particularly affects people with a pre-damaged respiratory and cardiovascular system – these people more often experience a severe course. With an efficient filter solution based on filter testing in accordance with ISO 16890, geared to the local air quality of the respective process location, we make a significant contribution to minimizing the risks of hazardous particulate matter and protecting people’s health.
ISO 16890 - Closer to reality
The new ISO 16890 enables the best filter solution