Aren’t you excited about ISO standard 16890?
Wait! Come back! You didn’t give me a chance to explain how this intimidatingly-named industrial standard will affect human health. The International Standards Organization (ISO) is in the processes of issuing this new standard that involves air filters for general ventilation.
Why does it matter?
Filters that are used in an indoor environment have a big effect on human health. It’s worth noting here that we have a tendency to relegate air quality beneath other health concerns. For example, a lack of clean drinking water and food are frequently discussed as some of the greatest threats to human health, and with good reason. But consider that every day:
- You eat roughly 1.2 pounds of food
- You drink about 4.4 pounds of fluid
- You breathe around 33 pounds of air
Simply put, good air quality is one of the basic necessities to human health, as are healthy food and water.
When reading about air quality and filtration, you’ll hear the term particulate matter, or PM, mentioned frequently. It refers to solid particles of matter that are suspended in the air. Basically, the more PM in the air, the worse the effect on human health.
But there’s more to consider than simply the quantity of particulate matter in the air. The size of those particles is very important. PM10, for example, deals with particulates of 10 microns in size. PM1 deals with particles of 1 micron or less in size, and so forth.
Medical science is starting to understand that those smaller, ultrafine particles are the most dangerous. The reason for this is that the smaller the particle, the further into the human body it reaches. Large, coarse particles may only reach to the throat or upper respiratory system. Smaller pieces of matter may find their way into the lungs. The smallest particles make it to the bloodstream, brain, liver, and endocrine system. These tiny particles often carry polyaromatic hydrocarbons (PAH) with them, which have been shown to mutate human DNA. Not something you want in your major organs!
This issue is more important than ever, because studies have shown that these tiny particles are more numerous in population-dense areas, and because we’re spending more time indoors than previously. The World Health Organization (WHO) stated in 1999 that indoor air is 1000 times more dangerous than the air outside. The European Union has said that indoor air is 50 times more polluted than outdoor air. The concentration of harmful particles by indoor ventilation systems is part of the reason why. Additionally, it’s been reported that we’re spending up to 90% of our time in these indoor environments.
To combat the problem of poor-quality indoor air, we’ve produced a variety of filter elements to clean it up. Unfortunately, the various sizes, efficiencies, and ratings of the many filters available have made it difficult to choose a filter that will do the best job in keeping our precious air safe. Which leads me to my next questions:
What standards were already in place for general air filtration? Why do we need another one?
The standards were confusing and complicated. Consider:
- The USA uses the ASHRAE 52.2 standard to measure filtration efficiency. Its testing uses particles sized 0.3 – 10 micron, and results in three different classifications of filter. These three classes are often used to determine the commonly-used MERV (Minimum Efficiency Reporting Value) rating.
- Europe has adopted the EN779:2012 standard that used 0.4 micron particles in its testing.
- Asia and the Middle East have used a hodgepodge of ASHARE, EN779, and local systems in rating air filters.
These different systems were confusing and didn’t relate well to one another. It was particularly difficult to specify a standard for large construction projects, where design, engineering, and construction contractors might all be on different continents.
The difference between the standards is sometimes significant. The use of an electrostatic charge is one example. Some filters have such a charge applied to them in order to increase their efficiency. Unfortunately, that charge deteriorates as the filter ages, even in the first few weeks of use. Not all standards account for this change in efficiency over the life of the filter. Additionally, they mandate different sizes of dust for testing the filters.
The variables between these systems make it difficult to compare two different products if they use different standards. How can you tell how a product labeled using ASHRAE or MERV compares to a filter labeled with the EN779 system? If you’re not an air filtration expert, you probably can’t.
How are filters tested so that they can be classified?
Good question. Usually, it’s in a system that looks something like this:
It’s basically a duct system made into a circle. At one end, a dust feeder supplies a particulate into the duct. Next in the system is a device to measure the flow of air. Then comes a particle counter, followed by the filter being tested. Another particle counter is after the filter, and then a final high-efficiency filter is last, ensuring that test particles are not recycled through the system, skewing the results of the test. The system uses the two particle counters to determine how many particles are captured by the filter under test. Once you do the math, you have the efficiency of your filter.
What advantages are offered by the new standard?
Several, in fact:
- It will be used globally. The countries and organizations involved in writing this new standard approved it at a rate of 100%. Though approved, ISO standard 16890 has not yet been published. That is expected to happen in November 2016. The European Union has already agreed to adopt the new ISO standard, and will phase out EN779 likely in mid-2018. A longer process of adoption is expected for countries using the ASHRAE system.
- It standardizes a more rigorous system of testing. Now, for smaller particles, a filter’s rating is a reflection of how it performs both with and without an electrostatic charge. The size of dust under test is also mandated.
- It allows for an apples-to-apples comparison of different filtration products. Since all filters will eventually used this standard, they can be more easily compared to one another. This means that it’ll be easier to select the appropriate filter for your application.
The world of air filtration testing and international standards organizations may seem far removed from your day-to-day life. I know it does from mine. But everything done in the lab and the boardroom to create, publish, and enforce stricter, more accurate standards for air filtration is a step toward better human health. Keep an eye out in the years ahead for products that meet the ISO 16890 standard for filtration efficiency.
More information from a technical and health standpoint on the new standard can be found in an educational webinar prepared by Camfil and freely available on their website.