There is ever-increasing awareness of the chemicals and allergens we come into contact with every day, particularly if you or a member of your family has asthma or allergies. We created the asthma & allergy friendly® Certification Program to help you improve your indoor environment by identifying products and services that can help to reduce allergens and create a healthier home environment.
But what is it that makes some air cleaners better for the indoor environment than others, and where do we draw the line to decide to certify an air cleaner as asthma & allergy friendly® ? We hope that the questions below will clarify this. Let us know if you have more questions!
Why do we certify air cleaners?
Our goal in the asthma & allergy friendly® Certification Program is to create a healthier indoor environment for you and your family, as well as to reduce allergens in the home. So we look at all elements of the indoor air environment.
Effective air cleaners can help to remove airborne allergen from a room. Different allergen particles have different sizes and they behave differently in the air. For example, while pollen particles can be relatively large (up to 100 micrometers), cat allergen particles can be as small as 1 micrometer wide. A micrometer is one thousandth of a millimetre. By comparison, the width of a human hair ranges from 20 micrometers to 180 micrometers.
Allergen particles in the air sometimes remain suspended in this zone where they can be breathed in, or they can settle on surfaces like chairs and the floor. If they have settled on a surface, activity or motion can move them back into the breathing zone.
When we test air cleaners, we look to recreate what happens in the home, so that we are testing the appliance in a way that is relevant to users. We make sure that the air cleaner is removing allergen from the air, but we also make sure that the allergen is being captured by the air cleaner, instead of just settling in surfaces in the room.
How do we test air cleaners?
- We use a controlled environmental chamber to test air cleaners.
- We set this up to mimic different types of rooms. In one set-up we use a carpet floor, and in another we use a hard floor.
- We add some items of furniture to the chamber, like a table and chair, so that there are surfaces where allergen can settle, like in household rooms.
- We then introduce test dust that contains allergen into the room through a vent.
- We run the air cleaner and monitor the particle level in the room.
- We also do a test with no air cleaner so that we can compare the two scenarios.
1. Removal of Allergen
Once the test is finished, we suck all the air out of the room through a filter, so that any allergen that remains in the air is captured. We compare this to the amount of allergen in the air when there is no air cleaner in the room. Our requirement is that there must be over 70% less allergen in the air when the air cleaner is operating.
2. Capture of Allergen
Just because there is less allergen in the air when the air cleaner is operating doesn’t mean that the air cleaner is capturing the allergen. It could be that the allergen is settling on the surfaces and the flooring, or even on the walls. This takes it out of the breathing zone, but it could be reintroduced to the breathing zone if somebody walks on the floor or rubs against the wall.
We test the filter of the air cleaner, to make sure that at least half of the allergen removed from the air is captured in the filter.
Some appliances can produce ozone as a side-effect of their operation. We make sure that if certified air cleaners do produce ozone particles, that they are at an extremely low level so it is unlikely to have an impact on the indoor environment. Air cleaners that are certified by us release less than 0.05 parts per million of ozone. We do not certify air cleaners that use ozone as their main mechanism of air purification.
What do we look for in electrostatic/ionizing air cleaners?
Ionizers release charged particles (ions) into the environment – these have either a positive or negative charge, and when they transfer this charge to an allergen particle it causes the allergen particle to stick to a surface, removing it from the breathing zone. Because there is some research that supports the safety of negative ions, we require that the majority of ions produced by this type of air cleaner are negatively charged. These air cleaners must still meet all of the criteria listed above, to make sure they remove allergen from the air, capture it in the appliance’s filter, and do not release ozone.
Do we certify in-duct air cleaners?
Yes, we have a certification standard for in-duct electrostatic air cleaners. To test this type of air cleaner, we install the air cleaner in a duct connected to an environmentally controlled chamber. We introduce allergen-containing test dust to the chamber, and monitor the allergen levels and the general particulate levels in the chamber over a 24-hour period. We require that the allergen levels are reduced by 70% at multiple times over the 24-hour period, and that general particulate levels are reduced by 75% multiple times over the 24-hour period. We require the same low ozone emission as we require for all air cleaners. Finally, we require that the performance of the in-duct cleaner after cleaning is within 2% of the initial performance, to make sure that its performance does not drop over time.
What else do we certify?
We have 46 different asthma & allergy friendly® certification standards for products and services, addressing all areas of the indoor air environment. Some of these relate to products which remove allergens and dust from the indoor environment, like vacuum cleaners, air cleaners, dehumidifiers, and washing machines. Some of them relate to products where it is important not to provide an easy home for allergens and that it is possible to remove allergen from them – like bedding, toys, and flooring. And some of them relate to household products that should make as little an impact on the indoor environment as possible – like flooring and paint.
You can find out which products are certified asthma & allergy friendly® and read more here: www.asthmaandallergyfriendly.com