In the latest draft of the air purifier national standard publicity, we also saw a key indicator: the release of harmful substances.
People can't help but wonder: the air purifier is designed to eliminate toxic substances. If it still produces harmful substances, how to choose between the pros and cons?
Then, let us first understand what these two requirements mentioned in the new national standard are.
According to the formulation of the new national standard publicity draft, we found the expression in Chapter 32 of GB-4706.45:
"The ozone concentration produced by the ionization device should not exceed the specified requirements.
Experiment in a closed room, the size of the room is: 2.5m*3.5m*3.0m……
……The air purifier is energized at the rated voltage for 24H. ...
The ozone sampling tube is set at a position 50mm away from the air outlet of the air purifier. At the beginning of the test, the background ozone concentration is measured first, and then the maximum concentration measured in the test is subtracted from the background ozone concentration.
The percentage of ozone concentration should not exceed 50ppb. "
In GB21551.3, in addition to ozone, ultraviolet rays, TVOC and PM10 are added to the definition of hazardous substances, as shown in the following figure:
At present, the mainstream technology of purifiers on the market is HEPA filter type. Another major technology, electrostatic purifiers, produces ozone, which is the focus of consumers' attention.
Many consumers "talk about ozone and change color", or feel toxic when smelling ozone, which is actually caused by a psychological effect of excessive worry. Trace ozone has long been applied to various occasions that need to be disinfected, such as ozone dishwashers, ozone sterilizers, and ozone water purifiers. Under normal circumstances, ozone is extremely unstable and easily decomposed into oxygen. The half-life of ozone in the air is generally 20-50 minutes, which accelerates with the increase of temperature and humidity, and is volatile.
Therefore, after the introduction of the new national standard, merchants must indicate the amount of ozone released by their products according to the testing methods specified in the national standard. Consumers also have evidence to follow when shopping.
What needs to be reminded is that in order to improve the filtering effect and to remove formaldehyde, odor and other harmful substances, many businesses have added various technical means such as static electricity, negative ions, ultraviolet rays, activated carbon, photocatalyst, etc. in addition to HEPA filters. These technologies are likely to produce various harmful substances.