How small is a micron and why does it matter?

One micron is 1/25,000 of an inch. To understand just how small this is, consider that human hairs measure between 30 and 120 microns. Dust mites can measure from 100 to 300 microns and staphylococcus bacteria measures .7 micron. The size of a given particle helps to determine the degree of potential threat to human health. Particles ranging from .3 to .9 micron present the greatest health concern. This is why .3 microns is the standard by which HEPA filtration is measured. Particles in this size range are small enough to get past the tiny hairs that line our breathing passages and too large to be easily exhaled. This is why .3 micron sized particles are considered the most penetrating size particle.

Particles larger than this also cause issues. Though they may not penetrate as deep, they can lodge themselves in airways and nasal passages causing allergic or asthmatic reactions. Irritating mid-range particles include house and textile dust, pollen, pet dander, dust mites and their feces, many bacteria, auto exhaust, mold spores, and particles from laser printers and copiers.

While smaller particles (.1 to .3 micron) can be inhaled and exhaled more easily than mid-range particles, even these minute particles may irritate breathing passages and lungs. Smaller particle filtration is particularly beneficial to people living with allergies, asthma, other respiratory conditions, or cardiovascular disease.

Blueair's patented HEPASilent filter technology is proven effective at capturing 99.97% of the tiniest .1 micron particles. This same filter technology earned the Blueair 501 Best of Class ranking in independent testing of Clean Air Delivery Rate (CADR), a measure of overall system performance. When optimum filter capability is the priority, Blueair is clearly the system of choice.

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