Indoor Air Quality – Filtration Facts

Continuing our discussion of healthier workplaces, filtration is the topic for the day. To give you a visual, just picture the image of a custodian vacuuming with a Sanitaire that has the red cloth bag on the back. You know the ones…if the doorframe lightly touches the bag on its way around; there’s a “poof” of visible dirt. These vacuums boast the filtration levels of, well; they don’t publish anything other than “Filtration Standard” in the specs for these vacs.

Here’s another thing….the rate of fall for particulates that a vac such as this puts into the air is one foot per hour. So, the custodian empties the trash, dusts surfaces and then vacuums his or her way out of the office. That’s right; the last task puts dust into the air by the very act of removing dirt! And, of course, this settles on all the previously dusted surfaces by the time the lights are turned on (eight hours later) for the next day’s work. It’s no wonder that lack of dusting is one of the most frequent complaints a custodial company hears!

Just in case you think I’m picking on Sanitaire, I’m not. They manufacture a number of sealed HEPA vacuums which are designed for commercial use. These vacuums are filtering particles (keeping them inside the vacuum for removal from the building) of .3 micrometers in size with an efficiency of at least 99.97 percent. They are more expensive than the cloth bag models and they require paper filter bags, another cost item, but, assure that the soils are trapped until removal from the building. When these high filtration vacuums are introduced into a building, the amount of particulates decreases and the overall air quality increases. Asthma is one of the most common respiratory illnesses and symptoms can be greatly improved with cleaner air.

ULPA filtration sees even more efficiency with smaller particulate size. This technology is appropriate for most cleanroom environments, but, is overkill for general office or facility workplaces.

The vacuum cleaner: Seems like an insignificant part of the overall healthy building puzzle, but, is a key component of a successful Cleaning for Health Program. Prevention of soil entering a facility and then removal of what does get in are the goals!

Filtration Level

Particulate Size

Particulate Example



120 nanometers

Mold, bacteria



.3 micrometers

Dust mite feces, pollen