Saturday, March 8, 2014

Dust-Off Compressed Air Duster

"Air" - Includes List of Ingredients

Everyone calls this stuff "canned air," but that's not what it is. Sure it's canned, but it isn't air. Air, which is what we breathe, is a natural gas whose composition falls within a narrow range, at least on Earth. You can see he average composition at the bottom of the page.

A can of this stuff is actually filled with a substance called difluoroethane, which is an inert gas in the fluorocarbon family. Fluorocarbons are far more compressible than plain air, which is whhh they're often used as propellants and dusters instead of little pieces of the atmosphere.

Dust-Off comes in several sizes and packages. All of them have trigger sprays and most come with a tiny tube that you can fit into the spray nozzle. The tube gives you another four inches or so of reach so you can get into small spaces. A blast of compressed difluoroethane clears away dust, grit and cat hairs from sensitive gear like electronics, cameras, and audio-video equipment. I've used different brands of "canned air" for decades, going back to my very first SLR camera.

Difluoroethane is nasty stuff: it's what's called a volatile organic compound (VOC). When compressed into the can, it becomes a supercooled liquid with a boiling point of -25° C (that's -13° F). As a gas, it will suppress respiration. In its liquid form, which comes out the nozzle when the can's turned upside down, it can cause frostbite on human skin. If you use it as directed on electronic parts, however, the liquid contents expand immediately into a dry, anti-static gas that leaves no residue.

All brands have an added a "bitterant," a chemical whose nasty taste is intended to discourage "huffing." Some stores even require that buyers verify their age when buying this and similar products. VOCs such as difluoroethane are considered persistent organic pollutants, though Dust-Off claims that their product is "ozone-safe"

I've used lots of brands of "canned air" over the decades. Dust-Off may have a recognizable name, but in rality it's neither better nor worse than the others marketed since compressed hydrocarbons were replaced with fluorocarbons. Buy this one, or choose your air-powered dusters based on sale price.

PLUS: no residue, static or liquid; long reach
MINUS: nasty chemicals
WHAT THEY'RE SAYING: Most "canned air" products are pretty much the same, and none actually contains air. Let your bank account pick your next brand.

Standard composition of air at sea level with water vapor excluded:

Nitrogen (N2), 78.084%; oxygen (O2), 20.9476%; argon (Ar), 0.934%; carbon dioxide (CO2), 0.0383%; neon (Ne), 0.001818%; helium (He), 0.000524%; methane (CH4), 0.0001745%; krypton (Kr), 0.000114%; hydrogen (H), 0.000055%; xenon (Xe), 0.0000087%, etc....

There, now you've learned something!

No comments:

Post a Comment