09/01/2008

Canned Air Can Hurt

Air in a can? Sounds about as harmful as a butterfly in a jar. So why did a
canned-air product cause a flash fire in a recent incident? Read on for
important facts about the potentially harmful gases in these pressurized
products.

The canned-air products people use to blow dust from computers, shredders, and
other electronic equipment are fairly safe when used properly. Misused or
abused, however, they become much more than dust-blowers.

In a recent incident, an employee working in a bowling alley was cleaning a
paper shredder with a canned-air product. When she tilted the can, its contents
started to spill out in liquid form. The liquid soon became a gas, which
accumulated as a highly concentrated, flammable gas cloud. The gas ignited into
a flash fire, causing burns to the employee's face.

The US-American Washington State Department of Labor and Industries has
released a hazard alert on the improper use of canned-air products. This
article summarizes the safety tips in the alert.

What "canned air" really is

"Canned air" is not the air you breathe. It is simply a common name for
compressed gases used in dust-blowing products, many of which are highly
flammable. These gases may also be toxic, depending on their concentration and
the degree of exposure.

Inside the can, the gas layer sits above a liquid layer of the same substance.
The user must keep the can in an upright position during spraying, to release
only the gas layer from the nozzle. Tilting the can allows the liquefied gas to
escape. If that happens, especially in an enclosed or poorly ventilated area,
the gas may reach a concentration so as to create a flammable atmosphere. Any
ignition source, such as an electrical switch, flame or spark in the area, can
easily ignite the flammable gas.

Besides being a fire risk, the liquid in a canned-air product can also cause
serious frostbite if it touches a person's skin. That's why most canned-air
products carry a warning not to tilt or shake the can. High concentrations of
the gas may also cause oxygen deficiency and breathing problems, but only in
very high concentrations in enclosed, non-ventilated areas. Respiratory
symptoms tend to only occur when the product is intentionally inhaled (a form
of substance abuse).

Canned-air products come in different forms, using different gases. One
commonly used, highly flammable gas is difluoroethane. Check the product label
or Material Safety Data Sheet (MSDS) to find out exactly what's in the can.

Safe use of canned air

You can easily protect people in your workplace from the hazards of canned-air
products by using the product as directed by the manufacturer. If possible,
switch from a flammable product to a non-flammable alternative. Hold the can in
an upright position while using. Use canned air in open, well-ventilated areas.


More info


AplusA-online.de - Source: Canadian Centre for Occupational Health and Safety (CCOHS)