Canned Air - A Hazard?

Recently, Department of Labour and Industries Washington State, has issued a 'hazard alert' on 'canned-air' products. Most of us are aware of aerosols in cans and their associated hazards, but what is to do with canned-air? For that matter what is canned air?
'Canned air' is compressed gas used for dust-blowing purposes (used for cleaning keypads, small electronics etc). Normally, the substance (e.g. difluroethane) inside the can is a layer of liquid and gas above it .
An incident:
An employee who was cleaning a paper shredder with a canned-air product. The can was tilted too far so that the liquid contents spilled out and evaporated into a flammable cloud. The gas then ignited, burning the employee's face.

Note: The user must keep the can in an upright position during spraying to release the gas from the nozzle. Tilting the can allows liquified gas to escape leading to the formation of flammable atmosphere. A source of igntion (such as flame, spark) does the rest....

Basic safety measures
- Identify the potential areas and people using the canned air products
- Assess the risk (esp. for ventilation and confinement) for the area, consider alternate methods if necessary.
- Try to use a non-flammable gas based canned-air, if the use is necessary.
- Make sure, the user understands the hazards and sufficiently educated on safe handling and use of canned air
- Consider personal protection (if required)

Courtsey: Health and Safety Monitor, December 2008