Is it a good idea to use compressed air to remove dust from clothing, components or work surfaces?
These particles are a danger since they can enter a worker’s eyes or damage skin. The potential damage depends on the size, weight, shape, composition, and speed of the particles. The pressure and sound of compressed air can also cause hearing damage. Second, compressed air itself is also a serious hazard.
It is not a good idea to use compressed air to fulfil these tasks. Although many people know using compressed air to clean clothes can be hazardous, it is still used because of old habits and the easy availability of compressed air in many workplaces.
Air blown into the mouth can cause ruptures in the lungs or stomach. Compressed air can actually break through the skin. Now, this can cause minor injuries, but if that air enters the bloodstream and travels to the brain or heart, stroke or heart attack-like symptoms can occur.
Most compressed air applications are not connected to electricity, so people do not always consider what dangers may be lurking. But just as safety regulations must be observed for electrical machines and tools, compressed air components must also be treated with respect to avoid dangerous accidents.
First, compressed air is extremely forceful. Depending on its pressure, compressed air can dislodge particles. These particles are a danger since they can enter your eyes or abrade the skin. The possible damage would depend on the size, weight, shape, composition, and speed of the particles. The pressure used to remove the particles from machines and surfaces is also strong enough to blow the filings, shavings, chips and particles of metal into the eyes, ears or skin of people. Compressed air can enter the body where the skin is not present (i.e., ear, nose, rectum or any scratch or puncture in the skin, however small) and can cause damage. There have also been reports of hearing damage caused by the pressure of compressed air and by its sound.
Second, the compressed air itself is also a serious hazard. On rare occasions, some of the compressed air can enter the blood stream through a break in the skin or a body opening. An air bubble in the blood stream is known medically as an embolism, a dangerous medical condition in which a blood vessel is blocked, in this case, by an air bubble. An embolism of an artery can cause coma, paralysis or death depending upon its size, duration and location. While air embolisms are usually associated with incorrect diving procedures, they are possible with compressed air due to high pressures. While this seems improbable, the consequences of even a small quantity of air or other gas in the blood can quickly be fatal.
Third, using air to clean forces the dirt and dust particles into the air, making these contaminants airborne and creating a respiratory hazard.
“Very serious injuries, sometimes fatal, have occurred when the nozzle of the gun has been pointed towards the body, even at some distance from it. Many of the injuries occur when clothing is dusted down and because of this compressed air should never be used for cleaning clothing. Others are the result of horseplay.”
Is cleaning with compressed air allowed by law?
In some parts of the World (such as regions within Canada), cleaning with compressed air is not allowed by law. However, more and more companies are realizing the dangers posed by compressed air for blow-off, and now issue cautionary statements within their own company work rules which may result in written warnings or indeed more seriously dismissal.
OSHA and other North American Laws note
In the United States workplace safety is regulated by OSHA regulations. OSHA is the acronym for Occupational Safety and Health Administration. Compressed air use is governed by 1910.242.b, which says that air pressure in direct contact with the skin cannot exceed 210 kPa (30 psi). The use of protective air cones is generally accepted to protect the operator, but barriers, baffles or screens may be necessary to protect employees from being exposed to flying chips or particles.
In many Canadian jurisdictions, cleaning with compressed air is not allowed by law. Alberta, Newfoundland, Prince Edward Island, Quebec, and Saskatchewan specifically mention that compressed air shall not be used to clean clothes, or in other situations cleaning a person, machinery, work benches, etc. Reference to cleaning may also be included with specific mention to it being prohibited when there is a risk to the worker being injured or that the device must be specifically designed to safely clean a person or surface (federal regulations, Ontario, British Columbia, New Brunswick, Nova Scotia, North West Territories, Nunavut, and the Yukon).
In some cases, other legislation may apply. For example, cleaning with compressed air is prohibited in Manitoba and Ontario when working with asbestos.
Note: Air pressure is legislated by New Brunswick (69 kPa), Yukon (69 kPa/10 psi), and where permitted under federal (69 kPa/10 psi), British Columbia (70 kPa/10 psi), North West Territories, and Nunavut (68.9 kPa/10 P.S.I.) legislation.
The Nova Scotia regulation states:
101. (2) Where compressed air is used to clean a surface or person, an employer shall ensure that the device that is used to deliver the air is
(a) commercially manufactured and approved in the manufacturer’s specifications for the purpose of cleaning a surface or person with compressed air; or
(b) certified by an engineer as adequate for the purpose of cleaning a surface or person with compressed air.
Occupational Safety General Regulations N.S. Reg. 44/99 Section 101(2)
Ontario does not specify a pressure limit but does state:
66. A compressed air or other compressed gas blowing device shall not be used for blowing dust or other substances,
(a) from clothing worn by a worker except where the device limits increase in pressure when the nozzle is blocked; or
(b) in such a manner as to endanger the safety of any worker.
Industrial Establishments R.R.O. 1990, Reg. 851 Section 66
In addition, air guns should also be used with some local exhaust ventilation or facilities to control the generation of airborne particulates. When compressed air cleaning is unavoidable, hazards can be reduced by making adjustments to the air gun such as:
- chip guards or curtains that can deflect flying dust or debris,
- extension tubes that provide the worker a safer working distance, or
- air guns equipped with injection exhausts and particle collection bags.
Exactly what are the hazards of using compressed air for blow-off?
Compressed air is a concentrated stream of air at high pressure and high speed that can cause serious injury to the operator and the people around him. First, compressed air is itself is a serious hazard. It has been known for compressed air to enter the blood stream through a break in the skin or through a body opening. An air bubble in the blood stream is known medically as an embolism, a dangerous medical condition in which a blood vessel is blocked, in this case, by an air bubble.
An embolism of an artery can cause coma, paralysis or death depending upon its size, duration and location. While air embolisms are usually associated with incorrect scuba-diving procedures, they are possible with compressed air due to high pressures. This may all seem to be improbable, but the consequences of even a small quantity of air or other gas in the blood can quickly be fatal so it needs to be taken seriously.
Unfortunately, horseplay has been a cause of some serious workplace accidents caused by individuals not aware of the hazards of compressed air, or proper work procedures.
· Compressed air accidentally blown into the mouth can rupture the lungs, stomach or intestines
· Compressed air can enter the navel, even through a layer of clothing, and inflate and rupture the intestines
· Compressed air can enter the bloodstream, and death is possible if it makes its way to blood vessels in the brain
· Direct contact with compressed air can lead to serious medical conditions and even death
· Even safety nozzles which regulate compressed air pressure below 30 psi should not be used to clean the human body