By Janet L. Keyes, CIH
What’s the quickest way to remove dust from a surface? Blow it. Use your compressed air gun, cranked to maximum pressure, to get that surface clean. But that dust doesn’t disappear. It just moves from one surface to another. Some dust will settle quickly. Smaller dust particles can linger in the air for hours. You’ll breathe those in, as will everyone near you. A good idea? Not for your lungs and eyes.
Do you remember the anthrax attacks in 2001? Letters containing anthrax spores were sent through the US Postal Service to reporters and elected officials. As the letters went through postal facilities, they were sorted by high-speed machines and by hand. Each day, maintenance employees used compressed air to blow the accumulated paper dust off of the machines. When they did so, they spread the spores throughout the building. Four workers breathed in the spores and became infected with anthrax. Two died. Two mail processing facilities were closed down and decontaminated, at a cost of nearly $200 million. The post office doesn’t clean machines with compressed air anymore.
You’re not likely to have weaponized anthrax spores in your dust. But what will be in it? That depends on what it’s from. In the days when asbestos-containing brakes were common, the dust would contain asbestos fibers, good at causing respiratory cancer and good at remaining suspended in air for a long time. Is the dust from cleaning out mouse droppings? Breathing that dust puts you at risk of disease, asthma, and allergic reactions.
What if it’s just body filler and paint? Most of that dust does not have any specific toxic effect, but too much dust of any sort can be damaging to breathe.
There are alternatives to using compressed air for cleaning. Dust capture tools, attached to grinders and sanders, remove the dust when it is created. They keep your shop from getting a fine dust layer over everything. They can speed up the work, too, because employees don’t need to stop what they’re doing to blow off the dust. You don’t need to stop all work periodically to clean the shop. You won’t have to replace air filters as often. Capturing the dust at the source also reduces the fire risk from combustible dust, such as that from body filler.
You can use water to control dust. When asbestos brakes were common, that was a recommended way to control brake dust. Mechanics were to spray water with a detergent added to it to wet all brake and clutch parts and then wipe down the parts with a rag, to be disposed of as asbestos waste. People who work with stone routinely do it wet, too. The water they use effectively controls silica dust, as long as the dust isn’t allowed to dry out. Is that feasible for your work? Probably not.
If you can’t capture the dust when it is created, you can vacuum it up. But you’d want to use a vacuum with an efficient filter, so fine dust doesn’t come in one end and go out the other. Vacuuming cleans the shop floor, but takes a lot of time and effort – and it’s hard to vacuum irregular surfaces such as the clutter on top of tool boxes.
What if those methods won’t work? If you absolutely must blow it, do it right.
Require that everyone use OSHA-compliant air guns. These are designed so that blocking the tip doesn’t make the air hose pop off and whip around. They may have a port in the side of the nozzle, to divert the air flow (don’t let anyone cover that port with tape. Doing so is actually self-defeating, because that port creates a Venturi effect, actually increasing the tip pressure during normal use). Other compliant guns may have star-shaped tips or solid tips, with the air coming out from behind the tip. Those designs make it very hard to block the tip.
Require employees to wear safety glasses and hearing protection if they must use compressed air. The flying particles will get in eyes. The air itself is usually loud enough that it can damage hearing in minutes. There are air blow guns designed to be quiet (Silvent and Exair are two manufacturers of quieter compliant air guns), but they are more expensive. We rarely see those in the shops we visit.
Strongly discourage employees from using compressed air on themselves. That’s how people blow air into skin breaks, leading to infections. And never let anyone turn a blow gun on someone else.
Automotive work can be dusty. But there are better options than putting that dust back in the air.
OSHA safety grants have funded dust capture systems. For information about those, about dust control and evaluation or for other safety issues contact CHESS at 651-481-9787; toll free at 877-481-9787, or carkey@chess-safety.com.
This article originally appeared in AASP-MN News (December 2022). It is intended to provide general information (no advice) about current safety topics. To discuss your specific concerns and how CHESS may help, please contact CHESS at 651-481-9787 or chess@chess-safety.com.