Spray painting and sandblasting serve two entirely opposite functions, yet from a safety standpoint, they create many similar hazards for workers. Both operations rely upon the use of compressed air to spray a material across surfaces, but while spray painting is normally used to apply a coating to those surfaces, sandblasting uses the material to either remove its current coating or to prepare it for further finishing. In this article, we’ll explore the hazards inherent to both operations, as well as steps that can be taken to minimize risks.
What they are
Spray painting is used in a wide variety of industries to apply paint and similar coatings to an equally wide variety of parts and products. It offers two primary advantages: it allows surfaces to be coated in less time than with most manual methods, and it provides a finished surface that tends to be smoother and more even. Spray equipment may be used to deliver paints, varnishes, lacquers, resins, and other decorative and/or protective coatings, as well as adhesives.
What’s commonly called sandblasting involves spraying a variety of abrasives to remove coatings or contaminants from surfaces. In addition to various types of sand, spray blasting can employ other abrasives such as slag, steel shot, glass, and plastic beads or ground walnut shells.
Most of the hazards associated with spray painting are directly related to the chemicals being used. In addition to the material itself, many paints and similar chemicals contain solvents that may be hazardous or explosive. Workers using these materials may be exposed to mists, vapors, and particulates that can be inhaled or swallowed, come in contact with the eyes and mucous membranes, or be absorbed through the skin. In the short term, this exposure can create irritation and discomfort, but longer-term contact can lead to serious problems with the lungs, kidney, liver, or the brain.
Paints and coatings that contain flammable chemicals can be ignited by a number of sources on a jobsite, among them open flames and torches, hot surfaces such as motors and lightbulbs, sparks from tools, static electricity, and reactions from contact with other chemicals. When paint or material used with paint is stored improperly, spontaneous combustion is also a possibility.
Sandblasting and similar abrasive operations tend to be inherently noisy and dusty, and the materials being used (or the surface that’s being blasted) may include toxins that become airborne. For example, sandblasting to remove lead-based paint can distribute minute particles of lead into the air. Exposure to crystalline silica sand can lead to health problems such as silicosis and lung cancer. Many other abrasives can also cause lung damage.
Protection through engineering
As with most workplace hazards, the first step is to find ways to engineer solutions to the hazards. If exposure to the hazards cannot be eliminated completely, efforts should be made to minimize them. For spray painting operations, the use of spray booths can address both hazards to the individual who is doing the painting and co-workers in the immediate area. A properly ventilated booth will remove fumes and vapors from the jobsite, minimizing the potential for fire or explosion. In addition, water-based coatings may provide less of a hazard than solvent-based materials.
If a spray booth isn’t practical for the work to be performed, such as when it’s a temporary task at an item’s location, exhaust ventilation with a filtration system can limit the potential for overspray and protect nearby workers from fumes and fire hazards.
Engineering solutions for sandblasting and spraying other abrasives begin with choosing a less-toxic abrasive when possible, or selecting an abrasive that can be combined with water to form a slurry and reduce the amount of airborne dust. The work area can be isolated from the surrounding areas by using structures that are similar to spray booths, and ventilation can be used to move the dust away from workers.
Other ways to reduce risks
Administrative controls offer additional ways to reduce the hazards associated with spray painting and sandblasting. One of the most important is good housekeeping practices, such as the use of wet methods for cleaning or HEPA-filtered vacuuming to prevent the accumulation of toxic dusts, rather than using compressed air (which typically spreads dust around). Tasks that present hazards may also be scheduled for times when fewer workers are in the immediate area.
Supervisors can also encourage workers to use sound personal hygiene practices. As an example, eating and drinking should be prohibited in areas where spray painting or sandblasting take place. Showers and wash stations provide an opportunity to remove contaminants before the workers eat or drink, and to ensure that toxic materials don’t travel home with the workers. Providing a laundry service for work clothes can produce the same results.
Workers should also be issued the correct personal protective equipment for the specific tasks and the environment. That may include respiratory, hearing, and eye and face protection, as well as items such as leather gloves, coveralls, or boots.
Finally, training and hazard communication are critically important. All personnel performing spray painting or sandblasting, as well as other workers in the immediate area, should be trained about the hazards and the proper steps for safe operations. Safety data sheets for all materials being used must be readily available. When workers have a complete understanding of the hazards they face and reasons for protective steps, they’re better able to keep themselves safe and healthy.