Used in a variety of industries, sandblasting, also called abrasive blasting is used for removing coatings from various surfaces. Everything from paint to powdercoat is removed using the "blasting" method. In this article we will explore some of the topics related to sandblasting dust. Or, in other terms the particulates that become airborne while sandblasting. We will also consider some of the dangers associated with airborne particulates and how to protect workers from the effects of sandblasting dust.
Before we get into the information about sandblasting, let's first define the term. Abrasive blasting is a process whereby a high velocity stream of particles are projected at a surface using air or water. The abrasive material affects the surface by:
- Roughing a smooth surface.
- Smoothing a rough surface.
- Removing surface contaminants.
- Remove a coating from a surface.
Although the umbrella term "sandblasting" is used, there are actually many specific kinds of "blasting". There are a number of variations of blasting being done that utilize different blasting media. Some types of abrasive blasting include:
- Bead Blasting
- Wheel Blasting
- Wet Abrasive Blasting
- Vapor Blasting
- Micro-abrasive Blasting
- Dry-ice Blasting
- Bristle Blasting
It is easy to see from the list above, that it can become very confusing quickly if the type of blasting is not specifically stated. So for the purposes of this article we will be discussing dry blasting using sand as the blasting medium.
The Dust From Sandblasting
When blasting a surface using sand, the impact of the blasting medium (the sand in this case) with the sruface being blasted causes dust containing debris (or particles) of verious kinds. First, the sand itself is particulate and ends up in the dust that is generated from the blasting. Second, any surface contaminants or coatings that are being removed will produce airborne particles consisting of the material. Finally, the surface material itself may chip or be broken down into particulates that end up in the dust.
Since the substances being removed from surfaces being blasted and the surfaces themselves may consist of a wide variety of matter, there are virtually endless amounts of subtances that might be in sandblasting dust. Therefore, it is important to consider what kinds of particles could be in sandblasting dust. Here are some of the materials that can be in sandblasting dust:
The list goes on and on. The idea here is that depending on what surface is blasted and what other substances are on the surface, you can have virtually any particles in the dust that is generated by sandblasting.
Dangers of Sandblasting Dust
Because of the vast number of contaminants that could be in sandblasting dust, there are many ailments that come from breathing the dust. Since there are helath hazards associated with many of the substacnes that may be present in the dust, OSHA has guidelines for sandblasting workers. You will find that the document covers a variety of blast media in addition to sand.
Although there are numerous health issues that may stem from abrasive blasting, we will simply cover the effects of breathing respirable crystalline silica that results from using silica sand as the blasting medium.
Health Issues From Silica
As mentioned above, sandblasting with silica sand carries the risk of breathing particulates which are harmful to the respiratory system and even other parts of the body. One of these substances is silica. Here are some of the potential health issues that have been linked with respirable crystalline silica:
- Lung Scarring
- Kidney Disease
- Lung Disease
- Lung Cancer
Everyone would agree that any of the items in the above list describe ailments that we would not want. Thus, it is important to consider how to protect workers against breathing silica dust from sandblasting.
Control Sandblasting Dust
So how can sandblasting dust be controlled so that workers are not harmed by exposure to the silica in sandblasting dust? There are actually multiple ways that workers (and others in the area) are protected.
Personal Protective Equipment
One of the ways that sandblasters protect themselves is by using PPE. Protective equipment is one of the ways OSHA recommends for protecting workers from exposure. NOte the following quote taken from the document referenced above:
Use engineering and administrative controls, personal protective equipment (PPE), including respiratory protection, and training to protect workers involved in abrasive blasting activities. Engineering controls, such as substitution, isolation, containment, and ventilation are the primary means of preventing or reducing exposures to airborne hazards during abrasive blasting operations.
Among the PPE listed in the document referenced above are the following:
- Eye & Ear Protection
- Safety Shoes
- Leather Gloves
Other "personal" protections include knowing how to dress appropriately, clean up clothing properly, and use respiratory protection via a respirator. These and other guidelines are designed to prtoect the workers from all sorts of contaminates including crystalline silica.
Another method for controlling sandblasting dust so that it does not cause health effects in workers and others thorugh exposure is to control the air quality by various means. Ventilation is an environmental control that may be enacted using a variety of techniques and equipment. One piece of equipment that is mentiond in the Safety and Health Regulations for Construction are dust collectors. One of the statements made about dust collectors in that document are as follows:
The air exhausted from blast-cleaning equipment shall be discharged through dust collecting equipment. Dust collectors shall be set up so that the accumulated dust can be emptied and removed without contaminating other working areas.
Using environmental controls to protect workers from dust can be accomplished in a number of ways and using equipment to act as a sandblasting dust collector can help. Since the consequences of breathing contaminants are so severe, using as many protections as possible is a good idea. Of course, there are other ways sandblasting workers may be protected. However, they are so numerous, we cannot cover all of them here.
In conclusion, sandblasting produces all sorts of dust. The kinds of dust that are generated using sandblasting vary and depend on factors that will change based on the type of blasting, surface, and contaminants involved. To prevent workers from being affected by the dust through exposure, several safety precautions may be taken. The more of these your shop employs, the safer your work environment will be.