Media blasting is a process that combines abrasive media and water to clean and shape a variety of materials or structures. It can be used to remove coatings, clean steel, remediate mold and rid materials of other surface contaminants.

But what happens to the material or surface contaminants that get blasted away? They become airborne - and depending on the task performed, media blasting can generate harmful airborne pollution.

In fact, the likes of asbestos, lead, rust, metal fragments, silica dust and more may become airborne during blasting, which could lead to short and long-term health effects. It all underscores the importance of ensuring you're outfitted with the proper PPE while doing any sort of media blasting.

In this post, we'll discuss the different types of media blasting, the hazards associated with blasting, and why it's important to ensure you're protected while you're on the job (even if there's no OSHA requirement).

Wet vs. Dry Blasting: What You Need to Know

Two of the most common types of media blasting are wet and dry blasting. Wet blasting uses a mix of water with abrasive material, while dry blasting is media blasting without the presence of any water. Some of the common types of media used in both wet and dry blasting include garnet, sand, glass, coal slag, plastic, and aluminum oxide, among others.

Wet Blasting

Wet blasting is also commonly referred to as "vapor blasting" and "vapor honing," and it's an ideal method for removing surface contaminants from structures and materials. This may include old paint, coatings and more.

There are various benefits of using wet blasting:

  • It produces a softer and more uniform finish: If the surface is being blasted for painting or re-coating it, then a smooth, more uniform finish will help ensure better overall cohesion.
  • It produces less dust: One of the nice things about adding water to the blasting mix is that it helps to knock any dust or other airborne contaminants down. In fact, wet blasting is said to reduce the amount of dust by up to 95 percent compared to other methods of blasting.
  • It's safer: Water helps remove many electrical charges from the media, which can help reduce the risk of fire.
  • It's more environmentally friendly and safer for use around any sensitive or more dangerous equipment and materials. It can be safely used on metals, plastics, fiberglass, wood, glass, and PVC among others.
  • It's more affordable than other blasting media.

Dry Blasting

Compared to wet blasting, dry blasting is more aggressive - and for this reason, it's more likely to cause unwanted damage to the surface or the material it's being applied to. This is largely due to the angle the blasting particles ricochet at, which can create havoc on the substrate if you're not careful or not experienced. Conversely, in wet blasting, the water acts as a guard against any particle ricochet.

Does OSHA Have Blasting Standards?

Does OSHA have blasting standards? Yes. And no.

The Occupational Safety and Health Administration has PPE standards for dry abrasive blasting. However, it doesn't have any standard for wet blasting, largely because the process produces less overall dust. According to OSHA, these levels of dust aren't necessary to regulate with wet blasting.

The dry blasting standard requires a mix of PPE and environmental engineering controls. For example, isolation and containment are necessary. So too is proper ventilation. For PPE, workers should wear hearing protection, eye and face protection, a helmet, gloves, and boots. NIOSH-approved respiratory protection is also a requirement.

But still, based on some of the health hazards that we'll discuss in the next section, you can see why it's still important to wear proper PPE when performing any type of blasting - no matter whether it's dry or wet blasting.

Health Impact of Blast Media

As we noted above, OSHA doesn't regulate PPE for wet blasting, just for dry blasting. But because of the myriad of health effects of inhaling the airborne contaminants that are often a byproduct of blasting, there's good reason to ensure you're wearing the right PPE- no matter what type of blasting you're doing.

Here's a look at some of the health effects of blasting if the proper precautions are not taken:

  • Hearing loss
  • Respiratory problems, from breathing issues to lung cancer
  • Silicosis

PPE for Vapor Blasting

Dry blast methods require PPE, but the level of PPE is often dictated by the type of blast media that is being used. Even in cases of wet blasting where OSHA does not require PPE to be worn, it's better to be safe than sorry.

Even considering that wet blasting can reduce dust accumulation by 95 percent, there's still going to be some dust generated. With that said, here's a look at the PPE you want to ensure any workers are guarded with when performing media blasting:

  • Respirators: A respirator worn when performing media blasting must cover the head, neck, and shoulders. Not just any respirator will suffice for media blasting. Respirators need to be NIOSH-approved and properly fit-tested to prevent hazardous dust intake. There are generally two types of respirators that workers may choose from - those that are tight-fitting and those that are loose-fitting.
  • Hearing protection: Noise from media blasting has the potential to reach up to 120 decibels. Considering that sounds over 85 decibels can lead to hearing loss over long periods, hearing protection is imperative in media blasting. Hearing protection is often built into respirators. They can also be worn as standalone pieces of PPE.
  • Body protection: As we mentioned earlier in this post, dry blasting can cause the media to ricochet at odd angles, which could come back to harm the person performing the blasting. Hence, disposable coveralls are needed to stay safe. As a bonus, anything that gets onto the coveralls can be discarded along with them and not contaminate any other areas.
  • Gloves and shoes: This is standard PPE that should be worn for most work activities, and they're also a key part of any vapor abrasive blasting protective clothing. They help protect the hands and feet and can also help the worker perform more comfortably.
  • Face shields and safety glasses: These are often incorporated along with the respirator, but they may also be worn as a standalone piece of PPE. If the face shield is included with the respirator, there's no need for a secondary face shield to be worn.

Do you perform wet or dry media blasting? If so, now's the time to ensure your vapor abrasive blasting safety plan is up to par. Make sure you have the right PPE on hand to protect your workforce and stay within OSHA's requirements. When it comes to your people, you can't downplay the importance of safety, which is why we suggest wearing PPE when performing both wet and dry blasting tasks.