The Definition of Abrasive Blasting

Definition of Abrasive Blasting

Abrasive blasting is the process of propelling abrasive material, such as sand, steel grit, garnet, glass beads or crushed slag, against a surface at high velocity using compressed air, water or a spinning wheel to remove paint, rust, scale or contaminants. It is common in shipyards, bridge and tank maintenance, fabrication and painting. The process generates heavy dust from both the abrasive and the coating being removed, which can contain respirable crystalline silica, lead, cadmium, arsenic or chromium, and it also creates high noise levels, flying particles and risks from high-pressure equipment.

Key Facts About Abrasive Blasting

• Blasting with silica sand exposes workers to respirable crystalline silica, regulated by OSHA 1910.1053 and 1926.1153 with a PEL of 50 µg/m³ as an 8-hour TWA.
• Operators working in the blast stream need supplied-air abrasive-blasting respirators (NIOSH Type CE).
• OSHA 1910.94(a) sets ventilation and enclosure requirements for abrasive blasting operations.
• Blast nozzles must have a manually held operating valve, often called a deadman control, so flow stops if the operator lets go.
• Substitute abrasives reduce silica risk, but each abrasive and the coating being removed still need a hazard assessment, since some contain toxic metals.

Example of Abrasive Blasting

A shipyard replaces silica sand with a low-silica abrasive, moves blasting into a ventilated enclosure with a dust collector, and equips blasters with Type CE supplied-air hoods connected to a Grade D breathing air source. Pot tenders working nearby wear half-mask respirators and hearing protection based on air monitoring results.

How to Control Abrasive Blasting Hazards

• Substitution: use non-silica abrasives, wet blasting or water jetting where the job allows.
• Engineering controls: blast rooms and cabinets, local exhaust ventilation and dust collection.
• Administrative controls: restrict access to blast areas, provide wash facilities, prohibit eating in the area, and clean with HEPA vacuums rather than compressed air or dry sweeping.
• PPE: Type CE respirators, hearing protection, eye and face protection and protective clothing.
• Monitoring: conduct air monitoring for silica and metals, and medical surveillance where required.

Related Terms

• Silica Exposure
• Lead Exposure
• Respiratory Protection
• Noise-Induced Hearing Loss

Frequently Asked Questions: Abrasive Blasting

Is sandblasting with silica sand banned?

It is not banned under U.S. federal law, but it is tightly controlled by OSHA's silica standards, and NIOSH has recommended against using silica sand as a blasting abrasive since the 1970s. Several other countries restrict or ban the practice.

Who besides the blaster is at risk?

Pot tenders, helpers, painters and anyone working near the blast area can be exposed to dust, noise and rebounding abrasive, so exposure assessment and controls should cover the whole work zone, not only the nozzle operator.

Can an air-purifying respirator be used for abrasive blasting?

Not for operators inside the blast stream. They need an abrasive-blasting supplied-air respirator that protects the head and neck from rebounding material. Air-purifying respirators may be suitable for nearby workers if monitoring shows exposures within the respirator's protection factor.