What is the maximum percentage of free silica or lead allowed in abrasive blasting material?

• A. 0.5%
• B. 1%
• C. 2%
• D. 3%

Answer: (B)

The maximum percentage of free silica or lead allowed in abrasive blasting material is 1%. This limit is established to protect the health and safety of workers involved in abrasive blasting operations. Free silica, found in many common blasting materials, can pose significant respiratory hazards when inhaled as fine dust. Prolonged exposure to free silica can lead to serious health issues, including silicosis and other lung diseases.

Setting this threshold at 1% helps ensure that the risks associated with inhalation of these harmful materials are minimized. Lead is also a toxic substance, and its presence in blasting materials can result in poisoning and other health complications.

Therefore, maintaining the free silica and lead content at or below this level is crucial for workplace safety and compliance with health regulations in the mining and construction industries.