The Permissible Exposure Limit (PEL) for respirable crystalline silica is 50 μg/m³.
To find this, we need to understand what PEL means. PEL is a regulatory limit on the amount or concentration of a substance in the air. It is typically set by regulatory bodies such as OSHA (Occupational Safety and Health Administration).
Given these choices:
1. 25 μg/m³
2. 200 μg/m³
3. 500 μg/m³
4. 50 μg/m³
The correct Permissible Exposure Limit for respirable crystalline silica as per OSHA standards is 50 μg/m³.
So, the answer is:
50 μg/m³
