When flammable materials are used, all ignition sources must be at least how far away from the work location?

• A. 25 feet
• B. 50 feet
• C. 75 feet
• D. 100 feet

Answer: (B)

Keeping ignition sources distant from where flammable materials are used reduces the chance that flammable vapors will encounter a heat source. Flammable vapors can travel with air and can ignite from a spark, hot surface, open flame, or other ignition source even at low concentrations. Setting a minimum separation, such as 50 feet, creates a practical safety buffer that limits vapor migration and lowers the risk of ignition during handling and use of flammable materials.

Smaller distances raise the risk that vapors may reach a potential ignition source, while larger distances are generally more than necessary for typical work areas and can hinder operations. Always follow site-specific procedures, but the 50-foot rule serves as a standard, widely applied protection in this scenario.