During LOX servicing, non-involved personnel should maintain a distance of at least what distance?

• A. 30 feet
• B. 50 feet
• C. 20-foot radius
• D. 10 feet

Answer: (C)

During LOX servicing, keep a safety buffer around the operation because liquid oxygen is extremely cold and its vapors can rapidly alter the surrounding environment. The 20-foot radius provides a practical shield from splashes, cold contact, and the vapor cloud that can vent from the system. Contact with LOX can cause severe frostbite, and the cold oxygen-rich vapors can increase the fire risk by making materials more flammable in an enriched atmosphere. Non-involved personnel staying at least 20 feet away helps prevent cold burns, asphyxiation hazards in confined spaces, and unintended ignition risks from venting or spraying.

Options that imply shorter distances are unsafe, while much larger distances are unnecessarily restrictive for routine servicing. The 20-foot radius is the standard protective buffer for this operation.