Myth # 13: 15 to 1 is the NFPA (National Fire Protection Association) safety standard.
This is not true. The problem is the “Which came first analogy?” Professional rope users, as outlined by the NFPA, are supposed to use ½” ropes which break at approximately 9000 lbs. And years ago they said that a Fireman’s load would be defined as 600 lbs. (2 person load). Working backwards with these numbers. Hummmmmm! 9000 lbs divided by 600 lbs gives us a safety factor of 15 to 1. But history will tell us the 9000 lbs and the 600 lb numbers came first not the 15 to 1. It just conveniently worked out that way. The accepted and recognized rope user safety factor is 10 to 1.
