When should a sling be removed from service?

A sling should be removed from service when warning yarns are visible because this indicates that the sling has sustained damage and may no longer meet the safety standards required for lifting operations. Warning yarns serve as an indicator of wear; their visibility shows that the protective outer layer has deteriorated, potentially compromising the strength and integrity of the sling. This is particularly crucial in ensuring the safety of lifting operations, as utilizing a damaged sling can lead to catastrophic failures during a lift.

While other scenarios, such as a dirty sling or a missing tag, might suggest maintenance or inspection needs, they do not automatically deem a sling unsafe for use. A dirty sling can often be cleaned and inspected for integrity, and a missing tag may warrant further investigation but doesn't necessarily indicate immediate failure. Overuse can be a concern as well, but the condition signaled by visible warning yarns is a definitive indication that the sling is too compromised to be safely used. Hence, recognizing the visibility of warning yarns is paramount for safety in rigging and hoisting practices.