Do damaged extension cords need to be replaced?

Superficial nicks or abrasions — those that only slightly penetrate the outer jacket of an extension cord and do not permit the cord to bend more in that area than in the rest of the cord — are not considered a safety concern according to OSHA. Therefore, there is no need to repair or replace such a cord.

Repair or replacement of an extension cord, depending on its gauge, is required when the outer jacket is penetrated enough to cause that part of the cord to bend more than the undamaged part or penetrated completely, or when the conductors or their insulation inside are damaged. When repaired, the cord must be in the same condition as when it was new with regard to both design and safety.