OSHA requires that hazardous energy sources be "isolated and rendered inoperative" before work is started on the equipment in question.
A lockout hasp typically has a 1-inch inner shackle diameter and a lock body that can accommodate up to six padlocks. Lockout hasps are placed through a latch on the machinery to be locked out and each employee performing maintenance or service work attaches their padlock through one of the six holes within the hasp, together with a LOTO tag to warn and inform other workers of the ongoing LOTO procedure.