<P> Permit to work implementations usually use incompatible operations matrices . For example, to preclude one workgroup welding or grinding in the vicinity of another venting explosive or flammable gases . The permit to work system is for work being performed in accordance with pre-approved procedures and that has been macro scheduled, the purpose is to prevent conflicting short term activities of different workgroups to prevent hazardous interference . </P> <P> Once a permit to work has been issued to a workgroup, a lock - out tag - out system is used to restrict equipment state changes such as valve operations until the work specified in the permit is complete . Since the permit to work is the primary de-conflictation tool all work activities in high risk environments should have a permit to work, specific hazardous operations will then have a second permit for activities such as confined space or hot work . Here the hot work permit is minimising the risk of the individual task, the permit to work is minimising the risk of simultaneous incompatible activities . </P> <P> Permit to work systems that permit authorisation and its traceability are necessary if they are to be beneficial . Ideally one person should be delegated with this responsibility at any one time and all workers at the facility should be fully aware of who that person is and when the responsibility is transferred . </P> <P> A permit to work form typically contains these items . </P>

When should a permit to work be used