Permit to Work Systems

Permit to Work Systems

General principles

The following aspects should be considered with respect to Permit to Work Systems:

• Human factors;
• Management of the work permit systems;
• Poorly skilled work force;
• Unconscious and conscious incompetence;
• Objectives of the work permit system;
• Types of work permits required; and
• Contents of the work permits.

The following issues may contribute towards a major accident or hazard:

• Failing of the site safety management system;
• Failure to recognise a hazard before and during maintenance;
• Failure to comply with the work permit system in hazardous environments; and
• Communication failure during the use of a work permit system.

Contributory factors for an assessor to consider concerning the Work Permit System

The Safety Report should address the following points:

• Whether staff have been sufficiently informed, instructed, trained and supervised to minimise a potential human failing during operation of the work permit system;
• Whether the work permit system includes sufficient safety information, maintenance instructions, correct PPE and equipment for use;
• Whether the work permit contains sufficient information about the type of work required (Equipment removal, excavation, hot/cold work, repairing seals, vessel entry, waste disposal, isolation);
• Whether there is sufficient provision available to fulfil the requirements of the work permit system;
• Whether the employees responsible for control of the maintenance work are identified within the work permit system and that the work is properly authorised by a responsible person;
• Whether the work permit system is managed, regularly inspected and reviewed;
• Whether all work permits are kept on file;
• Human factors (stress, fatigue, shift work, attitude);
• Whether sufficient precautions are taken prior to initiating a work permit (isolation, draining, flushing, environmental monitoring, risk assessments, communication, time allotted for the work);
• Whether staff are aware of the type of environment they are working in during the operation of a work permit (flammable, corrosive, explosive, zones 0, 1 & 2, electricity supplies);
• Whether the person responsible for operating the plant is aware of the type of maintenance involved and how long it is likely to take; and
• Whether the work permit system involves a formal procedure whereby the maintained plant or equipment is handed back to operation.

Major hazards

Major hazards could arise from the following:

• Wrong type of work permit used;
• Wrong information about work required on the work permit;
• Failure to recognise the hazards where work is carried out (e.g. flammable substances);
• Introduction of ignition source in controlled flameproof area (e.g. welding, non spark-proof tools, non-intrinsically safe equipment used in intrinsically safe zones);
• Terms of work permit not adhered to (e.g. failure to isolate plant and/or drain lines of hazardous substances);
• Failure to hand-over plant in safe condition on completion of work/cancelling of work permit;
• Unauthorised staff performing work permit functions;
• Poor management of the work permit system; and
• Insufficient monitoring of the work permit system.