Permits to Work
What is a permit to work and how should it be implemented?
A permit to work system ensures that all necessary actions are taken, before, during and after particularly hazardous operations. They are formal documents specifying the work to be undertaken and what precautions are required. Work can not commence until safe procedures have been defined. The permit provides a written record identifying foreseeable hazards, required actions and control measures. It must be signed by a responsible officer in evidence of this and must also be in the possession of the person in charge of the operation before work can commence. Permits to work are normally used in relation to maintenance work which can only be carried out if normal safe working practices are not practical.
- Hot work i.e. welding, burning and work involving risk of fire and explosion.
- Work on electrical systems, notably high voltage equipment.
- Machinery maintenance, notably where maintenance workers may be hidden from those using or in control of the plant.
- Overhead travelling cranes.
- Working in confined spaces.
It is important to note that a permit to work is not the same as a safe system of work. In fact a safe system of work may call for a permit-to-work to be implemented as part of systematic risk control.
Operation of Permit To Work Systems.
1. Hazard Evaluation
Ideally, a long lasting system of precautions may be achieved via the introduction of a ‘Hazard appraisal programme’. All types of hazard that may be encountered must be identified together with commensurate means of eliminating or controlling them. Clearly work performed under emergency conditions requires more dynamic measures.
2. Precaution Planning
All relevant planning must be carried out by a ‘Competent person’, who should have appropriate knowledge and experience of the particular work, working environment, and legal considerations. Appropriate seniority to ensure that instructions are recognised and complied with is also a particular prerequisite.
3. Instruction of Operator and Supervisors
Similar skills and status are necessary in respect of the (ideally) single person responsible for the control and coordination of the permit-to-work throughout the organisation. Steps must be taken to ensure that everyone concerned, including external contractors, fully understands the terms of the permit and follows its instructions to the letter.
4. Issuing the permit
The permit should be signed by the issuer, and given to the person in charge of the work, who in turn should also sign for it. A copy should be displayed nearby for the duration that it remains in force, and further copies issued to other staff who may be involved to facilitate cooperation, coordination and communication. Critically, those responsible for the work must be carefully briefed by the person issuing the permit to supplement the written document.
5. Before starting work
Before work commences and where applicable:
- The plant should be isolated
- The work area should be isolated
- Water, steam, acid and gas supplies etc. should be locked off
- Scaffolding needs to be erected
- Temporary guards or barriers need to be provided
6. Checking and cancelling permits
Routine safety checks should be made during the operation of the permit-to-work and on completion it should be returned to the responsible person, who should check that all people and equipment are removed from the area and that it is safely returned to normal operation.