PTW – Permit To Work
What is PTW? A safe work permit is a written record that authorizes specific work, at a specific work location, for a specific time period. Permits are used for controlling and co-coordinating work to establish and maintain safe working conditions. They ensure that all foreseeable hazards have been considered and that the appropriate precautions are defined and carried out in the correct sequence. The permit is an agreement between the issuer and the receiver that documents the conditions, preparations, precautions, and limitations that need to be clearly understood before work begins.
What is PTW? The permit records the steps to be taken to prepare the equipment, building, or area for the work, and the safety precautions, safety equipment, or specific procedures that must be followed to enable the worker(s) to safety complete the work. The safe work permit helps to identify and control hazards, but does not, by itself, make the job safe.
Who Benefits from PTW? Any industry that has a significant risk because of particular hazards. Any prime contractor who lets out or sub-contracts work to others to do maintenance or other hazardous work. Organizations that have individual employees working in isolated areas and performing non-routine work.
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.
Accidents The following issues may contribute towards a major accident or hazard: Failing of the site safety management system; Failure to recognize 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.
Points to be Considered Whether staff have been sufficiently informed, instructed, trained and supervised to minimize 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 fulfill the requirements of the work permit system;
Points to be Considered 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);
Points to be Considered 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 Wrong type of work permit used; Wrong information about work required on the work permit; Failure to recognize 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; Unauthorized staff performing work permit functions; Poor management of the work permit system; and Insufficient monitoring of the work permit system.
Contents of PTW 1. description of task to be done 2. description of exact location/plant numbers etc 3. details of work party and tools to be used 4. details of potential hazards 5. details of precautions taken 6. details of protective equipment to be used or worn 7. other persons to be notified/approve 8. time of issue and period of validity 9. signature of person in charge of the work 10. signature of person issuing the permit 11. signature for handover of responsibilities between shifts 12. declaration by person in charge of work that work is complete or incomplete and site has been left in a safe condition 13. signature of person issuing the permit which confirms that site has been checked and that equipment may be reinstated or left safely isolated and that the permit is cancelled.
Training & Competence the person issuing the permit the person in charge of the work the workforce.
Training Requirements of Issuer & PIC legislation and industry guidance company policy, local rules and procedures responsibilities case histories of accidents or near misses involving failure of the P.T.W. system. o A written examination or suitable assessment should be included in the training
Permit Issuers Should Know… 1. plant and equipment layout 2. the process taking place ie production, drilling 3. potential hazards existing 4. the means of mitigating the hazards before issuing a permit 5. the specific responsibilities associated with issuing permits 6. applicable legal requirements 7. all the company and local rules applying to the operation of the P.T.W. system 8. the use of all the different forms and records associated with the P.T.W. system 9. communication skills (bearing in mind multi language locations) 10. shift handover requirements 11. action to be taken in an emergency situation 12. training requirements for role players 13. auditing and monitoring requirements.
Steps/Process Planning Preparation Issuance Process/Work Revalidation Cancellation Suspention
Hazards to be Verified 1. Liquid or gas under pressure. 2. Toxic materials. 3. Corrosive materials. 4. Flammable materials. 5. Hot materials. 6. O2 deficiency. 7. H2S area. 8. Naked flames or arcs. 9. Flying particles or sparks. 10. Electricity. 11. Radioactivity. 12. Moving Machinery. 13. Equipment generating sparks. 14. Crane operation. 15. Pressure testing. 16. Adjacent operations. 17. Wind, weather, sea state. 18. Danger of falling. 19. Access/egress. 20. Confined space. 21. Explosives. 22. Substances harmful to health. 23. Isolation of safety systems.