PERMIT TO WORK
A permit-to-work system is a safety document having instructions for safe execution of certain types of works which are potentially hazardous. This document not only specifies the works to be done but also underlines the precautions to be taken while performing several maintenance activities without affecting the environment. Industries following permit-to-work culture will undertake specific works when all safe procedures are defined and possible hazards are considered. A permit to undertake any work is required when normal safety parameters become ineffective or new threats or risks are introduced. Some of the examples of works which need work permit are hot works, maintenance or repair of large electrical installations, and pipeline works.
According to an HSE survey, one third of accidents happening in the chemical industry are maintenance-related, with the single largest cause being lack of, or deficiency in permit-to-work system.
The survey further revealed that in small and medium-sized chemical factories:
Two-thirds were not checking systems properly.
Two-thirds of permit system could not identify the potential hazards.
Nearly half of them did not know the importance of isolation of critical equipment, plant, electrical equipment, etc.
One third of permits could not specify the nature of personal protective wear.
A quarter of permits did not know how to formally hand-over the plant properly after the completion of maintenance works.
In many cases permit form design was not considered at all.
The above research though aimed primarily for chemical industry, the guidance and findings were applicable for other industries too.
ESSENTIALS OF THE PERMIT TO WORK FORM
Industries having permit-to-work system should not assume that their system was the best before put to test to challenging situations like accidents or other incidents. One should make the system reviewed critically by competent authorities. To understand the quality of the system one should analyse one’s system by asking the following questions.
Do we have the documentation for permit-to-work system which answers:
- How the system works.
- What are all the purposes the system can be used.
- People involved in training and their responsibilities; and
- How to verify its safe operation.
Is there any clarity as to who can do a particular job and their limits of authority, if any?
Who will be responsible for identifying the necessary precautions (eg., isolation, emergency arrangements, etc)?
Whether the permit form is clear with instructions?
Are there any questions and statements which are misleading and ambiguous?
Is it compatible to unusual circumstances?
Are contractors covered under the system?