Permit to Work (PTW) and its Types

The permit-to-work is a documented procedure that authorizes specific people to carry out specific work within a specified time frame. It sets out the mandatory precautions to complete the job safely and based on a risk assessment.

The PTW requires the declarations from the people permitting the work and carrying out the work. Sometimes it requires the declaration from those who involved in shift handover procedures or extensions of the work. At the end, before the equipment is put back into service, it will require a declaration from the permit originator that it is ready for normal use.

Types of PTW

Mostly there are two types of permit

1. Hot work permit

Hot work permit used for activities which involve flammable content or spark potential. It is RED colored. It used for welding, cutting, grinding and any activity which involves naked flame.

2. Cold work permit

Cold work permit: The Cold work permits, typically colored blue, are usually used to cover the variety of potentially hazardous activities that are not included in the hot work permit.

A cold work permit is required for the potentially hazardous work not covered by the other types of permits. Some examples include Chemical cleaning or the use of solvents, Handling of hazardous substances, the Use of resins typically used during the blade repairs, Any painting activity, Heavy lifts, Erecting or dismantling scaffolds, Any non-routine and potentially hazardous activity, Any activity requiring the specific control measures to the confirm safety.

Read also: Fault tree analysis

Other types of permits are given below

• Electrical work permit
• Confined space permit
• Excavation permit
• Isolation certificate
• Radiation permit

The permit to work must contain details of

• The permit numbers.
• The date and time of issue.
• The estimated duration of the work.
• The exact work location.
• A description of the work.
• The anticipated hazards, risks, and the probable result should the risk be realized.
• The precautions to be observed.
• Any appropriate test procedures.
• Details of any emergency procedures.
• An acknowledging signature of that person in control of the work understands the work, the hazards and the precautions to be taken.
• A signature of the person in charge of the work when it is completed or partially completed but delayed for some reason.
• A signature canceling the permit to work by the person who issued it.