What is a Work Permit?
A work permit is a written form used to authorize jobs that endanger workers to serious hazards. It recognizes the work to be done, the hazards involved, and the necessary preparation and precautions for the job. Examples of the jobs needing work permits are those requiring employees to enter and work in confined spaces, to repair, maintain, or inspect electrical installations or to use large or complex equipment.
Why Use a Work Permit?
When a job has the potential of causing serious injuries or death, it is necessary to formalize agreed-upon work procedures. This prevents the instructions from being missed, forgotten or misinterpreted. It also works as a checklist to ensure that all the hazards, protective measures, work procedures and general requirements are reviewed with and understood by the assigned worker(s).
A work permit serves as a record of the authorization and the completion of the specific work. The authorization must be provided by the competent person after all the necessary conditions have been met.
Different Types Of the Permits
The nature of permit-to-work procedures will vary depending on the job and the risks involved. However, a permit-to-work system is unlikely to be needed where, for example:
(a) the assessed risks are low and can be controlled easily;
(b) the system of work is very simple;
(c) other work being done nearby cannot affect the work concerned in a confined space entry or a welding operation.
However, where there are high risks and the work system is complex, and other operations may interfere, a formal permit to work (PTW) should be used.
The general permit should be used for work such as alterations to or overhaul of plant or machinery where mechanical, toxic or electrical hazards may arise; work on or near overhead crane tracks; work on pipelines with hazardous contents; repairs to railway tracks, tippers, conveyors; work with asbestos-based materials; work involving ionizing radiation; roof work; excavations to avoid underground services.
Hot Work Permit to Work System
What is Hot Work?
Hot work is described as the cutting and welding operations for the construction/demolition activities that involve the use of portable gas or arc welding equipment, or involve the soldering, grinding, or any other similar activities producing the spark, flame, or heat.
Hot Work Permit
The Hot work is usually taken to apply to the operation that could include the application of the heat or the ignition sources to tanks, vessels, pipelines etc which may contain or have contained flammable vapour, or in areas where the flammable atmospheres may be present.
The Hot work permits, typically coloured red or red-edged, are more generally applied to any type of work that includes the actual or the potential sources of the ignition and which is done in an area where there may be the risk of the fire or explosion, or which includes the emission of the toxic fumes from the application of the heat.
They are normally used for any welding or flame cutting, for the use of any tools which may produce sparks and for the use of any electrical equipment which is not intrinsically safe or of the suitably protected type. Some sites or installations distinguish between the high energy sources of the ignition like the naked flames, welding and spark-producing grinding wheels, which are virtually certain to ignite the flammable atmospheres, and the low energy sources like the hand tools and non-sparking portable electrical equipment, which are likely to cause the ignition only if there is the fault.
In some cases, to differentiate between these tasks, fire and the naked flame certificates or the electrical certificates have been used, to minimize the risk of electric shock to people carrying out any work on the electrical equipment.
When is a Hot Work Permit Necessary?
The Hot work permits are needed for all the cutting or welding activities that are conducted with the portable gas or the arc equipment or involve the soldering, grinding, or any other similar activities producing the spark, flame, or heat.
Where is the Hot Work Permit Necessary?
The Hot work permits are needed for each building where the hot work will be performed (utility tunnels are considered to be separate buildings). For example, if one contractor is performing the work at several different buildings for one project, a permit is necessary for each building.
Who Needs Hot Work Permits?
Hot work permits are needed for each and every contractor or sub-contractor/trade performing the hot work for a project. For example, if there are three different sub-contractors/trades performing the hot work on one project, each subcontractor/trade is liable for obtaining the permit for their own work.
Cold Work Permit
The Cold work permits, typically blue-edged or coloured blue, are usually used to cover a variety of potentially hazardous activities which are not of the type covered by the hot work permit.
The activities for which the cold work permit may be relevant will vary from site to site but should be clearly defined.
A cold work permit is required for potentially hazardous work not covered by the other types of work permits. Some examples include:
- Chemical cleaning or the use of solvents,
- Handling of hazardous substances (e.g., toxic/corrosive chemicals, asbestos, etc.)
- The Use of resins typically used during blade repairs,
- Any painting activity,
- Heavy lifts (refer to Crane/Lifting procedure for definition),
- Erecting or dismantling scaffolds,
- Any non-routine and potentially hazardous activity,
- Any activity requiring specific control measures to confirm safety.
Electrical Work Permit
An electrical permit-to-work is primarily the statement that the circuit or the item of the equipment is safe to work on. A permit should not be issued on the equipment that is live.
A permit is applied any time work is to be performed on or near electrical equipment that is in an energized state. Maybe the subset of the Permit to Work system must include the additional safety requirements and the approvals. Electrical Safe Work Practice, Annex H: Energized Electrical Work Permit Form for a sample of the Energized Electrical Specialized Work Permit and a description of the minimum requirements for this permit.
What is an Electrical Work Permit?
An EEWP (Energized Electrical Work Permit) is a document that clearly describes the following:
- The circuit, the equipment, and the location of the job/task at hand.
- The work that is to be done.
- Justification of why the circuit or the equipment cannot be de-energized or the work deferred until the next scheduled outage.
The EEWP document should also include the section for the Electrically Qualified Person to assess the task at the hand and determine if the job can be done safely. In order to do this he or she must be able to provide the following information:
- A detailed job description procedure to be used when performing the job/task at the hand.
- A description of the safe work practices to be employed.
- Results of the Arc Flash Hazard Analysis and the Shock Hazard Analysis.
- Shock Protection Boundaries.
- Necessary personal protective equipment to safely perform the assigned task.
- Means employed to restrict the access of unqualified persons from the work area.
- Evidence of the completion of the Job Briefing including the discussion of any job-related hazards.
The document shall include the signatures (and dates) of the following personnel:
- Electrically Qualified Person performing the job/task at hand
- Manufacturing Manager
- Safety Manager
- General Manager
- Maintenance or Engineering Manager
- Electrically Knowledgeable Person
- Equipment Disjointing Certificate/Breaking Containment Permit
This type of certificate is used for any operation that involves the disconnecting equipment or the pipework that contains (or has contained) any hazardous or high-pressure fluids or other substances. This type of certificate will normally be used for the insertion of the spades into the pipework, and for the removal of such spades. These permits are typically black-edged.
Confined Spaces Permit
The Confined space entry certificates (unless detailed on a hot work or cold work permit) are used to specify the precautions to be taken to eliminate exposure to dangerous fumes or to an oxygen-depleted atmosphere before the person is permitted to enter the confined space. The certificate should confirm that the space is free from dangerous fumes or asphyxiating gases.
It should also recognize the possibility of fumes desorbing from residues, oxygen depletion of the atmosphere as a result of the oxidation, or the ingress of airborne contaminants from the adjacent sources. The certificate should specify the precautions to be taken to protect the enclosed atmosphere against these hazards, e.g forced ventilation, physical isolation or the provision of personal protective equipment including the breathing apparatus.
Confined spaces include the chambers, tanks (sealed and open-top), vessels, furnaces, ducts, sewers, manholes, pits, flues, excavations, boilers, reactors, and ovens. Many fatal accidents have occurred where inadequate precautions were taken before and during the work involving entry into confined spaces.
The two main hazards are the potential presence of toxic or other dangerous substances and the absence of adequate oxygen. In addition, there may be mechanical hazards (entanglement on agitators), ingress of fluids, the risk of engulfment in a free-flowing solid like grain or sugar and raised temperatures.
The work to be carried out may itself be especially hazardous when done in a confined space, for example, the cleaning using solvents, cutting/welding work. Should the person working in the confined space get into difficulties for whatever reason, getting help in and getting the individual out may prove difficult and dangerous. Stringent preparation, isolation, air testing and other precautions are therefore essential and the experience shows that the use of a confined space entry permit is essential to confirm that all the appropriate precautions have been taken.
This type of certificate may be very similar to the machinery certificate or an electrical certificate. It is usually used as the means of ensuring that the particular equipment is mechanically and electrically isolated before it is worked on. It is possible that the similarly named certificate may be used for the chemical isolation of the plant before the work is done on it or entry is made. If so, these should be cross-referenced to the associated permits.
The Radiation certificates, typically coloured yellow, outline necessary control measures to minimize the risks of exposure to radioactive sources including the site inspection, the controls on source exposure, access or the containment barriers and radiation monitoring.
Control of Less Hazardous Work
The lowest level of control within the safe system of work involves ‘routine duties, which were assessed, detailed and the approved work instruction or the procedures define work that can be undertaken on-site (eg process operators changing filters). Some offshore sites may use a ‘T-card’ or other simplified certificates to enable the less hazardous work to be integrated with other more hazardous work (e.g. changing filters near hot work).
The effective operation of the permit system requires the involvement of many people. The following specific responsibilities can be identified:
(Note: all appointments, definitions of work requiring a permit, etc., must be in writing. All the categories of people identified below should receive training in the operation of the permit system as it affects them.)
- has overall responsibility for the operation and management of the permit system;
- Appoints a senior manager (normally the Chief Engineer) to act as a senior authorized person.
Senior authorized person
- is responsible to the Site Manager for the operation of the permit system;
- defines the work on the site which requires a permit;
- ensures that people responsible for this work are aware that it must only be done under the terms of a valid permit;
- appoints all necessarily authorized persons;
- Appoints a deputy to act in his/her absence.
- issue permits to competent persons and retains copies;
- personally inspect the site to ensure that the conditions and proposed precautions are adequate and that it is safe for the work to proceed;
- accompany the competent person to the site to ensure that the plant/equipment is correctly identified and that the competent person understands the permit;
- Cancel the permit on satisfactory completion of the work.
- receive permits from authorized persons;
- read the permit and make sure they fully understand the work to be done and the precautions to be taken;
- signify their acceptance of the permit by signing both copies;
- comply with the permit and make sure those under their supervision similarly understand and implement the required precautions;
- Upon completing the work, return the permit to the authorized person who issued it.
- Read the permit and comply with its requirements under the supervision of a competent person.
A number of permits require the advice/skills of specialists in order to operate effectively. Such specialists may include chemists, electrical engineers, health and safety advisers and fire officers. Their role may involve:
- isolations within his/her discipline – for example, electrical work;
- using suitable techniques and equipment to monitor the working environment for toxic or flammable materials or lack of oxygen;
- Advising managers on safe methods of working.
Specialists must not assume responsibility for the permit system. This lies with the Site Manager and the senior authorized person.
Engineers (and others responsible for work covered by permits)
- Ensure that permits are raised as required.
The permit system should be applied to contractors in the same way as to direct employees. The contractor must be given adequate information and training on the permit system, its restrictions, and the precautions it requires.