Permit to Work Types, Procedure & When PTW is Required

Permit to Work Types, Procedure & When PTW is Required

Permit To Work (PTW)

Permit to Work (PTW) is a system that provides a framework for identifying and controlling risks associated with work activities. It is used to assess the risks involved in carrying out specific tasks, and to determine the necessary controls to be put in place to ensure that these risks are minimized.

The PTW system has been developed to protect employees, the public, and the environment from the potential hazards associated with work activities. It is also used to ensure that work is carried out safely and in accordance with legal requirements.

The Purposes of a Permit To Work

The PTW system has been developed for the following purposes:

  • To protect employees from exposure to risks that could result in injury, ill health, or death
  • To protect the public from risks that could result in injury, ill health, or death
  • To protect the environment from risks that could result in damage
  • To ensure that work is carried out safely and in accordance with legal requirements.

The Objectives of a Permit To Work

The PTW system has the following objectives:

  • To ensure that risks are identified and assessed before work activities are undertaken
  • To ensure that appropriate controls are put in place to minimize these risks
  • To ensure that work is carried out safely and in accordance with legal requirements
  • To ensure that employees, the public, and the environment are protected from potential hazards associated with work activities.

When Is A Permit To Work Required?

A permit to work is required when there is a potential for serious harm to workers or the environment. This includes work that involves:

  • Hazardous materials
  • High voltage equipment
  • Working at heights
  • Excavations
  • Confined spaces
  • Working with machinery

It is important to note that this is not an exhaustive list, and there may be other circumstances where a permit to work is required. If you are unsure whether or not a permit is required, you should always check with the relevant authority.

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 workforce;
  • Unconscious and conscious incompetence;
  • Objectives of the work permit system;
  • Types of work permit required; and
  • Contents of the work permits.

The following issues may contribute to 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.
Permit to Work Types

Role and Function Of A Permit to Work System

Safe systems of work are crucial in work, such as the maintenance of chemical plants where the potential risks are high, and the careful coordination of activities and precautions is essential to safe working. In this situation and others of similar risk potential, the safe system of work is likely to take the form of a permit-to-work procedure.

The role of the permit-to-work procedure is to provide a specialized type of safe system of work to ensure that potentially very dangerous work (e.g. entry into the process plant and other confined spaces) is done safely.

Although this procedure has been developed and refined by the chemical industry, the principles of the permit-to-work procedure are equally applicable to the management of complex risks in other industries.

The function of the permit-to-work procedure is to ensure that certain defined operations are prohibited without the specific permission of a responsible manager, this permission is only granted once stringent checks have been made to ensure that all necessary precautions have been taken and that it is safe for work to go ahead.

The people doing the work take on responsibility for following and maintaining the safeguards set out in the permit, which will define the work to be done (no other work being permitted) and the timescale in which it must be carried out.

To be effective, the permit system requires the training needs of those involved to be identified and met, and the monitoring procedures must ensure that the system is operating as intended.

The Principles That Apply To Permits To Work

Permit systems must adhere to the following eight principles:

  1. Wherever possible, and especially with routine jobs that are done without a permit to work- hazards should be eliminated so the job can proceed safely.
  2. Although the Site Manager may delegate the responsibility for the operation of the permit system, the overall responsibility for ensuring safe operation rests with him/her.
  3. The permit must be recognized as the master instruction which, until it is canceled, overrides all other instructions.
  4. The permit applies to everyone on-site, including contractors.
  5. Information given in a permit must be detailed and accurate. It must state; Which plant/equipment has been made safe and the steps by which this has been achieved; Work may be done & The time at which the permit comes into effect.
  6. The permit remains in force until the work has been completed and the permit is canceled by the person who issued it or by the person nominated by management to take over the responsibility (e.g. at the end of a shift or during an absence).
  7. No work other than that specified is authorized. If it is found that the planned work has to be changed, the existing permit should be canceled and a new one issued.
  8. Responsibility for the plant must be clearly defined at all stages.

Permit To Work (PTW) Procedures

The permit-to-work procedure is a specialized type of safe system of work, under which certain categories of high-risk-potential work may only be done with the specific permission of an authorized manager. This permission (in the form of the permit to work) will be given only if the laid down precautions are in force and have been checked.

The permit document should specify the following key items of information:

  • the date, time, and duration of the permit;
  • a description and assessment of the task to be performed and its location;
  • the plant/equipment involved, and how it is identified;
  • the authorized persons to do the work;
  • the steps which have already been taken to make the plant safe;
  • potential hazards which remain, or which may arise as the work proceeds;
  • the precautions to be taken against these hazards;
  • the action to be taken prior to the task being started, such as the isolation of sources of energy and outlets; emergency procedures and equipment; ensuring the competency of those involved; communication arrangements; and reference to any other relevant documents.
  • the equipment to be released to those who are to carry out the work.

In accepting the permit, the person in charge of doing the authorized work normally undertakes to take/maintain whatever precautions are outlined in the permit, such as:

  • solation of the area;
  • carrying out atmospheric monitoring;
  • the provision and use of personal protective equipment;
  • the provision of suitable equipment including lighting and tools;
  • ensuring an adequate level of supervision; and
  • arrangements for any extension to or handover of the permit.

The permit will also include spaces for: 

  • signature certifying that the work is complete; and
  • a signature confirming the re-acceptance of the plant/ equipment.

Different Types Of the Permits

Work Requiring A Permit

The nature of permit-to-work procedures will vary in their scope depending on the job and the risks involved. However, a permit-to-work system is unlikely to be needed where, for example:

  1. the assessed risks are low and can be controlled easily;
  2. the system of work is very simple;
  3. other work being done nearby cannot affect the work concerned in say a confined space entry or a welding operation.

However, where there are high risks and the system of work is complex and other operations may interfere, a formal permit to work should be used.

The main types of permits and the work covered by each are identified below. 

General Permit

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. This is particularly important for: large machines where visual contact between workers is difficult; where work has to be done near dangerous parts of the machine; where there are multiple isolations for energy sources and/or dangerous substances, and where dangerous substances are being used in confined areas with poor ventilation;
  • work on or near overhead crane tracks;
  • work on pipelines with hazardous contents;
  • repairs to railway tracks, tippers, and conveyors;
  • work with asbestos-based materials;
  • work involving ionizing radiation; and
  • excavations to avoid underground services. 

Typical work tasks that might require a permit to work

Hot Work Permit

Hot work is potentially hazardous because:

  • it may act as a source of ignition in any plant in which flammable materials are handled;
  • it may act as a cause of fires in all processes, regardless of whether flammable materials are present.

Hot work includes cutting, welding, brazing, soldering, and any process involving the application of a naked flame. Drilling and grinding should also be included where a flammable atmosphere is potentially present.

Hot work should therefore be done under the terms of a hot work permit, the only exception being where hot work is done in a designated maintenance area suitable for the purpose. Typical controls include: 

  • A suitable fire extinguisher is nearby;
  • prompt removal of flammable waste material; and
  • the damping down of nearby wooden structures such as floors.

Cold Work Permit

To ensure the safety of employees and the smooth operation of company machinery, a Cold Work Permit must be obtained before any work that does not generate heat can be performed. This permit must be obtained from the safety department and filled out with the required information. The permit must then be hung in a visible location near the work area.

Work On High-voltage Apparatus (Including Testing)

Work on high-voltage apparatus (over about 600V) is potentially high risk. Hazards include:

  • possibly fatal electric shock/burns to the people doing the work;
  • electrical fires/explosions;
  • consequential danger from disruption of power supply to safety-critical plant and equipment. 

In view of the risk, this work must only be done by suitably trained and competent people acting under the terms of a high-voltage permit. The most important control is to ensure that the necessary isolation is provided.

Confined Space Permit

The safe systems of work required for confined spaces were discussed under 4.4.9. If the work and/ or confined space is very hazardous, then a permit to work will be required. This will ensure that a formal check is undertaken to make sure all the elements of a safe system of work are in place before people are allowed to enter or work in a confined space. It will also be a means of communication between site management, supervisors, and those carrying out the hazardous work. The essential features of such a permit to work are:

  • the clear identification of who may authorize particular jobs (and any limits to their authority) and who, including any contractors, is responsible for specifying the necessary precautions (e.g. isolation, air testing, and emergency arrangements);
  • any particular training and instruction that may be required; and
  • monitoring and auditing of the permit-to-work system. 

Many fatal accidents have occurred where inadequate precautions were taken before and during work involving entry into confined spaces. Two 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, 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, cleaning using solvents, or cutting/welding work. Should the person working in a 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 experience shows that the use of a confined space entry permit is essential to confirm that all the appropriate precautions have been taken.

Chemical Work Permit

When working with chemicals, it is important to have a permit in order to ensure the safety of both the workers and the public. A chemical permit is an agreement between the employer and the employee that outlines the specific duties and responsibilities of each party in relation to the use of chemicals. It also outlines the precautions that need to be taken in order to prevent accidents and injuries.

The permit should be made available to all employees who will be working with chemicals. It should be signed by both the employer and the employee, and a copy should be kept on file by the employer. The permit should be reviewed on a regular basis and updated as necessary.

Machinery Maintenance Permit

The Provision and Use of Work Equipment Regulations require that all work equipment should be maintained in an efficient state and in good repair. Any maintenance operations on the equipment should be carried out safely. The frequency and nature of maintenance should be determined through risk assessment, taking full account of:

  • the manufacturer’s recommendations;
  • the intensity and frequency of use;
  • operating environment (e.g. the effect of temperature, corrosion, and weathering);
  • user knowledge and experience; and
  • the risk to health and safety from any foreseeable failure or malfunction.

Maintenance work should only be undertaken by those who are competent to do the work, and who have been provided with sufficient information, instruction, and training. For high-risk equipment, positive means of disconnecting the equipment from the energy source may be required (e.g. isolation), along with means to prevent inadvertent reconnection (e.g. by locking off). Such procedures are best controlled using permits to work. Where possible, equipment should normally be shut down and any residual/stored energy safely released (e.g. pneumatic pressure dumped, parts with gravitational/rotational energy stopped or brought to a safe position). In some cases, it may not be possible to avoid particular significant hazards during the maintenance of work equipment so appropriate measures should be taken to protect people and minimize the risk. These may include:

  • physical measures, such as temporary guarding, slow speed hold-to-run control devices, safe means of access, and personal protective equipment;
  • management issues, including safe systems of work, supervision, and monitoring; and
  • personnel competence (training, skill, awareness, and knowledge of risk).

Work at Height Permit

A permit to work may be required for some hazardous work at height such as roof work to ensure that a fall arrest strategy is in place. This is particularly important where there are:

  • no permanent work platforms with fixed handrails on flat roofs;
  • on sloping or fragile roofs;
  • where specialist access equipment, like rope, and hung cradles, is required; and
  • where access is difficult.

Electrical Isolation Permit

Permit to work for Electrical Isolation is a procedure that is used to ensure the safety of workers who are going to be working with electrical equipment. This procedure is important because it helps to ensure that workers are not exposed to electrical hazards. The first step in the permit to work for an electrical isolation procedure is to identify the hazards that are present. The next step is to develop a plan to control the hazard. The final step is to implement the plan and monitor the work area to ensure that the hazard is controlled.

Excavation Permit

An excavation permit is required whenever excavations are made in the workplace. This includes all digging, trenching, and tunneling activities. The purpose of the permit is to ensure that excavations are made safely and in compliance with all applicable safety regulations.

Before any excavation work can begin, a permit must be obtained from the appropriate authority. The permit application must include a detailed description of the proposed excavation work, as well as a safety plan that outlines how the work will be carried out safely. Once the permit is approved, excavation work can begin.

Roles & Responsibilities

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.)

Permit Holder

The permit holder is responsible for ensuring that the work activity is carried out in accordance with the conditions of the PTW. The permit holder must also ensure that all employees involved in the work activity are aware of the risks involved and the controls that have been put in place to minimize these risks.


The employer is responsible for ensuring that the PTW system is implemented and used correctly. The employer must also ensure that all employees are made aware of the risks involved in the work activity and the controls that have been put in place to minimize these risks.

Site Manager

The Site Manager has overall responsibility for the operation and management of a permit system. They appoint a SOPs Officer, who acts as their senior authorized person in charge to manage all permits on-site efficiently while ensuring they are being followed correctly by employees under them at every level with clear guidelines about what needs doing when it comes down to each type or size project- this includes setting aside enough over time so people don’t get bored during slower times because that is where most new ideas come from!

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.

Authorized Person

  • issue permits to competent ones and retains copies
  • personally inspect the site to ensure that adequate conditions and proposed precautions have been put in place. They’ll also make sure it’s safe for work onsite!
  • 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.

Competent persons

  • 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;
  • on completion of 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:

  • solutions within his/her discipline – for example, electrical work;
  • using suitable techniques and equipment to monitor the working environment for toxic or flammable materials, or for lack of oxygen;
  • giving advice to 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, the restrictions it imposes and the precautions it requires.

Permit To Work (PTW)

Tips For Using A Permit To Work System

There are many benefits to using a permit-to-work system, but it is important to ensure that the system is used correctly in order to maximize its benefits. Here are some tips for using a permit-to-work system:

  • Make sure that all relevant personnel are aware of the system and understand how it works.
  • Clearly define the scope of work that requires a permit.
  • Make sure that the necessary paperwork is completed correctly and in full before work begins.
  • Make sure that all permits are authorized by the relevant personnel before work begins.
  • Monitor the progress of work covered by a permit and take action if necessary.
  • Make sure that all permits are closed off correctly once the work is completed.

By following these tips, you can ensure that your permit-to-work system is used effectively and provides maximum benefits.

Permit To Work System (PTW) Checklist

  • Do you have the required permits?
  • Are all workers aware of the hazards associated with the work?
  • Is there a safe work procedure in place?
  • Is there a designated supervisor for the job?
  • Have all potential hazards been identified and controlled?
  • Are all workers wearing the proper Personal Protective Equipment?
  • Are all tools and equipment in good condition?
  • Is the work area well-lit and free of trip hazards?
  • Has a pre-task meeting been conducted?
  • Are there any other potential hazards that have not been considered?

If you can answer yes to all of the above, then you are ready to begin work. Remember, safety is always the number one priority. If you have any doubts about the safety of the work, do not hesitate to ask for help.

Frequently Asked Questions (FAQs)

How can workers be better educated on the use of a Permit to Work system in their workplace safety plan?

Workers need to be properly trained in the use of PTW systems before they can be expected to follow them. PTW systems can be complex, and workers may not be familiar with all of the hazards associated with a particular task. In addition, PTW systems usually require that workers fill out paperwork and get approval from a supervisor before starting work. This can add to the complexity of the system and make it more difficult for workers to understand.

How long is a permit valid?

This will vary depending on the type of work being done and the hazards involved. Some permits may only be valid for a few hours, while others may be valid for a day or more. it is important to check with the issuing authority to determine how long a particular permit is valid.

Who Can Issue A Permit To Work

A PTW can be issued by a competent person who has been authorized to do so by the employer. The competent person must have the necessary knowledge, skills, and experience to assess the risks involved in the work activity and to determine the appropriate controls that need to be put in place.

Why do I need a work permit?

There are many reasons why you might need a permit to work. In some cases, it is required by law. In other cases, it may be necessary to protect your safety or the safety of others.

In some cases, you might need a permit to work in order to comply with local, state, or federal laws. For example, many states require contractors to have a license in order to work on certain types of projects. In other cases, you might need a permit in order to work in a certain area or on a specific type of project. For example, if you want to work on a construction project that is located in a historic district, you might need to get a permit from the local historical commission.

In some cases, you might need a permit to work in order to protect your safety or the safety of others. For example, if you are going to be working with hazardous materials, you will likely need to get a permit in order to do so. This is because you will need to follow specific safety protocols in order to protect yourself and those around you from potential harm.

In other cases, you might need a permit to work in order to comply with the terms of your insurance policy. For example, many homeowners’ insurance policies will not cover damage that is caused by contractors who do not have the proper permits. As such, if you are planning on doing any work on your home, it is important to check with your insurance company to see if you will need a permit in order to do so.

Overall, there are many reasons why you might need a permit to work.

What factors contribute to a major accident

There are many factors that can contribute to a major accident. These include:

  • Lack of understanding of the system by workers
  • Lack of training on the use of the system
  • Failure to follow the procedures set out in the system
  • Poor communication between workers and supervisors
  • Lack of coordination between different parts of the system

If any of these factors are present in a workplace, it can lead to a major accident.

What Is The Difference Between A PTW And A Safe Work Method Statement (SWMS)?

A PTW is a system that provides a framework for identifying and controlling risks associated with work activities. An SWMS is a document that outlines the safe work procedures for a specific task.

A PTW is required when there is a potential for harm to people, property, or the environment. An SWMS is only required when the work activity has been identified as being high risk.


PTW systems are an important part of any workplace safety plan, but they can only be effective if workers are properly educated in their use. Employers should provide workers with training on the use of PTW systems before they are expected to follow them. In addition, employers should make sure that PTW system procedures are clear and easy to understand.

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