Types of Work Permits in Safety
What is a Work Permit?
A work permit is a written form used to authorize the jobs that endanger workers to the serious hazards. It recognizes the work to be done, the hazards involved, and the necessary preparation and the 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 the electrical installations or to use the large or the complex equipment.
Why Use a Work Permit?
When a job has the potential of causing the serious injuries or death, it is necessary to formalize agreed upon work procedures. This prevents the instructions from being missed, forgotten or the misinterpreted. It also works as a checklist to ensure that all the hazards, protective measures, work procedures and the 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.
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 the portable gas or arc welding equipment, or involve the soldering, grinding, or any other similar activities producing the spark, flame, or the 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, the pipelines etc which may contain or have the contained flammable vapor, or in areas where the flammable atmospheres may be present.
The Hot work permits, typically colored red or the red-edged, are more generally applied to any type of the work which 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 the sparks and for the use of any electrical equipment which is not intrinsically safe or of the suitably protected type. Some sites or the installations distinguish between the high energy sources of the ignition like the naked flames, welding and the spark-producing the 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 the 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 the 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 the 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 the three different sub-contractors/trades performing the hot work on one project, each sub-contractor/trade is liable for obtaining the permit for their own work.
Cold Work Permit
The Cold work permits, typically blue-edged or the colored blue, are usually used to cover the variety of the 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 the site to site but should be clearly defined.
A cold work permit is required for the potentially hazardous work not covered by the other types of the work permits. Some examples include:
- Chemical cleaning or the use of solvents,
- Handling of the hazardous substances (e.g., toxic/corrosive chemicals, asbestos, etc.)
- The Use of resins typically used during the blade repairs,
- Any painting activity,
- Heavy lifts (refer to Crane/Lifting procedure for definition),
- Erecting or the dismantling scaffolds,
- Any non-routine and the potentially hazardous activity,
- Any activity requiring the specific control measures to the 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 applied any time work is to be the performed on or the near electrical equipment that is in an energized state. Maybe the subset of the Permit to Work system but 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 the 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.
- Means employed to the 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 the certificate is used for any operation that involves the disconnecting equipment
or the pipework that contains (or has contained) any hazardous or the high-pressure fluids or
other substances. This type of the certificate will normally be used for the insertion of the
spades into 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 the exposure to the dangerous fumes or to an oxygen-depleted atmosphere before the person is permitted to enter the confined space. The certificate should confirm that space is free from the dangerous fumes or asphyxiating gases.
It should also recognize the possibility of fumes absorbing 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 then closed atmosphere against these hazards, eg by forced ventilation, physical isolation or by the provision of the personal protective equipment including the breathing apparatus.
Confined spaces include the chambers, tanks (sealed and open-top), vessels, furnaces, the ducts, sewers, the manholes, pits, the files, excavations, boilers, the reactors, and the ovens. Many fatal accidents have occurred where inadequate precautions were taken before and during the work involving entry into the confined spaces.
The two main hazards are the potential presence of the toxic or other dangerous substances and the absence of the 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 the confined space,for example, the cleaning using solvents, cutting/welding work. Should the person working in the confined space get into the difficulties for whatever the reason, getting help in and getting the individual out may prove difficult and dangerous. Stringent preparation, the isolation, air testing and the 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 the 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 colored 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 the radiation monitoring.
Control of Less Hazardous Work
The lowest level of the control within the safe system of work involves ‘routine duties’, where 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).