Types of Permit to Work: Hot Work, Confined Space and More

Not all hazardous work involves heat, sparks or flames. A cold work permit is issued to authorise tasks that don't involve ignition sources but still carry significant risk — mechanical work, equipment removal, pipework dismantling, cleaning and inspection activities in hazardous areas.

The distinction matters because cold work is sometimes treated as lower-risk by default, which is a mistake. Working on pressurised systems, handling toxic process fluids, or disturbing equipment in a flammable atmosphere all require careful control regardless of whether heat is involved.
A cold work permit must address:

• Isolation and de-energisation - confirmation that the system or equipment has been properly isolated, depressurised, drained and locked out before work begins
• Atmospheric conditions - gas testing where the work is in or near areas with flammable or toxic atmospheres, even if the task itself produces no ignition source
• SIMOPS awareness - whether any concurrent hot work or other activities in the vicinity could introduce a hazard to what would otherwise be a safe cold work task
• PPE requirements - appropriate to the specific hazards present, which may include chemical resistance, respiratory protection or specialist gloves depending on the process
• Authorisation - sign-off from the responsible authority confirming conditions are safe and isolation is verified

The SIMOPS angle is particularly important. A cold work task carried out in isolation may be entirely safe. The same task carried out while hot work is happening 10 metres away, or while a nearby vessel is being opened, may not be. An electronic PTW system that shows all active permits on a plot plan makes this interaction visible before work starts.

An excavations permit is issued to authorise the digging or excavation of a hole or trench. This type of permit is typically required for any excavation that involves a depth greater than a certain threshold or is located in areas with underground utilities or sensitive environmental features.

The purpose of an excavations permit is to:

• Protect public safety: Ensure that excavations are conducted safely and do not pose a risk to pedestrians, motorists, or property.
• Prevent damage to underground utilities: Minimise the risk of damaging underground cables, pipes, or other infrastructure.
• Protect the environment: Ensure that excavations are carried out in a way that minimises environmental impact, such as erosion or pollution.
• Obtain necessary approvals: Require the approval of relevant authorities, such as local councils or utility companies, before excavations can begin.
• Document the work: Provide a record of the excavations, including their location, depth, and any safety measures taken.

A special hazards permit to work is a document issued to authorise work activities that involve particularly hazardous substances or conditions. This type of permit is typically required for work that involves the handling or use of highly toxic, corrosive, or explosive materials, or for work that takes place in extremely hazardous environments.

Some examples of special hazards that may require a permit include:

• Highly toxic substances: Substances that can cause serious health effects or death, even in small quantities.
• Corrosive substances: Substances that can cause skin burns or damage to materials.
• Explosive substances: Substances that can cause a sudden release of energy and pressure.
• Radioactive materials: Substances that emit ionising radiation.
• Biological hazards: Substances that can cause disease or infection.
• Extreme environments: Environments with extreme temperatures, pressures, or other hazardous conditions.

The purpose of a special hazards work permit is to:

• Identify and assess hazards: Ensure that all potential hazards associated with the special hazards work are identified and evaluated.
• Implement safety measures: Require the implementation of appropriate safety measures to prevent accidents and injuries, such as the use of specialised personal protective equipment, emergency response plans, and strict adherence to safety procedures.
• Obtain necessary approvals: Ensure that all necessary approvals from relevant departments or authorities have been obtained before the work can begin.
• Document the work: Provide a record of the special hazards work performed, including the types of hazards involved, the safety measures taken, and any incidents or near-misses that occurred.

A working at height permit is a issued to authorise work activities that involve working at a height. This type of permit is typically required for any work that involves working above ground level, such as construction, maintenance, or repair work.

The purpose of a working at height permit is to:

• Identify and assess hazards: Ensure that all potential hazards associated with working at height, such as falls, slips, or trips, are identified and evaluated.
• Implement safety measures: Require the implementation of appropriate safety measures to prevent falls, such as the use of fall protection equipment, safe access and egress, and adequate training for workers.
• Obtain necessary approvals: Ensure that all necessary approvals from relevant departments or authorities have been obtained before work at height can begin.
• Document the work: Provide a record of the work performed at height, including the safety measures taken, any incidents or near-misses, and the names of the workers involved.