One of a series of “Looking At Legislation” summary sheets, courtesy of NZ Safety.
What You Need To Know About…
Hold Your Fire: Safety Tips for Hot Work Activities To repair equipment and keep it in good working order, companies often need to carry out activities such as welding, grinding, soldering, or other work involving flames or generating sparks – activities collectively known as hot work. Statistics show that improperly managed hot work is a major cause of workplace fires and explosions—one insurer reported that 1 of every 20 reported fire losses was started by hot work that had not been properly managed. The sad truth is that all were preventable. As with any workplace hazard, planning and preparation go a long way toward preventing costly mishaps and serious injuries. How do you manage the risks of hot work so your business doesn’t go up in smoke?
What is hot work? Hot work is defined as, any work involving processes that have the potential to cause a fire or explosion. Hot work activities may involve using open flames, other heat sources, or equipment that generates sparks. Examples of hot work include any activities where an open flame torch or any other type of heat source is used – e.g., acetylene or propane torch, welding or soldering gear, or even an electric heat gun, as well as activities such as welding, grinding, soldering, gas cutting, brazing and paint stripping— all of which have the potential to ignite combustible materials.
Why is it so important to manage hot work? Hot work is, by its very nature, a roving fire hazard in your workplace. In addition, the fire ignition hazards of hot work activities often take place in or have access to areas not readily visible. This means a fire could easily spread unnoticed until it is well-established. Many fires arising from hot work activities smoulder for several hours before they break out into open flames, which mean they can go undetected until well after your facility is shut down for the day. The potential for fire losses is huge.
How can hot work start fires? Obvious ignition can result from sparks, slag and falling hot debris. These fire hazards can be easily controlled by making sure other combustible materials are removed from the work area and placing fire screens around the work place. Less obvious but often the cause of fires is radiated and conducted heat – e.g., protracted work on metal pipe passing through a wall. In this case, the opening in the wall is appropriately sealed and the immediate area is clear of combustibles, but heat travels along the pipe and ignites material such as insulation inside the wall, a combustible coating on the other side of the wall, or other combustible material hanging on or in contact with the pipe. Always check what you can’t see.
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One of a series of “Looking At Legislation” summary sheets, courtesy of NZ Safety.
What precautions are required for hot work on drums and tanks? It is particularly important that any hot work on a drum or tank is double-checked to ensure there are no remnants of combustible material left in the drum or tank. These combustibles may not be visible, but they can be trapped in seams and welds and only released when heating occurs. Any degassing MUST be done IMMEDIATELY prior to work commencing and vapours should be checked using a gas detector. The Department of Labour have an excellent booklet on their web site at http://www.osh.govt.nz/order/catalogue/pdf/hotwork.pdf
What is a Hot Work Permit? A Hot Work Permit should be issued whenever Hot Work is to be carried out on a building or area where combustible materials are being stored. The permit must be issued by a person other than the one carrying out the work. A Hot Work Permit is essentially a checklist designed to ensure all practicable steps are taken to make the hot work area safe. It is designed to ensure hazards are identified and assessed, and to ensure appropriate controls are determined and implemented (i.e., precautions taken) before any hot work begins, and to ensure the process is controlled throughout – before, during and after hot work activities. The Hot Work permit details information such as: • Nature and scope of work to be carried out • Time-frame of work to be undertaken (thus the duration of the validity period of the permit) • Areas where hot work will take place and relevant precautions, including removal or isolation of any combustible materials • Emergency response requirements and preparations, including specifications and availability of sprinklers, appropriate fire extinguishers and other firefighting equipment in the area • Details of how the area will be made safe before work occurs and after tasks have been completed, including fire watch requirements following completion of hot work • Precautions to prevent ignition during hot work activities • Who specifically will undertake the work, what supervision is required, and training requirements for each person– e.g., competent safety observer, fire extinguishers, etc • Communication requirements A competent person is usually authorised to issue hot work permits on behalf of the site. This individual is responsible for verifying that all hot work requirements are adequately and appropriately addressed before the permit is authorised (signed), and for signing off satisfactory completion of the work once the entire process (including fire watch) has been completed. The work permit is only valid when authorised by the competent person, and the work is only complete when the authorised competent person deems it safe and complete.
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One of a series of “Looking At Legislation” summary sheets, courtesy of NZ Safety.
What are the key considerations for managing hot work activities? Hot work should only be carried out by competent personnel who have been trained in the particular risks of hot work. They must understand the procedures and requirements for managing hot work. One option may be for personnel to be trained as a Safety Observer (NZQA Unit Standard 17596) to control, monitor and maintain safety during activities such as hot work. Identify all hot work to be carried out, and always conduct a thorough hazard identification and analysis before commencing work. If hot work is to be conducted in a dedicated hot work area (i.e., restricted and controlled areas such as an engineers’ workshop), a hot work permit may be waived; in any other situation, the permit must be completed before starting any work. Preparation required for hot work includes removal or isolation of any combustible materials. Identify all hot work areas where an ignition source could be spread without being easily seen, where a fire could smoulder undetected and take hold without being noticed. Take particular care to manage hot work in areas such as: • Operating HVAC systems • Openings around pipes extending through walls or floors • Openings in floors • Concealed spaces with combustible construction • Equipment with combustible linings • Conveyors Identify emergency response requirements and ensure all required equipment and personnel are ready and available if needed. All arrangements for responding to a fire or other emergency must be put in place before starting any hot work tasks. Detail communication requirements and arrangements to ensure people are informed and aware of hot work activities. Identify and assign any specific responsibilities for communicating with others during the hot work process.
What precautions should be taken before starting hot work tasks? The follow conditions are usually specified on the Hot Work Permit and must be met as a minimum: • Suitable fire extinguisher available nearby and ready to use if needed • ‘Runout’ fire hose reel or hydrant hose available nearby • Floors and surroundings swept clean and wetted down throughout hot work activities • Any device creating a draught is turned off – e.g., fans, blowers, etc • All combustibles located at least 11 metres from hot work operations or protected with non-combustible curtains, metal guards or flame-proofed covers (NB: NOT ordinary tarpaulins – they will burn) • All wall and floor openings are covered to prevent any burning materials from slipping through
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One of a series of “Looking At Legislation” summary sheets, courtesy of NZ Safety.
Why should contractors be supervised when carrying out hot work? Contractors bring specialised skills to the job, but their expertise is focused on their main business activity, rather than on property loss prevention of hazards specific to your site. Historical data shows that fire risks can more than double when contractors perform hot work without active supervision by site personnel. One insurer claimed unsupervised contractors accounted for an astonishing 74% of hot work losses at properties they had insured. It’s important to realise that when contractors carry out hot work, they don’t have as much stake in loss prevention as employees. Contractors are also less aware than site personnel of what can burn on your site or how their work can initiate a fire, so it’s important to ensure knowledgeable employees supervise contractor hot work activities at all times.
Why does hot work require surveillance for such a long time after the work is finished? Have you noticed how many factory fires set off alarms in the middle of the night? The combustible materials involved in many hot work fires can smoulder for several hours before breaking out into open flames, allowing a fire to take hold and go undetected for some time – long after personnel finish work for the day and well into the time when everyone has left the site. In addition, many hot work activities take place in areas that are concealed to some degree, which means a fire won’t be noticeable until well after site operations have finished for the day. Having a person on fire watch for several hours after hot work has been completed will make it much easier to spot a fire in its early stages, preventing the extensive damage of an established fire that is burning out of control. As with any other hazard, it’s most effective to prevent the fire and minimise the possibility of it spreading, rather than finding yourself in the position where you need to bring a raging fire under control. Where the risk of fire is lower – e.g., where buildings are constructed from noncombustible materials, all burnable materials have been relocated at least 11 metres away from hot work, and there are no other hazards that present an ignition source (e.g., grouped cables) – fire watch time may be reduced accordingly. This should only be done on the basis of a thorough risk assessment. Means of post-hot work fire watch monitoring may include: • Automatic smoke detection systems • Security video cameras • Routine security / maintenance rounds • Plant personnel working in area • Inspections at intervals of no more than 20 minutes
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One of a series of “Looking At Legislation” summary sheets, courtesy of NZ Safety.
How can I manage hot work hazards effectively using the hierarchy of controls? To eliminate requirements for hot work activities: • Install equipment that is assembled with mechanical connections instead of welded ones. • Change existing equipment designs to use bolted assemblies instead of welded ones. • Use safer alternative equipment: o Instead of cutting torch or powered radial saw, use a reciprocating saw, manual hydraulic shear or hand saw. o Replace tack welding or brazing with self-tapping screws. o Replace sweat-soldered pipe with threaded pipe. To isolate hot work hazards: • Designate an area specifically constructed, protected and arranged to accommodate and manage hot work, which will replace the need for a permit system, but fire safety conditions need to be maintained at all times. To reduce hot work hazards (minimise): • Substitute electric arc-stick welding with heliarc welding. • Replace open-flame torches with electric heat gun. • Trade torch soldering for electric soldering iron. NB: These hot work control options still require hot work management.
How can I find out more about hot work safety issues? The Department of Labour (OSH) offers a publication called Hot Work on Tanks and drums – available on their website www.osh.govt.nz The USA’s OSHA website offers information about hot work safety in the context of shipbreaking – the concepts are generally applicable in hot work situation: http://www.osha.gov/SLTC/etools/shipyard/ship_breaking/hotwork/index_hw.html A Google search on the internet for “hot work” will provide a number of examples that may assist in managing specific hot work situations, and there are many examples of hot work permits posted on various websites. The way you manage hot work may mean the difference between controlling a minor, temporary risk vs. experiencing a major threat to your company’s future. Make sure hot work activities at your site don’t become a burning issue.
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