Written by CMSE Safety Consultant Jake Bumpus
According to Regulation 173 of the General Application Regulations 2007, there is a legal duty on employers to “ensure that, where required by the explosion protection document… a system of permits to work is applied for carrying out both hazardous activities and activities which may interact with other work to cause hazards”. Carrying out a welding operation in an ATEX-rated area, which creates the potential to ignite a potentially explosive atmosphere, is a typical example of a hazardous activity which would require the use of a Hot Work Permit.
The types of controls which should be considered as part of the Hot Work Permit are:
- Removing or reducing the source of the explosive atmosphere as far as possible, for example by shutting down operations and/or draining storage vessels of any flammable substances.
- When the area is connected to other areas which are still “live”, then the area must be properly isolated. Any isolations should follow a formal lock-out-tag-out process (LOTO) that prevents the re-energisation of the system.
- Similarly, when vessels/tanks have been drained of flammables and washed out, this must be verified before hot work is carried out, e.g. by visual inspection and/or flammable gas detection.
- Additional means of controlling flammable vapours may be installed, such as temporary additional ventilations.
- The area should be cleared of any combustibles which may be ignited by the sparks generated by the welding activity.
- Temporary fire screens could be installed to prevent sparks travelling to a wider area and causing ignition. Research has indicated that welding/grinding sparks can travel as much as 11 m horizontally form the source of the work activity if not contained.
- Workers should wear personal flammable gas (LEL) detectors/alarms at all times while carrying out the work, and should wear suitable PPE.
- Workers should bring portable firefighting equipment (e.g. fire extinguishers, fire blankets) and should be trained in their use.
- A fire watch could be implemented, where workers observe for any early signs of fire (smouldering/smoking etc.) for a suitable period of time after the work has been completed.
At the end of the working period, the Hot Work Permit should be signed off by those carrying out the work that it is complete, or that work is not yet complete and needs to be continued, and returned to the permit issuer. This helps to ensure that area will only be returned to service only once it is safe to do so.
CMSE Consultancy offers top quality ATEX consultancy and support service to our clients nationwide. We have extensive ATEX experience and a proven track record in providing these services across many industrial sectors. Our ATEX consultants have both process and electrical safety expertise which makes our solutions both legally compliant and beneficial from the perspective of potential cost reductions and savings.
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