Employees contemplating 'hot work' on used containers, and managers overseeing it, are being urged to check that the correct working procedures are followed after two people were killed in separate incidents in North East Scotland while cutting up drums.
'Hot work' includes any process that generates a source of ignition, such as naked flames, heat or sparks arising from working methods such as welding, flame cutting, grinding and using disc cutters.
HSE is issuing a Safety Alert to remind duty holders of the risk of explosion when undertaking 'hot work' on containers that contain, or have contained, flammable or combustible substances like waste thinners, new or used engine oil, anti-freeze, solvents, petrol or diesel fuel.
The use of these materials is widespread across industries such as manufacturing, and although some containers may appear to be empty, sufficient liquid residue can exist in seams, creases or folds in the container to give rise to explosive vapours.
Even where the contents of a container may not have been classified as flammable under normal conditions, hot work can generate such extreme temperatures that the contents may ignite.
HSE principal inspector Edward Marshall, comments: "This alert is not issuing new guidance but is to ensure all relevant workers are aware and familiar with the comprehensive advice that already exists. In many cases hot work may not actually be necessary, and those ultimately responsible for the work should consider safer alternatives, such as the disposal of drums rather than the repair, and the use of cold-cutting techniques or cold repair methods.
"If there is no alternative employers should aim to avoid the risks, by using specialist companies, or reduce them using methods such as gas-freeing, cleaning or inerting before starting hot work.
"It is essential that all employees have had the right training for the job and know what precautions to take to protect themselves and others."
The Safety Alert can be found at www.hse.gov.uk/safetybulletins/hotwork.htm.
For further guidance detailing the risks involved and the precautions which should be adopted, a brief guide is also available on HSE website at http://www.hse.gov.uk/pubns/indg314.pdf.
More detailed information is contained in the Approved Code of Practice and Guidance publication (L137) entitled 'Safe maintenance, repair and cleaning procedures', Dangerous Substances and Explosive Atmospheres Regulations 2002 (http://www.hse.gov.uk/pubns/books/l137.htm.)