Deadly explosions during cutting of drums and containers

Health and Safety Executive - Safety alert

Introduction:

Duty holders are being reminded of the dangers of undertaking hot work on containers that contain, or have contained, flammable or combustible substances following two recent fatal accidents in North East Scotland where employees were killed whilst cutting up drums.

'Hot work' includes any process that generates a source of ignition (eg naked flames, heat, sparks) arising from working methods such as welding, flame cutting, grinding and using disc cutters. There is a risk of explosion causing serious injury or death if hot work is carried out on drums, containers, or any receptacle which contains, or has contained flammable or combustible liquids (eg waste thinners, new or used engine oil, anti-freeze, solvents, petrol or diesel fuel).

Background:

The use of combustible, flammable and highly flammable materials (eg petrol, diesel, paints, inks, solvents, dyes etc) is widespread across industry. Flammable materials may be supplied in a variety of containers and receptacles of different sizes. There is a significant risk of injury if hot work is used to cut up, alter or repair such containers or the containers are used as a support during hot work activities, such as welding.

A container may appear empty, however seams, creases and folds in the container may still harbour sufficient liquid residue to give rise to an explosive vapour and so the risk of ignition and injury remains. Even where the contents of a container may not have been classified as flammable under normal conditions, the extreme temperatures which can be generated during hot work can heat the vessel contents sufficiently to cause them to ignite.

Duty holders may also find additional uses for drums and containers meaning that the vessels contents may not reflect the original labelling.

Action required:

The Health and Safety Executive has investigated a number of serious and fatal accidents involving hot work over the years, for example in repair of diesel tanks in motor vehicle repair. As a consequence guidance has been published which details the risks involved and the precautions which should be adopted. Leaflet INDG314 entitled 'Hot work on small tanks and drums' provides a brief guide on the issue . 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.

Anyone contemplating hot work on used drums or similar containers or anyone that manages staff who use welding and cutting equipment, must urgently review their working and training procedures in line with this guidance to ensure that risks are adequately controlled. In many cases hot work may not be necessary. Safer alternative methods of working could be employed. These may include :

• Disposal or replacement of drums and tanks rather than repairing;
• Use of cold cutting techniques (eg hydraulic shears, pneumatic chisels);
• Use of cold repair methods;

If hot work is necessary, the risks should be avoided by using a specialist company or  reduced by using methods such as gas-freeing, cleaning or inerting before hot working. All employees engaged in hot work must have received adequate training in the risks involved and the precautions required.

Relevant legal documents:

• The Health and Safety at Work etc Act 1974
• The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) 2002
• The Management of Health and Safety at Work Regulations 1999

References:

• INDG314 'Hot work on small tanks and drums'
• L137 'Safe maintenance, repair and cleaning procedures', Dangerous Substances and Explosive Atmospheres Regulations 2002, Approved Code of Practice and Guidance;

Further information:

Health and Safety Executive
DSEAR Knowledge Hub: [email protected]

General note:

Please pass this information to a colleague who may operate this type of system/process.