THE NSW Department of Primary Industries (DPI) has released a safety bulletin on the safe use of electric welders.
A recent Industrial Relations Court of NSW hearing into the death of a person while using an electric welder, and continued occurrences of poor work practices and welding equipment found in poor condition at mine sites, have instigated the alert.
Testing as part of the investigation into the death identified “that the mere presence of dampness or perspiration on clothing resulted in the welding task falling into a high-risk category of welding”.
AS 1674.2: 2007 – Electrical Safety in Welding and Allied Processes identifies that “in general, the wetter the person’s skin and the larger the surface area of body contact, the higher will be the current flowing through the body and, therefore, the greater will be the risk of electrocution … where there is dampness or perspiration, 25 volt AC may be enough to give a fatal electric shock …”.
If the welding equipment is in poor condition or the work practices are deficient, the risk of electrocution is also greatly increased.
Recommendations
The NSW DPI recommends all mines to review their welding equipment, processes and procedures and ensure the following elements are provided for:
• The use of DC welders in preference to AC welders
• The welding machines, welding cables and welding appliances are suitable for the environment in which they are used
• Voltage reduction devices (VRDs) or equivalent devices are provided, used and maintained
• The welding machines, welding cables and welding appliances are in good condition
• The welding machines, welding cables and welding appliances are regularly checked by a competent person and defective equipment is restored to a fit-for-purpose state before it is re-used
• Procedures and processes comply with AS 1674.2 Safety in welding and allied processes — Electrical as a minimum
• A risk assessment checklist and procedures for welding work, including the identification of different welding environments and the required risk controls for the type of environment
• Employees and contractors who carry out or supervise welding work are trained in the use of these checklists and procedures
• The use of welding mats and other insulated mediums
• Procedures for identifying when to change work clothing due to dampness / perspiration
• Dry clothing and welding PPE is always available.
Other useful references
AS 1796:2001 ‘Certification of welders and welding supervisors’
AS/NZS 1995:2003 ‘Welding cables’
AS/NZS 3195:2002 ‘Approval and test specification – Portable machines for electric arc welding and allied processes’
AS 60974.1:2006 ‘Arc welding equipment – Welding power sources (IEC 60974- 1:2000, MOD)’
AS 60974.6:2006 ‘Arc welding equipment – Limited duty portable arc welding and allied process power sources (IEC 60974-6:2003, MOD)’
AS 60974.11:2005 ‘Arc welding equipment – Electrode holders’
To download the bulletin, click here
View more safety alerts at www.dpi.nsw.gov.au/minerals/safety/safety-alerts
If you would like to receive safety alerts by email, send your contact details to mine.safetyalert@dpi.nsw.gov.au