This safety alert reminds people of the precautions required when carrying out hot work in the workplace, for example grinding, welding, oxy cutting or other processes which produce a flame or other ignition source.
In February 2018, a serious fire developed on a building demolition site when plastic mesh screening ignited whilst hot work was being undertaken. The demolition work involved the cutting of a metal beam using an oxy acetylene torch. The fire engulfed the site and approximately 20 people were treated on site for smoke inhalation.
The incident demonstrates one of the hazards associated with hot work, a fire caused by heat, sparks, molten metal or direct contact with the flame. Others include:
Many materials and substances found in workplaces are flammable or combustible. They can be solids, liquids or gases.
The risks associated with a certain material or substance may not be immediately obvious. For example, flammable substances can give off enough vapour at room temperatures to form burnable mixtures with air or generate toxic fumes. However the vapours are usually invisible and often have no odour, and are therefore difficult to detect without the use of special instruments.
Any hot work process can be a potential ignition source for a flammable or combustible material.
Serious or fatal injuries can occur when hot works are undertaken on or in close proximity to flammable or combustible materials/ substances without appropriate control measures. Such injuries may occur as a result of the primary ignition, or secondary effects such as smoke, toxic fumes, oxygen depletion, or structural collapse.
Prior to carrying out any hot work on site it is essential to implement a hot work permit system, which includes a detailed review, to identify all potential hazards associated with the proposed hot work activity and to eliminate the hazards or, where this is not reasonably practicable, control the resulting risks.
Typical key measures to be considered include:
The hot work permit system should incorporate a check list to address all hazards and controls and should be reviewed and signed off by the persons in control of the site and involved in the hot work activity. A copy of the hot work permit should be kept in the site file as well as being displayed at the site.
The hot work permit should also address housekeeping and other measures such as inspection of work site and identification and handling of hot products subsequent to the hot work activity.
Training and awareness should be provided to all site personnel and contractors covering:
The Australian Standard AS 1674.1 Safety in Welding and Allied Processes Part 1: Fire Precautions provides guidelines with regards to hot work activities and an example of a typical hot work permit.
This video safety alert below highlights the dangers of cutting used drums for storage, feed trays etc. Flammable substances can still be present in old drums. Even if they have been cleaned and rinsed, the introduction of an ignition source can create a disastrous explosion.