THE POTENTIAL FIRE RISKS INVOLVED IN THE PROCESS OF WELDING ARE MAINLY FROM:-
the escape of flammable gases such as PROPANE
and ACETYLENE (propane has a distinctive fish
like smell and acetylene has a distinctive
garlic like smell, both of which will warn
you of any possible leaks).
oxygen enrichment in the air.
the mixing of oxygen and grease.
the mixing of acetylene and copper.
OTHER POSSIBLE CAUSES OF FIRE CAN BE FROM :-
Flammable pipe coatings.
The conduction of heat.
Hot metal spatter.
Concealed combustible materials.
The burn out of earth leads.
Cracks in electrode holders.
Health and safety regulations require that you :-
Remove all combustible materials from the work area.
Use a glass fibre woven fire smothering cloth to prevent sparks
or hot spatter falling on any remaining combustible materials.
Use fire retardant PVC sheeting if it is necessary to form a
containment area during burning and welding operations.
Fumes and Gases
A fume is a cloud of very fine particles. The particles can be collected by filters, unlike
gases which pass straight through.
During welding operations, fumes can be produced by :-
the filler rod vaporising
the rod coating vaporising
the parent metal itself vaporising.
The main release mechanisms for gases during welding operations are :-
release from filler rod coatings
release from fluxes
release of gases such as ozone due to the effects UV light.
The common toxic chemicals that you may be exposed to during welding operations are
carbon monoxide, the oxides of nitrogen and ozone, and metal fumes.
People affected by carbon monoxide poisoning should be removed from the dangerous
atmosphere and any tight clothing loosened. Medical assistance should then be sought.
Symptoms following exposure to welding gases and fumes can be delayed. Tell friends and
family what to watch out for and what to do.
A person affected by metal fume inhalation should be kept in bed with a hot water bottle
and plenty of fluids should be given, but no food.
Personal Safety
To maximise your safety whilst welding, you must always ensure that :-
Your work area is adequately ventilated to protect you from harmful gases and fumes.
All additional safety facilities such as air fed masks, portable and fixed extractor
systems and orinasal masks etc. are used if the fume and gas conditions deem them necessary.
Your eyes and body are protected equally well to prevent harm resulting from burns.
Care is taken when you are using electricity.
Remember that nearly all welding and burning operations are
potentially dangerous and therefore require care and attention.
Safety in Work Areas
Gas cylinders must be treated with care, as any heavy knocks or
falls will damage them and make them dangerous.
Overheating can also damage gas cylinders, so they should be kept
away from any heat sources.
Always keep acetylene and other fuel gas cylinders upright and
secured to prevent them from falling.
Oxygen cylinders are usually round bottomed and can be stacked
horizontally with wedges located at both sides of the stack.
Oxygen cylinders should be stored separately from fuel gas
cylinders and their cylinder valves closed.
Before welding or cutting in a confined space, you should check
that there is good ventilation; it could save your life.
Before beginning to weld a vessel, it is essential that you first
find out what the vessel contained and then treat it accordingly
to remove any potentially explosive substances left in it.
Radiography to test welded joints should only be carried out by
a trained and registered specialist. Anyone not involved should
be kept well clear of the area and barriers and warning signs
should be displayed.
The Safe Use of Equipment
The correct use, maintenance and careful handling of welding
equipment are all vital for safe welding practices.
If a flashback arrestor and hose check valves are fitted to a
system, a flashback should not travel beyond the torch.
Regulators are a must to get the correct gas pressures needed
for welding. Different types of regulator must be fitted for
different types of gases.
The hoses that are used on gas cylinders are colour coded and
should kept tidy to avoid trip hazards.
Electrode holders should always be checked for damage before use.
Cables and cable couplings should also be checked for signs of wear and tear.