Page 37 - Australasian Paint & Panel Magazine Mar-Apr 2021

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STOP FUMING
WELDING FUMES ARE HAZARDOUS TO BOTH THE WELDER’S HEALTH AND OTHERS IN THE WORKSHOP. 3M’S GEORGE DISCALA EXPLAINS WHY AND HOW YOU CAN PROTECT YOUR TEAM.
AS YOU WELD THERE IS AN AMOUNT OF
metal fume produced. This is basically comprised of microscopic particles of hot metal and gases that are small enough and buoyant enough to be re- leased from the welding arc and rise in a cloud of metal fume into the workplace air. This fume is then able to be inhaled by the welder or others close to the source. There can be significant expo- sures to workers if effective controls are not in place, potentially leading to seri- ous short and long term health effects.
The visible part of the fume cloud is mainly particles of metal, metal oxides and flux (if used). The exact level of risk from the fume will depend on what met- als are involved in the work e.g. iron, al- uminium, lead, manganese, chromium, nickel and others. Each of these can have different toxic effects on the body, so exposure needs to be controlled.
Toxic gases arising in welding, which are not visible, include carbon monoxide. Chlorinated hydrocarbon solvents, such as methylene chloride can react with the arc to form phos- gene gas. Even small amounts of phos- gene may be deadly. Early symptoms
of exposure include dizziness, chills, and coughs usually taking 5 or 6 hours to appear. As a result of this effect, arc welding should never be performed within 60 metres of degreasing equip- ment or solvents.
Ultraviolet radiation given off by weld- ing also reacts with oxygen and nitrogen in the air to form ozone and nitrogen ox- ides. Overexposure to these gases can cause irritation of the nose and throat and serious lung disease.
Welders should understand the hazards of the materials they are working with, and refer to the relevant Safety Data Sheets and identification of size and scale of exposures to welding fume. OH&S Regulations re- quires employers to provide informa- tion and training for workers on expo- sure to hazardous materials in the workplace.
Welding surfaces should be as clean as practicable of any coating or oil/grease etc that could potentially increase the overall exposure to air- borne concentrations of hazardous particles or vapours.
Workers should position themselves in respect of the fume source as eff-
ciently as possible to avoid or re- duce exposure to the welding fume and gases.
Local exhaust ventilation sys- tems can be used to remove fume and gases from the welder’s breathing zone. Any air extraction system inlet should be located as close to the plume source as possi- ble to remove the maximum amount of fume and gases. Keep any exhaust points away from other workers.
USE OF APPROPRIATE RESPIRATORY PROTECTION EQUIPMENT
In March 2017, the Internation- al Agency for Research on Can- cer (France) evaluated the car- cinogenicity of welding fume. Based on substantial new evi- dence through observational and experimental studies, welding fume has now been re- classified to its new Group 1 classification as “Carcinogenic to Humans”. The working
group concluded that there is “suffi- cient evidence in humans” that welding fumes cause lung cancer and limited evidence for kidney cancer.
Australian Standard AS/NZS1715 "Selec- tion, use and maintenance of respiratory protective devices" recommends that ther- mally generated contaminants require at least a P2 class filter to capture the fume. 3M has a wide range of respirators for use for welding, from maintenance free and re- usable respirators to powered air purifying respirators and airline systems.
For more information contact your local 3M representative or customer service on: 131 131.
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