Welding...how dangerous can it be?

Welding, it’s just joining two pieces of metal together, right? How dangerous can it be? The process of permanently bonding metal together involves the use of a variety of energy sources, including: gas flames, electric arcs, electric resistance, lasers, electron beams, friction, molten metal baths and ultrasound. Once the material reaches the liquefied state they are joined together with or without the use of additional filler materials. In fact, the welding process is quite risky. Welders face life-threatening hazards each and every day they turn up for their shift. The risk of electrocution, fire and explosion, burns, electric shock, vision damage, inhalation of poisonous gases and fumes, and exposure to intense ultraviolet radiation is a real and present danger. Apart from the immediate dangers the activity of welding presents, they also need to be aware of the risks that arise within their work environment, such as conducting their activity in a confined space, at height or even underwater.

 

The plume...welding fume that can kill.

Although the life of a welder is fraught with many dangers, of major concern are the respiratory hazards potentially generated during the welding process. The plume, the clearly visible column of fume that rises directly from the spot of welding or cutting generated during welding is an intricate mixture of diverse metal fumes and gases. Short-term exposures to these contaminants may result in eye, nose and throat irritation, dizziness and nausea or metal fume fever. Prolonged exposure to these hazards has also been associated with different types of cancers and other serious health effects.

Millions of workers are exposed to welding fumes worldwide, and although evidence of negative health effects existed, it was designated as a substance that is probably toxic to humans. In March 2017, the International Agency for Research on Cancer (IARC) reclassified welding fumes based on substantial new evidence through observational and experimental studies, from “possibly carcinogenic to humans” as it was originally classified in 1989 to its new Group 1 classification as “carcinogenic to humans”. Welders are now considered at risk of illness or disease from prolonged exposure to welding fumes. The agency concluded that there is “sufficient evidence in humans” that welding fumes cause lung cancer. Workers who are regularly exposed to welding fumes have an increased incidence of lung cancer and pneumonia related to lifelong cumulative exposure. There is also mounting evidence that exposure to welding fumes increase the risk of welders developing kidney cancer.

This reclassification of welding fumes as a known carcinogen authenticates concerns related to the dangers posed by long-term workplace exposures and the potential for cancers occurring decades later. Put simply, the brave men and women who work to keep our cars, planes, buildings, in fact a host of metal objects we all use, from falling apart through their time-honoured tradition of joining metals through a craft that dates back several millennia are now being told that there is a direct relationship between inhaling welding fume and contracting cancer.

 

Where to from here?

As a person conducting a business or undertaking (PCBU), you must ensure that no person at the workplace is exposed to a substance or mixture in an airborne concentration that exceeds the exposure standard for the substance or mixture. Exposure standards provide airborne concentrations of individual substances, which according to current knowledge, should not cause adverse health effects nor cause undue discomfort to nearly all workers.

The current Australian workplace exposure limit for general welding fume is 5 mg/m³ TWA (Time Weighted Average). This means that the maximum average airborne concentration of total welding fume when calculated over an 8-hour working day, over a five-day working week, must not exceed 5 milligrams of welding fume per cubic metre of air in the breathing zone (inside the welder’s welding helmet when worn). Based on the typical respiratory rate of 20 litres of air per minute or 2,300 m³ of air per year, a welder operating within the workplace exposure standards for general welding fume (5 mg/m³), wearing no respiratory protection could inhale up to 11 grams of carcinogenic welding fume per year. It is of interest to note how we stack up in comparison to other parts of the world where they are more precautionary. In Germany, for example, welders have an exposure limit of 1.25 mg/m³, in the Netherlands it is 1 mg/m³. Therefore, an Australian welder can be potentially exposed to 4 times the level of a known carcinogen than that of a German welder and 5 times that of a Dutch welder.

Although the airborne hazards related to welding differ depending on the working environment, the risks from welding fume exposure intensify when the following conditions exist:

• There is insufficient exhaust ventilation to draw the fumes away from the workers’ breathing zone.
• There is no, or inadequate, personal protective equipment (PPE) used to protect the worker from hazardous concentrations of particulates and gases produced during welding.
• Welders remove their shield/helmet or respirator prior to complete dispersion of the fume cloud.

To minimise a welder’s risk of exposure to the toxic fumes employers should:

• Ensure workers are informed of the risks accompanying welding activities.
• Use engineering controls, as far as is practicable, to minimise exposure to welding fume.
• Provide welders with suitable respirators and ensure they are trained in their use and maintenance as per AS/NZS 1715 Selection, use and maintenance of respiratory protective equipment.
• Provide supplied or powered air respirators with proper particulate and gas filters installed, in addition to protective clothing and a UV helmet or shield when welding is conducted over extended periods of time.
• Regularly confirm that workers are using the PPE provided and that workplace health and safety policies and procedures are being followed.

In the majority of cases, PPE must be worn by workers when welding to supplement higher levels of controls such as ventilation systems or administrative controls. In the 2017 Occupational Cancer Risk Series on Welding released by the Cancer Council, they advise that welders should wear either air supplied or air purifying respiratory protection and use a full face welding helmet, with a UV filtered lens as well as suitable clothing, welding gloves and welding boots.

 

Choosing the right welding safety equipment.

3M™ Speedglas™ Welding Helmet 9100MP with Adflo™ PAPR

Whether you are a welder or a safety manager, the need for eye and face protection is well known when it comes to welding. But the less visible risks of welding, like welding fumes, are not so well known and can result in illnesses that can present themselves immediately or in weeks, months or years to come when inhaled.

With the recent reclassification of welding fume as carcinogenic to humans, powered air respiratory protection for welders has never been more important. A Powered Air Purifying Respirator, or PAPR, is a portable air filtration system that can provide effective protection against potentially hazardous particulates, fumes and some gases present when welding, cutting or grinding. By using a welding PAPR, you get a continuous flow of filtered air that provides increased respiratory protection and all-day comfort by taking some of the heat and sweat out of welding.

The 3M™Adflo™ PAPR unit is a lightweight, portable belt-mounted respirator that connects to the 3M™ Speedglas™ 9100 respiratory welding helmets. Available with a range of stackable particulate and gas filters, the Adflo PAPR system provides a Required Minimum Protection Factor of 50 - meaning the air that you breathe in through the system has at least 50 times lower concentration of particles and fumes than the surrounding air.

No two welders are the same. Your welding safety needs and in particular your respiratory protection requirements will differ. We can assist you in identifying the proper gear to help keep you safe for your environment. If you’d like more information on the hazards of welding fume or selecting suitable respiratory protection for your specific welding application please visit our welding safety portal to get in touch with Australian Welding Supplies (AWS), our exclusive distributor for 3M Speedglas products in Australia and New Zealand.