WELDING FUMES

This article looks at some of the safety issues arising from fumes produced by various welding processes, and at how you can best protect yourself and your employees.

Welding is classified as a “hot work” process, and as such attracts its own set of regulatory obligations on the part of the employer; especially in confined spaces. However, the hazards posed by airborne products of the welding and soldering processes are diverse and insidious, deserving careful consideration by employers and welders themselves.

METAL FUME FEVER

Heating metals causes a small quantity to be oxidised and vapourised.  The microscopic particles become part of the atmosphere which the welder and bystanders are breathing. Each of the metals used in welding processes has its own toxicology, but a typical cocktail, if inhaled over time, produces an array of symptoms; one in particular commonly known as “Metal Fume Fever”. Symptoms can resemble those of the flu, and tend to abate when welding is discontinued, for instance at weekends. Sufferers often report a metallic taste in the mouth.  In extreme exposure cases they will experience chronic and life threatening symptoms especially when welding galvanized products.  Transient though some of these acute symptoms may be, welding fumes can cause long-term physiological damage, including brain damage and various forms of cancer. Arc welding produces ozone, which irritates the upper respiratory tract, often with delayed long-term effects. 

As well as inhaled contaminants, various toxic metals like chromium compounds that are released in the welding of stainless steels can cause skin irritations, accelerating the onset of various forms of dermatitis.

OTHER CONTAMINANTS

In addition to metal fumes from the welding process, welding performed on existing structures can release all sorts of toxic vapours from paint and other substances adjacent to the heated weld area.    

With such a diverse range of toxins to protect your workers from, it makes sense to take measures aimed at precluding, or at least minimising any exposure of your workers to them. By the same token, the diversity of risk mechanisms means that no single measure will be successful, meaning employers and managers should use a combination of personal protection – hoods, goggles, gloves, etc. – together with workplace control measures, to achieve a safe welding environment.

We’ll come to personal protection in a moment, but first, here are some workplace steps you should consider:

1. Use effective local ventilation. Removing the vapours from the immediate site of the work is recommended. Fumes extracted in this way should be voided to the exterior of the building; taking into account the impact on “neighbours”.
2. Make sure your workplace is generally well ventilated. Whatever local measures you may take to ventilate the immediate site of the work, some toxins are further diluted by a good general building ventilation system.
3. Workplace design – keep welding areas separate from the rest of the workspace.  Also, where possible, train the welder to position so that fumes do not “flood” the breathing zone.
4. Make sure that work pieces are clean, degreased and any solvents removedfrom them before any heating takes place. That way the only toxins you may counter are those from the welding process itself, and also the hazard of fire is reduced. Fuel tanks, of course, require special attention in this regard.
5. Make sure you are using the least hazardous materials capable of efficiently doing the job in hand. Manufacturers of welding consumables are required by law to produce Safety Data Sheets (SDS) listing the hazards of their products.  You MUST HAVE a SDS for every toxic substance in the workplace and you are required to prove your efforts to substitute less toxic materials as well as following SDS recommendations.  It’s worth reviewing your processes to see where these can be used to minimise the risk in your welding work processes.

The Welding Technology Institute of Australia has invaluable guidance on fume minimisation.

PERSONAL PROTECTION

Equip your welders, and any assistants who may be required to stand close to the work, with the best possible personal protective equipment and apparel. A wide range of personal protection is available. Air-fed helmets, air-purifying respirators, eye protection, protective clothing, gloves, screens and ventilation equipment should have Australian Standards certification, and you should only use products which meet or exceed these.  Don’t consider cheap imports with no standards licenses.

1. Respirators – Airborne hazards from welding include both vaporous and particulate matter so the respirator you buy must cope with both. Only respirators that meet Australian Standard AS 1716 should be used. Filter media are available for all kinds of airborne hazards, so it’s important that you seek expert advice as to the correct choice for the welding application. The 3M respirator kit is suitable for many welding applications. Your SafetyQuip consultant will help you choose the right respirators for the welding you perform.
2. Helmets – All welders should have protection for the face and eyes, at least to AS/NZS 1337 with its comprehensive impact rating criteria. In the case of arc welding, where a large component of ultraviolet and infrared is produced, protection must comply with both AS/NZS 1337 and AS/NZS 1338. The Unisafe Flip Up Front welder’s helmet or the Unisafe Auto Darkening Welding Helmet are excellent designs for consideration. 
3. Gloves – Gloves should of course be flame-proof, and have extensive cuff protection. Leather is an ideal material, and thumb and finger pad reinforcement is often desirable. SafetyQuip distributes the Prochoice Pyromate range, which are good examples of welder’s gloves. Pyromate apparel also includes protective aprons, caps, hoods, jackets, sleeves and spats. 

The team at SafetyQuip are well trained and will be happy to assist you in selecting the right equipment to protect your workforce.  They also have access to the best supplier knowledge in the world for the added “insurance” of Local Knowledge; Safer Workers.