Aluminum is used in many industries: aerospace, building materials, automobile, trains, trucks, bikes, trailers, and many more. As a result, welding aluminum and aluminum alloys has become increasingly common, and so have the health issues related to aluminum fume.
When heated during welding, aluminum produces a white fume mainly composed of aluminum oxide as well as ozone. Aluminum oxide is an irritant. Ozone is a toxic gas. Welding aluminum without appropriate protection can cause respiratory and lung diseases like aluminosis and affect the nervous system.
Processes using an inert gas (argon, helium), such as TIG (gas tungsten arc welding) and MIG, are generally the most common for aluminum welding. This is because the inert gas will prevent the material from reacting with the atmosphere.
This article will detail the composition of those welding fumes, their dangers, and share solutions to protect welders.
Aluminum fume composition
Aluminum welding fume composition and concentration will change depending on factors such as the type of aluminum or aluminum alloy, the welding process, welding parameters, the type and size of consumables, the inert gas, etc. But two toxic substances are always present and shouldn’t be inhaled: aluminum oxide and ozone.
Aluminum welding fume:
- Particle size: 0.01 – 0.1 micrometer
- Density: 169 lb/ft3 (2702 kg/m3)
- Molecular weight: 101.96 Daltons
- Melting point: 3659 F (2015 °C)
- Boiling point: 5396 F (2980 °C)
Aluminum oxide (Al2O3)
When welding aluminum, the material transition from the filler to the base material mainly produces aluminum oxide, a chemical compound of aluminum and oxygen. Aluminum oxide particles in welding fume are usually between 0.01 to 0.1 microns, can easily be inhaled, and will deposit throughout the respiratory system.
Aluminum welding generates significant levels of ozone, formed by the effect of the ultraviolet radiation produced when welding on air (dioxygen, or O2). The radiation effect is magnified by aluminum’s reflectiveness, which makes it more problematic.Ozone, or trioxygen, is a pale blue gas with a distinctive smell (a bit like chlorine).
It is interesting to know that, although TIG welding on aluminum and aluminum alloys produces much less fume than MIG welding, ozone concentrations will be much higher. The ozone production is also higher when welding aluminum-silicon alloys compared to pure aluminum or aluminum-magnesium alloys.
It is counterintuitive, but ozone production tends to be higher when less fume is formed for two reasons. First, the presence of fume limits the spreading of UV rays, reducing ozone production. Ozone can otherwise be produced even at a distance from the arc if UV rays are not stopped. Secondly, ozone tends to be unstable and decompose into oxygen when mixed with fumes.
Other metals and gases that could be in aluminum welding fume
Consumables also play an essential part in the composition of welding fume, and it is crucial to know the materials contained in those products as well. Some are toxic and even carcinogenic (beryllium and hexavalent chromium, for example).
Aluminum wire and rod usually contain:
- Aluminum (lung irritant)
- Beryllium (carcinogen, metal fume fever)
- Chromium (irritant, hexavalent chromium is a carcinogen)
- Copper (irritant, metal fume fever)
- Iron (siderosis)
- Magnesium (irritant, metal fume fever)
- Manganese (metal fume fever, manganism)
- Silicon (fibrotic)
- Zinc (metal fume fever)
Nitrous gases, carbon monoxide, and carbon dioxide can also be formed when welding aluminum.
What happens if you inhale aluminum fumes? Health Risks & Symptoms
Here is a list of common symptoms that appear while or after breathing aluminum welding fume. If a welders feel any of these symptoms, he needs to be better protected.
- Irritation of the eyes, nose, and throat
- Chest tightness
- Shortness of breath
Breathing too much aluminum welding fume can also have different health consequences for welders. Unfortunately, some can have dramatic and irreversible effects.
- Metal fume fever (flu-like symptoms)
- Aluminosis (also called aluminum lung, an incurable respiratory disease)
- Bronchitis (inflammation of the bronchial tubes)
- Hemorrhage (blood loss)
- Pulmonary edema (fluid in the lungs)
- Decreased nervous system performance (source: National Library of Medicine)
- Pulmonary fibrosis (lung tissue damaged and scarred)
- Pneumoconiosis (occupational interstitial lung disease, source: PubMed)
- Motor dysfunction
- Peripheral neuropathy (damage to the nerves)
The presence of beryllium or hexavalent chromium in the fume would also increase the risk of cancer for welders. In addition, ozone is also classified as carcinogenic in some countries, such as Germany (see Technical Rules for Hazardous Substances 905).
It is essential to protect welders and their colleagues as well as possible and reduce exposure to hazardous substances to a minimum.
Aluminum welding fume regulations
In the US, the Occupational Safety and Health Administration (OSHA) is responsible for setting and enforcing exposure limits for air contaminants. In California, Cal/OSHA is the local agency.
In Canada, there are 14 health and safety agencies. One for each of the 13 provinces and territories and a federal agency that covers federal government employees.
Abbreviations used in the tables:
- TWA: Time-Weighted Average for 8 hours
- STEL: Short-Term Exposure Limit (maximum for 15 minutes)
- C: Ceiling (must never be exceeded)
- (i): Inhalable particles
- (r): Respirable particles
- ALARA: As Low As Reasonably Achievable
Aluminum welding fume regulations in the US
To know more about the maximum concentrations allowed for other substances, you can read the following article: Welding Fume Regulations and Exposure Limits in the US
To know more about the maximum concentrations allowed for other substances, you can read the following article: Welding Fume Regulations and Exposure Limits in California
If you have any questions about welding fume, do not hesitate to contact us. We will be happy to give you some insight, and we can even visit you for free in the US and Canada.
Aluminum welding fume regulations in Canada
|British Columbia|| 10mg/m3 (i)|
|New Brunswick|| 10mg/m3 (i)|
|Newfoundland and Labrador|| 10mg/m3 (i)|
|Northwest Territories||5mg/m3||10 mg/m3||None|
|Nova Scotia||10mg/m3 (i)|
|Prince Edward Island||10mg/m3 (i)|
|Newfoundland and Labrador||1mg/m3(r)||None||None|
|Prince Edward Island||1mg/m3(r)||None||None|
|Newfoundland and Labrador||0.05ppm||None||None|
|Prince Edward Island||0.05ppm||None||None|
To know more about the maximum concentrations allowed for other substances, you can read the following article: Welding Fume Regulations and Exposure Limits in Canada
Do I need to wear a respirator when welding aluminum?
In general, with proper local exhaust and ambient ventilation, respirators are not needed when welding aluminum. In fact, health and safety agencies require employers to prioritize other measures. They should only be worn for short periods when permissible exposure limits cannot be met.
Here is a methodology to protect welders and other workers around from aluminum welding fume:
- Only weld when it is necessary. Other processes can sometimes replace manual welding (bolts, fasteners, robotic welding).
- Isolate welding operations from other workers (have an area or building dedicated to welding only, for example, or at least use welding screens).
- Use consumables and materials that produce less toxic fume. For example, you should remove paint or coatings and avoid carcinogenic substances (beryllium, hexavalent chromium, etc.).
- Use welding fume extractors. For more information, see our page about welding fume extraction for aluminum welding.
- Make sure welders position themselves to avoid breathing fumes and gases. For example, they should not leave their head between the weld pool and the fume extractor. Or they can use the wind to drive the fumes away when welding outside.
- Make sure your factory is adequately ventilated.
- Use personal protective equipment such as masks and respirators if the previous measures are insufficient to reduce exposure to safe levels. They should be fitted for each worker individually.
Learn more about our step-by-step method to solve welding fume problems. You will find more details and tips on this page.
Welding fume extraction for aluminum welding
Unfortunately, aluminum welders have been forgotten by the fume extraction industry in the past, mainly because there is no push-pull fume extraction welding gun. But over the years, we have helped many manufacturers solve their issues by adapting our fume extraction MIG guns or offering viable alternative solutions.
The best method to extract MIG aluminum welding fume
If you are currently using a standard or a push-pull MIG welding gun, a fume extraction MIG gun will be the best solution to extract aluminum welding fume. For better results, you will need to use a low-friction liner and keep the welding gun as short as possible.
We have successfully used this solution on many projects, which is viable for most situations without impacting quality or productivity. Portable units or central vacuum systems can provide the necessary vacuum depending on the number of workstations to cover and the flexibility required.
The best method to extract TIG aluminum welding fume
Flexible fume extraction arms with a blower will be the best way to remove aluminum fume for TIG welding. Know that extracting the fume from above the arc is always better. That way, the smoke provides the best shield to minimize ozone formation.
Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.