Aluminum, a widely used metal in various sectors such as aerospace, construction, automobile, and transportation, is frequently welded, consequently leading to the generation of health-endangering aluminum fumes.
When subjected to the heat of welding, aluminum releases a white fume primarily comprised of aluminum oxide and ozone. Aluminum oxide is known to cause irritation, while ozone is a harmful gas. Unprotected welding of aluminum could lead to serious health issues including respiratory and lung diseases like aluminosis, in addition to negatively impacting the nervous system.
Techniques employing an inert gas (argon, helium), like TIG (gas tungsten arc welding) and MIG, are generally the most prevalent for aluminum welding. This is because the inert gas prevents the material from interacting with the environment.
This article will detail the composition of those welding fumes, their dangers, and share solutions to protect welders.
Composition of Aluminum fume
The composition and concentration of aluminum welding fumes will vary based on factors such as the kind of aluminum or aluminum alloy, the welding technique, welding parameters, the type and size of consumables, the inert gas, etc. However, two toxic substances are invariably present and should not be inhaled: aluminum oxide and ozone.
Aluminum welding fume characteristics:
- 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)
During aluminum welding, the transition from the filler to the base material mainly generates aluminum oxide, a chemical compound of aluminum and oxygen. Aluminum oxide particles in welding fumes usually measure between 0.01 to 0.1 microns, can therefore be inhaled, and will deposit throughout the respiratory tract.
Ozone (O3)
Aluminum welding produces significant levels of ozone, created by the reaction of air (dioxygen, or O2) to the ultraviolet radiation emitted during welding. The radiation effect is intensified by aluminum’s reflectiveness, amplifying the issues. Ozone, or trioxygen, is a pale blue gas with a unique odor, somewhat similar to chlorine.
Interestingly, despite TIG welding on aluminum and aluminum alloys generating considerably less fume than MIG welding, the concentrations of ozone are much higher. The ozone output is also elevated when welding aluminum-silicon alloys compared to pure aluminum or aluminum-magnesium alloys.
Contrary to what one might expect, ozone production tends to surge when less fume is generated for two reasons. Firstly, the presence of fumes restricts the dispersion of UV rays, hence lessening ozone production. If the UV rays are not blocked, ozone can be produced even far from the arc. Secondly, ozone tends to be unstable and decomposes into oxygen when mixed with fumes.
Other metals and gases possibly found in aluminum welding fume
The consumables also significantly contribute to the composition of welding fumes, and it is vital to understand the materials contained in those products. Some are toxic and even potentially carcinogenic (beryllium and hexavalent chromium, for instance).
Typically, aluminum wire and rod 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)
- Titanium
- Zirconium
- Zinc (metal fume fever)
Nitrous gases, carbon monoxide, and carbon dioxide can also be produced during aluminum welding.
What happens if you inhale aluminum fumes? Health Risks & Symptoms
Here is a list of typical symptoms that manifest during or after inhaling aluminum welding emissions. If a welder experiences any of these symptoms, they require better protection.
- Irritation of the eyes, nose, and throat
- Chest tightness
- Headache
- Shortness of breath
- Cough
- Wheeze
- Nausea
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. Moreover, ozone is classified as a carcinogen in some regions, such as Germany (refer to Technical Rules for Hazardous Substances 905).
It’s critical to protect welders and their co-workers to the best extent possible and decrease exposure to harmful substances to the lowest possible level.
Regulations on Aluminum Welding Fume
In the United States, the Occupational Safety and Health Administration (OSHA) is in charge of establishing and enforcing exposure limits for air pollutants. In California, the local entity is Cal/OSHA.
Canada is home to 14 health and safety agencies. Each of the 13 provinces and territories has one, and a federal agency 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
| OSHA PEL | TWA | STEL | C |
| Welding Fumes | 5mg/m3(r) | None | None |
| Aluminum | 5mg/m3(r) | None | None |
| Ozone | 0.1ppm | 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 the US
| Cal/OSHA PEL | TWA | STEL | C |
| Welding Fumes | 5mg/m3(r) | None | None |
| Aluminum | 5mg/m3(r) | None | None |
| Ozone | 0.1ppm | 0.3ppm | 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 California
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Aluminum welding fume regulations in Canada
| Welding Fumes | TWA | STEL | C |
| Alberta | ALARA | ALARA | ALARA |
| British Columbia | 10mg/m3 (i) 3mg/m3 (r) | 30mg/m3 9mg/m3 | 50mg/m3 15mg/m3 |
| Manitoba | 10mg/m3 (i) 3mg/m3 (r) | None | None |
| New Brunswick | 10mg/m3 (i) 3mg/m3 (r) | None | None |
| Newfoundland and Labrador | 10mg/m3 (i) 3mg/m3 (r) | 30 mg/m3 9 mg/m3 | 50 mg/m3 15 mg/m3 |
| Northwest Territories | 5mg/m3 | 10 mg/m3 | None |
| Nova Scotia | 10mg/m3 (i) 3mg/m3 (r) | None | None |
| Nunavut | 5mg/m3 | 10mg/m3 | None |
| Ontario | 10mg/m3 (i) 3mg/m3 (r) | 30mg/m3 9mg/m3 | 50mg/m3 15mg/m3 |
| Prince Edward Island | 10mg/m3 (i) 3mg/m3 (r) | None | None |
| Quebec | 5mg/m3 | 15mg/m3 | 25mg/m3 |
| Saskatchewan | 5mg/m3 | 10mg/m3 | None |
| Yukon | 5mg/m3 | 5mg/m3 | None |
| Aluminum | TWA | STEL | C |
| Alberta | 10mg/m3 | None | None |
| British Columbia | 1mg/m3(r) | None | None |
| Manitoba | 1mg/m3(r) | None | None |
| New Brunswick | 10mg/m3(r) | None | None |
| Newfoundland and Labrador | 1mg/m3(r) | None | None |
| Northwest Territories | 10mg/m3 | 20mg/m3 | None |
| Nova Scotia | 1mg/m3(r) | None | None |
| Nunavut | 10mg/m3 | 20mg/m3 | None |
| Ontario | 1mg/m3(r) | None | None |
| Prince Edward Island | 1mg/m3(r) | None | None |
| Quebec | 5mg/m3 | None | None |
| Saskatchewan | 10mg/m3 | 20mg/m3 | None |
| Yukon | None | None | None |
| Ozone | TWA | STEL | C |
| Alberta | 0.1ppm | 0.3ppm | None |
| British Columbia | 0.05ppm | None | None |
| Manitoba | 0.05ppm | None | None |
| New Brunswick | 0.05ppm | None | None |
| Newfoundland and Labrador | 0.05ppm | None | None |
| Northwest Territories | 0.05ppm | 0.15ppm | None |
| Nova Scotia | 0.05ppm | None | None |
| Nunavut | 0.05ppm | 0.15ppm | None |
| Ontario | None | None | 0.1ppm |
| Prince Edward Island | 0.05ppm | None | None |
| Quebec* | None | None | 0.1ppm |
| Saskatchewan | 0.05ppm | 0.15ppm | None |
| Yukon | 0.1ppm | 0.3ppm | 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
Is a respirator necessary when welding aluminum?
Typically, with proper local exhaust and ambient ventilation, respirators aren’t necessary when welding aluminum. In fact, health and safety agencies mandate that employers prioritize other strategies. Respirators should only be worn temporarily when permissible exposure limits can’t be met.
Here’s a strategy to protect welders and other employees from aluminum welding fumes:
- 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
Regrettably, aluminum welders have been overlooked by the fume extraction industry in the past, primarily because there is no push-pull fume extraction welding gun. However, over the years, we’ve assisted many manufacturers in resolving their issues by modifying our fume extraction MIG guns or proposing viable alternative solutions.
The Optimal Method for Extracting MIG Aluminum Welding Fume
If you’re currently using a standard or a push-pull MIG welding gun, a fume extraction MIG gun will be the optimal solution for extracting aluminum welding fume. For better results, you’ll need to use a low-friction liner and keep the welding gun as short as possible.
This solution has been successful in many of our projects, and it is feasible for most scenarios without compromising 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 Optimal Method for Extracting TIG Aluminum Welding Fume
Flexible fume extraction arms with a blower are the best solution for removing aluminum fumes in TIG welding. Keep in mind that extracting the fume from above the arc is always preferable. This way, the smoke provides the most efficient shield to minimize ozone formation.
Any Questions?
Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.
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