Since the 1980s, we have led the way in North America with our welding fume extraction solutions. This blog post will discuss exposure limits in the US for some of the most commonly encountered hazardous gases and metals present in welding fumes.
When a metal is heated beyond its boiling point, fumes are generated as the vapors condense into extremely fine particles. These particles can range in size from 0.005 to 20 µm, with the majority measuring less than 1 µm, enabling them to deposit throughout the respiratory system.
Several factors contribute to the composition of the fume, including the material being welded, the electrode, any coatings or fluxes, and the shielding gas, among others. To determine the exact composition of hazardous and regulated substances in your workplace, air sampling is typically required. However, obtaining data on the metals, gases, and consumables used in the welding process can provide a preliminary understanding.
Which particles in welding fumes are potentially harmful?
This article will highlight some common hazardous gases and metals typically found in welding fumes:
- Aluminum
- Antimony
- Arsenic
- Beryllium
- Cadmium
- Chromium
- Cobalt
- Copper
- Iron oxide
- Lead
- Manganese (learn more about manganese in welding fumes)
- Molybdenum
- Nickel
- Silver
- Tin
- Titanium dioxide
- Vanadium
- Zinc
- Argon
- Carbon Dioxide
- Carbon Monoxide
- Helium
- Hydrogen Fluoride
- Nitric Oxide
- Nitrogen
- Nitrogen Dioxide
- Ozone
- Phosgene
In the US, the Occupational Safety and Health Administration (OSHA) is tasked with establishing and enforcing exposure limits for air pollutants. For specific regulations applicable to California, please refer to the specific article where you will find the Cal/OSHA welding fume standards.
This blog will also discuss the recommendations of two prominent organizations that influence OSHA: the National Institute for Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH).
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Abbreviations used in the tables:
- TWA: Time-Weighted Average for 8 hours
- STEL: Short-Term Exposure Limit (maximum for 15 minutes, no more than four times per day, with at least 60 minutes in between)
- C: Ceiling (must never be exceeded)
- (i): Inhalable particles (smaller than 100 µm)
- (r): Respirable particles (smaller than 4 µm)
OSHA – Permissible Exposure Limits for Welding Fume, Metals, and Gases
| PEL | TWA | STEL | C |
| Welding Fumes* | 5mg/m3(r) | None | None |
| PEL | TWA | STEL | C |
| Aluminum | 5mg/m3(r) | None | None |
| Antimony | 0.5mg/m3 | None | None |
| Arsenic, inorganic | 10µg/m3 | None | None |
| Arsenic, organic | 0.5mg/m3 | None | None |
| Beryllium | 0.2µg/m3 | 2µg/m3 | None |
| Cadmium | 5µg/m3 | None | None |
| Chromium (II) & (III) | 0.5mg/m3 | None | None |
| Chromium (VI) | 5µg/m3 | None | None |
| Cobalt | 0.1mg/m3 | None | None |
| Copper | 0.1mg/m3 | None | None |
| Iron oxide | 10mg/m3 | None | None |
| Lead | 50µg/m3* | None | None |
| Manganese | None | None | 5mg/m3 |
| Molybdenum | 5mg/m3 | None | None |
| Nickel | 1mg/m3 | None | None |
| Silver | 0.01mg/m3 | None | None |
| Tin, inorganic | 2mg/m3 | None | None |
| Tin, organic | 0.1mg/m3 | None | None |
| Titanium dioxide | 15mg/m3 | None | None |
| Vanadium | None | None | 0.1mg/m3 |
| Zinc | 5mg/m3 | None | None |
You can make sure these PELs are still applicable on OSHA’s website.
| PEL | TWA | STEL | C |
| Argon* | None | None | None |
| Carbon Dioxide | 5,000ppm | None | None |
| Carbon Monoxide | 50ppm | None | None |
| Helium* | None | None | None |
| Hydrogen Fluoride | 3ppm | None | None |
| Nitric Oxide | 25ppm | None | None |
| Nitrogen* | None | None | None |
| Nitrogen Dioxide | None | None | 5ppm |
| Ozone | 0.1ppm | None | None |
| Phosgene | 0.1ppm | None | None |
You can make sure these PELs are still applicable on OSHA’s website.
NIOSH – Recommended Exposure Limits for Welding Fume, Metals, and Gases
| REL | TWA | STEL | C |
| Welding Fumes | TBD | TBD | TBD |
| REL | TWA | STEL | C |
| Aluminum | 5mg/m3 | None | None |
| Antimony | 0.5mg/m3 | None | None |
| Arsenic, inorganic | None | None | 2µg/m3 |
| Arsenic, organic | None | None | None |
| Beryllium | None | None | 0.5 µg/m3 |
| Cadmium | TBD | TBD | TBD |
| Chromium (II) & (III) | 0.5mg/m3 | None | None |
| Chromium (VI) | 1µg/m3 | None | None |
| Cobalt | 0.05mg/m3 | None | None |
| Copper | 0.1mg/m3 | None | None |
| Iron | 5mg/m3 | None | None |
| Lead | 0.05mg/m3 | None | None |
| Manganese | 1mg/m3 | 3mg/m3 | None |
| Molybdenum | TBD | TBD | TBD |
| Nickel | 15µg/m3 | None | None |
| Silver | 0.01mg/m3 | None | None |
| Tin | 2mg/m3 | None | None |
| Titanium dioxide | TBD | TBD | TBD |
| Vanadium | None | None | 0.05mg/m3 |
| Zinc oxide | 5mg/m3 | 10mg/m3 | None |
| REL | TWA | STEL | C |
| Argon | None | None | None |
| Carbon Dioxide | 5,000ppm | 30,000ppm | None |
| Carbon Monoxide | 35ppm | None | 200ppm |
| Helium | None | None | None |
| Hydrogen Fluoride | 3ppm | None | 6ppm |
| Nitric Oxide | 25ppm | None | None |
| Nitrogen | None | None | None |
| Nitrogen Dioxide | None | 1ppm | None |
| Ozone | None | None | 0.1ppm |
| Phosgene | 0.1ppm | None | 0.2ppm |
ACGIH – Threshold Limit Values for Welding Fume, Metals, and Gases
ACGIH has copyright over TLVs and they cannot be replicated on other sites. Links to relevant pages on their website can be found below.
ACGIH has not offered a specific recommendation for welding fumes. As such, they are categorized under Particulates Not Otherwise Regulated. For these particulates, ACGIH suggests a TLV-TWA of 3mg/m3 for respirable particles and 10mg/m3 for inhalable particles.
- Aluminum
- Antimony
- Arsenic
- Beryllium
- Cadmium
- Chromium
- Cobalt
- Copper
- Iron Oxide
- Lead
- Manganese
- Molybdenum
- Nickel
- Silver
- Tin, organic
- Tin oxide & inorganic
- Titanium
- Vanadium
- Zinc Oxide
- Argon*
- Carbon Dioxide
- Carbon Monoxide
- Helium*
- Hydrogen Fluoride
- Nitric Oxide
- Nitrogen*
- Nitrogen Dioxide
- Ozone
- Phosgene
* A concentration limit is not included because available oxygen is the limiting factor.
Health Consequences of Inhaling Welding Fumes
Based on data from OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Canada), exposure to welding fumes may result in the following health issues:
- Irritation of the eyes, nose, and throat
- Dizziness and nausea
- Respiratory difficulties, which may lead to suffocation or asphyxiation
- Metal fume fever
- Lung damage and various forms of cancer
- Gastric ulcers
- Kidney damage
- Neurological system damage
- Manganism
- Chest pain
- Asthma
- Bleedings
- Skin conditions such as dermatitis or eczema
- Kidney disease
- Bone and joint ailments
- Siderosis (iron oxide in lung tissue from inhalation)
- Stannosis (tin oxide in lung tissue from inhalation)
- Anthracosis (poisoning due to inhalation of carbon dust)
- Berylliosis (poisoning due to inhalation of beryllium dust)
- Pulmonary edema (fluid accumulation in the lungs)
These potential health risks underline the importance of safeguarding welders, complying with regulations, and striving to eliminate pollutants as effectively as possible. Welding fume extractors serve as an optimal solution for this purpose.
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.
1-866-800-8421
info@airgomig.com