Since the 1980s, we have led the way in North America with our welding fume extraction solutions. This blog post presents the exposure limits for several frequently encountered hazardous metals and gases in welding fumes in the state of California.
Fumes materialize when a metal is heated beyond its boiling point, causing its vapors to solidify into very fine particles. These particles vary in size from 0.005 to 20 µm, with the majority being less than 1 µm, and can deposit throughout the respiratory system.
The fume’s composition is influenced by several factors, including the material being welded, the electrode, the coatings, the flux, and the shielding gas, among others. It is generally necessary to conduct air sampling to identify the hazardous and regulated substances present in your workplace. However, obtaining data on the metals, gases, and consumables used in the welding process is typically an effective first step.
What particulates are potentially dangerous in welding fume?
This page will discuss some of the frequently encountered harmful metals and gases 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 California, exposure limits for air contaminants are set and enforced by the Division of Occupational Safety and Health (DOSH), also known as Cal/OSHA. For information regarding other US states, refer to our article on welding fume regulations in the US.
This blog post will also outline the recommendations from two key 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)
Cal/OSHA – Permissible Exposure Limits for Welding Fume, Metals, and Gases
| PEL | TWA | STEL | C |
| Welding Fumes | 5mg/m3 | None | None |
| PEL | TWA | STEL | C |
| Aluminum | 5mg/m3 | None | None |
| Antimony | 0.5mg/m3 | None | None |
| Arsenic, inorganic | 0.01mg/m3 | None | None |
| Arsenic, organic | 0.2mg/m3 | None | None |
| Beryllium | 0.2µg/m3 | 2µg/m3 | 0.025mg/m3 |
| Cadmium | 5µg/m3 | None | None |
| Chromium (II) & (III) | 0.5mg/m3 | None | None |
| Chromium (VI) | 5µg/m3 | None | 0.1mg/m3 |
| Cobalt | 0.02mg/m3 | None | None |
| Copper | 0.1mg/m3 | None | None |
| Iron | 5mg/m3 | None | None |
| Lead | 0.05mg/m3 | None | None |
| Manganese | 0.2mg/m3 | 3mg/m3 | None |
| Molybdenum | 3mg/m3(r) | None | None |
| Nickel | 0.5mg/m3 | None | None |
| Silver | 0.01mg/m3 | None | None |
| Tin, organic | 0.1mg/m3 | 0.2mg/m3 | None |
| Tin oxide & inorganic | 2mg/m3 | None | None |
| Titanium* | 5mg/m3(r) | None | None |
| Vanadium | 0.05mg/m3 | None | None |
| 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 | 30,000ppm | None |
| Carbon Monoxide | 25ppm | None | 200ppm |
| Helium* | None | None | None |
| Hydrogen Fluoride | 0.4ppm | 1ppm | None |
| Nitric Oxide | 25ppm | None | None |
| Nitrogen* | None | None | None |
| Nitrogen Dioxide | None | 1ppm | None |
| Ozone | 0.1ppm | 0.3ppm | 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
TLVs are under copyright by ACGIH and cannot be copied onto other websites. However, links to the relevant pages on their website are provided below.
ACGIH has yet to issue a specific guideline for welding fumes in general. As a result, they are classified under the Particulates Not Otherwise Regulated category. In this scenario, ACGIH’s recommendation is 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 risks associated with breathing welding fumes
According to OSHA, the Centers for Disease Control and Prevention, the International Agency for Research on Cancer, and the CNESST (Canada), inhaling welding fumes may lead to the following health impacts:
- Irritation of the eyes, nose, and throat
- Dizziness and nausea
- Breathing complications that could result in suffocation or asphyxiation
- Metal fume fever
- Lung injury and various types of cancer
- Stomach ulcers
- Kidney injury
- Damage to the nervous system
- Manganism
- Chest discomfort
- Asthma
- Bleeding
- Dermatitis or eczema
- Kidney disease
- Bone and joint disorders
- Siderosis (iron oxide in lung tissue after inhalation)
- Stannosis (tin oxide in lung tissue after inhalation)
- Anthracosis (poisoning after inhalation of carbon dust)
- Berylliosis (poisoning after inhalation of beryllium dust)
- Fluid accumulation in the lungs
These concerns emphasize the need to safeguard welders, adhere to the standards, and efficiently eliminate pollutants. Welding fume extractors are the most effective way to achieve this.
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