The welding process produces smoke that contains harmful metal fume and gas by-products. Fumes are formed when a metal is heated above its boiling point, and its vapors condense into very fine particles.

If you feel any symptoms while or after inhaling welding fumes, leave the area if you are still there, get some fresh air, and hydrate. If you have some difficulty breathing or if the symptoms worsen, persist, or reappear, you should seek medical attention to get a diagnosis and take any steps necessary to recover.

If you are not a professional welder and have just inhaled a little bit of welding fume by accident, if you do not feel any symptoms, there is nothing to do except being careful in the future to avoid breathing more.

But beware if you work in a poorly ventilated environment where some welding is done, as fumes can travel and won’t disappear by themselves. As a result, you could be subject to the same symptoms described in this article even if you do not weld yourself. It is one of the risks of working close to welding operations.

As you will see, welding fumes can have immediate, short term and long-term effects on a welder’s health. Therefore, reducing exposure to these toxic fumes is essential. The best way to do so is by using welding fumes extractors.

Welding fumes composition

Welding fumes contain gases (Argon, Helium, Nitrogen, Carbon Dioxide, Nitric Oxide, Nitrogen Dioxide, Carbon Monoxide, Ozone, Phosgene, Hydrogen Fluoride) and metal (Aluminum, Antimony, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Manganese, Molybdenum, Nickel, Silver, Tin, Titanium, Vanadium, Zinc).

The composition of welding fumes is determined by the material being welded, the electrode, coatings, and other factors. Stainless steels, for example, tend to generate more chromium, including hexavalent chromium, or nickel in the fume. Aluminum welding fumes have significant amounts of aluminum oxide (harmful to the lungs) and ozone (classified as a toxic, carcinogenic gas).

The size of welding fume particles ranges between 0.005 and 20 µm. Almost all particles are smaller than 1 µm, and inhaled particles may deposit throughout the respiratory system.

What to do if you inhale welding fumes and feel sick at work

According to OSHA, breathing welding fumes could cause the following immediate health effects:

  • eye, nose, and throat irritation;
  • dizziness and nausea;
  • breathing difficulties that could lead to suffocation or asphyxiation.

If you feel any of the symptoms described above, follow this advice.

Leave the area

It may seem obvious, but if any of the previous symptoms appear, you should immediately remove yourself from the contaminated area. The longer you breathe toxic welding fumes, the worse the symptoms could get. It is better to be safe than sorry whether your symptoms are related to welding or not.

Get some fresh air and hydrate

Go to any place where you can get some fresh air, outside or in an office where the air is not contaminated, and drink some water to stay hydrated.

Get medical attention

If you have some difficulty breathing or if the symptoms worsen, persist, or reappear, make sure to see a medical professional as soon as possible to get a diagnosis and take any steps necessary for your recovery.

Short-term health effects caused by welding fumes

Metal fume fever is a common occupational disease amongst welders. It is also known as Monday morning fever or welder’s cough. Flu-like symptoms such as fever, chills, joint pains, muscle pain, headache, cough, nausea, and malaise typically occur 4 to 10 hours after exposure.

Hundreds of documented cases of metal fume fever occur annually in the USA only.

And by the way, there is no scientific evidence that drinking milk reduces health problems caused by welding, such as fume fever. It is just an old myth circulating among welders.

Take a break from work

According to, metal fume fever is typically a benign disease with spontaneous resolution of symptoms after 12 to 48 hours following cessation of exposure. But it does have the potential to be serious, especially for workers with pre-existing medical conditions.

Wait until the symptoms are gone before welding again.

Get medical attention

Make sure to see a medical professional as soon as possible to get a diagnosis and take any steps necessary for your recovery.

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.

Henlex Inc.

Long-term health effects caused by welding fumes

Once again, according to OSHA, breathing welding fumes could cause the following long-term health effects:

  • lung damage and various types of cancer;
  • stomach ulcers;
  • kidney damage;
  • nervous system damage;
  • prolonged exposure to manganese fume can cause Parkinson–like symptoms.

According to a publication from the Centers for Disease Control and Prevention (CDC), welding fumes are classified as carcinogenic.

Protect welders against welding fumes efficiently

Addressing health issues is very important, but solving the fumes problem must be considered. Here are a few tips to sustainably prevent health problems caused by welding fumes:

  1. Only weld when it is necessary. Other processes can sometimes replace manual welding.
  2. Use welding processes and materials that produce less fumes. Some welding wires have been designed to be less toxic, for example.
  3. Use welding fume extractors. For more information, see our general article about welding fume extractors, or one specifically about MIG welding fume extraction if that’s the process you are using.
  4. 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 from them when welding outside.
  5. Make sure your factory is adequately ventilated.
  6. Use personal protective equipment if the previous measures are not enough to reduce exposures to safe levels.

Learn more about our step-by-step method to solve welding fume problems.

In the US, OSHA has established a Permissible Exposure Limits or PEL for welding fumes of 5 mg/m3. It is the weighted average concentration of the substance in the air over 8 hours inside the welder’s breathing zone. Some substances found in welding fumes must also be kept below their PEL. It will be necessary to analyze the components involved in the welding process to determine which ones must be monitored. Sampling the welding fume could also be required.

Each province or territory in Canada has established its own exposure limit, usually between 3 and 10 mg/m3. Some jurisdictions also make a distinction between inhalable and respirable particles. In addition, several toxic substances found in welding fumes (such as chromium or nickel) also have their concentration limits.

Here are the exposure limits for welding fumes in each Province and Territory in Canada.

  • TWA: Time-Weighted Average over 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)
  • ALARA: As low as reasonably achievable
BC 10mg/m3(i)*
3 mg/m3(r)*
NB 10mg/m3(i)*
NL 10mg/m3(i)*
3 mg/m3(r)*
QC5mg/m315mg/m3 **25mg/m3

* Based on ACGIH recommendations.
** For 30 minutes during a workday.

It is virtually impossible to achieve these results with general ventilation only, and fume extractors are a must.

Welding in a poorly ventilated area amplifies all the risks. Please read our blog post on the dangers of welding in poorly ventilated or confined spaces to learn more.

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.