Why Clean Air?
Joe Kiwior
Why Clean Air?
Fumes & Smoke in Metal Fabricating
Fumes and smoke are a given in any metal fabrication process, and without proper ventilation or filtration, you end up breathing them in. But why worry about it? Here are a few reasons.
- Fumes and smoke from metal fabrication processes contain hazardous substances.
- They may be generating at toxic levels, and can remove oxygen from the air, causing a breathing hazard.
- Being exposed to fumes and smoke for extended periods of time can cause dizziness and sickness, and in rare cases unconsciousness and even death.
Make sure you are protecting yourself from these health risks. Proper filtration and improved air quality are important factors to consider in today’s metal fabrication industry. For more information about the health risks of your specific process, see the “
Applications” page.
Air Quality
Apart from health concerns from smoke and fumes in the air, what is the advantage of improving air quality in your facility? Here are some things to consider.
- Field studies have shown that employee productivity increases, and the number of sick or missed days are reduced when air quality in metal fabrication facilities is improved.
- Proper filtration and ventilation has been proven to reduce heating and cooling costs in fabrication facilities. When dirty air from welding or cutting processes is exhausted outside, it takes the heated (or cooled) air with it, making it harder to keep a consistent temperature inside, and increasing the costs to heat or cool facilities. Filtration returns clean air into the facility, saving money.
- Reduce your equipment downtime. Smoke and dust from metal fabrication processes get into nearby machinery and sensitive electronics and can cause problems.
- OSHA and the EPA both have air quality standards to be met. Meeting or exceeding government air quality regulations will improve a company’s image with customers and employees, and is key to attracting skilled workers and new clients.
More than ever, workers are concerned about the environment they are working in. Improved air quality is good for facilities, people, equipment, and good for business overall.
Refer to Applications pages for information on your specific processes, or to Products pages for units that work to capture and filter out smoke and dust.
Frequently Asked Questions
Q. What do I need to know about a fume and smoke control system, and how can I make sure it will work?
A. Many fabricators today have been disappointed with fume extraction systems for their processes, as improper sizing and misapplication of equipment is the #1 cause for a system’s failure. In fact, it has been proven that over 50% of the fume extraction systems installed in the metal fabrication industry do not work as well as intended, and often from the time of installation.
Some factors to consider:
- What metal fabrication process (or processes) are taking place (Welding, grinding, plasma cutting, etc.)
- Further information on Manual Welding, Robotic Welding, Ambient Ventilation and Weld Schools
- How many workers are being exposed to smoke and fumes
- Size of facilities
- An estimate of how much smoke/fume is being produced
- Budgetary considerations
Q. Can I just blow dirty air outside?
A. There is often no issue blowing dirty air outside from an environmental standpoint. Although government regulations on this will tighten up over time, most companies are allowed to blow a certain amount of dirty air outside.
The issue with exhausting the air outdoors is the negative pressure produced on the facility (and other issues, see “Air Quality” section). This is usually OK in the summer, with open doors allowing air back into the facility. During the winter, exhaust fans don’t work well with the doors closed, as no air is allowed back in to replace the air that is sent outside, creating negative pressure.
Q. How often would I have to change filters in a filtration system?
A. This depends on your fabrication process, but a filtration system properly sized for your process and facility should get between 6-12 months filter life in normal conditions. See
Products for further details.
Q. What kind of ventilation system is best for my operation? I am hearing the terms “filtration”, “exhaust” and “source capture”, what do they mean?
A. With employee health and plant safety and cleanliness becoming more of a priority for the metal fabrication industry, the ventilation industry has developed a wide range of methods and products.
Here are some examples:

General Ventilation – Exhaust
Large exhaust fans draw dirty air from the plant and exhaust it directly into the environment, typically through the roof or walls. This is a traditional method and often results in negative air pressure, and also makes it very difficult to climate-control your facility.
General Ventilation – Filtration
Large blowers and air cleaning equipment draw contaminated air from the plant (typically at the ceiling level), filter it and return it to the plant. This is a proven solution in facilities fabricating large parts with overhead cranes. It reduces the haze in the air, resulting in a cleaner facility, with no negative pressure or heat loss.
Source Capture – Exhaust
Air in the immediate area of the process is captured in a hood, sent through ductwork, and exhausted directly into the environment. The intent of this system is to exhaust as little of the plant air as possible, while still catching the fumes. This is a lower cost alternative to filtration but tends to result in large ducting systems and negative pressure problems.
Source Capture – Filtration
Air in the immediate area of the welding activity is captured in a hood system, then filtered and returned to the plant. This is the best solution whenever possible. It allows for a more flexible system and removes the smoke directly from the operator’s breathing zone.
Q. What is considered “good” air quality?
A. Generally speaking, if the air is visibly clear and you are comfortable working in the facility the way it is, that would be considered “good” air quality. The best way to ensure that air quality meets or exceeds the OSHA Permissible Exposure Limit (or PEL) and/or other regulations is to have an industrial hygienist do an evaluation on your workers and facility as a whole.