In both construction and general industry, cutting and welding is a daily occurrence. Numerous tasks are performed using these operations ranging from new construction and demolition to maintenance. However, many of the same hazards are present regardless of the job. When analyzing safe work practices for the job, we tend to concentrate on fire hazards when looking at cutting and welding. After all, when we can see a bright blue, white or orange flame, it’s pretty obvious there is a fire hazard present. But what about the hazards we can’t see, such as fumes and gases? They can be just as dangerous, if not more because they can be the silent killer. It’s safe to say that when we feel heat we move or when we get burned we feel the pain immediately. Unfortunately, breathing certain gases and or fumes can be causing damage to our bodies and we have no idea. These fumes can be caused by welding or cutting on the base material, or they can be created from something as simple as a coating on the base material itself. Materials containing such elements as Arsenic, Chromium, Lead, or Manganese just to name a few, can be hazardous if identified as more than trace constituents in welding and/or cutting operations.
So how do we protect against fume hazards? First we need to know what elements are present and in what amount. This can be determined by looking at the Material Safety Data Sheets for all base metals, coatings, and cleaners that may be present. Once we know what is present we can determine how to protect against the hazard. It may be as simple as assuring good ventilation is established or as complex as requiring respirators with supplied air. (When wearing a respirator, the user must be medically cleared, fit tested and trained in the use of his or her respirator.) Depending on the material involved in the cutting or welding process, overexposure may only lead to irritation of the eyes, skin or lungs. In more serious cases such as overexposure to Manganese, the central nervous system can be affected leading to speech impairment and muscle movement. Overexposure to fumes can also cause nausea, headaches, dizziness, and metal fume fever. The results of overexposure can be immediate or may take several days or longer to become apparent. Certain gases can lead to other hazards as well. When working in confined spaces, certain gases may not be lethal but could displace oxygen leading to asphyxiation. This is why air monitoring must be conducted and monitored when performing welding or cutting in any confined space where hot work is performed. If you are unsure of the exposure to employees, an Industrial Hygienist should be used to conduct air sampling.
Additional ways to avoid exposure include:
- Keep your head and face out of the fumes
- Avoid breathing the fumes
- Establish enough ventilation to keep fumes out of the breathing zone
- Use mechanical ventilation
- Make sure to know the permissible exposure limits for various fumes as established by OSHA
- Test the air to determine exposure levels
As previously stated, fires and explosions are a major concern when welding and cutting are occurring. Can these fire and or explosions be caused by the release of fumes and gases? They certainly can. We must always remember, just because we can’t see the hazard certainly doesn’t mean it’s not there. Knowing the materials we will be working with, their reaction to heat or fumes that may be generated, and the permissible exposure limits must be carefully considered for any and all cutting and welding operations.