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Pulmonary and Upper Respiratory Insults from arc Welding

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  • Pulmonary and Upper Respiratory Insults from arc Welding

    Hi Guys,

    I would like to ask a few elementary questions about the following and have a discussion regarding the following:

    1. welding fumes
    2. welding particulates
    3. venting indoor spaces
    4. respiratory filtering masks

    I have stated the following, more than several times, over the course of several years. I have never taken a formal class in welding. What little I know has basically been gleaned from this Forum.

    I feel confident that anytime one strikes an arc (TIG, MIG, or Stick) a plethora of particulates and noxious fumes will be generated in the work area. I rarely Stick weld so most of my questions are directed towards MIG and TIG welding.

    A) Based on your experience, which are of greatest concern to you when welding, fumes or particulate?
    B) Do you make a practice ventilating your work area when MIG or TIG welding?
    C) Do you routinely wear a filtering mask when welding?
    D) Which mask, if any, do you prefer to use?

    Please feel free to elaborate on your answers.

    Thanks,
    Harold
    For those having fought for it, Freedom has a flavor the protected will never know.
    Freedom is only one generation away from extinction.

  • #2
    I'm not a medical doctor by any means of measure, nor a professional welder....so just my two cents worth of opinion I would reason that fumes are perhaps more precarious than particulate, for the simple reason that they may not be visually detectable. Especially with TIG welding there is often quite little visible smoke or particulates generated, but metal at arc temperatures does evaporate noticeably. One would not feel comfortable walking into a room filled with a smoky haze, but a room that is full of basically invisible metal fumes shall strike no alarm bells. But really, for practical purposes both fumes and particulates are always generated in a combined manner when an arc is struck, so separating them from one another is theoretical at best.
    Proper ventilation is your best friend, or rather the proper evacuation of the generated gases. A mask sure does help, but a proper ventilation/evacuation system is something that I would put most emphasis on, if I was to weld in enclosed areas often.

    Comment


    • #3
      Originally posted by markx View Post
      I'm not a medical doctor by any means of measure, nor a professional welder....so just my two cents worth of opinion I would reason that fumes are perhaps more precarious than particulate, for the simple reason that they may not be visually detectable. Especially with TIG welding there is often quite little visible smoke or particulates generated, but metal at arc temperatures does evaporate noticeably. One would not feel comfortable walking into a room filled with a smoky haze, but a room that is full of basically invisible metal fumes shall strike no alarm bells. But really, for practical purposes both fumes and particulates are always generated in a combined manner when an arc is struck, so separating them from one another is theoretical at best.
      Proper ventilation is your best friend, or rather the proper evacuation of the generated gases. A mask sure does help, but a proper ventilation/evacuation system is something that I would put most emphasis on, if I was to weld in enclosed areas often.
      Good Morning Markx!
      I really like the way you think. It was good to see your statement regarding TIG, smoke and particulates. The lack of smoke and particulates has been my observation over a course of time and your statement seemed to corroborate my TIG welding experience/observation. Right or wrong, it's reasonable to assume that metal loss occurs (escapes into the surroundings) when metal is heated above critical temperature.
      Again, I agree that it's psychologically more comforting to enter an area seemingly free of smoke and perceivable fumes than to walk into an area filled with smoke and fumes. Still, we know gases and particulate **are** generated, hence present, and we should not lose sight of that fact when TIG welding.
      When I first bought my TIG welder, I would practice for hours without opening shop doors for ventilation basically because I saw no smoke and smelled no fumes. Secondly, it's cold here (Alaska) in the winter and only brief ventilation lowers shop temperature drastically. Conversely, even though we still have a wee bit of cold weather, I am compelled to open doors and windows when MIG welding. Quickly, smoke fills the shop and hangs around for quite some time. Simply seeing smoke raises my level of concern regarding health issues.
      Short of getting a self-contained closed circuit breathing system, a good filtering mask would, in my opinion, remove some particulate while hovering over molting metal. As you pointed out, I doubt than any passive filtering mask would selectively remove harmful gases. For this reason, I fully agree that a evacuation system, e.g., a negative pressure welding hood, should be used over the immediate welding site.

      Thanks for your comments.
      Harold
      For those having fought for it, Freedom has a flavor the protected will never know.
      Freedom is only one generation away from extinction.

      Comment


      • #4
        In my practice the breathing systems and filters are kind of restricting and really make precision work uncomfortable, at least for me. Stacking hoses on you hip and filters underneath the welding mask does not sound like a very liberating situation. And very probably one still has leaks (through facial hair e.g. ) or gets a whiff of the good stuff when taking off the protective equipment to inspect the weld seam more closely. I have not looked at prices, but intuitively I tend to think that an improvised ventilation system constructed from salvaged materials might run a fair bit cheaper than a high tech self contained breathing apparatus....and when designed properly shall probably do a way better job of keeping you away from the effects of the off fumes.

        Metal fumes are really only a part of the stuff that forms in a plasma arc....there are also nitrogen oxides that may be formed under the high temperature conditions and ozone that is generated due to the ultraviolet radiation given off by the welding arc. Both ozone and nitric oxides seem to smell very similar in low concentrations. The ozone can be generated a fair bit away from the actual arc welding spot, all around where the UV hits through the air. TIG arc seems to possess an especially suitable spectrum for the generation of secondary ozone. Also it seems to be the most damaging type of UV as far as damage to unprotected skin goes. I've once made the mistake of doing a quick TIG weld in a t-shirt, just an inch worth of weld at 60A -ish.....boy did I regret that decision. Doing the same with a stick or mig would have left me totally unharmed, but the TIG radiation is vicious.

        Comment


        • #5
          Originally posted by markx View Post
          .......TIG arc seems to possess an especially suitable spectrum for the generation of secondary ozone. Also it seems to be the most damaging type of UV as far as damage to unprotected skin goes. I've once made the mistake of doing a quick TIG weld in a t-shirt, just an inch worth of weld at 60A -ish.....boy did I regret that decision. Doing the same with a stick or mig would have left me totally unharmed, but the TIG radiation is vicious.
          Hi Markx
          Markx you have made a good point with regard to Ozone and UV radiation. With respect to UV radiation, UV consist of two types of radiation:

          1. UV-A
          2. UV-B

          With regards to UV-A, UV-A is likely the most damaging source of radiation because it penetrates the skin deeper than UV-B. UV-A is responsible for tanning and causing skin cancer e.g., Melanoma and Basal Cell Carcinoma with Melanoma being the most aggressive and dangerous due to the ease with which it can metastasize.

          UV-B radiation is responsible for "sunburns". Aside from burns (which can be bad), UV-B is associated with premature aging of the skin and loss of skin-elasticity as well as thinning of the skin. For years, UV-B has been used, in therapeutic doses, to threat Psoriasis and other skin diseases. The drawback to UV-B treatments has been burns which frequently occurred. In the past 15 years, researchers learned that a very narrow spectrum of UV-B radiation could be effectively used to treat certain skin conditions thus medical providers now speak of UV-B as “narrow band” and “broad band”. It seems that a narrow band of ~420 nm is just about the right therapeutic wave length to treat skin conditions WITHOUT burns.

          All that being said, the weldor is exposed to the full gamut of radiation (visible and invisible spectrum e.g. from IR to UV). I have read that our welding hoods protect (filters) our eyes from most harmful radiation. So this brings me to the Inverse Proportion Square Law. I realize this Law deals with a relationship between light intensity and illuminated surface area. The further you are from the light source the greater the surface area that’s covered by the light but intensity of light decreases inversely to the square of the distance. So how does this Law apply when one uses magnification in the hood? It would seem that magnification is defeating the Inverse Law and increasing the chance of burning one’s eyes.

          Years ago, our better cameras had “curtains” for shutters. Most shutters were made from cloth but later a foil. If you attempted to photograph the sun, even with filters, there was a good chance that the focused beam of light would physically burn a hole in the shutter. You could also burn your eye when attempting to focus. This was especially true when using fully articulated 4X5” and 8X10” field cameras.

          So my point is, if you magnify the arc and focus you eyes on the arc, and if you think of your eyes being the camera shutter, it would seem that you are magnifying the intensity of emanating radiation increasing the risk of burning one’s eyes.

          Am I comparing apples to oranges?

          Harold
          For those having fought for it, Freedom has a flavor the protected will never know.
          Freedom is only one generation away from extinction.

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