Dealing with Fumes: Caution and Respirators

The deadliest part of working with a welder is the cloud of mephitic fumes that pours off the welding site while you are playing your arc or flame across it. Short of an exploding gas tank, fumes are the fastest-killing hazard of the welding process. They also have longer-term health effects on those who are frequently exposed to them at sub-toxic levels, as is witnessed by the fact that career welders experience a 40% higher incidence of lung cancer than the general population. It therefore behooves you to protect both yourself and others from these poisonous vapors as much as possible while welding.

Outdoor welding is one solution, with the breezes of Mother Nature wafting the vapors harmlessly away. Those who engage in farm welding will probably need no precautions beyond a respirator and common sense, since the fumes are likely to move quickly away from them and cannot build up to the point where harmful effects occur. Caution and alertness are always in order, however.

The toxic particles which boil off a weld in progress can be filtered out using a half-mask respirator, preferably an N-type respirator with a rating between 95 and 100 and OSHA approval. This mask will keep out particles and vapors, but there is always some risk while using a welder, especially in limited spaces. Since a visible “welding plume” will rise off the point of welding, you should take care to keep your face clear of this smoky-looking vapor, regardless of the protection you are wearing. This is not the only precaution that is needed to keep you safe from the haze of metals and gases rising above your welding arc, however.
 
Ventilation fans are a must for indoor welding, in order to pull fumes out of the work area and vent them to the outdoors. The place chosen for welding should not be in a cellar, because in this case, there is nowhere for the fumes to escape except into the building above the workshop, where there are likely to be people who have no protection from the vapors. Even venting will not prevent possible danger to people in the building above a cellar welding workshop, unless the room has been sealed to the standards used in laboratories and nuclear reactors.

There should also be some supply of fresh air in your work area, and it is prudent to avoid working in very cramped environments. Even neutral shielding gas, which does not pose a direct poison threat to you, will displace the oxygen you need to stay alive if the volume of air around you is small or if the environment has no fresh air source. The threat it poses is particularly sinister because you will pass out and be unable to help yourself, and will thus lie unconscious until you die – which will not take long, so a miraculous rescue is unlikely. Headaches and dizziness, as well as suddenly sleepiness or a feeling of heavy, almost paralytic languor, are signs that you are in immediate, fatal danger and should waste no time in leaving the welding area.