Looks like the trouble comes from zinc, magnesium, and cadmium oxide fumes.
It reminds me a lot of our mandated switch to light bulbs that contain mercury.
It's utterly absurd; something commonly used has a largely theoretical environmental hazard potential and so we willy-nilly, without carefully thinking through all the possible consequences, switch to something much more probably hazardous.
An ordinary light bulb is generally only hazardous if you break it; you might cut yourself on the glass. These new ones contain mercury. I work in health care, and you can't find a mercury thermometer nor sphygmomanometer these days for love nor money, because the mercury is hazardous. We're putting it in everyone's house, though, in their light bulbs!
We've used lead ammunition for generations without poisoning ourselves, for the most part, but the lead is "harzardous" so an army switches to steel ammo and now they may be giving their people lung problems!
I am really, really sick and tired of environmentalists.