Your theatrical fog knowledge is now historic. Today it is generated by machines using either mineral oil or a combination of any of 7 different glycols or glycerin. These machines make "haze," "fog," and "smoke" effects. When the lights on stage beam while the air appears clear, this is "haze" which is a one micron size mineral oil or glycol mist. If you can see clouds of "fog" or "smoke," the mist is denser and may be of a different particle size and composition. There are even e-cigarettes which emit propylene glycol fog to fake smoking on stage.
Low lying fogs are dry ice generated. No professional production uses zinc chloride, ammonium chloride or any of the inorganic chemicals or burns any organic matter for fog effects. These have been shown to be far too toxic to performers.
I am an observer on the Fog Working Group of Entertainment Services Technology Association (ESTA) that sets US standards for these machines and chemicals. This group has obtained ANSI accreditation and approval for these standards.
NIOSH and several other groups have studied the effects of the glycol and oil mist fogs and found they also cause adverse respiratory effects in performers. ESTA began setting standards in order to limit exposure. And there have been enough union actions and lawsuits brought by injured performers to insure that the MSDSs identify the chemicals in these products.
As for the Precautionary Principle, it is here at last. I rejoice.
And geez, Alan, after all this time: my name is Monona.
In a message dated 6/12/2010 2:00:48 PM Eastern Daylight Time, ahalltoxic**At_Symbol_Here**MSN.COM writes:
Once again, you take a long harangue (commom to us old Mountain/Desert Men and Mark Twain afficianados) and cut to the basis of the discussion. I actually have carried theatrical fog in this manner - since it wouldn't stay lighted - I'd suggest zinc chloride inhalational toxicity -- can lead to severe chemical pneumonitis and even bronchiolitis obliterans, but NOT in this exposure scenario to my knowledge; yours may be different) and therefore was no risk to anybody except us poor folks trying to use red phosphorus-based matches --we all seem to have survived) and finally decided to use charcoal briquettes with dowsed water as an alternative. Neither was particularly safe, and neither caused illness in the particular theater in which we were doing this amateur performance in Alaska.
Geez, Romona, are we with Rin-Tin-Tin and his side-kick Rusty and Lt. Rip Masters going to come over the hills with the mythical "White Buffalo" going to be the ones?
The EU "precautionary principle" seems to me to be the epitomy of "NIMBY" "not it my backyard" which leads to the "Banana" principle "Build Absolutely Nothing Anywhere Near Anything." Not that it's wrong, but water and air are not "safe" in certain circustances: Query: should we stop drinking water and breathing air? That's what the "Precautionary Principle" would imply, unless we can be absolutery sure and ceriain that neither are harmful. (O2 at hyperbaric pressures for more than 4 hours has toxicity -- see the Navy Diving Tables; hypoxia, I doubt anyone who has taken a Basic Life Support Course would doubt; high oxygen pO2s in premature neonates can result in serious damage to the eyes, and prolonged O2 in anyone can cause severe lung injuries). Persons with a certain "hyperdipsia" of water (a potentially fatal psychologcal condition) can dilute out the electrolytes in their serum, resulting in serious cardiac and brain toxicity (ill-advised use of certain cathartics in childhood ingestion poisonings has had the same regretable result). I suggest on a medical basis that stopping breathing air would result in fatal brain hypoxic damage within 5 minutes and that failing to be able to drink water would result in fatal issues in 3-5 days.
"Is cyanide more toxic that water?" If the cyanide is a a proper container and stored in a proper exhaust hood, or if you were dropped from a helicopter into the middle of Lake Erie in December, which is more toxic?
To answer the question, "Why do all of us eventually die?" We have to look at the fact that we are oxygen breathers and that this inevitably leads to formation of reactive oxygen species within cells, eventuating either necrosis or apotosis, and cell death and when this happens in too great of numbers, it cannot be survived.
As always, we agree to disagree. And as I have said for ages, MSDSs are a VERY, VERY poor source of information. Go to all of the resources avalable to anyone, such as from the Specialized Information System of the National Library of Medicine: http:/nlm.nih.gov
Yes, the more we know about chemical exposures, the better off we'll be. But even in foods (without any contaminants), we can be exposed to millions of chemicals over a lifetime. In the end, all life is chemical. As the Good Doctor Harry has said, being a chemist implies chemical exposure. It does not mean that anyone should ever be overexposed. So whatever any and all of do, let's do our best to prevent overexposure.
The best thing in the world is to find a worthy adversary, even if most of the time we're on the same page.
Alan H. Hall, M.D.
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