Re: Cigarette/campfire smoke
Paul H. Brown (phbrown@CAPACCESS.ORG)
Mon, 31 Mar 1997 21:26:34 -0500
I'm not a chemical engineer (nor, do I play one on TV). But, I have some
professional knowledge of combustion, etc.
Wood is a pretty homogeneous mixture of hydrocarbons and other elements
that make up the ash that remains from combustion. As wood smolders,
gasses are driven off. These gasses ignite, and we see a flame. The
wood doesn't burn, but the gasses do. The composition of the wood, the
moisture content, and the temperature of the fire will determine how much
of the gasses combust, and how much of what is driven off condenses into
smoke without being combusted to carbon dioxide and water.
This is vastly simplified, because I'm a pretty simple person.
Tobacco, as sold in cigarettes, is a complicated mixture of tobacco
leaves, licorice, glycerine, and RJ Reynolds-only-knows stuff. Literally
hundreds of chemical compounds are combined with the shredded tobacco
leaves. The tobacco companies are required to report their recipes to
the FDA. (I think the law requiring reporting went into effect a little
over 10 years ago, but the reports are "trade secrets." Not available
under FOIA.) Each company has its own recipes for its finished tobacco.
Tobacco burns the same as wood, except the smoldering is what is
desired. The tobacco leaves (containing nicotine, etc.), along with the
chemical compounds, smolder into a very complex mixture of stuff in
tobacco smoke.
The carbon to carbon dioxide and water combustion equation we learned in
high school is ideal, but over-simplified. Sometimes, the gasses that
are driven off don't combust, but recombine into new chemical compounds.
These are known as PICs, or products of incomplete combustion, by the
environmental community. Among these are the infamous chlorinated
dioxins, toxic in tiny concentrations (the toxicity is a matter of some
debate: your local Greenpeace representative will probably not agree with
a Dow Chemical value, and vice versa). I don't know whether tobacco
smoke or wood smoke has more of these compounds. I suspect that the owod
smoke is cleaner, as it starts off with fewer chemicals.
YiS,
Paul H. Brown, KD4UPD
I used to be an Antelope, WB 82-66
Pack Committee Chairman, Unit Commissioner, Roundtable Commissioner
George Washington District, National Capital Area Council, BSA
Terry Howerton Sakima Group, Inc. SCOUTER Magazine Kansas City |
