Tips and Myths
Don't light matches unnecessarily.
There is no “afterglow” in a match once the match
is extinguished - but be sure it is out completely before throwing
it away.
Safety precautions do not end when the match has fulfilled its
purpose. Unattended camp fires are a frequent cause of fires.
Question:
A safety match is a match that can only be struck on the
box of the matches. Why can they only be lit on
the box.
Answer:
Almost all types of match use phosphorus. There are two allotropes
of phosphorus. (An allotrope is a certain crystaline arrangement
of atoms in an element. Most elements can have several possible
crystaline arrangements of their atoms.) One allotrope of phosphorus
is white, the other is red. White phosphorus is highly reactive
and will ignite, given oxygen, with extremely little friction.
It is therefore stored and cut under water. Red phosphorus,the
other allotrope, is also quite reactive, but nowhere near as reactive
as white phosphorus. Strike anywhere matches contain a white phosphorus
tip. Just behind that tip is a mixture of oxidizers and reducers.
(Just a bunch of chemicals put there to react and release a lot
of heat.) This ignites the wood part of the match.
Safety matches are somewhat different. The match
head contains oxidizers, reducers, and very fine particles designed
to create friction. The striking surface is the key. It contains
red phosphorus. The firction of a match head scraping against
it causes a small amount of it to ignite. The heat from this is
not enough to ignite the whole striking surface, because red phosphorus
is not as reactive as white. It does, however, start the reaction
between the oxidizers and reducers in the match head, which, again,
light the wooden or cardboard part of the match.
If you tried to strike a safety match somewhere
other than on the striker, it wouldn't create enough heat to start
the reaction between the oxidizers and the reducers. But notice
that if you give them heat, by putting a match head in a flame
or against a hot burner on your stove, it will ignite.
P.S. One interesting note - cardboard matches
are treated with a fire-retardant chemical. If they weren't, the
match would burn up too fast.