Actually, I don't worry too much about burning synthetic fibers along with cotton, since the smoke from burning cotton contains at least 11 known carcinogens anyways. However, I avoid burning wool because it releases cyanide gas. This is much more undesirable, don't you think?
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)