11. Water Vapor is a product of combustion reactions .-- Diletante 22 : 12, 26 February 2007 ( UTC) 12. They're designed to operate at 99 percent efficiency or above, which destroys most of the products of combustion . 13. Gas dryers must always be vented outdoors, as the products of combustion are mixed with the moist air. 14. Most of the PM2 . 5 fraction is caused by by-products of combustion , which may contain more carcinogens. 15. Some of these substances are absorbed by tobacco plants from the soil, while others are products of combustion . 16. Volcanic ash is not the product of combustion like the fluffy ash from a wood stove or charcoal barbecue. 17. Nitrogen oxide, a chemical by-product of combustion , forms ozone when exposed to hot sun, and can increase water's acidity. 18. :( ec )'Burnt'usually implies that there are products of combustion ( or pyrolysis, if in a low-oxygen environment ) present. 19. Developed under Johann Joachim Becher and Georg Ernst Stahl, phlogiston theory was an attempt to account for products of combustion . 20. Vented : Products of combustion are vented outside the home through natural draft, requiring a pipe or chimney through the roof.
