1,3,5-Trioxane

1,3,5-Trioxane, sometimes also called trioxane or trioxin, is a chemical compound with molecular formula C$3$H$3$O$6$. It is a white, highly water-soluble solid with a chloroform-like odor. It is a stable cyclic trimer of formaldehyde, and one of the three trioxane isomers; its molecular backbone consists of a six-membered ring with three carbon atoms alternating with three oxygen atoms.

Production
Trioxane can be obtained by the acid-catalyzed cyclic trimerization of formaldehyde in concentrated aqueous solution.
 * Trioxane Synthesis V.1.svg

Uses
Trioxane can be used interchangeably with formaldehyde and with paraformaldehyde, however the cyclic structure is more stable and it can require high temperatures in order to react. It is a precursor for the production of polyoxymethylene plastics, of which about one million tons per year are produced. Other applications exploit its tendency to release formaldehyde. As such it is used as a binder in textiles, wood products, etc. Trioxane is combined with hexamine and compressed into solid bars to make hexamine fuel tablets, used by the military and outdoorsmen as a cooking fuel.

In the laboratory, trioxane is used as an anhydrous source of formaldehyde.