Formaldehida
 Formaldehyde is the simplest aldehyde. Its pure form is a colorless gas with an irritating odor, but it can also be condensed into a cyclic trimer (metaformaldehyde or trioxane) or a linear polymer (paraformaldehyde) which are white solids. A solution of formaldehyde in water is called formalin and widely used as a disinfectant and preservative for biological specimens. Formaldehyde is polymerized into polyoxymethylene (POM) or co-polymerized with urea, melamine, or phenol to create a suite of thermosetting resins that are indispensable to everyday life. These resins are found in fiberboards, adhesives, countertops, kitchenware, billiard balls, mechanical parts, and all sorts of molded plastic objects. Thus, millions of tons of formaldehyde are produced yearly via oxidation of methanol. Formaldehyde has a moderate acute toxicity and causes headaches and airway irritation. Numerous studies have concluded that chronic exposure is carcinogenic, which led to increased safety regulations