Formaldehyde

Most formaldehyde is sold as formalin, an aqueous solution of formaldehyde with some methanol. While available and used in a variety of concentrations, formaldehyde is most commonly used in 37% formalin solutions. Profoundly simple, inexpensive and useful, formaldehyde is found in many products, including resins and adhesives, permanent press fabric treatments, tissue preservatives, lawn fertilizers, cosmetics and disinfectants.

Formaldehyde has been linked to cancer in humans and may cause adverse reproductive outcomes. Off-gassed from construction products and released by manufacturing facilities and combustion sources, formaldehyde is almost ubiquitous at low levels in both indoor and outdoor air. It is often targeted as a cause of health complaints associated with "sick building syndrome," such as respiratory irritation and headaches.