Formaldehyde

A flammable, colorless gas with a strong, suffocating odor; first synthesized in 1859, but it occurs naturally in coal and wood smoke, as an outdoor air pollutant in large cities, and found in indoor environments from items such as new particle board, freshly laid carpet, foam, adhesives, insulation, and new fabrics. Formaldehyde is a powerful reducing agent reacts with many materials on contact.