Formaldehyde is regularly used in the chemical and medical industries, and it has preservative and sterilizing properties. It is also used to treat various types of building materials and in the creation of foam insulation and some types of fabric.
Formaldehyde has a very particular smell, but it is colorless. It is most commonly know as the solution used to preserve harvested organs for medical research in the past. It is also found in cigarette smoke. While very small levels of the formaldehyde are normal in the atmosphere, the U.S. Environmental Protection Agency and the International Agency for Research on Cancer both believe the substance could be linked to cancer in humans.