Indoor Air
Higher
Formaldehyde contamination of indoor air can result from off-gassing of certain building materials (e.g., some forms of particle board and other pressed wood products; new carpeting), and from mainstream and second-hand cigarette smoke. For those reasons, indoor levels of formaldehyde can be substantial, even in non-smoking homes. Formaldehyde is also used in medical settings, and in preservatives of biological samples often in school settings.