The use of formocresol is ubiquitous. Its use in pediatric dentistry over the century has been well established. Formaldehyde, a primary component in formocresol, is a hazardous substance and is considered a probable carcinogen by the International Agency for Research on Cancer Health, Canada. Humans inhale and ingest formaldehyde during cellular metabolism. The human body is physiologically equipped to handle formaldehyde through multiple conversion pathways. The purpose of this review was to examine more recent research about formaldehyde metabolism, pharmacokinetics, and carcinogenicity, results indicate formaldehyde is probably not a potent human carcinogen under low exposure conditions.