Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Formaldehyde
Medically reviewed by Min Clinic Staff | Updated: January 2026
Formaldehyde: A pungent gas, with the chemical formula HCHO, used as an antiseptic, disinfectant, and especially today as a fixative for histology (the study of tissues under the microscope).
Formalin is a 37% aqueous (water) solution of formaldehyde.