The Adverse Effect Of Formalin: A Warning Against Mishandling

Abstract

Formalin is a clear solution of 37% formaldehyde in water. It is used in dentistry as a disinfectant, antiseptic and mainly as tissue fixative for preserving biologic specimens for histopathologic examination. The human knowledge on systemic formaldehyde intoxication is inadequate as only few cases of formalin ingestion have been reported. This paper presents a brief communication of the adverse effect of formalin to the human tissue.

Accidental Intra-Oral Injection of Xylene Instead of Local Anesthetic Agent in Endodontic Retreatment

“…6 Accidental injury from dental chemicals may occur with a number of substances like formalin, sodium hypochlorite. 7,8,9,10 Formalin being a tissue preservative and sodium hypochlorite being an irrigant in endodontic procedures. 11 Xylene is used as a gutta percha solvent for retreatment in root canal treatment.…”

Accidental Intraoral Formalin Injection: A Rare Case Report

“…for preserving pathologic tissue specimens in histopathology) properties. 1 Formaldehyde is a colorless, flammable gas at room temperature with a characteristic pungent odor. 2 It has been used in clinical, diagnostic and research laboratories as a preservative or tissue fixative for over a century.…”

“…Both are capable of releasing formaldehyde gas, 6 the active principle which is responsible for the above noted properties.The terms formaldehyde and formalin are often used interchangeably, but a fixative labeled as 10% buffered formalin is in fact a 4% solution of formaldehyde ( i.e ., a 10% solution made from a 37-40% commercially pure solution of formaldehyde). 1 Formalin can enter the body by either ingestion or inhalation. Once ingested, the metabolism of formaldehyde is similar to that of methanol with formic acid as an intermediate that accumulates within the body leading to fatal metabolic acidosis.…”

“…12 The very few reports available demonstrate marked accumulation of formic acid, after ingestion of formaldehyde. 1 The fatal dose of formaldehyde after oral ingestion is approximately 50-100 mL, however usually exposure of this magnitude is encountered in suicide cases. 8 In dentistry, there was a case reported in literature where formalin solution was accidentally used as an irrigating solution during third molar surgery instead of isotonic saline solution.…”

Effects of oral administration of formaldehyde on albino rat stomach

“…Formaldehyde-based resins are used as adhesives and impregnating resins in the manufacture of particle board, plywood, furniture, and other wood products [2,3]. Also, formaldehyde has been used for tissue fixative for preserving biologic specimens and disinfection, as well as an antimicrobial agent in consumer products such as cosmetic products, fungicides, textiles, and embalming fluids [4,5].…”