Formaldehyde gastrointestinal system

Little information is available about immunological and lymphoreticular effects of formaldehyde ingestion in humans. Splenomegaly was observed in one woman who ingested formaldehyde in a suicide attempt (Koppel et al. 1990). However, this effect was most likely secondary to extensive hemorrhaging and necrosis of the gastrointestinal system. 

Formaldehyde is absorbed from the gastrointestinal system after ingestion. Eells et al. (1981) described the case of a 41-year-old woman who swallowed 120 mL (624 mg/kg) of a formaldehyde solution (as formalin). Formic acid accumulated in the blood rapidly after formaldehyde ingestion. Burkhart et al. (1990) describe the case of a 58-year-old man who swallowed 4 ounces of a formaldehyde solution... 

Methyl alcohol is readily absorbed from the gastrointestinal tract, but is very slowly oxidized by the tissues. Approximately 30 percent of the absorbed alcohol remains unoxidized in the tissues 48 hours after ingestion. Roughly 40 percent of the compound is oxidized to formaldehyde and formic acid and a considerable quantity escapes in the exhaled air unchanged. Much of the formic acid formed is excreted in the urine as its sodium and ammonium salts. In addition to the depressant action of methyl alcohol upon the central nervous system, characteristic of the aliphatic alcohols, the compound elicits a definite toxic specificity for the optic nerve. 

Formaldehyde vapors are readily absorbed from the respiratory tract. Due to rapid metabolism to formate, little, if any, intact formaldehyde can be found in the blood of humans or animals exposed to formaldehyde. Fonnaldehyde is also readily absorbed from the gastrointestinal tract and meets with the same metabolic fate as formaldehyde after inhalation exposure. The studies available in the open literature suggest that very little formaldehyde is absorbed via the dermal route. In all cases, absorption appears to be limited to cell layers immediately adjacent to the point of contact. Entry of formaldehyde into the blood (i.e., systemic absorption) occurs to a very limited extent, if at all. 

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