Formaldehyde in the Operating Room
Louis J. Auguste, MD

Formaldehyde, represented by the chemical formula CH2O, is also called Methanal. This compound is produced by the human body and most other living organisms in minute amount as part of the normal metabolic process. Natural enzymes break down Formaldehyde into formic acid and eventually into carbon dioxide, which is then excreted. It is also broken down in the air within hours and dissolves in water as well.  In much stronger concentration, formaldehyde is a colorless, acrid smelling gas that is widely used in the construction industry, in household cleaning and cosmetic products, in the food industry and for embalmment.  Formaldehyde is also extensively used in medicine, most often in the form of Formalin, that is a saturated solution of formaldehyde (37%) and methanol (6-13%) in water. This solution is a powerful germicidal and preservative, which is universally used for the preservation of tissue specimens sent to the pathology laboratory for a histological diagnosis or for the preservation of human body parts intended for surgical training or anatomical demonstration.

Thus, formalin is omnipresent in all operating rooms, in physicians’ offices, radiology suites and other places where biopsies are done. It is easily detected due to its characteristic smell, associated with eye, nose and throat irritation. Acutely, formalin can trigger watery eyes, itching, coughing, wheezing and allergic reactions that can be severe. It can also cause significant irritation of the skin resulting in disabling dermatitis and life-threatening asthma-like attacks.  The National Institute for Occupational Safety and Health (NIOSH) has established that 20 parts per million of formaldehyde (ppm) as the immediately dangerous to life and health dose (IDLH).

More than an irritant, formalin has been associated with carcinogenesis. In the laboratory setting, application of formalin on the skin of mice resulted in the development of skin cancers, while ingestion of solution of formalin by rats led to the development of gastric neoplasms and inhalation of that gas was associated with naso-pharyngeal carcinomas and leukemia. Similarly regular and sustained exposure to formalin in the workplace (mortuary, production plants of formaldehyde, glues, etc…)  has been found to be associated with cancers of the naso-pharynx and of the nasal sinuses as well as leukemia, more specifically myeloid leukemia.  The mechanism of action is through genetic alteration in the aero-digestive tract and in alteration of the cell lines associated with leukopoiesis. Therefore, while the Environmental Protection Agency has it classified as a “probable human carcinogen (Group B-1)”, the International Agency for research on Cancer and the National Toxicology Program, which consists of representatives from the National health Institute, the Center for Disease Control and the Food and Drug Administration, have listed formaldehyde as a “human carcinogen”.

In the operating room, the circulating nurse is responsible for the initial processing of all tissues or organs removed during an intervention. Besides labeling the containers and entering all identification data, the nurses have to place the specimens in different sizes of containers filled with formalin. This can be repeated on an average 7 to 10 times during the day. During that process, it is not unusual to observe splashing of formalin on the nurses’ skin, while the well-known smell spreads throughout the operating room. In addition, it is common that formalin solution would leak out of the imperfectly sealed container, resulting in repeated, albeit limited, exposure to formaldehyde. The nurses do report that they are given information regarding the risks associated with Formalin. OSHA has established a permissible exposure limit in the workplace of 0.75 ppm parts of air for an 8-hour time weighted average. Nevertheless, it is a protracted exposure and it is not apparent that any steps are taken to monitor the exposure of the operating room personnel to that particular carcinogen. Notwithstanding the fact that there has not been an overwhelming incidence of naso-pharyngeal or hematologic cancers among the nursing staff, proper protection should be afforded to these workers.  One simple solution would be to have all the pathology specimens processed in one location, under a vented hood that would prevent any splashing and would scavenge all possible noxious emanations from the solution.

References: accessed on October 29, 2016

Kerns,W.D.,   Pavkov, K.L.,   Donofrio,D.J. , Gralla, E.J.,  and Swenberg, J.A.: Carcinogenicity of Formaldehyde in Rats and Mice after Long-Term Inhalation Exposure. Cancer Res. September 1 1983 43 (9) 4382-4392;



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