Anyone who has spent much time around autopsy facilities or pathology departments knows the unmistakable smell of formaldehyde that often seems to emanate from these areas. From preserving tissue specimens to instrument sterilization to medical examiners’ autopsy suites, formaldehyde is one of the most commonly used chemicals in forensic pathology. It is typically used in an aqueous solution known as formalin that may or may not be mixed with other chemicals. But improper or careless use can cause a plethora of problems. In this column, we will take a closer look at the hazards of formaldehyde and how to safely use this common preservative.

WHY WORRY?
Just take a look at the physical and chemical properties and initial exposure effects for starters. Formaldehyde is a flammable, colorless gas with a pungent, suffocating odor. The vapor is just slightly heavier than air. It is classed as both a powerful irritant and a sensitizer. It is intensely irritating to mucous membranes and its presence is easily felt, even in very low concentrations. Published studies have shown the odor threshold to be well below one part per million (ppm). The eyes, nose, and throat are first to feel the tingling and then burning sensation. High concentrations, above five ppm, cannot be tolerated by most individuals. One can experience severe tearing in the eyes, as well as coughing and irritation ofthe upper respiratory tract.

What many people fail to note is that formaldehyde can quickly fatigue the senses. The initially irritating effects, especially from low level concentrations, which are so easily felt upon first exposure, will gradually dissipate with continued exposure as the chemical’s numbing effect takes over. We have met many employees not wanting to be labeled complainers that tell us they just “tough it out” for a few minutes and the feeling goes away. They just do not understand that they are still being exposed.

Formaldehyde is also a skin irritant and may cause dermatitis and possible allergic reactions from repeated exposures due to skin sensitization. Vapors or solutions may cause pain, white discoloration, roughness, and burns. In exposed individuals, subsequent exposures may result in a sensitization dermatitis characterized by the sudden eruption of blisters on the eyelids, face, neck, scrotum, and arms. Prolonged or repeated exposures may cause burns, numbness, itching rash, fingernail damage, hardening or tanning of the skin, and sensitization. Absorption through the skin also adds to the total exposure.

WHAT’S THE HARM?
Potentially serious health effects can result from formaldehyde exposures. In addition to the mucous membrane and skin effects, which are largely reversible upon removal of the exposure, formaldehyde may cause biological effects. These can range from central nervous system depression, and kidney and liver damage. Repeated or prolonged low level exposure may cause headache, rhinitis, nausea, drowsiness, and respiratory impairment. Neuropsychological effects may include sleep disorders, irritability, altered sense of balance, memory deficits, loss of concentration, and mood alterations.

As if all these symptoms and exposure effects are not enough, formaldehyde is also listed by the World Health Organization’s International Agency for Research on Cancer (IARC) as a Group 1 human carcinogen. Long-term exposure may increase risk of upper respiratory tract cancers including those of the nose and throat.

WHAT SHOULD WE DO?
First and foremost, determine where and how formaldehyde is used in your facility. Inspect all those areas and observe employee activities while they are on-going. Note any odors. Interview employees on their procedures. Note the type of formaldehyde products used and whether personal protective equipment is worn. With this information, evaluate the exposure hazards.