IDENTIFICATION AND USE: Glutaraldehyde is a colorless liquid. It is registered for pesticide use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. It is used as algaecide, bactericide and fungicide. Glutaraldehyde is used as a tissue fixative in histology and electron and light microscopy, generally as a 1.5-6% aqueous solution. Glutaraldehyde is used, generally in conjunction with wetting agents, to control viruses and other micro-organisms in fish farming.

Glutaraldehyde based products are effective sterilant and disinfectants for medical devices that cannot be steam sterilized, are particularly heat-sensitive, for lensed instruments that are commonly subjected to high-level disinfection between patient uses. It is a colorless, oily liquid with a pungent odor. As a cold sterilizer, it is commonly used as a 2%-4% aqueous solution, and it is found in Ultizyme. Glutaraldehyde has also been used as a preservative in chemical products such as fabric softeners, antiperspirants and fixatives for biological specimens.”

Glutaraldehyde is allowed as a preservative in cosmetics in Europe at concentrations up to 0.1%. It is not allowed in aerosols and sprays. Glutaraldehyde is a biocide commonly used in a 2% concentration for cold sterilization of surgical and dental equipment. Biocides, such as glutaraldehyde, are added to eliminate bacterial growth in fracturing fluids.

HUMAN EXPOSURE AND TOXICITY: Exposure to concentrations < 1 ppm by inhalation or skin contact may cause irritation of the skin and/or mucous membranes. The critical effects of glutaraldehyde exposure are eye, skin, and respiratory irritation, skin sensitization and occupational asthma. Nose and throat irritation has been observed in humans at vapor concentrations below 0.2 ppm. Occupational asthma has also been reported in workers exposed to dilute solutions of glutaraldehyde.

Contact dermatitis and eye irritation have been reported in workers using glutaraldehyde solutions, usually 2% or higher. Skin sensitization has been confirmed in workers using dilute solutions.

Other symptoms that may be brought on by glutaraldehyde exposure include heart palpitations and tachycardia. The incidence of death and incidence of cancer deaths in 186 male employees at a glutaraldehyde production unit were compared to those of US white males and to 29,000 other chemical workers during the period 1959 – 1978. All subjects were observed for 10 yr. The number of deaths was less than expected, as was the incidence of cancer deaths.

ANIMAL STUDIES: Glutaraldehyde was corrosive to the skin and eyes of rabbits at high concentrations, with signs of skin irritation evident at 2%, and eye irritation at 0.2%. In an inhalation study where mice were exposed to glutaraldehyde at concentrations of 33 or 133 ppb for 24 hours, the animals exhibited panting and increased grooming, mice that inhaled the highest concentration developed toxic hepatitis.

Following a single whole-body inhalation exposure at 1 ppm for 1 day, rats and mice developed coagulation pathology of the upper respiratory tract squamous epithelium. After 4 days of such exposures, inflammatory granulocytic infiltrate into the squamous epithelium and lamina propria with thickened epithelium of the nasal lumen ensued. In those animals inhaling 0.5 or 1 ppm glutaraldehyde for four days, the nasal passages became obstructed with intraluminal debris; degenerative/hyperplastic erosions with epithelial abscesses extended as far as the nasopharyngeal meatus in the 1-ppm exposure group.

A study of male and female rats given glutaraldehyde in drinking water at concentrations of 0, 50, 250, or 100 ppm through two generations indicated a dose-related decrease in parental water consumption and body weight (attributed to adverse taste) and decrease in offspring (1000-ppm group) body weights. No adverse reproductive effects were observed. In other study, there was a significant dose-dependent reduction in the average of maternal body weight gain and a significant increase in the number of stunted (body weight) and malformed fetuses at the 5 mL/mg/day dose level.

Early mutagenicity studies were negative, but more recent studies have indicated that glutaraldehyde is mutagenic in vitro in bacterial assays and tests in mammalian cells. In vivo genotoxicity tests to date have proven negative. Groups of 50 male and 50 female rats and mice were exposed to glutaraldehyde vapor at concentrations of 0, 0.25, 0.50, or 0.75 (rats) and 0, 0.062, 0.12, or 0.25 ppm (mice) 6 hr/day, 5 days /week.

The incidences of non-neoplastic lesions of the nose were reported to be significantly increased in the 0.50 and 0.75-ppm exposed rats and in the 0.12 and 0.25-ppm exposed male and female mice.

ECOTOXICITY STUDIES: Available chronic toxicity data for glutaraldehyde indicate that continuous exposure results in measurable effects on cold-water fish at a concentration of 5.1 mg a.i./L. A second study on cold-water fish resulted in measurable effects at 2.5 mg a.i./L. Measurable effects on freshwater invertebrates were noted at concentrations of 8.5 mg/L product and 4.9 mg a.i./L.