Acute and subchronic toxicity studies of rats exposed to vapors of methyl mercaptan and other reduced‐sulfur compounds

Abstract

Acute inhalation experiments were conducted to determine 24-h LC50 values for adult Sprague-Dawley rats of both sexes exposed to vapors of methyl mercaptan and other reduced-S compounds for 4 h periods. Using calculated gas concentrations, the following LC50 value for each gas and combination was determined: metyhl mercaptan, 675 ppm; dimethyl sulfide, 40,250 ppm; dimethyl disulfide, 805 ppm; hydrogen sulfide, 444 ppm; and an equimolar mixture of methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, 550 ppm. The effects of body and tissue weights, gross metabolic performance, O2 consumption, systolic blood pressure, various blood parameters, and intestinal transit time associated with 3-mo exposures of young adult male rats to chemically verified concentrations of 2, 17, and 57 ppm methyl mercaptan vapor are summarized in this report. No mortality was experienced by any group. Histopathological findings were essentially nil except for microscopic suggestions of liver damage. The most readily apparent phenomenon was the decrease in body weight. Average values of terminal body weights for all exposed groups were lower than that for the sham control group. This difference was significant in the 57 ppm group and followed a statistically significant dose-related trend.

Fatality due to inhalation of dimethyl sulfide in a confined space: A case report and animal experiments

“…They became unable to move around 0.7-1min after exposure. This is similar to previous observations on the acute toxicity and fatality of DMS inhalation as follows: exposure to 4% DMS for 4 h killed 50% of rats within 24 h [8]: a concentration of 5% DMS killed 1 rat in 15 min [9]: a concentration of 9.6% DMS caused 50% rats to be comatose [10]. As the DMS concentration increased, the time until the onset of inability to stand and respiratory arrest became shorter (Table 2).…”

Disulfide Oil Hazard Assessment Using Categorical Analysis and a Mode of Action Determination

“…99 Comparable studies with DMDS revealed an oral LD 50 value for rats of greater than 190 mg/kg, a dermal LD 50 value for rabbits that was greater than 2000 mg/kg, and a 4-hour inhalation LC 50 value for rats of 805 ppm (3.10 mg/L). [100][101][102] A concentration-related increase in olfactory epithelial degeneration was observed in the nasal turbinates of rats exposed to 8.9, 12.6, and 18.4 ppm of DMDS for 24 hours, but a 5.0 ppm exposure for the same duration was free from this effect. 103 A functional observational battery performed on rats exposed to 100, 200, or 700 ppm of DMDS for 6 hours revealed an increased incidence of partial eyelid closure, grooming behavior, and urination, and a decrease in motor and locomotor activity at the highest exposure concentration.…”

Brain, Learning, and Memory: Role of H2S in Neurodegenerative Diseases

“…The conjunctivitis caused by prolonged low-concentration exposure (about 20 ppm) (Lambert et al 2006) is peculiarly associated with reversible chromatic distortion and visual changes. These symptoms are sometimes accompanied by blepharospasm and photophobia (Tansy et al 1981;Milby and Baselt 1999). H 2 S is an odorous gas at low concentration (0.01-0.3 ppm).…”