Toxicology and industrial health
-
To document two cases of patients who were fatally exposed to tetramethylammonium hydroxide (TMAH) on the skin and to establish a rat model to investigate the effects of dermal exposure to TMAH. The charts of two workers who died from occupational accidental exposure to TMAH were reviewed. The 4-hour lethal dose (LD₅₀) of TMAH was determined by applying solutions mimicking the two most common industrially used concentrations (2.38% and 25%) of TMAH to the skin of Sprague-Dawley rats. ⋯ The level of blood urea nitrogen decreased significantly in rats exposed to the 2.38% TMAH, and rats exposed to the 25% solution had a significant decrease in the serum concentration of sodium. Injection of atropine after 5 minutes of exposure did not significantly overcome any of the toxic effects observed with either solution of TMAH. The preliminary results in the rat model indicated that the lethality of TMAH cannot be fully explained by the severity of the patients' chemical burns, and the physiologic effects on respiratory and kidney functions were probably involved.