Decontamination of tetramethylammonium hydroxide (TMAH) splashes: promising results with Diphoterine® in vitro
Céline Fosse1, Laurence Mathieu1, Alan H. Hall2,3, Elena Bocchietto4, François Burgher1, Michel Fischbach4, and Howard I. Maibach5
1Laboratoire Prevor, Valmondois, France, 2Toxicology Consulting and Medical Translating Services, Inc. (TCMTS, Inc.), Laramie, Wyoming, USA, 3Colorado School of Public Health, Denver, Colorado, USA, 4ABICH Srl, Verbano, Italy, and 5Department of Dermatology, University of California–San Francisco, San Francisco, California, USA
Tetramethylammonium hydroxide (TMAH), used in microelectronic industries and research and development, has both corrosive properties and systemic toxicity. Two fatal TMAH occupational exposure cases have been published. Studies comparing initial TMAH decontamination with Diphoterine® versus tap water were performed: an in vitro pH titration study and an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) in vitro cytotoxicity cell viability assay. For pH normalization, 17 times more tap water than Diphoterine® was required. In the cytotoxicity test, two-thirds of the cells remained viable after Diphoterine® washing, compared with only one-third after tap water washing (p < .001). Diphoterine® washing is a promising TMAH decontamination method.