Acute effects of isopropyl alcohol exposure on the middle ear mucosa

Abstract

Guinea pigs were exposed to 400 ppm or 5500 ppm of isopropyl alcohol (IPA) for 24 successive hours, and then middle ear mucosal samples in both proximal and distal sites to the eustachian tube were obtained for functional and morphological examinations. The ciliary activity was examined according to the photoelectric method of Ohashi and Nakai. The morphology of the middle ear lining was examined by transmission electron microscopy. The results showed that IPA at the allowable level of 400 ppm has an acute effect on the mucociliary system of the middle ear mucosa. Recovery from damage occurs within two weeks. At higher levels of exposure to IPA (more than 10 times the allowable level) moderate deterioration of the ciliary activity and severe damage of epithelial cells were observed and recovery within two weeks was not seen. It is concluded that IPA at the allowable level of 400 ppm does not cause significant middle ear disorders, but workers exposed to higher levels of IPA should be given careful otolaryngological examinations and follow-up observations.

Biocompatibility of “On-command” dissolvable tympanostomy tube in the rat model

“…Ethanol has been previously reported as ototoxic in the animal models, causing a decrease in cochlear microphonic and endocochlear potential in guinea pigs and chinchillas, respectively . Ohashi and colleagues, in their experimentation with vaporized isopropyl alcohol and guinea pig middle ear mucosa, found moderate deterioration of the ciliary activity and severe damage of epithelial cells with exposure to extremely high concentrations of isopropyl alcohol . Because of this concern about ototoxicity, we have focused future studies exclusively on hydrogen peroxide, H 2 O 2 , which breaks down into water and oxygen, and also appears to degrade on PMB polymer in a rapid fashion.…”