A 1996 study found that triethanolamine (TEA) occasionally causes contact allergy.[7] A 2001 study found TEA in a sunscreen caused an allergic contact dermatitis.[8] A 2007 study found TEA in ear drops caused a contact allergy.[9] Systemic and respiratory tract (RT) toxicity was analyzed for 28 days in a nose specific inhalation 2008 study in Wistar rats; TEA seems to be less potent in regard to systemic toxicity and RT irritancy than diethanolamine (DEA). Exposure to TEA resulted in focal inflammation, starting in single male animals from 20 mg/m3 concentrations.[10]
A 2009 study stated patch test reactions reveal a slight irritant potential instead of a true allergic response in several cases and also indicated the risk of skin sensitization to TEA seems to be very low.[