Complex sentence: 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.
Split into simpler sentences: A 2009 study stated patch test reactions reveal a slight irritant potential instead of a true allergic response in several cases. The study 2009 study also shown the risk of skin sensitization to TEA seems to be very low.