Trichloroethanol up-regulates matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in HaCaT cells

► We assess sensitizing potential of trichloroethanol or trichloroacetic acid in vitro. ► We use HaCaT cell line as mode cell and matrix metalloproteinases as responders. ► TCOH could induce MMP-9 increase in a dose-effect mode in HaCaT cell. ► TCA could not induce such a response in HaCaT cell. ► TCOH might play important roles in trichloroethylene-induced hypersensitivity reaction.