Dichlorooctylisothiazolinone, DCOIT or DCOI, is the organic compound with the formula SC(Cl)=C(Cl)C(O)NC7H15. It is a white solid that melts near room temperature. It is an isothiazolinone, a class of heterocyclic compounds used as biocides. DCOIT has attracted attention as an antifouling compound. It is a replacement for organotin compounds that have been largely banned for causing environmental damage. DCOIT however is itself controversial.[1]
Isothiazolinones are highly bioactive and have attracted scrutiny for causing contact dermatitis.[1]