I-phthalic anhydride (C8H4O3) — inhlanganisela emhlophe eyikhrisitali eyenziwa ngokufaka umoya-mpilo ku-ortho-xylene noma ku-naphthalene. Kuyinsizakusebenza eyinhloko yokwenza ama-pigment e-phthalocyanine, ama-resin e-alkyd nezithambisi zepulasitiki. Kucasula isikhumba nemigudu yomoya — kusebenzise lapho kunomoya ophelele.