Butylhydroxytoluene (Butylated hydroxytoluene, BHT, ionol, dibunol, agidol-1, E321).
Formula (CH3)(tert-C4H9)2C6H2ooh
A cikin tsantsar foda-fari. Fasaha ionol-rawaya foda.
Ana amfani da shi azaman antioxidant a cikin samar da kayan abinci, mai mai, rubbers, robobi, da dai sauransu.
Har ila yau, wani fili ne na farawa don haɗa nau'o'in abubuwan da suka samo asali na phenols masu hana sararin samaniya, yawancin su suna da aikin nazarin halittu ko ana amfani da su a masana'antu.