A method for fumigating psyllium husk. The method comprises filling a fumigation chamber with psyllium husk chamber is at least 35% filled with bags of psyllium husk, fumigating the psyllium husk with at least 40 g/m3 of methyl bromide for at least 24 hours, and degassing the chamber for at least 6 hours to form fumigated psyllium husk. The fumigated psyllium husk comprises less than 50 ppm inorganic bromide residue and the fumigated psyllium husk does not comprise an insect infestation or a khapra beetle infestation.
