This standard specifies 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl in food contact materials paper and recycled fiber materials. High performance liquid chromatography method for the determination of methyl-4-isothiazolin-3-one. This standard applies to 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl in food contact materials paper and recycled fiber materials. Determination of methyl-4-isothiazolin-3-one.