Idaho Code § 67-5231: Invalidity of rules not adopted in compliance with this chapter — Time limitation.

(1) Rules may be promulgated by an agency only when specifically authorized by statute. A temporary or final rule adopted and becoming effective after July 1, 1993, is voidable unless adopted in substantial compliance with the requirements of this chapter.

(2) A proceeding, either administrative or judicial, to contest any rule on the ground of noncompliance with the procedural requirements of this chapter must be commenced within two (2) years from the effective date of the rule.