Any interested person may at any time file a petition with the Administrator for an amendment to the regulations contained in this part or for an amendment to a wage order applicable to that person. In view of the statutory requirement that the minimum rates of wages established by order under section 6 of the Act be reviewed by an industry committee at least biennially, substantial cause must be shown in support of any petition for an amendment of a wage order out of regular course. Any interested person may also file a petition at any time with the Administrator for a public hearing under section 13(e) of the Act to determine whether economic conditions warrant rules or regulations providing reasonable limitations or allowing reasonable variations, tolerances, or exemptions to or from any or all of the provisions of section 7 of the Act with respect to employees in American Samoa for whom the Secretary of Labor has established minimum wage rates under section 6(a)(3) of the Act and the regulations contained in this part. Whenever it appears to the Secretary of Labor, by reason of such a petition or otherwise, to be probable that such a hearing is likely to reveal that economic conditions warrant such action, notice of such hearing specifying the procedure to be followed will be published in the Federal Register.