(1) If, as respects any worker employed or desiring to be employed in such circumstances that an employment regulation order which fixes remuneration applies or will apply to him, the appropriate joint labour committee is satisfied, on application being made to it for a permit under this section either by the worker or the employer or a prospective employer, that the worker is affected by infirmity or physical incapacity which renders him incapable of earning the statutory minimum remuneration, the committee may, if it thinks fit, grant, subject to such conditions (if any) as it may determine, a permit authorising his employment at less than the statutory minimum remuneration, and while the permit is in force the remuneration authorised to be paid to him by the permit shall, if those conditions are complied with, be deemed, for the purposes of this Act, to be the statutory minimum remuneration.