3—A failure on the part of any person to observe any provision of a code of practice which is for the time being in force under this Part of this Schedule shall not of itself render him liable to any proceedings ; but in any proceedings before an industrial tribunal under this Act—
(a)any such code of practice shall be admissible in evidence, and
(b)any provision of such a code of practice which appears to the tribunal to be relevant to any question arising in the proceedings shall be taken into account by the tribunal in determining that question.