Section 5
SEC. 5. Exemption from the provisions of sections two, and three hereof may be granted by the Secretary of labor in the interest of the public, or if, in his opinion, such exemption is justifiable either because the organization or nature of the work requires it, or because of lack or insufficiency of competent laborers in a locality or because the relieving of laborers must be done under certain conditions, or by reason of any other exceptional circumstances or conditions of the work or industry concerned; but when such exemption is granted employees and laborers will be paid at least twenty-five per centum in addition to their regular salaries or wages for the time in excess of eight hours.