For the purposes of clause 3(4)(b) of Schedule 5 to the Act, the following grounds are prescribed as grounds on which the Registrar may refuse to grant an authority, within the meaning of that Schedule:

(a) the fact that the applicant for such an authority is not the holder of a certificate of competency in relation to the listed chemical product proposed to be handled under that authority;

(b) the fact that the applicant is under 18 years of age.