In addition to all other powers and duties conferred above, the Department of Finance shall have authority to prepare and adopt written specifications for all purchases and contracts within the scope of its purchasing authority, subject to the following guidelines.

(a) Consult with the department heads and other officials of using departments to determine their precise requirements and endeavor to prescribe those standards which meet the needs of the majority of such department.

(b) Make use of the laboratory and engineering facilities of the using departments and technical staffs thereof in connection with the preparation and adoption of standards and written specifications.

(c) Consult with experts outside the using agencies for technical assistance in the preparation and adoption of standards and written specification.

(d) All specifications shall be definite and certain and shall permit competition, provided, however, that the provisions of this subsection shall not apply to non-competitive types and kinds of supplies and services.

(e) Maintain a file of all written specifications and current standards adopted, which file shall be made available for inspection by using departments and the general public.

(f) Upon written memoranda stating the reason therefore, exempt any using department from use of the supply described in any standard specification.