(a) Unless otherwise ordered by the Department of Administrative Services, the purchase of supplies, materials, equipment, and services, other than professional and personal employment services, through the Department of Administrative Services shall not be mandatory in the following cases:

(1) Technical instruments and supplies and technical books and other printed matter on technical subjects; also manuscripts, maps, books, pamphlets, and periodicals for the use of the State Library or any other library in the state supported by state funds; also services;

(2) Livestock for slaughter and perishable articles such as fresh vegetables, fresh meat, fish and oysters, butter, eggs, poultry, and milk. No other article shall be considered perishable within the meaning of this clause unless so classified by the Department of Administrative Services; and

(3) Emergency supplies of drugs, chemicals and sundries, dental supplies, and equipment.

(b) In the purchasing of emergency supplies under paragraph (3) of subsection (a) of this Code section, it shall be the duty of the department making such purchases to report same to the Department of Administrative Services, giving the circumstances necessitating the purchases.

(c) Nothing in this part shall be construed to give the Department of Administrative Services any supervision over the selection or purchase of school textbooks, which is vested by law in the Department of Education.