The county purchasing agent under such terms and conditions as the Board of Commissioners may prescribe, may authorize in writing any Office, department, institution or agency of the county government to purchase in the open market without filing a requisition or estimate, any supplies, material or equipment for immediate delivery to meet actual emergencies. A full written account of the circumstances necessitating any such emergency purchase, together with a requisition upon which the emergency purchase was secured shall be submitted at once to the county purchasing agent by the head of the Office, department, institution or agency of the county government concerned. The records of such transactions shall be open to public inspection.