Syringe drivers, sharps trays, trolleys, intravenous drip stands and bed frames were among pieces of medical kit found contaminated with blood and body fluids during a probe at University Hospital Ayr in early April.
While most areas of the hospital were found to be clean, inspectors were so concerned with the state of the A&E department, which treats 44,000 cases a year, that they returned for a second unannounced inspection less than two weeks later.
After being quizzed by the Healthcare Environment Inspectorate (HEI) team, the department's senior charge nurse admitted that the system for cleaning the department and reusable patient equipment was "not working".
After the damning inspection, NHS Ayrshire and Arran put an action plan in place, with measures including increasing cleaning cover by three hours a day.
The investigation also found equipment in use that was so old that it could not be cleaned properly. That included rusty trolleys and a lamp held together with dressing tape.
Susan Brimelow, HEI Chief Inspector, said: "During inspection on April 1 and 2 we were not satisfied with standard of cleanliness seen in the accident and emergency department.
"The standard of environmental cleaning was poor and we found patient equipment which was not clean. We escalated our concerns to senior management and requested that immediate action be taken to improve the standard of cleanliness."
On a return inspection "significant improvements" had been made, Ms Brimelow said, although "further attention to detail was still required."
Positive results were reported with regard to hand-washing among staff and the majority of patients responding to a survey said they considered equipment clean.
However, clinical waste bins in intensive care and high dependency units were found to be overflowing.
Overall, inspectors ruled the department should fulfil six requirements, including that staff are aware of the correct procedures for cleaning blood spillages, that the management of clinical waste is reviewed and that patient equipment in the A&E department is cleaned in line with national guidance.
John Burns, the health board's chief executive said immediate action had been taken to address concerns about the cleanliness. Building work has begun on a new A&E department.
Mr Burns added: "I want to reassure the public that we take prevention and control of infection extremely seriously … we have increased our focus on our own programme of unannounced inspections and audits to reinforce those provided by the Healthcare Environment Inspectorate."