Infection Control Verification Services

  • Infection Control Consulting and Monitoring for Construction Projects.
  • Isolation Room Pressurization and Air Change Certification (Recommended semi-annually).
  • Operating Room (OR) and other Critical Room Pressurization and Air Change Certification (Recommended semi-annually).

Operating Room Common Sense

The temperature and the humidity (not less than 55%) play a very important role in maintaining staff and patient comfort. They must be carefully regulated and monitored. In low humidity there is a danger of the production of electrostatic sparks. Ideally, the operating room should be 1ºC cooler than the outer area. This aids in the outward movement of air because the warmer air in the outer area rises and the cooler air from within the operating theater moves to replace it.

Ideal Air Ventilation System: Air Supply and Exhaust

Positive pressure ventilation with respect to the corridors and adjacent areas in the operating theater where surgical procedures are performed should be maintained. The number of operating theaters supplied by air handling units (AHUs) should be consistent with the number specified by the AHU manufacturer. Also, there should be routine maintenance of the AHUs and these units should not be turned off unless being serviced.

Design features

Parameters to have in place if possible based on available resources are:

Air changes

Maintenance of 15-20 air changes per hour, of which at least 3 should be fresh air from outside.


Filter all air with appropriate pre-filters (e.g. filtration efficiency of 30%) followed by final filter (e.g. 90%)

Air supply

Air should enter at the ceiling and be exhausted near the floor(important: furniture or other portable items placed against a wall exhaust at floor level will inhibit the air changeover in a OR and  therefore should be monitored and abated).

Ultraviolet Germicidal Irradiation (UVGI)

Do not use UVGI in the operating theater to prevent SSI.


Keep OR doors closed except as needed for passage of equipment, personnel and the patient.


Limit the number of personnel entering the OR to only those necessary for the surgical procedure. The microbial level in the OR is directly proportional to the number of people moving about in the theater.

Laminar flow and ultra-clean air

Laminar airflow is designed to move particle free air over the aseptic operating field in one direction. It can be designed to flow vertically or horizontally and is usually combined with high efficiency particulate air (HEPA) filters. HEPA filters remove particles > 0.3 micron in diameter with an efficiency of 99.97%. Ultra clean air can reduce the incidence of SSIs especially for orthopedic implant operations; however, some studies suggest that other interventions such as appropriate timing of preoperative antibiotics and good OR practices such as limiting nonessential traffic can also lower incidence. Therefore, if resources are limited, laminar flow with HEPA filtration is not required for high quality surgical care.

Guidelines for Environmental Infection Control in Healthcare Facilities