in-house completed projects

Design and fabrication of a bacterial filtration efficiency tester

Investigators: Dr. K. P. Chellamani and Mr. S. Thiruppathi


Healthcare workers involved in treating and caring for individuals injured or sick, as well as the patient, can be exposed to biological aerosols capable of transmitting diseases.  These diseases, which may be caused by a variety of micro organisms, can pose significant risks to life and health. Concerns over infection in the operating room have stimulated research into improved surgical gowns and drapes.  At present, indigenous instruments are not available to assess the bacterial filtration characteristics of medical fabrics and imported instruments are cost-prohibitive.  SITRA has conducted a project to design and fabricate a Bacterial Filtration Efficiency Tester.

Major accomplishments 

SITRA’s Bacterial Filtration Efficiency Tester

SITRA has designed and fabricated an instrument “Bacterial Filtration Efficiency Tester”.  This instrument could be used to assess the barrier properties of woven and non woven fabrics. The mean particle size of the bacteria that are used to assess the bacterial filteration efficiency is 3µm + 0.3 µm.   Woven surgical gowns (without any anti microbial finish) used in hospitals show a reduction in bacterial filtration efficiency with increase in the number of industrial launderings.  For the type of hospital gowns covered in the study, 17 – 18 washes appear to be the termination point from the view point of acceptable level of bacterial filtration efficiency.  Surgical gowns, after washing and sterilisation are kept in the sterile room in hospitals till they are taken by the surgeons for use.  Growth of different types of bacteria was found to occur on the gowns that are kept in the sterile room without any wrap over them.  However, in fabrics with either a single wrap or multiple wraps, no bacterial growth was found to occur even after 45 days of storage in the sterile room.

Research reports / Publications: Available at SITRA