UV LAMP EFFICACY TEST
WHAT IS UV LIGHT?
The light with a wavelength of 10-400 nano meters (nm) in sunlight is called ultraviolet light, and it can be divided into UVA, UVB, and UVC (200 nm to 275 nm) according to different wavelength bands. Among them C-band ultraviolet rays destroy the DNA of bacteria and viruses and play a role in disinfection and sterilization. Continuous low doses of far ultraviolet C (far-UVC) light can kill airborne flu viruses without harming human tissues, according to a study at the Center for Radiological Research at Columbia University Irving Medical Center (CUIMC).
The findings suggest that use of overhead far-UVC light in hospitals, doctors’ offices, schools, airports, airplanes, and other public spaces could provide a powerful check on seasonal influenza epidemics, as well as influenza pandemics.
UV Efficacy test procedure :
This test is Applicable for UV lamps of pass box, laminar air flow bench and garments box ,UV light of Dispensing Booth and Sampling Booth.
For test take the viable culture suspension of staphylococcus aureus/ready made culture suspension (with tracebility certificates containing 10-100 cfu .
Take seven Petri dishes and to pipette 1 ml of culture suspension into each of seven sterile petri dishes.
and add 15-20 ml sterile soyabean casein digest agar in to each petri dishes that previously has been melted and cooled to approximately 45°c.
To cover the petri dishes, mix the culture with the agar by tilting or rotating the dishes, and allow the contents to solidify at room temperature.
To expose the six agar petri dishes contains culture by removing lid under the UV lamp of LAF bench and one agar petri dishes contains culture without exposing to UV lamp which act as positive control.
To prepare one agar petri dishes with out add the culture for negative control.
At every 5 minutes interval remove one exposed agar petri dishes and label 1st petri dishes as 5 minutes, 2nd petri dishes as 10 minutes, 3rd petri dishes as 15 minutes , 4th petri dishes as 20 minutes, 5th petri dishes as 25minutes and 6th petri dishes as 30 minutes
After completion of exposure of petri dishes, close the petri dishes. invert the petri dishes and incubate along with negative control and positive control at 30–35 °c for 48 hours.
Repeat the same procedure for three consecutive days to validate the process.
and also the same above procedure shall be followed for UV lamps of pass box, garment box,Dispensing and Sampling Booth.
To record the observation and record the number of CFU.
Always on the UV lamps and during uses and transferring any material through UV pass box, material should be exposed under UV light.
UV exposure time should be equal to UV efficacy time.
Be ensure the culture , samples, positive cultures are transferring through pass box into testing room should not be exposed under UV.
UV Light Efficacy Testing Frequency – once in 6 months/ as per requirement lamps.
UV light replacements shall be recorded.
Specification of test – No colonies observed at a specific duration of exposure time, the same timings shall be considered as UV efficacy time.
UV efficacy Challenge test