Uv burning hours for LAF and BSC

Dear sir,
Can u tell me the maximun burning hours for uv light used in LAF and BSC with reffered guidelines or standards

just 15 minutes of on the UV its enough.

Approx 8000 hours. You can also refer vendor certificate

6000 hrs, after that we need to change UV lamp.

I think…Max 2000 burning hours for LAF n pass box UV…after that we need to change…

Replacement frequency is once a year or 9000 to 12000 burning hours