method of checking filter integrity of hepa filters

hello all,

can anybody tell me the procedure for checking the filter integrity of Hepa filters installed in dry powder injectable area,when are they checked and how?



What ever the product you manaufacture inside your sterile area, HEPA filters are tested by applying monodisprsed droplets of PAO(Poly alpha Oleiphin) at upstream of filter .

These particles are observed at the down stream side by an instrument that is placed at 4 corners and centre. This detector is placed at a distance of 2 inches from the filter.

Filter Integrity testing is done every 6 months once.

I agree 6 months should be good .