Hepa filter test with a particle counter

Hello everybody, first of all i´m from spain and i´m sorry if my english isn´t very well, i hope you understand me.

I want to do an integrity test in HEPA filters with a particle counter, in a laminar flow cabinet. Looking the UNE 14644-3 (it is the same as ISO 14644-3 but here in Spain), in the section B.6.3, it explains how to do it, but i don´t undertand some section. In section B. it says that i have to calculate the standard leak penetration (PL) with the equation: PL = K x Ps, and I have to choose “K” from a table in function of Ps (Maximum allowable penetration). The table shows different values of Ps and the “K” you have to choose, and the minimum value to “Ps” is 5x10-4 and “K” is 10, that i think it belongs to HEPA filter U15 (in this case i think it´s called ULPA filter). My problem is that in the HEPA filters H14, Ps is 5x10-3 and i don´t know which value of “K” i have to choose.

Please help me!! I´m very desperate!!! I really hope you have understood me.

Thank you very much!!!

Please!!! can anyone help me??? I need help!!!

Dear nebpmp,

try posting this thread in the Good Engineering Practice forum, (
). In the cleaning validation forum very few people may have sufficient knowledge of this topic to answer you.

Best regards


Dear Alfred,

thank you very much for your piece of advice.