You have to apply recovery factors as per Material Of Construction (MOC) of Equipments used.
I.e., if you calculate the recovery factor of one product in Stainless Steel Surface, apply the same to equipment having same MOC (stainless steel surface) used for manufacture of the product.
You can use these recovery factors in your Standard Test Procedure (Analysis of equipment cleaning samples of product) as correction factors for results obtained instead of applying at MACO stage.
Hope it clarifies your query. Anything further kindly let us know.[/quote]
I agree with Mr.Noor & I would like to add something to this…
Recovery studies can be done in the following ways:
a) Spike the sample on the specified coupon (say 10cm x 10cm) and by applying swab techniques (Immediately) as per the protocol / VMP, and findout the recovery% and calculate the recovery factor.
b) Spike the sample on the specified coupon and air dry the sample for a particular period, to simulate the manufacturing practices (sometimes, swab may be taken after longtime of cleaning, so, it should be simulated) and apply the swab techniques as per the protocol/VMP and findout the recovery% and calculate the recovery factor.
c) Spike the sample on lesser quality like SS316 (even if your equipment MOC is SS316L), and follow any of the above mentioned (a / b).
If you get the recovery on SS316, you may get more recovery on SS316L, since the surface of SS316L is good rather than SS316.
Note: Some of the product contact surfaces may be SS316 & SS316L. In this case, point © will be useful for us, in reducing the validation activity.
With Best Regards,