Swab limit for cleaning validation

Swab limit for cleaning validation

Q. How do you calculate the swab limit for cleaning validation, once it has been extracted in solution?

A. In general the swab limit calculations go as follows:

  • swab limit (ug residue/swab) = acceptance criteria (ug residue/cm2) X swab area (cm2) X swab recovery (%);
  • acceptance criteria = ug residue/cm2 of a given residue;
  • swab area = cm2 of area swabbed; swab recovery = the percent actually detected compared to a spiked surface area of known amount of residue (amount detected/amount swabbed X 100).


To convert swab limits to test result limits by converting ug residue/swab to ug residue/mL based on the extraction volume that is used to extract the swab for analysis.


The general equation is:

test result limit (ug residue/mL) = swab limit (ug residue/swab) / mL of extraction solution.


If you need help calculating the swab limit for cleaning validation, contact the experts at cleaning@alconox.com.


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