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[ReadyForLiftoff]

While looking at USP 61, Microbiological Examination of Nonsterile Products: Microbial Enumeration Tests, the Interpretation of the Results section. It states the following:

 

When an acceptance criterion for microbiological quality is prescribed, it is interpreted as follows:

 

10¹ cfu: maximum acceptable count = 20;

10² cfu: maximum acceptable count = 200;

10³ cfu: maximum acceptable count = 2000;

 

and so forth.

 

How is 10¹ CFU maximum acceptable count interpreted as 20? Shouldn't it be 10? The same goes for 10² and 10³. Shouldn't they be 100 and 1,000?

 

Thank you in advance.

 

[Charles.C]

 

While looking at USP 61, Microbiological Examination of Nonsterile Products: Microbial Enumeration Tests, the Interpretation of the Results section. It states the following:

 

When an acceptance criterion for microbiological quality is prescribed, it is interpreted as follows:

 

10¹ cfu: maximum acceptable count = 20;

10² cfu: maximum acceptable count = 200;

10³ cfu: maximum acceptable count = 2000;

 

and so forth.

 

How is 10¹ CFU maximum acceptable count interpreted as 20? Shouldn't it be 10? The same goes for 10² and 10³. Shouldn't they be 100 and 1,000?

 

Thank you in advance.

 

Hi RFL,

 

The answer (if any) likely relates to the context of the data quoted which is unfortunately unknown.

 

Offhand, I note the word "interpreted" which can have a zillion meanings.