What is the definition of Visually Clean and where to draw the line? Please discuss

An age old question that is constantly regurgitated in our organisation.

What is the definition of Visually Clean and where to draw the line?
We used to employ a method of visually clean that when performing the visual examination and found a small spot of residue on an equipment part, we would get the operator to wipe the part with a cloth moistened with purifed water, recheck it and deem it as visually clean before swabbing.

QA then said that this should not be the case. If an equipment part is visually not clean in the first instance then the entire Cleaning Validation has failed to which i agree but the whole thing falls down at the first hurdle.

This has now opened up a debate as to what exactly can be declared as “visually clean”.

We all know that the fundamental reasoning for Cleaning Validation is to show that our cleaning procedures are working, are confident in them and to prevent cross contamination with active and detergent residues.

If a speck of let’s say for instance a white residue was found. Should that be deemed as visually un-clean? What happens if after swabbing the white speck and performing the rinse testing the results come back as negative or below the acceptance criteria for active and detergent which is fundamentally what we are looking for? Should that be determined as “not clean”.

So here is my question to all,

As this is a subjective test likening it to determining intensities of spots on a TLC plate (everyone has varying levels of eyeight and opinion), would it be possible to ascertain a level of what is acceptable and what is not?

With elegance testing on tablets, a number of minor, major and critical are allowed. Would it be possible to have a certain amount of minor residues found, majors and zero criticals? (N.B Determining what would be considered a minor, major and critical is another topic altogether) Swab and rinse testing on these would still apply and have a zero tolerance if the HPLC or TOC testing resulted in active/detergent found above the acceptance criteria failing the CV, or if it is less than acceptance criteria, justifying that “yes, minor residues were found but testing showed they were not product, active or residual detergent (which is what we look for), therefore this is accepted as clean and will not affect the next product manufactured.”

Please discuss as I believe when manual cleaning procedures are performed, it is nigh on impossible to validate something with so many variable factors involved. CIP does exist in our organisation but only on certain equipment. We employ an Authorised Persons check to be performed before we go down to visual inspect, swab, etc, but things are still missed and I worry that failing an entire Cleaning Validation because of one small speck that isn’t active or detergent is being over the top somewhat?

Dear Rooky,
Setting limits for visually cleaning levels and visual inspector qualification is a huge process. An excellent and statistically valid method has been developed by Mr. Ovais, an pharmaceutical scientist. Have a look at the attachment (Ovai’s article), for brief knowledge on visual cleaning levels

[attach]551[/attach]

VEERRAJU


Statistically Justifiable Visible Residue Limits.pdf (832.9 KB)

[quote=ramyaraj725]Dear Rooky,
Setting limits for visually cleaning levels and visual inspector qualification is a huge process. An excellent and statistically valid method has been developed by Mr. Ovais, an pharmaceutical scientist. Have a look at the attachment (Ovai’s article), for brief knowledge on visual cleaning levels

[attach]551[/attach]

VEERRAJU[/quote]

Thanks Veerraju,

I found this article sometime ago and many others relating to this topic. Seems to be a genuine common thread where there is no right or wrong answer.

With such a subjective test with so many variables there doesn’t seem to be any easy or straight forward answer to this.

Thanks for replying