Glass flask calibration

[Axar]

Hey guys!!!
Our QM department wants us to calibrate glass flasks (class A) in laboratory. Is it normal or they lost their mind?
If it is normal, can u share some links to regulatory docs please!
Thank you!

[adeputy]

They have lost their collective minds.

[Johnny Rod]

I agree. You should be able to get some sort of cert of conformity from the flask supplier which tells you the typical tolerance for the grade you've got.

[paulw]

Most class A glassware will give a +/- on the glassware of accuracy. I have never been in a GLP environment that required the lab to calibrate glassware. We typically have so many volumetric flasks that it would be a never ending process. I've also never labeled and logged a specific piece of volumetric glassware, which you would have to do if you wanted to have calibration records for them.

[JGK]

Most class A glassware will give a +/- on the glassware of accuracy. I have never been in a GLP environment that required the lab to calibrate glassware. We typically have so many volumetric flasks that it would be a never ending process. I've also never labeled and logged a specific piece of volumetric glassware, which you would have to do if you wanted to have calibration records for them.

When I worked in a GLP envirinment, a QA inspector once asked this question. After we stopped laughing he was told the cost implications of his request he relented. If he hadn't my action would be to demand a scientific justification as to what effects would produce a change in size for the glassware sufficient to produce a change in size significant enough to affect results. If he had managed that I would have put a warning not to use glassware under those conditions in the SOP.

[Axar]

Thank you very much!
It really helps!

[FragranceChem]

You might as well start making glassware if they are going to ask you to do that.

[Alexandre]

In ISO 17025 environment you need to calibrate your glassware.
It is critical for reference labs, primary methods, chem. metrology, regulatory and in compliance testing. It affects bias/uncertainty.

I some labs a person is employed full time just to do QC, including glassware and other calibrations, e.g. pipettes, dispensers, syringes etc.

Labs do verify all equipment, e.g. chromatographs. The same with vol .flasks (VF), you have to be sure that they pass. Individual No. are engraved so they can be traced back to calibration records. Some labs combine glassware for non critical jobs that pass specification, and for critical jobs use special one that kept away from daily routine with exact known volume. Operation procedure/work instructions should be available for staff how to maintain calibrated glassware, eg how to wash, keep, dry, re-calibrate.

In Pharmacopoeia environment you have to check water that it is water… There are certain properties of H2O that should pass, and it is not stupid. I worked in pharm. production and once we received NaOH drum that at the end was found to be KOH, it was discovered after all test animals died of K salt “medicine”, more toxic than Na. The certificate was for NaOH.

Also keep track (record in worksheet) of VF No. in daily works, mistakes can be made in dilution factor; one can mistakenly use 20-mL VF instead of 25, or 100 instead of 50…

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"If your experiment needs statistics, you ought to have done a better experiment." Rutherford

[Johnny Rod]

This depends on the magnitude of the uncertainties in your whole analysis. If the tolerance of the flask volume is trivial then it'll become apparent when you calculate your uncertainty. Pharma work for FDA doesn't require certified volumetrics in my experience. ISO17025 can be more demanding but it depends really on what you're doing.

Calibration of dispensing equipment such as syringe pumps is a different story as they're not made to give a fixed volume and operation is automatic whereas a flask has one volume and a person checks the liquid matches the line.

[Consumer Products Guy]

If volumetrics need that, then better do volumetric pipets as well. And so on.

Our QA asked if we assay stuff like primary standards, and our response was: with what. Sooner or later one has to trust something.

For example: if one bought potassium hydrogen phthalate. Maybe an assay would be a titration with sodium hydroxide solution. But first one would need to purchase pre-made NaOH titrant, or prepare it oneself. But what to standardize the pre-made solution with?? A different lot of KHP ? And what was the purchased NaOH titrant standardized against? And so on. It would never end.

[FragranceChem]

If volumetrics need that, then better do volumetric pipets as well. And so on.

Our QA asked if we assay stuff like primary standards, and our response was: with what. Sooner or later one has to trust something.

For example: if one bought potassium hydrogen phthalate. Maybe an assay would be a titration with sodium hydroxide solution. But first one would need to purchase pre-made NaOH titrant, or prepare it oneself. But what to standardize the pre-made solution with?? A different lot of KHP ? And what was the purchased NaOH titrant standardized against? And so on. It would never end.

That's kind of what I was getting at when I said you might as well start making glassware. If you wanted to calibrate Class A volumetric glassware you would need a method of calibration that was more precise than Class A volumetric glassware. If your lab is equipped to do that then you might as well just start selling glassware.