Glassware cleaning within microbiology labs

You asked

Question - When washing and reusing glassware that can impact the recovery of organisms, does the laboratory require a procedure to test for residual detergents ? Is this mandatory or purely a best practice ?

Yes, indeed a procedure is required for any equipment where in your case, contamination, interferences or inhibitors may impact the validity of results. This should be part of your validation. You should suitable verification tests initially and thereafter as often as necessary to ensure the process is in control. Typically this may be every 6 or 12 months or before you change the detergent or procedure (e.g. hand washing versus dishwasher)/

Depending on the method, you could also consider routinely including two process QC blanks per batch – one where the glassware had additional rinsing and one following normal washing practice.

You also asked

Should a test such as this be written in to the SOP ?"

To ensure that the procedure is standardised and enforced, yes it is advisable to include in a SOP or quality control manual.

The following article may be of interest:

What does ISO 17025:2017 require for laboratory measurement equipment and related procedures? at https://advisera.com/17025academy/blog/2019/07/25/iso-17025-measurement-requirements-of-the-standard/
and the ISO 17025 document template: Equipment and Calibration Procedure at https://advisera.com/17025academy/documentation/equipment-and-calibration-procedure//