I take your point on this & I'm not sure that a standard BRC auditor would actually understand what would constitute "documented justification" anyway - none of the BRC auditors I have met appear to be microbiology specialists.
Certainly in a laboratory setting (where you are ISO17025 accredited) to add a new method to the scope of your laboratory accreditation you have to prove that the new method will deliver the correct results against a standard ISO/AOAC when used for your product matrix....usually this means comparative testing & for pathogens might involve several different serotypes, this is a considerable amount of testing work to demonstrate compliance (especially if none of the tests offered by a laboratory are accredited)
The interpretation notes for BRC 8 offer this information.
Interpretation Analyses critical to safety and legality
This clause applies to tests which are critical to product safety or legality. Results from such tests must be credible and may be called upon in a court of law.
The company needs to identify which tests are critical to product safety or legality, such as compliance with label claims/declarations (e.g. nutritional claims, alcohol content) and tests for contamination (e.g. by pesticides, aﬂatoxins).
Note that while the laboratory itself may have accreditation, the actual test methods must also be accredited. Any method of analysis that is not accredited needs justiﬁcation as to why it was used (e.g. it may be a method for which no accreditation is yet available). Where critical tests are carried out by non-accredited laboratories (either contracted or on-site laboratories), there must be suitable documentary assurances that the laboratory is working to the requirements and principles of ISO 17025.
This must include conﬁrmation of the laboratory’s procedures to meet the following general principles:
• staﬀ competency and documented training
• documented test methodology based on accepted standards
• equipment that is ﬁt for purpose and appropriately calibrated
• a documented quality assurance programme, including paired testing, ring testing etc.
• completion of internal audits of the laboratory’s operation.
Thus, I think what BRC is trying to say is that your laboratory (and methods) may not be accredited but the laboratory itself has to work to ISO17025 standards & you would need documentation to prove this.
But as KASI4bala is based in India BRC might not be an issue & their customers might not have this requirement?