As far as I know, there is no definition per clause. But the general definitions for critical, major and minor non-conformities are in the BRC-standard it self.
You can find it in part III: audit protocol.
There are three levels of non-conformity:
- Critical: Where there is a critical failure to comply with a food safety or legal issue.
- Major: where there is a substantial failure to meet the requirements of a 'statement of intent' or any clause of the Standard or a situation is identified which would, on the basis of objective evidence, raise significant doubt as to the conformity of the product being supplied.
- Minor: where a clause has not been fully met but, on the basis of objectives evidence, the conformity of the products is not in doubt.
During opening meeting I translate this as follows:
Critical: direct or potential food safety issue or legal issue;
Major: not complying to the requirement (statement of intent is also a requirement). Product is not conforming or serious risk that product will not be conforming, where this is not related to food safety or legal requirements.
Minor: small deviation to al clause.
My guess is that the above is definitive, ie it's up to the auditor. Unless of course you disagree later or an auditor later changes his mind (possible?).
Please note that auditors get thoroughly training and also by internal (within CB) and external (by standard owners) calibration trainings, auditors are trained to do a good evaluation in different situations.