Presumably, safety-wise, it depends on (haccp) Risk Assessment and preferred degrees of Risk Aversion.
the allergenic risk (R) due cross-contamination of adjacent vertically (and horizontally?) stored, disparate, allergens is theoretically Likelihood x Severity.
It seems to me that in many situations, eg "well-packed" product / efficient transfer operations, R = (Very Low x Very High)(VL x VH). The Risk can then be Significant or non-Significant depending on whether the Risk matrix is structured to be strongly or weakly Risk-Averse, eg whether Likelihood or Severity is prioritized. Since customer usage is unlikely to eliminate inadvertent allergens, Regulatory bodies /publications seem to traditionally opt for the "Strong" as far as allergens are concerned hence the typical storage rules.
afaik, the basic storage situation for microbiological zero-tolerant pathogens tends to be similar, eg RTE above NRTE
In contrast, IMEX, the preferred risk aversion for Process haccp micro. risk matrices in NRTE foods is often the opposite of above, ie VL x VH > Non-Significant hazard since customer usage, ie cooking, is assumed to eliminate vegetative pathogenic species.
Edited by Charles.C, 24 December 2021 - 08:46 AM.