Abstract:Background: This study investigates whether essential oil-bacteriophage combinations may be screened for food
safety using a transparent qualitative approach, therefore filling a gap in which synergy is frequently reported for
efficacy but seldom examined for safety.
Methods: Hazards of main essential oil elements were profiled in the OECD QSAR Toolbox, translated into
qualitative concern tiers, and aggregated to the oil level using composition weighting and dominance principles.
Bacteriophage safety was evaluated by dossier using eight criteria: genetic integrity, manufacturing and process
quality, stability, host range, effectiveness in food-like settings, regulatory precedent, and uncertainty, with
specific STOP criteria for genomic or manufacturing failures. A conservative maximum rule was used to combine
the essential oil and phage tiers, which were then mapped to screening labels using an FAO/WHO-style matrix
with likelihood categories for purely lytic, Good Manufacturing Practice-grade phages.
Results: When applied to oregano, thyme, and dittany against Escherichia coli, all combinations mapped to Low
screening output, within the qualitative and conservative boundaries of the framework, despite oregano and
dittany presenting Moderate–High essential oil tiers due to cautious QSAR alerts.
Conclusions: The methodology provides an early-stage safety screen that supports feasibility under rigorous in
clusion criteria, while remaining preliminary and hypothesis-generating. Validation in food matrices and EO
phage compatibility (titre-stability) confirmation under intended-use circumstances will be required before
practical implementation; formulation solutions may be considered if titre-stability data reveal a major loss of
infectivity at the desired EO dose.
