IN Brief:
- EFSA assessed eight Alternaria toxins across food and animal feed.
- Five toxins were considered genotoxic, while exposure to two others was assessed as unlikely to raise health concerns.
- Cereals, fruit products, juices and vegetables are among the foods contributing to dietary exposure.
The European Food Safety Authority (EFSA) has identified five Alternaria mycotoxins as genotoxic in an updated assessment of their presence in food and animal feed. Published on 11 November, the scientific opinion examines eight substances produced by Alternaria moulds, using new occurrence information, toxicological evidence and estimates of dietary exposure. The findings distinguish substances for which DNA-damaging properties have been established from others where available data support lower concern or leave important uncertainty.
Alternaria fungi occur in the environment and can contaminate agricultural crops before harvesting or during subsequent storage and handling. Their toxins may therefore enter processed foods through raw materials rather than being introduced at a particular manufacturing step. EFSA identified cereal-based products, fruit products and juices, tomatoes, other vegetables, grain-derived foods, olive oil and sunflower oil among the contributors to dietary exposure. Contamination patterns vary between ingredients and products, so the new opinion does not provide a single exposure figure or risk rating applicable to all food categories.
The five substances identified as genotoxic are alternariol (AOH), alternariol monomethyl ether (AME), altertoxin I (ATX-I), altertoxin II (ATX-II), and stemphyltoxin III (STTX-III). Genotoxicity means that a substance is capable of damaging genetic material under the conditions studied; it is not equivalent to a finding that every contaminated food causes harm. The risk assessment must also consider how much of a substance people are likely to ingest, the relevant toxicological mechanism and the strength of the evidence available for each compound.
AOH and AME have a particularly developed evidence base in the assessment. EFSA concluded that their DNA-damaging action operates through a non-threshold mechanism and compared estimated chronic dietary intake with a threshold of toxicological concern of 2.5 nanograms per kilogram of body weight per day. Mean exposure estimates exceeded that screening value in most population groups. Exceeding the threshold does not itself quantify a person’s likelihood of disease; it indicates that a very low exposure benchmark for substances with potential DNA-reactive properties has been crossed and that the safety concern cannot be dismissed through that screening approach.
The remaining three genotoxic toxins present a different evidential problem. ATX-I, ATX-II and STTX-III were classified as genotoxic, but occurrence data were too sparse for the same dietary-exposure assessment to be completed. Consequently, absence of a quantified exposure estimate should not be interpreted as evidence of negligible exposure. The available monitoring data do not yet support the level of risk characterisation achieved for AOH and AME. This distinction is important when translating an assessment of hazard into testing priorities for ingredients and finished foods.
Tenuazonic acid (TeA) was the toxin detected most frequently in food. Particularly high occurrence values were reported in mulberries, paprika powder and processed tomato products, with tomatoes also prominent in the wider food exposure data. EFSA could not reach a firm conclusion on whether TeA is genotoxic. Separately, its assessment of non-genotoxic effects concluded with 98% certainty that estimated dietary exposure across population groups would not exceed the relevant Cramer Class III threshold of toxicological concern. The conclusion for those effects does not resolve the outstanding question about possible genotoxic properties.
Two other assessed compounds, altenuene (ALT) and tentoxin (TEN), were treated differently again. Estimated dietary exposures were below the applicable toxicological screening level, leading EFSA to consider adverse effects unlikely at current exposure estimates. Infants, toddlers and other young children generally had higher exposure relative to body weight than older population groups, a pattern that affects the way results are interpreted across age categories. The assessment also considered animal feed, where data gaps limited conclusions for most species and some potential concerns could not be excluded.
Grain, fruit concentrates, paprika, tomatoes and edible oils pass through multiple suppliers and processing stages, making raw material acceptance and sampling plans central to the practical response. A producer using grain, fruit concentrates, paprika or tomato ingredients cannot infer the condition of an individual consignment from European average exposure estimates. Product-specific decisions still depend on applicable legal requirements, sampling plans, analytical methods and the characteristics of the raw material. Managing moisture, storage conditions and damaged inputs remains relevant to mould controls, although control measures for fungal growth cannot be assumed to remove toxins already present.
EFSA recommends collecting more occurrence data and undertaking further research to reduce the uncertainties in its opinion. It also explored a non-animal approach to estimating exposure levels for TeA, but did not use those results in the final risk characterisation because of unresolved uncertainties. The updated assessment is scientific evidence for risk management; it is not, on its own, a new maximum limit for each toxin or an instruction that every food manufacturer must begin a specified test. Any subsequent regulatory action would require its own process and technical detail.
