Ethylene oxide has not been approved for use on food in the European Union since 1991. It is classified as a mutagen and a carcinogen, there is no permitted level, and any finding means the product comes off the market. Given all that, a reasonable person would expect it to be a settled issue. It is not. Since 2020 it has produced one of the longest-running sequences of alerts and recalls in the European food trade, and spices sit near the centre of it.
Why a substance banned for decades keeps appearing
Two things explain the persistence.
The first is that the ban is European, not global. Ethylene oxide remains a legal and widely used decontamination method in a number of producing countries, where it is an effective way of reducing microbial load in a product that is hard to treat otherwise. Material treated entirely lawfully at origin becomes non-compliant the moment it is placed on the EU market.
The second is that the exposure usually arrives indirectly. The recalls that have caused the most disruption did not involve manufacturers who treated their own products. They involved manufacturers who bought an ingredient — sesame, a spice, a gum, an additive — that carried a residue. Since 2020 the EU alert system has carried a long series of notifications across sesame, spices, herbs and nuts, and the pattern is consistent: the company recalling the product is rarely the company that applied the treatment.
The residue definition is the part that surprises people
This is the technical detail that turns a historical issue into a current one, and it is worth understanding properly.
Ethylene oxide itself dissipates. If the measurement were of ethylene oxide alone, treated material would often test clean after a period. But the EU residue definition covers the sum of ethylene oxide and 2-chloroethanol, expressed as ethylene oxide — and 2-chloroethanol arises from the treatment and persists.
The practical consequences follow directly. Material treated months earlier can still test positive. An ingredient treated several steps upstream carries the marker into every product it enters. And a negative result for ethylene oxide alone is not evidence of compliance, because it is not what is being measured. A buyer reviewing a certificate should check that the analysis covers both substances against the combined definition rather than assuming it does.
The risk concentrates in the ingredients nobody examines
In a spice blend or a seasoning, scrutiny naturally follows volume. The main components get specified, sampled and audited. A minor spice at low inclusion, a carrier, an anti-caking agent or a colour gets bought on a supplier's word.
The residue definition does not care about inclusion rate. It applies to the product placed on the market. An input contributing a small fraction of the weight can carry enough residue to put the finished batch over, and it will be the input nobody thought to question.
The only workable response is unglamorous: every input, including the small ones, carries the same question and the same documentation requirement. A blend is only as compliant as its least examined component.
Steam treatment, with its trade-offs stated
The established residue-free alternative is steam treatment. It reduces microbial load using heat and moisture rather than a chemical agent, leaves no residue, and is compatible with organic supply chains.
It is not without cost. Heat and moisture can affect the volatile aromatic fraction and, in some products, colour — which for a spice bought precisely for its aroma is not a trivial side effect. The processing has to be controlled to manage that, and a heavily treated spice can be noticeably flatter than an untreated one.
That trade-off is exactly why the treatment method belongs in the specification rather than being delegated. A brief that states a microbiological target without stating how it may be achieved has left the most consequential decision to whoever is filling the order.
The three lines that prevent the problem
Ask, before ordering, whether the product or any of its components has been treated with ethylene oxide at any point. Write the answer into the specification as a prohibition rather than a preference. Require analysis against the combined residue definition, with the method named.
TeraVella works in spices as a sourcing partner rather than a processor — we do not claim to own a mill. What we do is put the treatment question at the front of the brief, fix the answer in the written specification, and define batch analysis parameters with the destination requirements in mind. We hold ISO 9001, ISO 22000 and ISO 27001 and make no organic or other certification claim; where certified product is required, those documents come from the source. This is a category where a supplier who answers the question precisely, including about what they do not know, is worth more than one who answers it reassuringly. Volumes and prices are confirmed at quotation.
