E-numbers / Preservatives / E243
also: LAE · Lauric arginate · Ethyl-N-lauroyl-L-arginate hydrochloride · Ethyl lauroyl arginate HCl
A preservative derived from lauric acid and the amino acid arginine, used to stop bacterial growth on the surface of processed meats.
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Animal studies at high doses found significant reductions in white blood cell and lymphocyte counts.
Why it’s worth knowing. Animal studies at high doses found significant reductions in white blood cell and lymphocyte counts. Regulators could not explain the biological mechanism and the concern remains unresolved. Children eating processed meat regularly may reach the acceptable daily intake at the 95th percentile of intake.
Ethyl lauroyl arginate is a synthetic antimicrobial preservative made by combining lauric acid (a fatty acid found in coconut oil) with the amino acid L-arginine and ethanol. It is a cationic surfactant, meaning it carries a positive electric charge, which lets it disrupt the outer membrane of bacterial cells.
It kills or suppresses the growth of a broad range of bacteria, yeasts and moulds by inserting itself into their cell membranes and disrupting the membrane structure, causing the cells to lose their contents and die. It is primarily effective as a surface antimicrobial, added to food coatings or applied as a spray or dip.
Used almost exclusively in processed and heat-treated meat products: cooked ham, cooked poultry slices, luncheon meat, frankfurters and similar cooked sausages. It may also appear in some chewing gum formulations. On an ingredient list it appears as 'ethyl lauroyl arginate', 'LAE' or 'E243'.
In rat feeding studies, doses above 400 mg/kg body weight per day produced statistically significant, dose-dependent falls in white blood cell and lymphocyte counts. The EFSA panel reviewed the raw data and confirmed the effect was real, but could not identify the biological mechanism or determine whether it has any relevance to humans at food-use levels. Because the mechanism remained unexplained, the panel treated it as an unresolved safety signal rather than dismissing it.
Dose-dependent decreases in white blood cell and lymphocyte counts were observed in rats at doses above 400 mg/kg bw/day; the toxicological relevance of these haematological findings could not be determined by the panel.
In a multi-generation rat study, female offspring exposed to the highest test dose (around 500 mg/kg body weight per day) showed vaginal opening approximately four days later than controls. EFSA considered this a toxicologically relevant endpoint, though it occurs at doses far above any realistic food exposure. The applicant argued it was transient; the panel disagreed with that characterisation.
Delayed vaginal opening in female rat offspring was observed at the highest dose tested and was considered a toxicologically relevant finding by EFSA.
The original EFSA review in 2007 set an acceptable daily intake of 0.5 mg/kg body weight per day. A 2019 review was triggered by a request to extend permitted uses and raise the ADI to 5 mg/kg, a tenfold increase. EFSA refused: it found that even at the existing, lower maximum levels, toddlers and children eating processed meat regularly could already reach the current ADI at the 95th percentile of intake. The proposed extensions would have pushed mean intakes above the ADI for all age groups.
EFSA maintained the ADI at 0.5 mg/kg bw/day and refused the proposed tenfold increase, noting that toddlers and children could reach this limit at the 95th percentile under existing permitted levels.
Laboratory studies confirm that ethyl lauroyl arginate disrupts bacterial cell membranes across a broad range of pathogens including Listeria monocytogenes, Salmonella, E. coli and Staphylococcus aureus. The effect is primarily surface-level: it works when food is coated or sprayed rather than throughout the bulk of the product.
Ethyl lauroyl arginate showed broad-spectrum antimicrobial activity against both gram-positive and gram-negative bacteria in laboratory tests, acting by disrupting cell membrane integrity.
Children who eat processed meat products frequently are the population most likely to approach the ADI boundary. Parents monitoring processed meat intake in young children should check ingredient labels for 'ethyl lauroyl arginate', 'LAE' or 'E243'. Anyone avoiding additives derived from animal-origin processing aids should also check, as the manufacturing process involves amino acid sourcing.
The science on E243 sits in an unusual position: a regulator has confirmed real effects in animal blood studies but cannot explain why they occur, leaving the concern technically open. EFSA did not say the additive is harmful at current food-use levels, but it also did not close the question, and it blocked a proposed expansion on the back of these unresolved signals. The doses at which haematological effects appeared in rats are substantially above what you would expect from food, but the exposure modelling showed children eating processed meat at the high end of typical intake can approach the regulatory limit under current rules. The 2019 refusal to expand uses is the clearest signal that regulators are not fully comfortable with the evidence base.
No. E243 is a permitted food additive in the UK under assimilated EU legislation. It is authorised specifically in heat-treated meat products at a maximum level of 200 mg/kg. A 2019 EFSA review refused to extend its uses or raise its acceptable daily intake, but the existing authorisation was maintained.
EFSA rejected the application because it found unresolved questions in the safety evidence. Animal studies had shown dose-dependent falls in white blood cell counts and a reproductive signal in female offspring. The applicant could not explain the mechanism behind the blood effects to the panel's satisfaction. EFSA also calculated that toddlers and children would reach the existing daily intake limit at high but realistic levels of processed meat consumption, leaving no safety margin to support expansion.
E243 is permitted only in heat-treated meat products: cooked ham, cooked poultry slices, luncheon meat, frankfurters and similar cooked sausages. It may appear on the label as 'ethyl lauroyl arginate', 'LAE' or 'E243'.
E243 is synthesised from lauric acid (a plant-derived fatty acid, commonly from coconut) and L-arginine (an amino acid that can be fermented from plant sources or derived from animal sources depending on the manufacturer). The finished preservative is used almost exclusively in meat products, so in practice it will not appear in vegan food. Anyone following a strict vegan diet should contact the manufacturer to confirm the sourcing of the arginine used in production.
Last reviewed: 20 June 2026
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