On 7 August 2026, the European Food Safety Authority (EFSA) published a scientific opinion concluding that sodium nitrite, used as a silage additive for pigs, bovines, poultry, sheep, goats, rabbits and horses, is safe for the target species, consumers and the environment. The opinion, adopted on 30 June 2026 by the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), found that residual nitrite concentrations in silage treated with up to 900 mg sodium nitrite per kg of fresh material fall within the range naturally present in untreated silage, so animal exposure would not substantially change. However, the Panel could not conclude on the additive's efficacy when used alone, due to a lack of data, and noted that sodium nitrite should be considered an eye irritant for users.
The assessment responds to a request from the European Commission under Regulation (EC) No 1831/2003, which governs the authorisation of feed additives. The application, submitted by ADDCON Europe GmbH, sought the re-evaluation of sodium nitrite as an existing authorised additive. The dossier was received by EFSA on 11 January 2012 and deemed valid on 4 December 2020, marking a lengthy review process. The additive is intended for use only in premixtures, up to a maximum concentration of 245 g sodium nitrite per kg of premixture, and silage should not be fed to animals before a four-week fermentation period.
The Panel's safety conclusion rests on a comparison of residual nitrite levels in treated and untreated silage. In studies provided by the applicant, silages inoculated with up to 900 mg sodium nitrite per kg of fresh material showed residual nitrite concentrations of 0.5–10 mg per kg dry matter, while untreated silages from various plant sources contained 1.5–25.3 mg per kg dry matter. Because nitrite is a normal constituent of silage, the Panel concluded that the additive does not significantly increase animal exposure, and therefore poses no risk to consumers or the environment.
Regarding user safety, the Panel noted that sodium nitrite is irritating to the eyes and mucous membranes, based on the safety data sheet, but could not draw conclusions on skin irritation or sensitisation due to the absence of studies. The Panel also could not establish the efficacy of sodium nitrite alone as a silage additive, though it acknowledged that combining it with other substances could improve nutrient preservation and aerobic stability in easy-to-ensile materials.
The opinion will inform the European Commission's decision on whether to renew the authorisation of sodium nitrite as a feed additive. The Commission will weigh the safety findings against the unresolved efficacy questions, potentially affecting the additive's regulatory status and its availability to livestock producers who rely on it for silage preservation. The outcome could also influence the competitive position of ADDCON Europe GmbH and other producers of silage additives, as well as the regulatory burden on farmers and feed manufacturers who may need to adjust their ensiling practices if the additive's authorisation is not renewed or is subject to new conditions.