Hexamethylene tetramine and sodium nitrite

In the current application an authorisation is sought under Article 4(1) for hexamethylene tetramine and sodium nitrite under the category 1 “technological additives”, functional group (k) ”silage additive”, according to the classification system of Annex I of Regulation (EC) No 1831/2003. Specifically, the authorisation is sought for the use of the feed additive for all animal species.
According to the Applicant, the feed additive consists of a combination of the active agents hexamethylene tetramine (HMTA) and sodium nitrite with a minimum purity of 99.0 % (w/w) and 98.5 (w/w) respectively. The product is marketed as liquid premixture containing 164 g/kg and 245 g/kg of HMTA and sodium nitrite respectively. According to the Applicant, the feed additive is intended to be used in silage with a maximum level of 600 mg/kg and 900 mg/kg of HMTA and sodium nitrite respectively.
For the determination of sodium nitrite in the feed additive the Applicant submitted a single-laboratory validated and further verified spectrophotometric method based on the principle described in the EN 26777 standard. Based on the available and satisfactory performance characteristics, the EURL recommends for official control the single-laboratory validated and further verified spectrophotometric method.
For the determination of HMTA in the feed additive the Applicant submitted a single-laboratory validated and further verified method based on high pressure liquid chromatography with refractive index detector (HPLC-RI). Based on the available and satisfactory performance characteristics, the EURL recommends for official control the above mentioned single-laboratory validated and further verified method based on high pressure liquid chromatography with refractive index detector (HPLC-RI) for the quantification of HMTA in the feed additive.
According to the Applicant, the feed additive is not stable during the fermentation process of ensilaging. As a consequence, the accurate quantification of HMTA and sodium nitrite in silage is not achievable experimentally. Therefore, the EURL cannot evaluate nor recommend any method for official control for the determination of HMTA and sodium nitrite in silage.
Further testing or validation of the methods to be performed through the consortium of National Reference Laboratories as specified by Article 10 (Commission Regulation (EC) No 378/2005, as last amended by Regulation (EU) 2015/1761) is not considered necessary.