3-nitrooxypropanol - 4c1

In the current application authorisation is sought under Article 4(1) for 3-nitrooxypropanol (preparation of minimum of 10 % of 3-nitrooxypropanol) under the category / functional group 4(c) ‘zootechnical additives’ /’substances which favourably affect the environment’, according to Annex I of Regulation (EC) No 1831/2003. Specifically, the authorisation is sought for the use of the feed additive for dairy cows and cows for reproduction, dairy sheep and ewes for reproduction, dairy goats and goats for reproduction, other ruminants for milk production and reproduction. 

The feed additive is a white powder preparation containing a minimum of 10 % (w/w) of 3-nitrooxypropanol as an active substance. The feed additive also contains propylene glycol and silicon dioxide as carriers. 

The feed additive is intended to be incorporated into premixtures and feedingstuffs. The Applicant proposed levels of 3-nitrooxypropanol ranging from 53 to 88 mg/kg complete feedingstuffs. 

For the quantification of the 3-nitrooxypropanol content in the feed additive, premixtures and feedingstuffs the Applicant proposed a single-laboratory validated and further verified method based on reversed phase high performance liquid chromatography (HPLC) coupled to spectrophotometric (UV) detection. 

The following performance characteristics were reported by the Applicant in the frame of the validation and verification studies for the quantification of 3-nitrooxypropanol content:

• in the feed additive: a relative standard deviation for repeatability (RSD_r) ranging from 0.2 to 1.0 %; a relative standard deviation for intermediate precision (RSD_ip) ranging from 0.3 to 1.0 %; and a recovery rate (Rrec) ranging from 100 to 101 %. 
• in premixtures (2870 to 17390 mg/kg): a RSD_r ranging from 0.4 to 1.1 %; a RSDip ranging from 0.8 to 1.5 %; and a R_rec ranging from 100 to 101 %. 
• in feedingstuffs (29 to 132 mg/kg): a RSD_r ranging from 0.6 to 5.2 %; a RSD_ip ranging from 1.0 to 5.2 %; a R_rec ranging from 98 to 101 %; and a limit of quantification (LOQ) ranging from 8 to 14 mg of 3-nitrooxypropanol /kg feedingstuffs.

Based on the experimental evidence available the EURL recommends for the official control the above mentioned single-laboratory validated and further verified reversed phase HPLC-UV method for the quantification of 3-nitrooxypropanol in the feed additive, premixtures and feedingstuffs.

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.

Recommended Method

as of:

Commission Implementing Regulation (EU) 2022/565 

For the quantification of 3-nitrooxypropanol in the feed additive, premixtures and compound feed:

— reversed phase high performance liquid chromatography with spectrophotometric detection (HPLC-UV)