COMMISSION IMPLEMENTING REGUL ATION (EU) 2020/1091 
of 24 July 2020 
concer ning the author isation of L-threonine as a feed additiv e for all animal species 
(Text with EEA relevance) 
THE EUR OPEAN COMMISSION, 
Havi ng regar d to the Treaty on the Functioning of the European Union, 
Havi ng rega rd to Regulation (EC) No 1831/2003 of the European Parliament and of the Council of 22 Sept ember 2003 on 
additives for use in animal nutr ition (1), and in particular Article 9(2) thereof, 
Whereas: 
(1) Regulation (EC) No 1831/2003 provid es for the author isation of additives for use in animal nutr ition and for the 
grounds and procedures for granting such author isation. 
(2) In accordance with Article 7 of Regulation (EC) No 1831/2003, an application was submitted for the author isation 
of L-threonin e produced by Escher ichia coli CGMCC 11473 as a feed additive for use in feed for all animal species. 
The application was accompan ied by the particulars and documents required under Article 7(3) of that Regulation. 
(3) This application concer ns the author isation of L-threonine produced by Escher ichia coli CGMCC 11473 as a feed 
additive for all animal species to be classifie d in the additive categor y ‘nutr itional additives’. 
(4) The European Food Safety Author ity (‘the Authority’) concluded in its opinion of 5 July 2017 (2) combined with the 
opinion of 4 October 2019 (3) that, under the proposed conditions of use, L-threonine produced by Escher ichia coli 
CGMCC 11473 does not have an adverse effect on animal health, consumer health or the environment. It also 
could not conclude on the potential of L-thr eonine produced by Escher ichia coli CGMCC 11473 to be a skin 
sensitiser and irritant to the skin and eyes, and stated an inhalation risk to endoto xins for the users of the additive. 
Theref ore, appropr iate prote ctive measures should be taken to prevent adverse effects on human health, in 
particular as regards the users of the additive. The Authority also concluded that the additive is an efficacious source 
of the amino acid L-threonin e for all animal species and that in order to be as efficacious in ruminants as in non- 
ruminant species, the additive should be protect ed again st degradation in the rumen. The Authority does not 
consider that there is a need for specifi c requirements of post-market monitori ng. It also verified the repor t on the 
method of analysis of the feed additive in feed submitte d by the Reference Laboratory set up by Regulation 
(EC) No 1831/2003. 
(5) The assessment of L-thr eonine produced by Escher ichia coli CGMCC 11473 shows that the conditions for 
author isation, as provided for in Article 5 of Regulation (EC) No 1831/2003, are satisfied. According ly, the use of 
this additive should be author ised as specifi ed in the Annex to this Regulation. 
(6) The measures provid ed for in this Regulation are in accordance with the opinion of the Standing Committ ee on 
Plants, Animals, Food and Feed, 
(1)OJ L 268, 18.10.2003, p. 29. 
(2)EFSA Journal 2017;15(7):4939. 
(3)EFSA Journal 2019;17(11):5885. EN Offi cial Jour nal of the European Union L 241/6                                                                                                                                           27.7.2020   HAS ADOPTED THIS REGUL ATION: 
Article 1 
The substance specifi ed in the Annex, belonging to the additive categor y ‘nutr itional additives ’ and to the functional group 
‘amino acids, their salts and analogues’, is author ised as an additive in animal nutr ition, subject to the conditions laid down 
in that Annex. 
Article 2 
This Regulation shall enter into force on the twentieth day followi ng that of its publication in the Official Journal of the 
European Union. 
This Regulation shall be binding in its entirety and directly applicable in all Member States. 
Done at Brussels, 24 July 2020.  
For the Commission 
The President 
Ursula VON DER LEYEN     EN Offi cial Jour nal of the European Union 27.7.2020                                                                                                                                           L 241/7   ANNEX 
Identif ica-
tion 
number of 
the 
additiv e Name of 
the 
holder of 
author i-
sation Additiv e Composition, chemical formula, 
descr iption, analytical method. Species or 
categor y of 
animal Maximum 
age Minimum 
content Maximum 
content 
Other provisions End of period of 
author isation mg/kg of complete feed 
with a moistu re content 
of 12 % 
Categor y of nutr itional additiv es. Functional group: amino acids, their salts and analogues 
3c411 - L-threonine Additiv e composition: 
Powder with a minimum of 98 % L- 
threonine and a maximum moisture 
cont ent of 1 % All species - - - 1. L- threonine may be placed on the 
mark et and used as an additive con­
sisting of a preparation. 
2. L-threonin e may be used via wate r 
for drinking. 
3.For users of the additive and pre­
mixtures, feed business operators 
shall establish operational proce­
dures and organisational measures 
to address poten tial risks by inhala­
tion, dermal contact or eyes con­
tact. Where those risks cannot be 
eliminated or reduced to a mini­
mum by such procedures and mea­
sures, the additive and premixtures 
shall be used with personal protec­
tive equipment, including breathing 
prote ction, safety glasses and 
gloves. 
4.The endoto xin cont ent of the addi­
tive and its dusting potential shall 
ensure a maximal endoto xin expo­
sure of 1600 IU endoto xins/m3 
air (2). 16.8.2030 
Character isation of the activ e sub­
stance: 
L-threonine produced by fermentation 
with Escher ichia coli CGMCC 11473 
Chemical formula: C4H9NO 3 
CAS Number: 72-19-5. 
Analytical methods (1): 
For the determi nation of L-threonine in 
the feed additive: 
— Food Chemical Codex ‘L-threonine 
monograph’ and 
— Ion exchange chromat ography 
coupled with post-column derivati­
sation and optical detection (IEC- 
VIS/FLD) – EN ISO 17180. 
For the determination of threonine in 
premixtures: 
— ion exchang e chromat ography 
coupled with post-column derivati­
sation and optical detection (IEC- 
VIS/FLD) – EN ISO 17180 and 
— ion exchang e chromat ography 
coupled with post-column derivati­
sation and photome tric detection 
(IEC- VIS), Commission Regulation 
(EC) No 152/2009 (Annex III, F). EN Offi cial Jour nal of the European Union L 241/8                                                                                                                                           27.7.2020   5. The labelling of the additive and 
premixtures shall indicate the fol­
lowing: 
‘The supplementation with L-threo­
nine, in particular via water for 
drinking, should take into account 
all essential and conditional essen­
tial amino acids in order to avoid 
imbalances.’ For the determination of threonine in 
compo und feed and feed mat erials: 
— Ion exchange chromat ography 
coupled with post-column derivati­
sation and photome tric detection 
(IEC- VIS): Commission Regulation 
(EC) No 152/2009 (Annex III, F). 
For the determination of threonine in 
water: 
— ion exchang e chromat ography 
coupled with post-column derivati­
sation and optical detection (IEC- 
VIS/FLD). 
(1) Details of the analytical methods are avail able at the follo wing address of the Reference Laboratory : https://ec.europa.eu/jrc/en/eurl/feed-additives/evaluation-repor ts 
(2) Exposure calculated based on the endoto xin level and the dusting potential of the additive according to the method used by EFSA (EFSA Journal 2017;15(7):4939); analytical method: European Phar macopoeia 
2.6.14. (bacterial endoto xins).   EN Offi cial Jour nal of the European Union 27.7.2020                                                                                                                                           L 241/9