COMMISSION IMPLEMENTING REGUL ATION (EU) 2020/1397 
of 5 Oct ober 2020 
concer ning the renewal of the author isation of L-isoleucine produced by Escherichia coli FERM 
ABP-10641 as a nutr itional additiv e, its extension of use and the author isation of L-isoleucine 
produced by Cor ynebacter ium glutamicum KCCM 80189 as a feed additiv e for all animal species, and 
repealing Regulation (EU) No 348/2010 
(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 and renewing such author isation. 
(2) L-isoleucine produced by Escher ichia coli FERM ABP -10641 was author ised for 10 years as a feed additive for all 
animal species by Commission Regulation (EU) No 348/2010 (2). 
(3) In accordance with Article 14 of Regulation (EC) No 1831/2003, an application was submitte d for the renewal of 
the author isation of L-isoleucine produced by Escher ichia coli FERM ABP -10641 as a feed additive for all animal 
species, requesting this additive to be classifie d in the additive categor y ‘nutr itional additives ’, functional group 
‘amino acids, their salts and analogues ’. This application was accompan ied by the particulars and documents 
required under Article 14(2) of Regulation (EC) No 1831/2003. Moreover , the application requeste d, in accordance 
with Article 7 of Regulation (EC) No 1831/2003, L-iso leucine produced by Escheri chia coli FERM ABP -10641 to be 
author ised for use in water for drinking in the additive cate gory ‘nutr itional additives ’, functional group ‘amino acids, 
their salts and analogues ’ for all animal species, and for use in feed to be classified in the additive cate gory ‘sensor y 
additives ’, functional group ‘flavouri ng compo unds ’. The application was accompan ied by the particulars and 
documents required under Article 7(3) of Regulation (EC) No 1831/2003. 
(4) In accordance with Article 7 of Regulation (EC) No 1831/2003, an application was submitted for the author isation 
of L-isoleucine produced by Corynebacter ium glutamicum KCCM 80 189 as a feed additive for use in feed and in wate r 
for drinking for all animal species. The application concer ns the author isation of L-isoleucine produced by 
Corynebacter ium glutamicum KCCM 80 189 as a feed additive for all animal species to be classified in the additive 
catego ry ‘nutr itional additives ’, functional group ‘amino acids, their salts and analogues’. That application was 
accompan ied by the particulars and documents required under Article 7(3) of Regulation (EC) No 1831/2003. 
(5) The European Food Safety Author ity (‘the Auth ority’) concluded in its opinions of 28 Januar y 2020 (3)(4) that, under 
the proposed conditions of use, L-isoleucine produced by Escher ichia coli FERM ABP -10641 or Corynebacter ium 
glutamicum KCCM 80 189 does not have an adverse effect on animal health, consumer health or the environment. It 
also state d that L-isoleucine produced by Escher ichia coli FERM ABP -10641 was hazardous by inhalation for persons 
handling the additive. Theref ore, the Commission considers that appropr iate protective measures should be taken to 
prevent adverse effects on human health, in particular as regar ds the users of this additive. No adverse effects on user 
safety were stated for L-isoleucine produced by Corynebacter ium glutamicum KCCM 80 189. The Authority also 
concluded that the additive is an efficacious source of the essential amino acid isoleucine for non-r uminant animals 
and that for the supplemental L-isoleucine to be fully efficacious in ruminants, it should be protect ed against 
degradation in the rumen. The Auth ority expressed concer ns on the simultaneous oral administration of the amino 
acid via water for drinking and feed. However , the Auth ority did not propose a maximum content for L-isoleucine. 
Thus, in the case of supplementation with L-iso leucine via water for drinking, it is appropr iate to alert the user to 
take into account the dietar y supply with all the essential and conditionally essential amino acids. 
(1)OJ L 268, 18.10.2003, p. 29. 
(2)Commission Regulation (EU) No 348/2010 of 23 Apr il 2010 concer ning the author isation of L-isoleucine as a feed additive for all 
animal species (OJ L 104, 24.4.2010, p. 29). 
(3)EFSA Jour nal 2020;18(2):6022. 
(4)EFSA Jour nal 2020;18(2):6021. EN Offi cial Jour nal of the European Union 6.10.2020                                                                                                                                         L 324/19   (6) Restr ictions and conditions should be provided for to allow for a better control for L-isoleucine when used as 
flavouring. For L-isoleucine used as flavouri ng, the recommended content should be indicated on the label. Where 
such content is exceed ed, certain information should be indicated on the label of the additive and premixtures. As 
regards the use of L-isoleucine as a flavouri ng, the Author ity states that no further demonstration of efficacy is 
necessar y when the substance is used at the recommended dose level. The use of L-iso leucine as a flavouring 
compo und is not author ised in water for drinking. The fact that the use of the L-isoleucine is not author ised for use 
as a flavouring in wate r for drinking, does not preclude its use in compo und feed, which is administered via water . 
(7) The Author ity does not consider that there is a need for specif ic requirements of post-market monit oring. It also 
verified the repor ts on the method of analysis of the feed additive in feed submitted by the Reference Laboratory set 
up by Regulation (EC) No 1831/2003. 
(8) The assessment of L-isoleucine produced by Escher ichia coli FERM ABP -10641 and by Corynebacter ium glutamicum 
KCCM 80 189 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. 
(9) As a consequence of the renewal of the author isation of L-isoleucine produced by Escher ichia coli FERM ABP -10641 
as a feed additive under the conditions laid down in the Annex to this Regulation, Regulation (EU) No 348/2010 
should be repealed. 
(10) Since safet y reasons do not require the immediate application of the modifications to the conditions of author isation 
for L-isoleucine produced by Escher ichia coli FERM ABP -10641, it is appropr iate to provid e a transitional period for 
inter ested parties to prepare themselves to meet the new requirements resulting from the renewal of the 
author isation. 
(11) 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, 
HAS ADOPTED THIS REGUL ATION: 
Article 1 
1. The author isation of L-isoleucine produced by Escher ichia coli FERM ABP -10641, belonging to the additive cate gory 
‘nutr itional additives ’ and to the functional group ‘amino acids, their salts and analogues’, is renewed, extended to its use 
via wate r for drinking, subject to the conditions laid down in the Annex. 
L-isoleucine produced by Escher ichia coli FERM ABP -10641 belonging to the additive categor y ‘sensor y additives’ and to the 
functional group ‘flavouring compo unds ’, is author ised as an additive in animal nutr ition, subject to the conditions laid 
down in the Annex. 
2. L-isoleucine produced by Corynebacter ium glutamicum KCCM 80 189, 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 the Annex. 
Article 2 
1. L-isoleucine produced by Escher ichia coli FERM ABP -10641 and premixtures containing it, which are produced and 
labelled before 26 Apr il 2021 in accordance with the rules applicable before 26 October 2020 may continue to be placed 
on the mark et and used until the existing stoc ks are exhaust ed. 
2. Feed mater ials and compound feed containing L-isoleucine produced by Escher ichia coli FERM ABP -10641 and 
premixtures containing it, which are produced and labelled before 26 October 2021 in accordance with the rules 
applicable before 26 October 2020 may continue to be placed on the mark et and used until the existing stoc ks are 
exhaust ed if they are intende d for food-producing animals. 
3. Feed mater ials and compound feed containing L-isoleucine produced by Escher ichia coli FERM ABP -10641 and 
premixtures containing it, which are produced and labelled before 26 October 2022 in accordance with the rules 
applicable before 26 October 2020 may continue to be placed on the mark et and used until the existing stoc ks are 
exhaust ed if they are intende d for non-f ood-producing animals. EN Offi cial Jour nal of the European Union L 324/20                                                                                                                                         6.10.2020   Article 3 
Regulation (EU) No 348/2010 is repealed. 
Article 4 
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, 5 October 2020.  
For the Commission 
The President 
Ursula VON DER LEYEN     EN Offi cial Jour nal of the European Union 6.10.2020                                                                                                                                         L 324/21   ANNEX 
Identifica-
tion number 
of the 
additive Name of the 
holder of 
author isa-
tion Additive Composition, chem ical formula, descr iption, 
analytical method. Species or 
categ ory of 
animal Maximum 
age Minimum 
content Maximum 
conten t 
Other provisions End of period 
of 
author isation mg/kg of complet e feed 
with a moisture content 
of 12 % 
Categor y: nutr itional additiv es. Functional group: amino acids, their salts and analogues. 
3c381 - L-isoleu­
cine Additive composition 
Powder with a minimum content of L-isoleucine 
of 93,4 % (on a dry matte r basis) All animal 
species - - - 1. L-isoleucine may be placed on the 
mark et and used as an additive 
consisting of a preparation. 
2. In the directions for use of the 
additive and premixture, the sto­
rage conditions, the stability to 
heat treatment and in water shall 
be indicated. 
3. The additive may be used via 
water for drinking. 
4. Declaration to be made on the 
label of the additive and premix­
ture: 
— ‘The supplementation with L- 
isoleucine, in particular via 
water for drinking, shall take 
into account all essential and 
conditionally essential amino 
acids in order to avoid imbal­
ances.’ 
— L-isoleucine conte nt. 
5.The endoto xin cont ent of the ad­
ditive and its dusting potential 
shall ensure a maximal endoto xin 
exposure of 1 600 IU endoto x­
ins/m3 air  (3). 26 October 
2030 
Char acter isation of the activ e substance 
L-isoleucine produced by fermentation with 
Escher ichia coli FERM ABP -10641 
IUPAC name: (2S,3S)-2-amino-3-meth ylpenta­
noic acid 
Chemical formula: C6H13NO2 
CAS number : 73-32-5 
Analytical method (1) 
For the identif ication of L-isoleucine in the feed 
additive: 
—Food Chemical Codex ‘L-isoleucine mono­
graph’ 
For the quantifi cation of isoleucine in the feed 
additive: 
— ion exchange chromat ography coupled with 
post-column derivatisation and optical 
detection (IEC- VIS/FLD) or 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) 
For the quantifi cation of isoleucine in premix­
tures: 
— ion-ex change chromat ography coupled with 
post-column derivatisation and optical 
detection (IEC- VIS/FLD) or 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) – Regulation 
(EC) No 152/2009 (2) (Annex III, F) EN Offi cial Jour nal of the European Union L 324/22                                                                                                                                         6.10.2020   6.For users of the additive and pre­
mixture, feed business operators 
shall establish operational proce­
dures and organisational mea­
sures to address poten tial risks 
by inhalation. Where those risks 
cannot be eliminated or reduced 
to a minimum by such proce­
dures and measures, the additive 
and premixture shall be used with 
personal protective equipment. For the quantific ation of isoleucine in com­
pound feed and feed mater ials: 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) – Regulation 
(EC) No 152/2009 (Annex III, F) 
For the quantifi cation of isoleucine in water: 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) 
3c383 - L-isoleu­
cine Additive composition 
Powder with a minimum content of L-isoleucine 
of 90 % All animal 
species - - - 1. L-isoleucine may be placed on the 
mark et and used as an additive 
consisting of a preparation. 
2. In the directions for use of the 
additive and premixture, the sto­
rage conditions, the stability to 
heat treatment and in water shall 
be indicated. 
3. The additive may be used via 
water for drinking. 
4. Declaration to be made on the 
label of the additive and premix­
ture: 
— ‘The supplementation with L- 
isoleucine, in particular via 
water for drinking, shall take 
into account all essential and 
conditionally essential amino 
acids in order to avoid imbal­
ances.’ 
— L-isoleucine conte nt. 26 October 
2030 
Char acter isation of the activ e substance 
L-isoleucine produced by fermentation with Cor­
ynebacter ium glutamicum KCCM 80189 
IUPAC name: (2S,3S)-2-amino-3-meth ylpenta­
noic acid 
Chemical formula: C6H13NO2 
CAS number : 73-32-5 
Analytical method (1) 
For the identif ication of L-isoleucine in the feed 
additive: 
—Food Chemical Codex ‘L-isoleucine mono­
graph’ 
For the quantifi cation of isoleucine in the feed 
additive: 
— ion exchange chromat ography coupled with 
post-column derivatisation and optical 
detection (IEC- VIS/FLD) or 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) 
For the quantifi cation of isoleucine in premix­
tures: 
— ion-ex change chromat ography coupled with 
post-column derivatisation and optical 
detection (IEC- VIS/FLD) or EN Offi cial Jour nal of the European Union 6.10.2020                                                                                                                                         L 324/23   — ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) – Regulation 
(EC) No 152/2009 (Annex III, F) 
For the quantific ation of isoleucine in com­
pound feed and feed mater ials: 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) – Regulation 
(EC) No 152/2009 (Annex III, F) 
For the quantifi cation of isoleucine in water: 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) 
Categor y: Sensor y additiv es. Functional group: Flavour ing compounds 
3c381 - L-isoleu­
cine Additive composition 
Powder with a minimum content of L-isoleucine 
of 93,4 % (on a dry matte r basis) All animal 
species  - - 1. L-isoleucine may be placed on the 
mark et and used as an additive 
consisting of a preparation. 
2.The additive shall be incor po­
rated into the feed in the form 
of a premixture. 
3. In the directions for use of the 
additive and premixture, the sto­
rage conditions and the stability 
to heat treatment shall be indi­
cated . 
4. On the label of the additive the 
follo wing shall be indicated: ‘Re­
commended maximum content 
of the active substance of com­
plete feedingstuff with a moisture 
conte nt of 12 %: 25 mg/kg.’ 
5.The functional group, the identi­
fication number , the name and 
the added amount of the active 
substance shall be indicated on 
the label of the premixtures, if 
the followi ng conte nt of the ac­
tive substance in complet e fee­
dingstuff with a moisture content 
of 12 % is excee ded: 25 mg/kg. 26 October 
2030 
Char acter isation of the activ e substance 
L-isoleucine) produced by fermentation with 
Escher ichia coli FERM ABP -10641 
IUPAC name: (2S,3S)-2-amino-3-meth ylpenta­
noic acid 
Chemical formula: C6H13NO2 
CAS number : 73-32-5 
Analytical method (1) 
For the identif ication of L-isoleucine in the feed 
additive: 
—Food Chemical Codex ‘L-isoleucine mono­
graph’ 
For the quantifi cation of isoleucine in the feed 
additive: 
— ion exchange chromat ography coupled with 
post-column derivatisation and optical 
detection (IEC- VIS/FLD) or 
— ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) 
For the quantifi cation of isoleucine in premix­
tures: 
— ion-ex change chromat ography coupled with 
post-column derivatisation and optical 
detection (IEC- VIS/FLD) or EN Offi cial Jour nal of the European Union L 324/24                                                                                                                                         6.10.2020   6.The endoto xin cont ent of the ad­
ditive and its dusting potential 
shall ensure a maximal endoto xin 
exposure of 1 600 IU endoto x­
ins/m3 air (3). 
7.For users of the additive and pre­
mixture, feed business operators 
shall establish operational proce­
dures and organisational mea­
sures to address potential by in­
halation. Where those risks 
cannot be eliminated or reduced 
to a minimum by such proce­
dures and measures, the additive 
and premixture shall be used with 
personal protective equipment. — ion exchange chromat ography coupled with 
post-column derivatisation and photo­
metr ic detec tion (IEC- VIS) – Regulation 
(EC) No 152/2009 (Annex III, F)) 
(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) Commission Regulation (EC) No 152/2009 of 27 Januar y 2009 laying down the methods of sampling and analysis for the official control of feed (OJ L 54, 26.2.2009, p. 1). 
(3) Exposure calculated based on the endoto xin level and the dusting potential of the additive according to the method used by EFSA (EFSA Jour nal 2020;18(2):6022); analytical method: European Phar macopoeia 
2.6.14. (bacterial endoto xins).   EN Offi cial Jour nal of the European Union 6.10.2020                                                                                                                                         L 324/25