Safety and efficacy of Kelforce® (l‐glutamic acid, N,N‐diacetic acid, tetrasodium salt (GLDA‐Na4)) as a feed additive for chickens for fattening

Zootechnical additives, substances which favourably affect the environment, otherzootechnical additives, Kelforce®, GLDA-Na4, safety, efficacy
First published in the EFSA Journal
18 May 2018
19 April 2018
Last Updated
10 September 2018. This version replaces the previous one/s.
10 September 2018. This version replaces the previous one/s.
Scientific Opinion


l‐Glutamic acid, N,N‐diacetic acid, tetrasodium salt (GLDA‐Na4) (Kelforce®) is sought to be used as a zootechnical feed additive in chickens for fattening to improve the absorption of zinc from feed, reducing zinc emissions through manure and thus, affecting favourably the environment. The product has not been authorised in the European Union as a feed additive. Kelforce® is intended to be marketed as a liquid and solid formulation, containing ≥ 47% and ≥ 30% of GLDA‐Na4, respectively. Kelforce® is safe for chickens for fattening at the maximum level of 1,000 mg GLDA‐Na4/kg complete feed. Based on the toxicological profile of GLDA‐Na4 and the consumer exposure to GLDA‐Na4 and to nitrilotriacetic acid trisodium salt (NTA‐Na3; an impurity of the additive), the use of Kelforce® at the maximum proposed level in feed of chickens for fattening is of no concern for consumer safety. Due to its low inhalation toxicity, the exposure to GLDA‐Na4is unlikely to pose a risk by inhalation. However, owing to the high‐dusting potential of the solid formulation, a risk from such high level of dust, even if toxicologically inert, cannot be excluded. Kelforce® is not a skin/eye irritant or skin sensitiser. No risks for the terrestrial compartment were identified at the maximum use level of the additive. Risks for the aquatic compartment cannot be excluded based on the secondary effect of the additive on green algae. In the absence of data, the Panel cannot conclude on the safety for the sediment compartment or the possible ground water contamination. The risk of bioaccumulation and secondary poisoning caused by the additive is considered very low. Owing to the inconsistent and conflicting results from the studies assessed, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) cannot conclude on the efficacy of the additive. The Panel made a recommendation regarding the levels of formaldehyde and cyanide in the active substance.

Panel members at the time of adoption

Gabriele Aquilina, Giovanna Azimonti, Vasileios Bampidis, Maria de Lourdes Bastos, Georges Bories, Andrew Chesson, Pier Sandro Cocconcelli, Gerhard Flachowsky, Jürgen Gropp, Boris Kolar, Maryline Kouba, Marta López‐Alonso, Secundino López Puente, Alberto Mantovani, Baltasar Mayo, Fernando Ramos, Guido Rychen, Maria Saarela, Roberto Edoardo Villa, Robert John Wallace and Pieter Wester.
Panel on Additives and Products or Substances used in Animal Feed
feedap [at]
EFSA Journal 2018;16(5):5279
Question Number
On request from
European Commission
Relevant information or parts of this scientific output have been blackened in accordance with the European Commission decision on the confidentiality requests formulated by the applicant and further confidentiality requests formulated by the applicant for which a decision by the European Commission is pending. The blackened text will be subject to review once the full decision on the confidentiality requests is adopted by the European Commission. The full output was shared with the European Commission, EU Member States and the applicant.