Statement on the translocation potential by Pseudomonas chlororaphis MA342 in plants after seed treatment of cereals and peas and assessment of the risk to humans

Pseudomonas chlororaphis MA342, metabolite, DDR, genotoxicity, aneugenicity, seed treatment, cereals, peas, translocation, human risk assessment
First published in the EFSA Journal
24 October 2020
Type
Statement

Abstract

The European Commission requested EFSA to provide scientific advice on the translocation potential by Pseudomonas chlororaphis MA342 in plants after seed treatment of cereals and peas and, if applicable, for a revision of the assessment of the risk to humans by its metabolite 2,3‐deepoxy‐2,3‐didehydro‐rhizoxin (DDR) and this based on the evidence available in the dossier for renewal of the approval. The information from other P. chlororaphis strains than MA342 was taken into account with care, because the studies available in the dossier did not confirm the identity of the strain MA342 as belonging to the species P. chlororaphis. It has been concluded that there is a potential for translocation of P. chlororaphis MA342 to edible plant parts following seed treatment till an estimated concentration up to about 105 cfu/g and some exposure can be assumed by consumption of fresh commodities. Also, production of the metabolite DDR in the plant cannot be excluded. Regarding levels of DDR in the raw agricultural commodities, exposure estimates based on the limit of quantification (LOQ) for DDR in cereals cannot be further refined while there is no information on the levels of DDR in peas in the dossier. As regards genotoxicity, DDR induced chromosomal damage; however, it was not possible to conclude whether it is through an aneugenic or clastogenic mechanism. Hence, it is not possible to draw a reliable conclusion that DDR is producing an aneugenic effect nor to determine a threshold dose for aneugenicity. Thus, it is not possible to revise the human risk assessment as regards exposure to DDR. The concerns identified in the EFSA conclusion of 2017 remain.

Contact
pesticides.peerreview [at] efsa.europa.eu
doi
10.2903/j.efsa.2020.6276
EFSA Journal 2020;18(10):6276
Question Number
On request from
European Commission