Adverse Outcome Pathways Mechanistically Describing Hepatotoxicity.

Adverse outcome pathways (AOPs) describe toxicological processes from a dynamic perspective by linking a molecular initiating event to a specific adverse outcome via a series of key events and key event relationships. In the field of computational toxicology, AOPs can potentially facilitate the design and development of in silico prediction models for hazard identification. Various AOPs have been introduced for several types of hepatotoxicity, such as steatosis, cholestasis, fibrosis, and liver cancer. This chapter provides an overview of AOPs on hepatotoxicity, including their development, assessment, and applications in toxicology.

Peer review of the pesticide risk assessment of the active substance pirimicarb.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Sweden for the pesticide active substance pirimicarb are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative use(s) of pirimicarb as an insecticide on winter and spring wheat and sugar beet via foliar spray application and on ornamental pot plants in permanent greenhouses. The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

Peer review of the pesticide risk assessment of the active substance pyrimethanil.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Czech Republic and co-rapporteur Member State Austria for the pesticide active substance pyrimethanil and of confirmatory data following the maximum residue limit (MRL) review under Article 12 of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of pyrimethanil as a fungicide on grapevine and pome fruit (field uses), strawberry and lettuce (field and greenhouse uses). The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

Peer review of the pesticide risk assessment of the active substance elemental iron.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State Austria for the pesticide active substance elemental iron and the considerations as regards the inclusion of the substance in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of elemental iron in field and greenhouses (permanent and non-permanent structures) via granule application by spreading on all edible and non-edible crops, ornamental plants and amenity grassland to control molluscs. The reliable endpoints, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed.

In vitro and in silico characterization of the transport of selected perfluoroalkyl carboxylic acids and perfluoroalkyl sulfonic acids by human organic anion transporter 1 (OAT1), OAT2 and OAT3.

Perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) belong to the group of poly- and perfluoroalkyl substances (PFASs), which may accumulate in humans due to their limited excretion. To provide more insight into the active renal excretion potential of PFASs in humans, this work investigated in vitro the transport of three PFCAs (PFHpA, PFOA, PFNA) and three PFSAs (PFBS, PFHxS and PFOS) using OAT1-, OAT2- or OAT3-transduced human embryonic kidney (HEK) cells. Only PFHpA and PFOA showed clear uptake in OAT1-transduced HEK cells, while no transport was observed for PFASs in OAT2-transduced HEK cells. In OAT3-transduced HEK cells only PFHpA, PFOA, PFNA, and PFHxS showed clear uptake. To study the interaction with the transporters, molecular docking and dynamics simulation were performed for PFHpA and PFHxS, for which a relatively short and long half-life in humans has been reported, respectively. Docking analyses could not always distinguish the in vitro transported from the non-transported PFASs (PFHpA vs. PFHxS), whereas molecular dynamic simulations could, as only a stable interaction of the PFAS with the inner part of transporter mouth was detected for those that were transported in vitro (PFHpA with OAT1, none with OAT2, and PFHpA and PFHxS with OAT3). Altogether, this study presents in vitro and in silico insight with respect to the selected PFASs transport by the human renal secretory transporters OAT1, OAT2, and OAT3, which provides further understanding about the differences between the capability of PFAS congeners to accumulate in humans.

Peer review of the pesticide risk assessment of the active substance Bacillus subtilis strain RTI477.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State the Netherlands for the pesticide active substance Bacillus subtilis strain RTI477 are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of B. subtilis strain RTI477 as a fungicide for the control of soil-borne diseases in greenhouses (permanent) and walk-in tunnels and field crops; by drip and drench irrigation on lettuce, cucurbit and solanaceous vegetables; field application by treating tubers whilst laying in furrow on potato; seed treatment application on maize, sunflower, sugar beet and winter oilseed rape. The reliable endpoints, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported when identified.

Peer review of the pesticide risk assessment of the active substance Bacillus velezensis RTI301.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State The Netherlands for the pesticide active substance Bacillus velezensis strain RTI301 are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of B. velezensis strain RTI301 as a fungicide for the control of soil-borne diseases in greenhouses (permanent) and walk-in tunnels (non-permanent) and field crops; by drip and drench irrigation on lettuce, cucurbit and solanaceous vegetables; field application by treating tubers whilst laying in furrow on potato; seed treatment application on maize, sunflower, sugar beet and winter oilseed rape. The reliable endpoints, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported when identified.

Peer review of the pesticide risk assessment of the active substance flufenacet.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Poland and co-rapporteur Member State France for the pesticide active substance flufenacet are reported. In addition, the assessment of the confirmatory data following the Article 12 maximum residue limit (MRL) review of Regulation (EC) No 396/2005 is also reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012. The conclusions were reached on the basis of the evaluation of the representative use of flufenacet as a herbicide on winter cereals. Confirmatory data following the Article 12 MRL review were assessed. The reliable end points, appropriate for use in regulatory risk assessment and the assessment of confirmatory data following the Article 12 MRL review, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment of the active substance amidosulfuron.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Finland, and co-rapporteur Member State, Croatia, for the pesticide active substance amidosulfuron and the assessment of confirmatory data following the Article 12 MRL review are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of amidosulfuron as a post-emergence herbicide on winter cereals, spring cereals, flax and grass/pasture (all field uses). The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment of the active substance bensulfuron-methyl.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Italy and co-rapporteur Member State Spain for the pesticide active substance bensulfuron-methyl are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of bensulfuron-methyl as an herbicide on rice and spring cereals (spring wheat, spring barley, oat, rye, triticale). The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

Optimized methods for measuring competitive binding of chemical substances to thyroid hormone distributor proteins transthyretin and thyroxine binding globulin.

Transthyretin (TTR) and thyroxine-binding globulin (TBG) are two major thyroid hormone (TH) distributor proteins in human plasma, playing important roles in stabilizing the TH levels in plasma, delivery of TH to target tissues, and trans-barrier transport. Binding of xenobiotics to these distributor proteins can potentially affect all these three important roles of distributor proteins. Therefore, fast and cost-effective experimental methods are required for both TTR and TBG to screen both existing and new chemicals for their potential binding. In the present study, the TTR-binding assay was therefore simplified, optimized and pre-validated, while a new TBG-binding assay was developed based on fluorescence polarization as a readout. Seven model compounds (including positive and negative controls) were tested in the pre-validation study of the optimized TTR-binding assay and in the newly developed TBG-binding assay. The dissociation constants of the natural ligand (thyroxine, T4) and potential competitors were determined and compared between two distributor proteins, showing striking differences for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA).

Transport of perfluoroalkyl substances across human induced pluripotent stem cell-derived intestinal epithelial cells in comparison with primary human intestinal epithelial cells and Caco-2 cells.

Humans can be exposed to per- and polyfluoroalkyl substances (PFASs) via many exposure routes, including diet, which may lead to several adverse health effects. So far, little is known about PFAS transport across the human intestinal barrier. In the current study, we aimed to assess the transport of 5 PFASs (PFOS, PFOA, PFNA, PFHxS and HFPO-DA) in a human induced pluripotent stem cell (hiPSC)-derived intestinal epithelial cell (IEC) model. This model was extensively characterized and compared with the widely applied human colonic adenocarcinoma cell line Caco-2 and a human primary IEC-based model, described to most closely resemble in vivo tissue. The hiPSC-derived IEC layers demonstrated polarized monolayers with tight junctions and a mucus layer. The monolayers consisted of enterocytes, stem cells, goblet cells, enteroendocrine cells, and Paneth cells that are also present in native tissue. Transcriptomics analysis revealed distinct differences in gene expression profiles, where the hiPSC-derived IECs showed the highest expression of intestinal tissue-specific genes relative to the primary IEC-based model and the Caco-2 cells clustered closer to the primary IEC-based model than the hiPSC-derived IECs. The order of PFAS transport was largely similar between the models and the apparent permeability (Papp) values of PFAS in apical to basolateral direction in the hiPSC-derived IEC model were in the following order: PFHxS > PFOA > HFPO-DA > PFNA > PFOS. In conclusion, the hiPSC-derived IEC model highly resembles human intestinal physiology and is therefore a promising novel in vitro model to study transport of chemicals across the intestinal barrier for risk assessment of chemicals.

Peer review of the pesticide risk assessment of the active substance 1-methylcyclopropene.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State The Netherlands for the pesticide active substance 1-methylcyclopropene are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council for an amendment in approval conditions. The current approval of 1-methylcyclopropene includes the specific provision 'Only uses as plant growth regulator for post-harvest storage in sealable warehouse may be authorised'. The applicant AgroFresh Holding France SAS submitted, in accordance with Article 7 of Reg. (EC) 1107/2009, an application to remove this specific provision in order to allow member states to authorise the use of products containing 1-methylcyclopropene on outdoor crops pre-harvest. The conclusions were reached on the basis of the evaluation of the representative use(s) of 1-methylcyclopropene as a plant growth regulator via spray application on pome fruit. The reliable endpoints, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment of the active substance Pythium oligandrum strain B301.

The conclusions of EFSA following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State Belgium for the pesticide active substance Pythium oligandrum strain B301 and the considerations as regards the inclusion of the substance in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of Pythium oligandrum strain B301 as a resistance inducer/elicitor to control trunk diseases on grapevines. The reliable endpoints, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment of the active substance triclopyr (variant triclopyr-butotyl).

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Poland and co-rapporteur Member State Hungary for the pesticide active substance triclopyr (variant triclopyr-butotyl) and the assessment of applications for maximum residue levels (MRLs) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of triclopyr (variant triclopyr-butotyl) as a herbicide on established pasture and non-recreational amenity grassland (field use). MRLs were assessed in rice. The reliable end points, appropriate for use in regulatory risk assessment and the proposed MRLs, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment of the active substance Phthorimaea operculella granulovirus.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authority of the rapporteur Member State, The Netherlands for the pesticide active substance Phthorimaea operculella granulovirus are reported. The context of the peer review was that required by Regulation (EC) No 1107/2009 of the European Parliament and of the Council. The conclusions were reached on the basis of the evaluation of the representative uses of Phthorimaea operculella granulovirus as an insecticide on tomato (field and greenhouse uses) and on potato (field use) via spraying (tractor drawn or knapsack sprayers) or overhead irrigation. The reliable endpoints, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed.

Peer review of the pesticide risk assessment of the active substance lenacil.

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Belgium, and co-rapporteur Member State, Austria, for the pesticide active substance lenacil are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of lenacil as a herbicide on sugar and fodder beet (field use). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment of the active substance mepiquat (evaluated variant mepiquat chloride).

The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Finland, and co-rapporteur Member State, Estonia, for the pesticide active substance mepiquat (evaluated variant mepiquat chloride) are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of mepiquat chloride as a plant growth regulator on cereals and grass (field uses). The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

Peer review of the pesticide risk assessment of the active substance paraffin oil (CAS 8042-47-5, chain lengths C17-C31).

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Greece, and co-rapporteur Member State, France, for the pesticide active substance paraffin oil are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of paraffin oil as an acaricide and insecticide on potatoes, ornamentals (flower bulbs) and orchards (pear/apple), on pome fruit and stone fruit, on field and permanent protected fruiting vegetables and on field and permanent protected roses and on citrus. The reliable end points appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are reported where identified.

Peer review of the pesticide risk assessment for the active substance difenoconazole in light of confirmatory data submitted.

The conclusions of the EFSA following the peer review of the initial risk assessment carried out by the competent authority of the rapporteur Member State, Spain, for the pesticide active substance difenoconazole are reported. The context of the peer review was that requested by the European Commission following the submission and evaluation of confirmatory information with regard to the consumer risk assessment. The conclusions were reached on the basis of the evaluation of the representative uses of difenoconazole as a fungicide on pome fruit, carrot, wheat, barley, triticale, rye and oats. The reliable endpoints concluded as being appropriate for use in regulatory risk assessment, derived from the available studies and/or literature in the dossier peer reviewed, are presented. Concerns were not identified.