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Corvaro M, Henriquez J, Settivari R, Mattson U, Forreryd A, Gradin R, Johansson H, Gehen S. GARD™skin and GARD™potency: A proof-of-concept study investigating applicability domain for agrochemical formulations. Regul Toxicol Pharmacol 2024; 148:105595. [PMID: 38453128 DOI: 10.1016/j.yrtph.2024.105595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/19/2024] [Accepted: 02/26/2024] [Indexed: 03/09/2024]
Abstract
Several New Approach Methodologies (NAMs) for hazard assessment of skin sensitisers have been formally validated. However, data regarding their applicability on certain product classes are limited. The purpose of this project was to provide initial evidence on the applicability domain of GARD™skin and GARD™potency for the product class of agrochemical formulations. For this proof of concept, 30 liquid and 12 solid agrochemical formulations were tested in GARDskin for hazard predictions. Formulations predicted as sensitisers were further evaluated in the GARDpotency assay to determine GHS skin sensitisation category. The selected formulations were of product types, efficacy groups and sensitisation hazard classes representative of the industry's products. The performance of GARDskin was estimated by comparing results to existing in vivo animal data. The overall accuracy, sensitivity, and specificity were 76.2% (32/42), 85.0% (17/20), and 68.2% (15/22), respectively, with the predictivity for liquid formulations being slightly higher compared to the solid formulations. GARDpotency correctly subcategorized 14 out of the 17 correctly predicted sensitisers. Lack of concordance was justifiable by compositional or borderline response analysis. In conclusion, GARDskin and GARDpotency showed satisfactory performance in this initial proof-of-concept study, which supports consideration of agrochemical formulations being within the applicability domain of the test methods.
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Affiliation(s)
| | | | | | | | | | | | | | - Sean Gehen
- Corteva™ Agriscience LCC, Indianapolis, IN, USA.
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2
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Corvaro M, Johnson K, Himmelstein M, Bianchi E, Mingoia R, Bartels M, Reiss R, Terry C, LaRocca J, Murphy L, Gehen S. P06-13 Spinosad – mode of action and human relevance assessment of dystocia in rats. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Strickland J, Truax J, Corvaro M, Settivari R, Henriquez J, McFadden J, Gulledge T, Johnson V, Gehen S, Germolec D, Allen DG, Kleinstreuer N. Application of Defined Approaches for Skin Sensitization to Agrochemical Products. Front Toxicol 2022; 4:852856. [PMID: 35586187 PMCID: PMC9108145 DOI: 10.3389/ftox.2022.852856] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Skin sensitization testing is a regulatory requirement for safety evaluations of pesticides in multiple countries. Globally harmonized test guidelines that include in chemico and in vitro methods reduce animal use, but no single assay is recommended as a complete replacement for animal tests. Defined approaches (DAs) that integrate data from multiple non-animal methods are accepted; however, the methods that comprise them have been evaluated using monoconstituent substances rather than mixtures or formulations. To address this data gap, we tested 27 agrochemical formulations in the direct peptide reactivity assay (DPRA), the KeratinoSens™ assay, and the human cell line activation test (h-CLAT). These data were used as inputs to evaluate three DAs for hazard classification of skin sensitization potential and two DAs for potency categorization. When compared to historical animal results, balanced accuracy for the DAs for predicting in vivo skin sensitization hazard (i.e., sensitizer vs. nonsensitizer) ranged from 56 to 78%. The best performing DA was the “2 out of 3 (2o3)” DA, in which the hazard classification was based on two concordant results from the DPRA, KeratinoSens, or h-CLAT. The KE 3/1 sequential testing strategy (STS), which uses h-CLAT and DPRA results, and the integrated testing strategy (ITSv2), which uses h-CLAT, DPRA, and an in silico hazard prediction from OECD QSAR Toolbox, had balanced accuracies of 56–57% for hazard classification. Of the individual test methods, KeratinoSens had the best performance for predicting in vivo hazard outcomes. Its balanced accuracy of 81% was similar to that of the 2o3 DA (78%). For predicting potency categories defined by the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), the correct classification rate of the STS was 52% and that of the ITSv2 was 43%. These results demonstrate that non-animal test methods have utility for evaluating the skin sensitization potential of agrochemical formulations as compared to animal reference data. While additional data generation is needed, testing strategies such as DAs anchored to human biology and mechanistic information provide a promising approach for agrochemical formulation testing.
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Affiliation(s)
- Judy Strickland
- Integrated Laboratory Systems, LLC, Research Triangle Park, NC, United States
- *Correspondence: Judy Strickland,
| | - James Truax
- Integrated Laboratory Systems, LLC, Research Triangle Park, NC, United States
| | - Marco Corvaro
- Corteva Agriscience, Regulatory Sciences R&D, Rome, Italy
| | - Raja Settivari
- Corteva Agriscience, General, Genetic, and Molecular Toxicology, Newark, DE, United States
| | - Joseph Henriquez
- Corteva Agriscience, Regulatory Toxicology and Risk Group, Indianapolis, IN, United States
| | - Jeremy McFadden
- Corteva Agriscience, Regulatory Toxicology and Risk Group, Indianapolis, IN, United States
| | - Travis Gulledge
- Burleson Research Technologies, Inc., Morrisville, NC, United States
| | - Victor Johnson
- Burleson Research Technologies, Inc., Morrisville, NC, United States
| | - Sean Gehen
- Corteva Agriscience, Regulatory Toxicology and Risk Group, Indianapolis, IN, United States
| | - Dori Germolec
- Systems Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
- National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - David G. Allen
- Integrated Laboratory Systems, LLC, Research Triangle Park, NC, United States
| | - Nicole Kleinstreuer
- National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
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Barlow SM, Terry C, Gehen S, Corvaro M. Developmental toxicity studies on triclopyr acid, triclopyr butoxyethyl ester and triclopyr triethylamine salt in the rabbit. Food Chem Toxicol 2022; 161:112845. [PMID: 35122930 DOI: 10.1016/j.fct.2022.112845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/25/2022] [Accepted: 01/28/2022] [Indexed: 10/19/2022]
Abstract
Developmental toxicity studies have been conducted in the rabbit on triclopyr acid and its active-ingredient variants, triclopyr triethylamine salt (T-TEA) and triclopyr butoxyethyl ester (T-BEE), which are dissociated or hydrolysed in vivo to triclopyr acid. In this paper, the available developmental toxicity studies on triclopyr acid, T-TEA and T-BEE are summarised and evaluated. For triclopyr acid and T-TEA, there was no evidence of impaired reproductive performance, fetotoxicity, or teratogenicity, even at maternally toxic doses. The no-observed-adverse-effect levels (NOAELs) for developmental toxicity were 75 mg/kg bw per day for triclopyr acid and 100 mg/kg bw per day for T-TEA, equivalent to 72 mg/kg bw per day expressed as triclopyr acid. A study on T-BEE showed increased post-implantation loss and slight increases in skeletal anomalies and variants at the highest dose tested of 100 mg/kg bw per day, a maternally toxic dose. In a follow-up study on T-BEE, focusing on post-implantation loss, no general increase in post-implantation loss was observed, but one animal at 100 mg/kg bw per day with maternal toxicity had complete resorption of implants. The NOAEL for post-implantation loss was 60 mg/kg bw per day, equivalent to 44 mg/kg bw per day expressed as triclopyr acid. It cannot be excluded that T-BEE may be associated with increased post-implantation loss, but it was only seen in association with maternal toxicity. It is concluded that triclopyr acid and its variants are not specifically toxic to the rabbit embryo and fetus, since post-implantation loss only occurred at doses causing maternal toxicity.
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Affiliation(s)
| | - Claire Terry
- Dow AgroSciences LCC, Member of Corteva Agriscience Group of Companies, 9330 Zionsville Rd, Indianapolis, IN, 46268, USA
| | - Sean Gehen
- Dow AgroSciences LCC, Member of Corteva Agriscience Group of Companies, 9330 Zionsville Rd, Indianapolis, IN, 46268, USA
| | - Marco Corvaro
- Dow Agrosciences Italia S.r.l, Member of Corteva Agriscience Group of Companies, Via dei Comizi Agrari 10, 26100, Cremona, CR, Italy.
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Barlow SM, Terry C, Gehen S, Corvaro M. Reproductive and developmental evaluations of triclopyr acid, triclopyr butoxyethyl ester and triclopyr triethylamine salt in the rat. Food Chem Toxicol 2022; 161:112806. [PMID: 34995710 DOI: 10.1016/j.fct.2021.112806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/29/2021] [Accepted: 12/31/2021] [Indexed: 11/30/2022]
Abstract
Reproductive and developmental toxicity studies have been conducted in rat and rabbit on triclopyr acid and its active-ingredient variants, triclopyr butoxyethyl ester (T-BEE) and triclopyr triethylamine salt (T-TEA). In this paper the results of a rat two-generation study on triclopyr acid are presented, together with a review of all the reproductive and developmental toxicity data available from the rat studies. In the rat two-generation study, triclopyr acid was administered in the diet, giving doses of 0, 5, 25 or 250 mg/kg bw per day. Parental toxicity, especially maternal toxicity, occurred at 250 mg/kg bw per day with reduced body weight and feed intake, organ weight changes, and kidney toxicity. Slight kidney toxicity was also evident at 25 mg/kg bw per day. Developmental toxicity, in the form of reduced postnatal survival in the F1 and F2 generations and reductions in pre-weaning offspring body weight in both generations, was seen only at a dose causing significant parental toxicity. There were no effects on any other reproductive or developmental parameters at any dose. It is concluded that the developmental toxicity, seen only at the highest dose, was most likely attributable to maternal toxicity. The no-observed-adverse-effect levels were 5 mg/kg bw per day for parental toxicity and 25 mg/kg bw per day for developmental toxicity. From the multigeneration and developmental toxicity studies on triclopyr and its variants, it can also be concluded that triclopyr is not specifically toxic to reproduction and is not selectively toxic to the embryo, fetus or neonate in the rat.
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Affiliation(s)
| | - Claire Terry
- Dow AgroSciences LCC, Member of Corteva Agriscience Group of Companies, 9330 Zionsville Rd, Indianapolis, IN, 46268, USA
| | - Sean Gehen
- Dow AgroSciences LCC, Member of Corteva Agriscience Group of Companies, 9330 Zionsville Rd, Indianapolis, IN, 46268, USA
| | - Marco Corvaro
- Dow Agrosciences Italia S.r.l, Member of Corteva Agriscience Group of Companies, Via dei Comizi Agrari 10, 26100, Cremona, CR, Italy.
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Yan ZJ, Bartels M, Gollapudi B, Driver J, Himmelstein M, Gehen S, Juberg D, van Wesenbeeck I, Terry C, Rasoulpour R. Weight of evidence analysis of the tumorigenic potential of 1,3-dichloropropene supports a threshold-based risk assessment. Crit Rev Toxicol 2021; 50:836-860. [PMID: 33528302 DOI: 10.1080/10408444.2020.1845119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
1,3-Dichloropropene (1,3-D; CAS #542-75-6) is a fumigant used for preplant treatment of soil to control parasitic nematodes and manage soil borne diseases for numerous fruit, vegetable, field and tree and vine crops across diverse global agricultural areas. In the USA, 1,3-D has historically been classified by the U.S. EPA as likely to be carcinogenic to humans via both oral and inhalation routes. This classification for the oral route was primarily based upon increases in multiple tumor types observed in National Toxicology Program (NTP) cancer bioassays in rats and mice, while the classification for the inhalation route was based upon increased benign bronchioloalveolar adenomas in a mouse study conducted by The Dow Chemical Company. Based on U.S. EPA standard risk assessment methodologies, a low-dose linear extrapolation approach has been used to estimate risks to humans. Furthermore, genotoxicity associated with 1,3-D was historically considered a potential mode of action (MOA) for its tumorigenicity. New information is available and additional studies have been conducted that reveal a different picture of the tumorigenic potential of 1,3-D. These data and information include: (1) initial cancer studies by the NTP were conducted on an antiquated form of 1,3-D which contained a known mutagen/carcinogen, epichlorohydrin, as a stabilizer while current 1,3-D fumigants use epoxidized soybean oil (ESO) as the stabilizer; (2) results from two additional oral rodent cancer bioassays conducted on the modern form of 1,3-D became available and these two studies reveal a lack of carcinogenicity; (3) a newly conducted Big Blue study in F344 rats via the oral route further confirms that 1,3-D is not an in vivo genotoxicant; and (4) a newly conducted repeat dose inhalation toxicokinetic (TK) study shows that linear dose proportionality is observed below 30 ppm, which demonstrates the non-relevance of 60 ppm 1,3-D-induced benign lung tumors in mice for human health assessment. This weight of evidence review is organized as follows: (a) the TK of 1,3-D are presented because of relevant considerations when evaluating test doses/concentrations and reported findings of tumorigenicity; (b) the genotoxicity profile of 1,3-D is presented, including a contemporary study in order to put a possible genotoxicity MOA into perspective; (c) the six available bioassays are reviewed followed by (d) scientifically supported points of departure (PODs) and evaluation of human exposure for use in risk assessment. Through this assessment, all available data support the conclusion that 1,3-D is not a tumorigen at doses below 12.5 mg/kg bw/day via the oral route or at doses below 30 ppm via the inhalation route. These findings and clearly identified PODs show that a linear low dose extrapolation approach is not appropriate and a threshold-based risk assessment for 1,3-D is human health protective. Finally, in 2019, the Cancer Assessment Review Committee (CARC) reevaluated the carcinogenic potential of 1,3-D. In accordance with the EPA's Final Guidelines for Carcinogen Risk Assessment, the CARC classified 1,3-D (Telone) as "Suggestive Evidence of Carcinogenic Potential based on the presence of liver tumors by the oral route in male rats only." Given this finding, EPA stated that "quantification of human cancer risk is not required. The CARC recommends using a non-linear approach (i.e. reference dose (RfD)) that will adequately account for all chronic toxicity including carcinogenicity, that could result from exposure to 1,3-dichloropropene."
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Affiliation(s)
| | | | | | | | | | - Sean Gehen
- Corteva Agriscience, Indianapolis, IN, USA
| | - Daland Juberg
- Juberg Toxicology Consulting LLC, Indianapolis, IN, USA
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7
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Badding M, Gollapudi BB, Gehen S, Yan Z(J. In vivo mutagenicity evaluation of the soil fumigant 1,3-dichloropropene. Mutagenesis 2020; 35:437-443. [DOI: 10.1093/mutage/geaa015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 06/09/2020] [Indexed: 11/14/2022] Open
Abstract
Abstract
1,3-Dichloropropene (1,3-D; CAS No. 542-75-6) is a soil fumigant used for the control of nematodes in agriculture. There is an extensive database on the genotoxicity of 1,3-D and many of the published studies are confounded by the presence of mutagenic stabilisers in the test substance. Mixed results were obtained in the in vitro assays, often due to the purity of the 1,3-D sample tested. In order to get further clarity, the mutagenic potential of 1,3-D was investigated in vivo in the transgenic Big Blue rodent models. Inhalation exposure of 150 ppm 1,3-D (×2.5 tumourigenic dose) to transgenic male B6C3F1 mice did not induce lacI mutations in either the lung (tumour target tissue) or liver. Similarly, dietary administration of 1,3-D up to 50 mg/kg/day to transgenic male Fischer 344 rats did not increase the cII mutant frequency in either the liver (tumour target) or kidney. These results, along with other available in vivo data, including the absence of DNA adducts and clastogenic/aneugenic potential, support the conclusion that 1,3-D is efficiently detoxified in vivo and, as such, does not pose a mutagenic hazard or risk.
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Affiliation(s)
- Melissa Badding
- Exponent, Inc., Center for Health Sciences, Alexandria, VA, USA
| | | | - Sean Gehen
- Research and Development, Corteva Agriscience, Indianapolis, IN, USA
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Bartels M, Brown C, Chung G, Chan M, Terry C, Gehen S, Corvaro M. Review of the pharmacokinetics and metabolism of triclopyr herbicide in mammals: Impact on safety assessments. Regul Toxicol Pharmacol 2020; 116:104714. [PMID: 32640299 DOI: 10.1016/j.yrtph.2020.104714] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 04/30/2020] [Accepted: 06/08/2020] [Indexed: 11/16/2022]
Abstract
A review of pharmacokinetic and metabolism studies show that triclopyr is well absorbed from the oral route in numerous species (≥80%), primarily as parent compound. Absorption is quite rapid in rats, dogs and human volunteers. Plasma or blood clearance is also rapid (t1/2 3-9 h), except for dog (12-96 h). Systemic exposure is not dose-proportional: in the rat above 20 mg/kg (dietary) or between 3 and 60 mg/kg (gavage), or in dogs above 5 mg/kg, with systemic exposure in human more comparable to rat than dog. Triclopyr is highly bound to protein in rat, dog and human plasma (≥97% at or below 7 μg/mL), indicating that species differences in systemic exposure are not due to differences in the free fraction of this test material in plasma. An in vitro flux study in renal proximal tubule cells showed that net renal transport of triclopyr is in the direction of secretion in rat and human donors, while reabsorption predominated in the dog, possibly via organic anion transporters such as OAT1/3. These results fit well into the framework of utilizing metabolism and toxicokinetics across species and exposure levels to allow for toxicity testing in the most relevant species as well as at proper dose levels.
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Affiliation(s)
| | | | - Git Chung
- Newcells Biotech, Newcastle Upon Tyne, UK
| | | | | | - Sean Gehen
- Corteva Agriscience™, Indianapolis, IN, USA
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9
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Affiliation(s)
- Sean Gehen
- Crop Protection Regulatory Sciences, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Marco Corvaro
- Crop Protection Regulatory Sciences, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Jennifer Jones
- Product Design & Process R&D, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Mingming Ma
- Crop Protection Regulatory Sciences, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
| | - Qiang Yang
- Product Design & Process R&D, Corteva Agriscience, 9330 Zionsville Road, Indianapolis, Indiana 46268, United States
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Clippinger AJ, Allen D, Jarabek AM, Corvaro M, Gaça M, Gehen S, Hotchkiss JA, Patlewicz G, Melbourne J, Hinderliter P, Yoon M, Huh D, Lowit A, Buckley B, Bartels M, BéruBé K, Wilson DM, Indans I, Vinken M. Alternative approaches for acute inhalation toxicity testing to address global regulatory and non-regulatory data requirements: An international workshop report. Toxicol In Vitro 2017; 48:53-70. [PMID: 29277654 DOI: 10.1016/j.tiv.2017.12.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/11/2017] [Accepted: 12/14/2017] [Indexed: 12/15/2022]
Abstract
Inhalation toxicity testing, which provides the basis for hazard labeling and risk management of chemicals with potential exposure to the respiratory tract, has traditionally been conducted using animals. Significant research efforts have been directed at the development of mechanistically based, non-animal testing approaches that hold promise to provide human-relevant data and an enhanced understanding of toxicity mechanisms. A September 2016 workshop, "Alternative Approaches for Acute Inhalation Toxicity Testing to Address Global Regulatory and Non-Regulatory Data Requirements", explored current testing requirements and ongoing efforts to achieve global regulatory acceptance for non-animal testing approaches. The importance of using integrated approaches that combine existing data with in vitro and/or computational approaches to generate new data was discussed. Approaches were also proposed to develop a strategy for identifying and overcoming obstacles to replacing animal tests. Attendees noted the importance of dosimetry considerations and of understanding mechanisms of acute toxicity, which could be facilitated by the development of adverse outcome pathways. Recommendations were made to (1) develop a database of existing acute inhalation toxicity data; (2) prepare a state-of-the-science review of dosimetry determinants, mechanisms of toxicity, and existing approaches to assess acute inhalation toxicity; (3) identify and optimize in silico models; and (4) develop a decision tree/testing strategy, considering physicochemical properties and dosimetry, and conduct proof-of-concept testing. Working groups have been established to implement these recommendations.
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Affiliation(s)
| | - David Allen
- Integrated Laboratory Systems, contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods, Research Triangle Park, NC, United States
| | - Annie M Jarabek
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Research Triangle Park, NC, United States
| | | | | | - Sean Gehen
- Dow AgroSciences, Indianapolis, IN, United States
| | | | - Grace Patlewicz
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Computational Toxicology, Research Triangle Park, NC, United States
| | | | | | - Miyoung Yoon
- Scitovation LLC, Research Triangle Park, NC, United States
| | - Dongeun Huh
- University of Pennsylvania, Philadelphia, PA, United States
| | - Anna Lowit
- U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention, Office of Pesticide Programs, Washington, DC, United States
| | - Barbara Buckley
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Research Triangle Park, NC, United States
| | | | - Kelly BéruBé
- Cardiff University, School of Biosciences, Cardiff, Wales, UK
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Corvaro M, Gehen S, Andrews K, Chatfield R, Macleod F, Mehta J. A retrospective analysis of in vivo eye irritation, skin irritation and skin sensitisation studies with agrochemical formulations: Setting the scene for development of alternative strategies. Regul Toxicol Pharmacol 2017; 89:131-147. [DOI: 10.1016/j.yrtph.2017.06.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 11/26/2022]
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Hamm J, Sullivan K, Clippinger AJ, Strickland J, Bell S, Bhhatarai B, Blaauboer B, Casey W, Dorman D, Forsby A, Garcia-Reyero N, Gehen S, Graepel R, Hotchkiss J, Lowit A, Matheson J, Reaves E, Scarano L, Sprankle C, Tunkel J, Wilson D, Xia M, Zhu H, Allen D. Alternative approaches for identifying acute systemic toxicity: Moving from research to regulatory testing. Toxicol In Vitro 2017; 41:245-259. [PMID: 28069485 DOI: 10.1016/j.tiv.2017.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/23/2016] [Accepted: 01/03/2017] [Indexed: 12/25/2022]
Abstract
Acute systemic toxicity testing provides the basis for hazard labeling and risk management of chemicals. A number of international efforts have been directed at identifying non-animal alternatives for in vivo acute systemic toxicity tests. A September 2015 workshop, Alternative Approaches for Identifying Acute Systemic Toxicity: Moving from Research to Regulatory Testing, reviewed the state-of-the-science of non-animal alternatives for this testing and explored ways to facilitate implementation of alternatives. Workshop attendees included representatives from international regulatory agencies, academia, nongovernmental organizations, and industry. Resources identified as necessary for meaningful progress in implementing alternatives included compiling and making available high-quality reference data, training on use and interpretation of in vitro and in silico approaches, and global harmonization of testing requirements. Attendees particularly noted the need to characterize variability in reference data to evaluate new approaches. They also noted the importance of understanding the mechanisms of acute toxicity, which could be facilitated by the development of adverse outcome pathways. Workshop breakout groups explored different approaches to reducing or replacing animal use for acute toxicity testing, with each group crafting a roadmap and strategy to accomplish near-term progress. The workshop steering committee has organized efforts to implement the recommendations of the workshop participants.
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Affiliation(s)
- Jon Hamm
- Integrated Laboratory Systems, Inc., Research Triangle Park, NC, USA.
| | - Kristie Sullivan
- Physicians Committee for Responsible Medicine, 5100 Wisconsin Ave NW, Ste 400, Washington, DC, USA
| | | | - Judy Strickland
- Integrated Laboratory Systems, Inc., Research Triangle Park, NC, USA
| | - Shannon Bell
- Integrated Laboratory Systems, Inc., Research Triangle Park, NC, USA
| | | | - Bas Blaauboer
- Institute for Risk Assessment Sciences, Division of Toxicology, Utrecht University, Utrecht, Netherlands
| | - Warren Casey
- NTP Interagency Center for the Evaluation of Alternative Toxicological Methods, Research Triangle Park, NC, USA
| | - David Dorman
- North Carolina State University, Raleigh, NC, USA
| | - Anna Forsby
- Stockholm University and Swedish Toxicology Sciences Research Center (Swetox), Södertälje, Sweden
| | | | | | - Rabea Graepel
- European Union Reference Laboratory for Alternatives to Animal Testing, Ispra, Italy
| | | | - Anna Lowit
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Joanna Matheson
- U.S. Consumer Product Safety Commission, Washington, DC, USA
| | - Elissa Reaves
- U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC, USA
| | - Louis Scarano
- U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Washington, DC, USA
| | | | | | - Dan Wilson
- The Dow Chemical Company, Midland, MI, USA
| | - Menghang Xia
- National Center for Advancing Translational Sciences, Rockville, MD, USA
| | - Hao Zhu
- Department of Chemistry(,) Rutgers University-Camden, Camden, NJ, USA
| | - David Allen
- Integrated Laboratory Systems, Inc., Research Triangle Park, NC, USA
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Corvaro M, Gehen S, Andrews K, Chatfield R, Arasti C, Mehta J. GHS additivity formula: A true replacement method for acute systemic toxicity testing of agrochemical formulations. Regul Toxicol Pharmacol 2016; 82:99-110. [DOI: 10.1016/j.yrtph.2016.10.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/09/2016] [Accepted: 10/16/2016] [Indexed: 11/25/2022]
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Driver JH, Price PS, Van Wesenbeeck I, Ross JH, Gehen S, Holden LR, Landenberger B, Hastings K, Yan ZJ, Rasoulpour R. Evaluation of potential human health effects associated with the agricultural uses of 1,3-D: Spatial and temporal stochastic risk analysis. Sci Total Environ 2016; 571:410-5. [PMID: 27461162 DOI: 10.1016/j.scitotenv.2016.06.172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 05/14/2023]
Abstract
Dow AgroSciences (DAS) markets and sells 1,3-Dichloropropene (1,3-D), the active ingredient in Telone®, which is used as a pre-plant soil fumigant nematicide in economically important crops in California. 1,3-D has been regulated as a "probable human carcinogen" and the California Department of Pesticide Regulation limits use of 1,3-D based on human health risk assessments for bystanders. This paper presents a risk characterization for bystanders based on advances in the assessment of both exposure and hazard. The revised bystander risk assessment incorporates significant advances: 1) new data on residency duration and mobility in communities where 1,3-D is in high demand; 2) new information on spatial and temporal concentrations of 1,3-D in air based on multi-year modeling using a validated model; and 3) a new stochastic spatial and temporal model of long-term exposures. Predicted distributions of long-term, chronic exposures indicate that current, and anticipated uses of 1,3-D would result in lifetime average daily doses lower than 0.002mg/kg/d, a dose associated with theoretical lifetime excess cancer risk of <10(-5) to >95% of the local population based on a non-threshold risk assessment approach. Additionally, examination of 1,3-D toxicity studies including new chronic toxicity data and mechanism of action supports the use of a non-linear, threshold based risk assessment approach. The estimated maximum annual average daily dose of <0.0016mg/kg/d derived from the updated exposure assessment was then compared with a threshold point of departure. The calculated margin of exposure is >1000-fold, a clear indication of acceptable risk for human health. In summary, the best available science supports 1,3-D's threshold nature of hazard and the revised exposure assessment supports that current agricultural uses of 1,3-D are associated with reasonable certainty of no harm, i.e., estimated long-term exposures pose insignificant health risks to bystanders even when the non-threshold approach is assumed.
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Affiliation(s)
- Jeffrey H Driver
- risksciences.net, LLC, 10009 Wisakon Trail, Manassas, VA 20111, USA.
| | - Paul S Price
- The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA
| | - Ian Van Wesenbeeck
- Dow AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - John H Ross
- risksciences.net, LLC, 5150 Fair Oaks Blvd., Ste. 101-370, Carmichael, CA 95608, USA
| | - Sean Gehen
- Dow AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Larry R Holden
- Larry R. Holden, Statistical Consulting, 1403 Post Oak Circle, College Station, TX, USA
| | | | - Kerry Hastings
- Dow AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Zhongyu June Yan
- Dow AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
| | - Reza Rasoulpour
- Dow AgroSciences, LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA
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Corvaro M, Gehen S, Andrews K, Chatfield R, Macleod F, Mikolajczak H, Moore J, Mehta J. Re-shaping acute toxicity testing of agrochemical formulations by combining the GHS ATE formula and in vitro approaches. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.2058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Corvaro M, Aggarwal M, Gehen S, Mehta J. Re-shaping acute toxicity testing agrochemical formulations by combining the GHS ATE formula and in vitro approaches. Toxicol Lett 2015. [DOI: 10.1016/j.toxlet.2015.08.955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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