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Wohlleben W, Mehling A, Landsiedel R. Lessons Learned from the Grouping of Chemicals to Assess Risks to Human Health. Angew Chem Int Ed Engl 2023; 62:e202210651. [PMID: 36254879 DOI: 10.1002/anie.202210651] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/15/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
Abstract
In analogy to the periodic system that groups elements by their similarity in structure and chemical properties, the hazard of chemicals can be assessed in groups having similar structures and similar toxicological properties. Here we review case studies of chemical grouping strategies that supported the assessment of hazard, exposure, and risk to human health. By the EU-REACH and the US-TSCA New Chemicals Program, structural similarity is commonly used as the basis for grouping, but that criterion is not always adequate and sufficient. Based on the lessons learned, we derive ten principles for grouping, including: transparency of the purpose, criteria, and boundaries of the group; adequacy of methods used to justify the group; and inclusion or exclusion of substances in the group by toxicological properties. These principles apply to initial grouping to prioritize further actions as well as to definitive grouping to generate data for risk assessment. Both can expedite effective risk management.
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Affiliation(s)
- Wendel Wohlleben
- Department of Analytical and Material Science, BASF SE, 67056, Ludwigshafen am Rhein, Germany
- Department of Experimental Toxicology and Ecology, BASF SE, 67056, Ludwigshafen am Rhein, Germany
| | - Annette Mehling
- Dept. of Advanced Formulation and Performance Technology, BASF Personal Care and Nutrition GmbH, 40589, Duesseldorf, Germany
| | - Robert Landsiedel
- Department of Experimental Toxicology and Ecology, BASF SE, 67056, Ludwigshafen am Rhein, Germany
- Free University of Berlin, Biology, Chemistry and Pharmacy-Pharmacology and Toxicology, 14195, Berlin, Germany
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2
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Wang Z, Wang YYL, Scott WC, Williams ES, Ciarlo M, DeLeo P, Brooks BW. Comparative influences of dermal and inhalational routes of exposure on hazards of cleaning product ingredients among mammalian model organisms. ENVIRONMENT INTERNATIONAL 2021; 157:106777. [PMID: 34314977 DOI: 10.1016/j.envint.2021.106777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 07/06/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Health risks resulting from dermal or inhalational exposures are frequently assessed based on rodent oral toxicity information due to a lack of species- or route-specific toxicity data. Default uncertainty factors (UFs; e.g., 10-fold) are also applied during risk assessments to account for variability such as inter-species, intra-species, exposure duration, dose-response, and route-to-route extrapolations. However, whether rodent oral data and a default UF approach can provide adequate protection for other mammalian species under dermal or inhalational exposure scenarios remains understudied, particularly for cleaning product ingredients. Therefore, we collated and examined publicly available median lethal dose (LD50), no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) values from different types of standard mammalian toxicity studies for rats (dermal and inhalational), mice, rabbits, guinea pigs, and dogs (oral, dermal and inhalational) using the Cleaning Product Ingredient Safety Initiative (CPISI) database. Probabilistic hazard assessments using chemical toxicity distributions (CTDs) were subsequently conducted, and threshold concentrations (TCs) and 95% confidence intervals (95% CIs) were derived to identify thresholds of toxicological concern (TTCs). Relative sensitivities among or between mammalian species, exposure routes, and chemical classes were also compared based on calculated TC5s and 95% CIs to support future toxicology studies and hazard and risk assessments. We then identified uncertainty factors (UFs) using both CTD comparisons and individual UF probability distributional approaches. Based on available rodent inhalational data, chemical category-specific UFs were derived for ethers. Additionally, we also determined whether default UFs of 10 or 100 would be protective for various distributions of cleaning product ingredients. Our novel observations among these routes of exposure and common mammalian model organisms appear particularly useful for read across and screening-level health hazard and risk assessments when limited data exists for specific chemicals.
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Affiliation(s)
- Zhen Wang
- Institute of Marine Sciences and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China.
| | - Yolina Yu Lin Wang
- Institute of Marine Sciences and Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - W Casan Scott
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | | | - Michael Ciarlo
- EA Engineering, Science & Technology, Inc., Baltimore, MD, USA
| | - Paul DeLeo
- American Cleaning Institute, Washington, DC, USA
| | - Bryan W Brooks
- Department of Environmental Science, Baylor University, Waco, TX, USA; School of Environment, Jinan University, Guangzhou 510632, China; Institute of Biomedical Studies, Baylor University, Waco, TX, USA.
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3
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Kawamoto T, Fuchs A, Fautz R, Morita O. Threshold of Toxicological Concern (TTC) for Botanical Extracts (Botanical-TTC) derived from a meta-analysis of repeated-dose toxicity studies. Toxicol Lett 2019; 316:1-9. [PMID: 31415786 DOI: 10.1016/j.toxlet.2019.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 07/31/2019] [Accepted: 08/08/2019] [Indexed: 12/31/2022]
Abstract
Threshold of Toxicological Concern (TTC) is a promising approach for evaluating the human health risk for systemic toxicity when there is a lack of toxicological information. The threshold for systemic toxicity is reportedly 1800, 540, and 90 μg/day for Cramer I-III chemical structures, according to Munro's structural decision tree, and 0.15 μg/day for genotoxic compounds. However, the concept of TTC has been developed for single substances; therefore, the applicability of TTC for mixtures remains unclear. To expand application of probability approach for mixtures, a validation study using the point of departures (PoDs) derived from mixtures is required. In the present study, we investigated novel TTC of botanical extracts (Botanical-TTC) for cosmetics from a meta-analysis based on the PoDs derived from repeated dose toxicity testing in botanical extracts. Accordingly, 213 PoDs were determined by repeated-dose toxicity studies and divided using a default uncertainty factor of 100 combined with the extrapolation factor of study duration to calculate the derived-no-effect-level (DNEL) and derived-minimal-effect-level (DMEL). The minimum DNEL/DMEL was 1.6-fold higher than the Cramer III TTC. In addition, because human health risk below the 1 st percentile value (663 μg/day) was considered as extremely limited, the exposure level can be proposed as Botanical-TTC.
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Affiliation(s)
- Taisuke Kawamoto
- Safety & Toxicology, Kao Germany GmbH, Pfungstädter Str. 98-100, D-64297, Darmstadt, Germany; Safety Science Research, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan.
| | - Anne Fuchs
- Safety & Toxicology, Kao Germany GmbH, Pfungstädter Str. 98-100, D-64297, Darmstadt, Germany
| | - Rolf Fautz
- Safety & Toxicology, Kao Germany GmbH, Pfungstädter Str. 98-100, D-64297, Darmstadt, Germany
| | - Osamu Morita
- Safety Science Research, Kao Corporation, 2-1-3, Bunka, Sumida-ku, Tokyo 131-8501, Japan
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Wang Z, Dinh D, Scott WC, Williams ES, Ciarlo M, DeLeo P, Brooks BW. Critical review and probabilistic health hazard assessment of cleaning product ingredients in all-purpose cleaners, dish care products, and laundry care products. ENVIRONMENT INTERNATIONAL 2019; 125:399-417. [PMID: 30743146 DOI: 10.1016/j.envint.2019.01.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 01/29/2019] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
Though numerous chemical ingredients are used in cleaning products, empirical mammalian toxicology information is often limited for many substances. Such limited data inherently presents challenges to environmental health practitioners performing hazard and risk assessments. Probabilistic hazard assessment using chemical toxicity distributions (CTDs) is an alternative approach for assessments of chemicals when toxicity information is lacking. The CTD concept allows for derivation of thresholds of toxicological concern (TTCs) to predict adverse effect thresholds for mammalian species. Unfortunately, comparative health hazard assessment of cleaning product ingredients in common use categories such as all-purpose cleaners (APC), dish care products (DCP) and laundry care products (LCP) has not been well studied. However, APC, DCP, and LCP are used routinely for household and industrial applications, resulting in residential and industrial occupational exposures. Therefore, we reviewed and then examined hazard information (median lethal dose (LD50), lowest-observed-adverse-effect level (LOAEL), and no-observed-adverse-effect level (NOAEL)) from different types of standard mammalian toxicity studies for oral toxicity in the rat model from the unique Cleaning Product Ingredient Safety Initiative mammalian toxicology database. Probabilistic distributions (CTDs) were subsequently constructed using LD50, NOAEL and LOAEL data from a specific toxicity study type for all available ingredients in these three use categories. Based on data availability, product type-specific and chemical category-specific CTDs were also generated and compared. For each CTD, threshold concentrations (TCs) and their 95% confidence intervals (95% CIs) at 1st, 5th, 10th, 50th, 90th, 95th and 99th percentiles were calculated using the log-normal model. To test whether the common default uncertainty factor (UF) approach (e.g., 3, 10) in mammalian health risk assessment provides sufficient protection, UFs were also derived for LOAEL-to-NOAEL and exposure duration (e.g., subchronic-to-chronic) extrapolations. Relationships between CTDs of acute LD50s and sublethal LOAELs/NOAELs were also examined for acute-to-chronic ratio calculations, which may be useful in extreme circumstances. Results from our critical review and meta-analysis appear particularly useful for hazard and risk practitioners when identifying TTCs for ingredients in product use categories, and other chemical classes. This approach can also support development of regulatory data dossiers through read across, chemical substitutions and screening-level health risk assessments when limited or no empirical toxicity information exists for industrial chemicals.
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Affiliation(s)
- Zhen Wang
- Department of Environmental Science, Baylor University, Waco, TX, USA; School of Environment, Jinan University, Guangzhou, China
| | - Dan Dinh
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | - W Casan Scott
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | | | - Michael Ciarlo
- EA Engineering, Science & Technology, Inc., Baltimore, MD, USA
| | - Paul DeLeo
- American Cleaning Institute, Washington, DC, USA
| | - Bryan W Brooks
- Department of Environmental Science, Baylor University, Waco, TX, USA; School of Environment, Jinan University, Guangzhou, China; Institute of Biomedical Studies, Baylor University, Waco, TX, USA.
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Baken KA, Sjerps RMA, Schriks M, van Wezel AP. Toxicological risk assessment and prioritization of drinking water relevant contaminants of emerging concern. ENVIRONMENT INTERNATIONAL 2018; 118:293-303. [PMID: 29909348 DOI: 10.1016/j.envint.2018.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 05/19/2023]
Abstract
Toxicological risk assessment of contaminants of emerging concern (CEC) in (sources of) drinking water is required to identify potential health risks and prioritize chemicals for abatement or monitoring. In such assessments, concentrations of chemicals in drinking water or sources are compared to either (i) health-based (statutory) drinking water guideline values, (ii) provisional guideline values based on recent toxicity data in absence of drinking water guidelines, or (iii) generic drinking water target values in absence of toxicity data. Here, we performed a toxicological risk assessment for 163 CEC that were selected as relevant for drinking water. This relevance was based on their presence in drinking water and/or groundwater and surface water sources in downstream parts of the Rhine and Meuse, in combination with concentration levels and physicochemical properties. Statutory and provisional drinking water guideline values could be derived from publically available toxicological information for 142 of the CEC. Based on measured concentrations it was concluded that the majority of substances do not occur in concentrations which individually pose an appreciable human health risk. A health concern could however not be excluded for vinylchloride, trichloroethene, bromodichloromethane, aniline, phenol, 2-chlorobenzenamine, mevinphos, 1,4-dioxane, and nitrolotriacetic acid. For part of the selected substances, toxicological risk assessment for drinking water could not be performed since either toxicity data (hazard) or drinking water concentrations (exposure) were lacking. In absence of toxicity data, the Threshold of Toxicological Concern (TTC) approach can be applied for screening level risk assessment. The toxicological information on the selected substances was used to evaluate whether drinking water target values based on existing TTC levels are sufficiently protective for drinking water relevant CEC. Generic drinking water target levels of 37 μg/L for Cramer class I substances and 4 μg/L for Cramer class III substances in drinking water were derived based on these CEC. These levels are in line with previously reported generic drinking water target levels based on original TTC values and are shown to be protective for health effects of the majority of contaminants of emerging concern evaluated in the present study. Since the human health impact of many chemicals appearing in the water cycle has been studied insufficiently, generic drinking water target levels are useful for early warning and prioritization of CEC with unknown toxicity in drinking water and its sources for future monitoring.
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Affiliation(s)
- Kirsten A Baken
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands.
| | - Rosa M A Sjerps
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands
| | - Merijn Schriks
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands
| | - Annemarie P van Wezel
- KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands; Copernicus Institute of Sustainable Development, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands
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6
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Hoersch J, Hoffmann-Doerr S, Keller D. Derivation of an inhalation TTC for the workplace based on DNEL values reported under REACH. Toxicol Lett 2018; 290:110-115. [PMID: 29596887 DOI: 10.1016/j.toxlet.2018.03.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/01/2018] [Accepted: 03/26/2018] [Indexed: 10/17/2022]
Abstract
The Threshold of Toxicological Concern (TTC) concept defines a generic tolerable exposure for chemicals of unknown toxicity below which the risk of adverse health effects is considered very small. The original concept was refined and extended over the years, based either on differentiated structural classes or on additional information on certain toxicological endpoints. Initially, the focus of the TTC application was only on systemic toxic effects after repeated oral intake and consisted of one value. However, under well-defined boundary conditions, a long-term systemic inhalation TTC could also serve as a cut-off criterion for occupational exposure in those cases where workers are exposed to very low levels of chemicals by inhalation contact and could therefore reduce the need to perform animal tests. Within the scope of the European REACH legislation, several thousand systemic long-term inhalation Derived No Effect Levels (DNELs) for workers have been published. By statistical evaluation of the DNEL distribution of 1876 chemicals and the resulting 99th percentiles, we propose an inhalation workplace TTC for systemic effects in the region of 50 μg/m3 (7 μg/kg body weight/day). Specific exclusion criteria apply for the discussed concept.
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Affiliation(s)
- Johanna Hoersch
- Henkel AG & Co. KGaA, Henkelstr. 67, 40589 Düsseldorf, Germany.
| | | | - Detlef Keller
- Henkel AG & Co. KGaA, Henkelstr. 67, 40589 Düsseldorf, Germany
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Smirnova L, Kleinstreuer N, Corvi R, Levchenko A, Fitzpatrick SC, Hartung T. 3S - Systematic, systemic, and systems biology and toxicology. ALTEX 2018; 35:139-162. [PMID: 29677694 PMCID: PMC6696989 DOI: 10.14573/altex.1804051] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 04/06/2018] [Indexed: 12/11/2022]
Abstract
A biological system is more than the sum of its parts - it accomplishes many functions via synergy. Deconstructing the system down to the molecular mechanism level necessitates the complement of reconstructing functions on all levels, i.e., in our conceptualization of biology and its perturbations, our experimental models and computer modelling. Toxicology contains the somewhat arbitrary subclass "systemic toxicities"; however, there is no relevant toxic insult or general disease that is not systemic. At least inflammation and repair are involved that require coordinated signaling mechanisms across the organism. However, the more body components involved, the greater the challenge to reca-pitulate such toxicities using non-animal models. Here, the shortcomings of current systemic testing and the development of alternative approaches are summarized. We argue that we need a systematic approach to integrating existing knowledge as exemplified by systematic reviews and other evidence-based approaches. Such knowledge can guide us in modelling these systems using bioengineering and virtual computer models, i.e., via systems biology or systems toxicology approaches. Experimental multi-organ-on-chip and microphysiological systems (MPS) provide a more physiological view of the organism, facilitating more comprehensive coverage of systemic toxicities, i.e., the perturbation on organism level, without using substitute organisms (animals). The next challenge is to establish disease models, i.e., micropathophysiological systems (MPPS), to expand their utility to encompass biomedicine. Combining computational and experimental systems approaches and the chal-lenges of validating them are discussed. The suggested 3S approach promises to leverage 21st century technology and systematic thinking to achieve a paradigm change in studying systemic effects.
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Affiliation(s)
- Lena Smirnova
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA
| | | | - Raffaella Corvi
- European Commission, Joint Research Centre (JRC), EU Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM), Ispra, (VA), Italy
| | - Andre Levchenko
- Yale Systems Biology Institute and Biomedical Engineering Department, Yale University, New Haven, CT, USA
| | - Suzanne C Fitzpatrick
- Food and Drug Administration (FDA), Center for Food Safety and Applied Nutrition, College Park, MD, USA
| | - Thomas Hartung
- Johns Hopkins University, Bloomberg School of Public Health, Center for Alternatives to Animal Testing (CAAT), Baltimore, MD, USA.
- CAAT-Europe, University of Konstanz, Konstanz, Germany
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The Threshold of Toxicological Concern for prenatal developmental toxicity in rats and rabbits. Regul Toxicol Pharmacol 2017. [PMID: 28645885 DOI: 10.1016/j.yrtph.2017.06.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Threshold Toxicological Concern (TTC) is based on the concept that in absence of experimental data reasonable assurance of safety can be given if exposure is sufficiently low. Using the REACH database the low 5th percentile of the NO(A)EL distribution, for prenatal developmental toxicity (OECD guideline 414) was determined. For rats, (434 NO(A)ELs values) for maternal toxicity, this value was 10 mg/kg-bw/day. For developmental toxicity (469 NO(A)ELs): 13 mg/kg-bw/day. For rabbits, (100 NO(A)ELs), the value for maternal toxicity was 4 mg/kg-bw/day, for developmental toxicity, (112 NO(A)EL values): 10 mg/kg-bw/day. The maternal organism may thus be slightly more sensitive than the fetus. Combining REACH- (industrial chemicals) and published BASF-data (mostly agrochemicals), 537 unique compounds with NO(A)EL values for developmental toxicity in rats and 150 in rabbits were evaluated. The low 5th percentile NO(A)EL for developmental toxicity in rats was 10 mg/kg-bw/day and 9.5 mg/kg-bw/day for rabbits. Using an assessment factor of 100, a TTC value for developmental toxicity of 100 μg/kg-bw/day for rats and 95 μg/kg-bw/day for rabbits is calculated. These values could serve as guidance whether or not to perform an animal experiment, if exposure is sufficiently low. In emergency situations this value may be useful for a first tier risk assessment.
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Examining the differences in current regulatory processes for sunscreens and proposed safety assessment paradigm. Regul Toxicol Pharmacol 2016; 79:125-141. [DOI: 10.1016/j.yrtph.2016.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/09/2016] [Accepted: 03/12/2016] [Indexed: 12/27/2022]
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Faria EC, Bercu JP, Dolan DG, Morinello EJ, Pecquet AM, Seaman C, Sehner C, Weideman PA. Using default methodologies to derive an acceptable daily exposure (ADE). Regul Toxicol Pharmacol 2016; 79 Suppl 1:S28-38. [DOI: 10.1016/j.yrtph.2016.05.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 05/19/2016] [Indexed: 02/05/2023]
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Gould J, Callis CM, Dolan DG, Stanard B, Weideman PA. Special endpoint and product specific considerations in pharmaceutical acceptable daily exposure derivation. Regul Toxicol Pharmacol 2016; 79 Suppl 1:S79-93. [PMID: 27233924 DOI: 10.1016/j.yrtph.2016.05.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 05/19/2016] [Indexed: 12/12/2022]
Abstract
Recently, a guideline has been published by the European Medicines Agency (EMA) on setting safe limits, permitted daily exposures (PDE) [also called acceptable daily exposures (ADE)], for medicines manufactured in multi-product facilities. The ADE provides a safe exposure limit for inadvertent exposure of a drug due to cross-contamination in manufacturing. The ADE determination encompasses a standard risk assessment, requiring an understanding of the toxicological and pharmacological effects, the mechanism of action, drug compound class, and the dose-response as well as the pharmacokinetic properties of the compound. While the ADE concept has broad application in pharmaceutical safety there are also nuances and specific challenges associated with some toxicological endpoints or drug product categories. In this manuscript we discuss considerations for setting ADEs when the following specific adverse health endpoints may constitute the critical effect: genotoxicity, developmental and reproductive toxicity (DART), and immune system modulation (immunostimulation or immunosuppression), and for specific drug classes, including antibody drug conjugates (ADCs), emerging medicinal therapeutic compounds, and compounds with limited datasets. These are challenging toxicological scenarios that require a careful evaluation of all of the available information in order to establish a health-based safe level.
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Review of the Threshold of Toxicological Concern (TTC) approach and development of new TTC decision tree. ACTA ACUST UNITED AC 2016. [DOI: 10.2903/sp.efsa.2016.en-1006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Blackburn K, Daston G, Fisher J, Lester C, Naciff JM, Rufer ES, Stuard SB, Woeller K. A strategy for safety assessment of chemicals with data gaps for developmental and/or reproductive toxicity. Regul Toxicol Pharmacol 2015; 72:202-15. [DOI: 10.1016/j.yrtph.2015.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 04/07/2015] [Accepted: 04/08/2015] [Indexed: 11/29/2022]
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Stanard B, Dolan DG, Hanneman W, Legare M, Bercu JP. Threshold of toxicological concern (TTC) for developmental and reproductive toxicity of anticancer compounds. Regul Toxicol Pharmacol 2015; 72:602-9. [PMID: 26025210 DOI: 10.1016/j.yrtph.2015.05.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/21/2015] [Accepted: 05/22/2015] [Indexed: 11/18/2022]
Abstract
Pharmaceutical companies develop specialized therapies to treat late stage cancer. In order to accelerate life-saving treatments and reduce animal testing, compounds to treat life-threatening malignancies are allowed modified requirements for preclinical toxicology testing. Limited data packages in early drug development can present product quality challenges at multi-product manufacturing facilities. The present analysis established an endpoint-specific threshold of toxicological concern (TTC) for developmental and reproductive toxicity (DART) for anticancer compounds. A comprehensive database was created consisting of over 300 no-observed adverse effect levels (NOAELs) for DART of 108 anticancer compounds. The 5th percentile NOAEL for developmental and reproductive toxicity was 0.005 mg/kg/day (300 μg/day), resulting in a human exposure threshold of 3 μg/day assuming standard uncertainty factors and a 60 kg human bodyweight. The analysis shows this threshold is protective for developmental and reproductive toxicity of highly potent groups of anticancer compounds. There were similar TTC values calculated for direct-acting and indirect-acting anticancer compounds.
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Affiliation(s)
- Brad Stanard
- MedImmune, One MedImmune Way, Gaithersburg, MD 20878, USA; Colorado State University, Department of Environmental and Radiological Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Ft. Collins, CO 80523, USA.
| | - David G Dolan
- Amgen, Inc., One Amgen Center Drive, MS 28-1A, Thousand Oaks, CA 91360, USA
| | - William Hanneman
- Colorado State University, Department of Environmental and Radiological Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Ft. Collins, CO 80523, USA
| | - Marie Legare
- Colorado State University, Department of Environmental and Radiological Health Sciences, College of Veterinary Medicine and Biomedical Sciences, Ft. Collins, CO 80523, USA
| | - Joel P Bercu
- Amgen, Inc., One Amgen Center Drive, MS 28-1A, Thousand Oaks, CA 91360, USA
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15
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Regulatory toxicology in the twenty-first century: challenges, perspectives and possible solutions. Arch Toxicol 2015; 89:823-50. [DOI: 10.1007/s00204-015-1510-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/17/2015] [Indexed: 10/23/2022]
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16
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Dewhurst I, Renwick A. Evaluation of the Threshold of Toxicological Concern (TTC) – Challenges and approaches. Regul Toxicol Pharmacol 2013; 65:168-77. [DOI: 10.1016/j.yrtph.2012.03.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 03/08/2012] [Indexed: 11/24/2022]
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17
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van Ravenzwaay B, Dammann M, Buesen R, Flick B, Schneider S. The threshold of toxicological concern for prenatal developmental toxicity in rabbits and a comparison to TTC values in rats. Regul Toxicol Pharmacol 2012; 64:1-8. [DOI: 10.1016/j.yrtph.2012.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 06/05/2012] [Accepted: 06/05/2012] [Indexed: 11/27/2022]
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18
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Scientific Opinion on Exploring options for providing advice about possible human health risks based on the concept of Threshold of Toxicological Concern (TTC). EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2750] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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19
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Hennes E. An overview of values for the threshold of toxicological concern. Toxicol Lett 2012; 211:296-303. [DOI: 10.1016/j.toxlet.2012.03.795] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 03/19/2012] [Accepted: 03/21/2012] [Indexed: 11/30/2022]
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Metabolomics: a tool for early detection of toxicological effects and an opportunity for biology based grouping of chemicals-from QSAR to QBAR. Mutat Res 2012; 746:144-50. [PMID: 22305969 DOI: 10.1016/j.mrgentox.2012.01.006] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 01/18/2012] [Indexed: 11/23/2022]
Abstract
BASF has developed a Metabolomics database (MetaMap(®) Tox) containing approximately 500 data rich chemicals, agrochemicals and drugs. This metabolome-database has been built based upon 28-day studies in rats (adapted to OECD 407 guideline) with blood sampling and metabolic profiling after 7, 14 and 28 days of test substance treatment. Numerous metabolome patterns have been established for different toxicological targets (liver, kidney, thyroid, testes, blood, nervous system and endocrine system) which are specific for different toxicological modes of action. With these patterns early detection of toxicological effects and the underlying mechanism can now be obtained from routine studies. Early recognition of toxicological mode of action will help to develop new compounds with a more favourable toxicological profile and will also help to reduce the number of animal studies necessary to do so. Thus this technology contributes to animal welfare by means of reduction through refinement (2R), but also has potential as a replacement method by analyzing samples from in vitro studies. With respect to the REACH legislation for which a large number of animal studies will need to be performed, one of the most promising methods to reduce the number of animal experiments is grouping of chemicals and read-across to those which are data rich. So far mostly chemical similarity or QSAR models are driving the selection process of chemical grouping. However, "omics" technologies such as metabolomics may help to optimize the chemical grouping process by providing biologically based criteria for toxicological equivalence. "From QSAR to QBAR" (quantitative biological activity relationship).
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Laufersweiler MC, Gadagbui B, Baskerville-Abraham IM, Maier A, Willis A, Scialli AR, Carr GJ, Felter SP, Blackburn K, Daston G. Correlation of chemical structure with reproductive and developmental toxicity as it relates to the use of the threshold of toxicological concern. Regul Toxicol Pharmacol 2011; 62:160-82. [PMID: 22019814 DOI: 10.1016/j.yrtph.2011.09.004] [Citation(s) in RCA: 1202] [Impact Index Per Article: 92.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 09/15/2011] [Accepted: 09/16/2011] [Indexed: 10/16/2022]
Abstract
In the absence of toxicological data on a chemical, the threshold of toxicological concern (TTC) approach provides a system to estimate a conservative exposure below which there is a low probability of risk for adverse health effects. The original toxicology dataset underlying the TTC was based on NOELs from repeat dose studies. Subsequently there have been several efforts to assess whether or not these limits are also protective for reproductive/developmental effects. This work expands the database of chemicals with reproductive and developmental data, presents these data in a comprehensive and transparent format and groups the chemicals according to the TTC "Cramer Class" rules. Distributions of NOAELs from each of these classes were used to assess whether the previously proposed TTC values based on repeat dose data are protective for reproductive/developmental toxicity endpoints as well. The present analysis indicates that, for each Cramer Class, the reproductive and developmental endpoints would be protected at the corresponding general TTC tiers derived by Munro et al. (1996).
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Rowbotham AL, Gibson RM. Exposure-driven risk assessment: Applying exposure-based waiving of toxicity tests under REACH. Food Chem Toxicol 2011; 49:1661-73. [DOI: 10.1016/j.fct.2011.03.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 03/22/2011] [Accepted: 03/27/2011] [Indexed: 10/18/2022]
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Kalkhof H, Herzler M, Stahlmann R, Gundert-Remy U. Threshold of toxicological concern values for non-genotoxic effects in industrial chemicals: re-evaluation of the Cramer classification. Arch Toxicol 2011; 86:17-25. [DOI: 10.1007/s00204-011-0732-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 06/16/2011] [Indexed: 11/25/2022]
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Blackburn K, Bjerke D, Daston G, Felter S, Mahony C, Naciff J, Robison S, Wu S. Case studies to test: A framework for using structural, reactivity, metabolic and physicochemical similarity to evaluate the suitability of analogs for SAR-based toxicological assessments. Regul Toxicol Pharmacol 2011; 60:120-35. [DOI: 10.1016/j.yrtph.2011.03.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/04/2011] [Accepted: 03/04/2011] [Indexed: 11/30/2022]
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van Ravenzwaay B, Dammann M, Buesen R, Schneider S. The threshold of toxicological concern for prenatal developmental toxicity. Regul Toxicol Pharmacol 2011; 59:81-90. [DOI: 10.1016/j.yrtph.2010.09.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 09/20/2010] [Accepted: 09/22/2010] [Indexed: 11/25/2022]
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Melching-Kollmuß S, Dekant W, Kalberlah F. Application of the “threshold of toxicological concern” to derive tolerable concentrations of “non-relevant metabolites” formed from plant protection products in ground and drinking water. Regul Toxicol Pharmacol 2010; 56:126-34. [DOI: 10.1016/j.yrtph.2009.09.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 09/02/2009] [Accepted: 09/15/2009] [Indexed: 10/20/2022]
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Brown R, Carter J, Dewhurst I, Stephenson C, Tessier S. Applicability of thresholds of toxicological concern in the dietary risk assessment of metabolites, degradation and reaction products of pesticides. ACTA ACUST UNITED AC 2010. [DOI: 10.2903/sp.efsa.2010.en-44] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Dekant W, Melching-Kollmuß S, Kalberlah F. Toxicity assessment strategies, data requirements, and risk assessment approaches to derive health based guidance values for non-relevant metabolites of plant protection products. Regul Toxicol Pharmacol 2010; 56:135-42. [DOI: 10.1016/j.yrtph.2009.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 09/28/2009] [Accepted: 10/22/2009] [Indexed: 10/20/2022]
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Williams ES, Panko J, Paustenbach DJ. The European Union’s REACH regulation: a review of its history and requirements. Crit Rev Toxicol 2009; 39:553-75. [PMID: 19650717 DOI: 10.1080/10408440903036056] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Exposure based waiving: The application of the toxicological threshold of concern (TTC) to inhalation exposure for aerosol ingredients in consumer products. Food Chem Toxicol 2009; 47:1287-95. [DOI: 10.1016/j.fct.2009.02.024] [Citation(s) in RCA: 1150] [Impact Index Per Article: 76.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 02/27/2009] [Accepted: 02/27/2009] [Indexed: 11/18/2022]
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REACH, non-testing approaches and the urgent need for a change in mind set. Regul Toxicol Pharmacol 2009; 53:70-80. [DOI: 10.1016/j.yrtph.2008.11.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 11/10/2008] [Accepted: 11/12/2008] [Indexed: 11/18/2022]
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Gundert-Remy U. REACH aus der Sicht des Umwelt- und Verbraucherschutzes. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2008; 51:1426-33. [DOI: 10.1007/s00103-008-0716-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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