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Lambré C, Barat Baviera JM, Bolognesi C, Chesson A, Cocconcelli PS, Crebelli R, Gott DM, Grob K, Mengelers M, Mortensen A, Rivière G, Steffensen I, Tlustos C, Van Loveren H, Vernis L, Zorn H, Dudler V, Milana MR, Papaspyrides C, Tavares Poças MDF, Colombo G, Comandella D, Lioupis A, Marano R, Munoz Guajardo IP, Savini E, Sfika V, Tsochatzis E, Volk K, Lampi E. Scientific Guidance on the criteria for the evaluation and on the preparation of applications for the safety assessment of post-consumer mechanical PET recycling processes intended to be used for manufacture of materials and articles in contact with food. EFSA J 2024; 22:e8879. [PMID: 39081816 PMCID: PMC11287194 DOI: 10.2903/j.efsa.2024.8879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024] Open
Abstract
In the context of entry into force of Regulation (EU) 2022/1616, EFSA updated the scientific guidance to assist applicants in the preparation of applications for the authorisation or for the modification of an existing authorisation of a 'post-consumer mechanical PET' recycling process (as defined in Annex I of Regulation (EU) 2022/1616) intended to be used for manufacturing materials and articles intended to come into contact with food. This Guidance describes the evaluation criteria and the scientific evaluation approach that EFSA will apply to assess the decontamination capability of recycling processes, as well as the information required to be included in an application dossier. The principle of the scientific evaluation approach is to apply the decontamination efficiency of a recycling process, obtained from a challenge test with surrogate contaminants, to a reference contamination level for post-consumer PET, set at 3 mg/kg PET for a contaminant resulting from possible misuse. The resulting residual concentration of each surrogate in recycled PET is then compared to a modelled concentration in PET that is calculated using generally recognised conservative migration models, such that the related migration does not give rise to a dietary exposure exceeding 0.0025 μg/kg body weight (bw) per day. This is the lowest threshold for toxicological concern (TTC) value, i.e. for potential genotoxicity, below which the risk to human health would be negligible. The information to be provided in the applications relates to: the recycling process (i.e. collection and pre-processing of the input, decontamination process, post-processing and intended use); the determination of the decontamination efficiency by the challenge test; the self-evaluation of the recycling process. On the basis of the submitted data, EFSA will assess the safety of the mechanical PET recycling process.
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Simon TW, Ryman J, Becker RA. Commentary: Value of information case study strongly supports use of the Threshold of Toxicological Concern (TTC). Regul Toxicol Pharmacol 2024; 149:105594. [PMID: 38555099 DOI: 10.1016/j.yrtph.2024.105594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/20/2024] [Accepted: 02/22/2024] [Indexed: 04/02/2024]
Abstract
A Value of Information (VOI) analysis can play a key role in decision-making for adopting new approach methodologies (NAMs). We applied EPA's recently developed VOI framework to the Threshold of Toxicological Concern (TTC). Obtaining/deriving a TTC value for use as a toxicity reference value (TRV) for substances with limited toxicity data was shown to provide equivalent or greater health protection, immense return on investment (ROI), greater net benefit, and substantially lower costs of delay (CoD) compared with TRVs derived from either traditional human health assessment (THHA) chronic toxicity testing in lab animals or the 5-day in vivo EPA Transcriptomic Assessment Product (ETAP). For all nine exposure scenarios examined, the TTC was more economical terms of CoD and ROI than the ETAP or the THHA; expected net benefit was similar for the TTC and ETAP with both of these more economical than the THHA The TTC ROI was immensely greater (5,000,000-fold on average) than the ROI for THHA and the ETAP ROI (100,000-fold on average). These results support the use of the TTC for substances within its domain of applicability to waive requiring certain in vivo tests, or at a minimum, as an initial screening step before conducting either the ETAP or THHA in vivo studies.
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Ponting DJ, Foster RS. Drawing a Line: Where Might the Cohort of Concern End? Org Process Res Dev 2023. [DOI: 10.1021/acs.oprd.3c00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Affiliation(s)
- David J. Ponting
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds LS11 5PS, United Kingdom
| | - Robert S. Foster
- Lhasa Limited, Granary Wharf House, 2 Canal Wharf, Leeds LS11 5PS, United Kingdom
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Lea I, Pham LL, Antonijevic T, Thompson C, Borghoff SJ. Assessment of the applicability of the threshold of toxicological concern for per- and polyfluoroalkyl substances. Regul Toxicol Pharmacol 2022; 133:105190. [PMID: 35662637 DOI: 10.1016/j.yrtph.2022.105190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 11/24/2022]
Abstract
While toxicity information is available for selected PFAS, little or no information is available for most, thereby necessitating a resource-effective approach to screen and prioritize those needing further safety assessment. The threshold of toxicological concern (TTC) approach proposes a de minimis exposure value based on chemical structure and toxicology of similar substances. The applicability of the TTC approach to PFAS was tested by incorporating a data set of no-observed-adverse-effect level (NOAEL) values for 27 PFAS into the Munro TTC data set. All substances were assigned into Cramer Class III and the cumulative distribution of the NOAELs evaluated. The TTC value for the PFAS-enriched data set was not statistically different compared to the Munro data set. Derived human exposure level for the PFAS-enriched data set was 1.3 μg/kg/day. Structural chemical profiles showed the PFAS-enriched data set had distinct chemotypes with lack of similarity to substances in the Munro data set using Maximum Common Structures. The incorporation of these 27 PFAS did not significantly change TTC Cramer Class III distribution and expanded the chemical space, supporting the potential use of the TTC approach for PFAS chemicals.
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Affiliation(s)
- Isabel Lea
- ToxStrategies, 1249 Kildaire Farm Road, #134, Cary, NC, 27511, USA
| | - Ly Ly Pham
- ToxStrategies Inc., 23123 Cinco Ranch Blvd, Katy, TX, 77494, USA
| | | | - Chad Thompson
- ToxStrategies Inc., 23123 Cinco Ranch Blvd, Katy, TX, 77494, USA
| | - Susan J Borghoff
- ToxStrategies, 1249 Kildaire Farm Road, #134, Cary, NC, 27511, USA.
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Gerding J, Anhäuser L, Eickmann U, Nienhaus A. A simple approach to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings. J Occup Med Toxicol 2022; 17:8. [PMID: 35365163 PMCID: PMC8973544 DOI: 10.1186/s12995-022-00349-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/21/2022] [Indexed: 11/10/2022] Open
Abstract
Background Several drugs for human use possess genotoxic properties as a necessary consequence of their intended therapeutic effect (e.g. antineoplastics). Health workers may be exposed to these chemicals in various occupational settings such as dose preparation and administration. To date, there are no quantitative risk assessment models to estimate the cancer risk of health workers due to the handling of genotoxic drugs. We therefore developed a quantitative risk assessment model to assess the cancer risk of occupational exposure to genotoxic drugs in healthcare settings based on the threshold of toxicological concern (TTC) concept. This model was used to evaluate the cancer risk of health workers due to the handling of genotoxic drugs in modern health care facilities. Methods We modified the threshold of toxicological concern (TTC) concept to fit the purpose of occupational cancer risk assessment. The risk model underlying ICH guideline M7 (R1): “assessment and control of DNA reactive (mutagenic) impurities in pharmaceuticals to limit potential carcinogenic risk” was used as a starting point for our model. We conducted a short review of studies on the occupational exposure of health workers to genotoxic drugs. These occupational exposure data were compared to the acceptable exposure levels resulting from our TTC based risk model. Results Based on the threshold of toxicological concern (TTC) concept, we defined an acceptable daily intake (ADI) of 4 μg/day as threshold of no concern for the exposure of health workers to genotoxic drugs. Regarding the dermal exposure of health workers to genotoxic drugs, we derived a corresponding acceptable surface contamination level (ASCL) of 20 ng/cm2. Both ADI and ASCL are usually not exceeded in modern healthcare settings. Current safety precautions provide sufficient protection to health workers. Conclusions The application of our model indicates that workers in modern healthcare facilities are not at risk of developing work related cancer above widely accepted cancer risk levels due to the occupational exposure to genotoxic drugs. Hence, the present study may assist employers and public authorities to make informed decisions concerning the need for (further) protective measures and during risk communication to health workers.
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Affiliation(s)
- Johannes Gerding
- Department for Occupational Medicine, Hazardous Substances and Public Health, German Social Accident Insurance, Institution for the Health and Welfare Services (BGW), Pappelallee 33/35/37, 22089, Hamburg, Germany.
| | - Lea Anhäuser
- Department for Occupational Medicine, Hazardous Substances and Public Health, German Social Accident Insurance, Institution for the Health and Welfare Services (BGW), Pappelallee 33/35/37, 22089, Hamburg, Germany
| | - Udo Eickmann
- Department for Occupational Medicine, Hazardous Substances and Public Health, German Social Accident Insurance, Institution for the Health and Welfare Services (BGW), Pappelallee 33/35/37, 22089, Hamburg, Germany
| | - Albert Nienhaus
- Department for Occupational Medicine, Hazardous Substances and Public Health, German Social Accident Insurance, Institution for the Health and Welfare Services (BGW), Pappelallee 33/35/37, 22089, Hamburg, Germany.,Competence Centre for Epidemiology and Health Services Research for Healthcare Professionals (CVcare), University Medical Centre Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
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Focusing Points on FSCJ’s Guideline Recently Established: Risk Assessment of Food Contact Materials. Food Saf (Tokyo) 2022; 10:57-69. [PMID: 35837505 PMCID: PMC9233751 DOI: 10.14252/foodsafetyfscj.d-21-00029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/13/2022] [Indexed: 11/21/2022] Open
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Carcinogenic hazard assessment of cobalt-containing alloys in medical devices: Review of in vivo studies. Regul Toxicol Pharmacol 2021; 122:104910. [DOI: 10.1016/j.yrtph.2021.104910] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/03/2021] [Accepted: 02/24/2021] [Indexed: 11/19/2022]
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Baderna D, Faoro R, Selvestrel G, Troise A, Luciani D, Andres S, Benfenati E. Defining the Human-Biota Thresholds of Toxicological Concern for Organic Chemicals in Freshwater: The Proposed Strategy of the LIFE VERMEER Project Using VEGA Tools. Molecules 2021; 26:1928. [PMID: 33808128 PMCID: PMC8037015 DOI: 10.3390/molecules26071928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/18/2021] [Accepted: 03/26/2021] [Indexed: 12/03/2022] Open
Abstract
Several tons of chemicals are released every year into the environment and it is essential to assess the risk of adverse effects on human health and ecosystems. Risk assessment is expensive and time-consuming and only partial information is available for many compounds. A consolidated approach to overcome this limitation is the Threshold of Toxicological Concern (TTC) for assessment of the potential health impact and, more recently, eco-TTCs for the ecological aspect. The aim is to allow a safe assessment of substances with poor toxicological characterization. Only limited attempts have been made to integrate the human and ecological risk assessment procedures in a "One Health" perspective. We are proposing a strategy to define the Human-Biota TTCs (HB-TTCs) as concentrations of organic chemicals in freshwater preserving both humans and ecological receptors at the same time. Two sets of thresholds were derived: general HB-TTCs as preliminary screening levels for compounds with no eco- and toxicological information, and compound-specific HB-TTCs for chemicals with known hazard assessment, in terms of Predicted No effect Concentration (PNEC) values for freshwater ecosystems and acceptable doses for human health. The proposed strategy is based on freely available public data and tools to characterize and group chemicals according to their toxicological profiles. Five generic HB-TTCs were defined, based on the ecotoxicological profiles reflected by the Verhaar classes, and compound-specific thresholds for more than 400 organic chemicals with complete eco- and toxicological profiles. To complete the strategy, the use of in silico models is proposed to predict the required toxicological properties and suitable models already available on the VEGAHUB platform are listed.
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Affiliation(s)
- Diego Baderna
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (R.F.); (G.S.); (D.L.)
| | - Roberta Faoro
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (R.F.); (G.S.); (D.L.)
| | - Gianluca Selvestrel
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (R.F.); (G.S.); (D.L.)
| | - Adrien Troise
- INERIS Institut National de l’Environnement Industriel et des Risques, Rue Jacques Taffanel, 60550 Verneuil-en-Halatt, France; (A.T.); (S.A.)
| | - Davide Luciani
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (R.F.); (G.S.); (D.L.)
| | - Sandrine Andres
- INERIS Institut National de l’Environnement Industriel et des Risques, Rue Jacques Taffanel, 60550 Verneuil-en-Halatt, France; (A.T.); (S.A.)
| | - Emilio Benfenati
- Laboratory of Environmental Chemistry and Toxicology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Via Mario Negri 2, 20156 Milano, Italy; (R.F.); (G.S.); (D.L.)
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Safety evaluation of recycling process used to produce recycled pulp for adult paper diapers. Regul Toxicol Pharmacol 2021; 122:104909. [PMID: 33652038 DOI: 10.1016/j.yrtph.2021.104909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 11/21/2022]
Abstract
Eight contaminants were used to perform a surrogate contamination test to evaluate safety of the process for producing recycled pulp for adult paper diapers. We performed a safety evaluation of the recycling process for producing recycled pulp following the European Food Safety Authority safety assessment for polyethylene terephthalate (PET) bottles using recycled PET. We also compared the first tier safety limit established on the basis of TTC (Climit) in the pulp that contained recycled pulp with residual contaminant concentrations (Cres). If Climit > Cres, there is no concern regarding safety of the recycling process. Climit was determined to be 0.46 mg/kg-pulp based on the human exposure threshold of 0.15 μg/person/day using the scenario in which a bedridden senior citizen uses four adult paper diapers manufactured with pulp containing 10% recycled pulp per day. Cres was derived from the initial concentration in used pulp (0.17 mg/kg-pulp), and decontamination rate was obtained from the surrogate contamination test. The Cres of the eight contaminants were between 0.0017 and 0.10 mg/kg-pulp, which were all below the Climit of 0.46 mg/kg-pulp. These results indicated there was no safety problem regarding this process for producing recycled pulp for adult paper diapers.
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Thomas R, Thresher A, Ponting DJ. Utilisation of parametric methods to improve percentile-based estimates for the carcinogenic potency of nitrosamines. Regul Toxicol Pharmacol 2021; 121:104875. [PMID: 33556416 DOI: 10.1016/j.yrtph.2021.104875] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/09/2020] [Accepted: 01/23/2021] [Indexed: 10/22/2022]
Abstract
N-Nitrosamines have recently been the subject of intense regulatory scrutiny, including the setting of low exposure limits (18 ng/day) (European Medicines Agency (EMA), 2020). This paper evaluates different methodologies to determine statistically robust bounds on the carcinogenic potency of chemical classes, using historic TD50 data (Peto et al., 1984; Thresher et al., 2019) and exemplified for N-nitrosamines. Initially, the distribution of TD50 values (TD50s) for N-nitrosamines of known potency was characterised. From this, it is possible to compare parametric and non-parametric methods to obtain percentiles of interest from the distribution of TD50s, which are shown to be robust to uncertainty in the initial TD50 estimates. These methods may then be applied to different chemical subclasses. The values obtained may be of use in refining acceptable intakes for N-nitrosamines and their subclasses.
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Rogiers V, Benfenati E, Bernauer U, Bodin L, Carmichael P, Chaudhry Q, Coenraads PJ, Cronin MT, Dent M, Dusinska M, Ellison C, Ezendam J, Gaffet E, Galli CL, Goebel C, Granum B, Hollnagel HM, Kern PS, Kosemund-Meynen K, Ouédraogo G, Panteri E, Rousselle C, Stepnik M, Vanhaecke T, von Goetz N, Worth A. The way forward for assessing the human health safety of cosmetics in the EU - Workshop proceedings. Toxicology 2020; 436:152421. [DOI: 10.1016/j.tox.2020.152421] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/21/2020] [Accepted: 02/25/2020] [Indexed: 12/20/2022]
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Mahony C, Bowtell P, Huber M, Kosemund K, Pfuhler S, Zhu T, Barlow S, McMillan DA. Threshold of toxicological concern (TTC) for botanicals - Concentration data analysis of potentially genotoxic constituents to substantiate and extend the TTC approach to botanicals. Food Chem Toxicol 2020; 138:111182. [DOI: 10.1016/j.fct.2020.111182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 12/21/2022]
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13
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Roe AL, McMillan DA, Mahony C. A Tiered Approach for the Evaluation of the Safety of Botanicals Used as Dietary Supplements: An Industry Strategy. Clin Pharmacol Ther 2018; 104:446-457. [PMID: 29882956 PMCID: PMC6175063 DOI: 10.1002/cpt.1132] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 05/23/2018] [Indexed: 12/20/2022]
Abstract
Exposure to botanicals in dietary supplements is increasing across many geographies; with increased expectations from consumers, regulators, and industry stewards centered on quality and safety of these products. We present a tiered approach to assess the safety of botanicals, and an in silico decision tree to address toxicity data gaps. Tier 1 describes a Threshold of Toxicologic Concern (TTC) approach that can be used to assess the safety of conceptual levels of botanicals. Tier 2 is an approach to document a history of safe human use for botanical exposures higher than the TTC. An assessment of botanical-drug interaction (BDI) may also be necessary at this stage. Tier 3 involves botanical chemical constituent identification and safety assessment and the in silico approach as needed. Our novel approaches to identify potential hazards and establish safe human use levels for botanicals is cost and time efficient and minimizes reliance on animal testing.
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Affiliation(s)
- Amy L. Roe
- The Procter and Gamble CompanyMason Business CenterCincinnatiOhioUSA
| | - Donna A. McMillan
- The Procter and Gamble CompanyMason Business CenterCincinnatiOhioUSA
| | - Catherine Mahony
- Procter and Gamble Technical Centres LtdGreater London Innovation CentreEghamUK
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Wang Z, Scott WC, Williams ES, Ciarlo M, DeLeo PC, Brooks BW. Identification of novel uncertainty factors and thresholds of toxicological concern for health hazard and risk assessment: Application to cleaning product ingredients. ENVIRONMENT INTERNATIONAL 2018; 113:357-376. [PMID: 29452931 DOI: 10.1016/j.envint.2018.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
Uncertainty factors (UFs) are commonly used during hazard and risk assessments to address uncertainties, including extrapolations among mammals and experimental durations. In risk assessment, default values are routinely used for interspecies extrapolation and interindividual variability. Whether default UFs are sufficient for various chemical uses or specific chemical classes remains understudied, particularly for ingredients in cleaning products. Therefore, we examined publicly available acute median lethal dose (LD50), and reproductive and developmental no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) values for the rat model (oral). We employed probabilistic chemical toxicity distributions to identify likelihoods of encountering acute, subacute, subchronic and chronic toxicity thresholds for specific chemical categories and ingredients in cleaning products. We subsequently identified thresholds of toxicological concern (TTC) and then various UFs for: 1) acute (LD50s)-to-chronic (reproductive/developmental NOAELs) ratios (ACRs), 2) exposure duration extrapolations (e.g., subchronic-to-chronic; reproductive/developmental), and 3) LOAEL-to-NOAEL ratios considering subacute/acute developmental responses. These ratios (95% CIs) were calculated from pairwise threshold levels using Monte Carlo simulations to identify UFs for all ingredients in cleaning products. Based on data availability, chemical category-specific UFs were also identified for aliphatic acids and salts, aliphatic alcohols, inorganic acids and salts, and alkyl sulfates. In a number of cases, derived UFs were smaller than default values (e.g., 10) employed by regulatory agencies; however, larger UFs were occasionally identified. Such UFs could be used by assessors instead of relying on default values. These approaches for identifying mammalian TTCs and diverse UFs represent robust alternatives to application of default values for ingredients in cleaning products and other chemical classes. Findings can also support chemical substitutions during alternatives assessment, and data dossier development (e.g., read across), identification of TTCs, and screening-level hazard and risk assessment when toxicity data is unavailable for specific chemicals.
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Affiliation(s)
- Zhen Wang
- Environmental Health Science Program, Department of Environmental Science, Baylor University, Waco, TX, USA
| | - W Casan Scott
- Environmental Health Science Program, Department of Environmental Science, Baylor University, Waco, TX, USA
| | - E Spencer Williams
- Environmental Health Science Program, Department of Environmental Science, Baylor University, Waco, TX, USA
| | - Michael Ciarlo
- EA Engineering, Science & Technology, Inc., Baltimore, MD, USA
| | - Paul C DeLeo
- American Cleaning Institute, Washington, DC, USA
| | - Bryan W Brooks
- Environmental Health Science Program, Department of Environmental Science, Baylor University, Waco, TX, USA; Institute of Biomedical Studies, Baylor University, Waco, TX, USA.
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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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Galloway SM. International regulatory requirements for genotoxicity testing for pharmaceuticals used in human medicine, and their impurities and metabolites. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:296-324. [PMID: 28299826 DOI: 10.1002/em.22077] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/05/2017] [Indexed: 06/06/2023]
Abstract
The process of developing international (ICH) guidelines is described, and the main guidelines reviewed are the ICH S2(R1) guideline that includes the genotoxicity test battery for human pharmaceuticals, and the ICH M7 guideline for assessing and limiting potentially mutagenic impurities and degradation products in drugs. Key aspects of the guidelines are reviewed in the context of drug development, for example the incorporation of genotoxicity assessment into non-clinical toxicity studies, and ways to develop and assess weight of evidence. In both guidelines, the existence of "thresholds" or non-linear dose responses for genotoxicity plays a part in the strategies. Differences in ICH S2(R1) protocol recommendations from OECD guidelines are highlighted and rationales explained. The use of genotoxicity data during clinical development and in assessment of carcinogenic potential is also described. There are no international guidelines on assessment of potentially genotoxic metabolites, but some approaches to safety assessment are discussed for these. Environ. Mol. Mutagen. 58:296-324, 2017. © 2017 Wiley Periodicals, Inc.
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Boobis A, Brown P, Cronin MTD, Edwards J, Galli CL, Goodman J, Jacobs A, Kirkland D, Luijten M, Marsaux C, Martin M, Yang C, Hollnagel HM. Origin of the TTC values for compounds that are genotoxic and/or carcinogenic and an approach for their re-evaluation. Crit Rev Toxicol 2017; 47:705-727. [PMID: 28510487 DOI: 10.1080/10408444.2017.1318822] [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: 02/08/2023]
Abstract
The threshold of toxicological concern (TTC) approach is a resource-effective de minimis method for the safety assessment of chemicals, based on distributional analysis of the results of a large number of toxicological studies. It is being increasingly used to screen and prioritize substances with low exposure for which there is little or no toxicological information. The first step in the approach is the identification of substances that may be DNA-reactive mutagens, to which the lowest TTC value is applied. This TTC value was based on the analysis of the cancer potency database and involved a number of assumptions that no longer reflect the state-of-the-science and some of which were not as transparent as they could have been. Hence, review and updating of the database is proposed, using inclusion and exclusion criteria reflecting current knowledge. A strategy for the selection of appropriate substances for TTC determination, based on consideration of weight of evidence for genotoxicity and carcinogenicity is outlined. Identification of substances that are carcinogenic by a DNA-reactive mutagenic mode of action and those that clearly act by a non-genotoxic mode of action will enable the protectiveness to be determined of both the TTC for DNA-reactive mutagenicity and that applied by default to substances that may be carcinogenic but are unlikely to be DNA-reactive mutagens (i.e. for Cramer class I-III compounds). Critical to the application of the TTC approach to substances that are likely to be DNA-reactive mutagens is the reliability of the software tools used to identify such compounds. Current methods for this task are reviewed and recommendations made for their application.
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Affiliation(s)
- Alan Boobis
- a Department of Medicine , Imperial College London , London , UK
| | - Paul Brown
- b US Food and Drug Administration , Silver Spring , MD , USA
| | | | - James Edwards
- d DSM Nutritional Products Ltd , Kaiseraugst , Switzerland
| | - Corrado Lodovico Galli
- e Department of Pharmacological and Biomolecular Sciences , University of Milan , Milan , Italy
| | - Jay Goodman
- f Department of Pharmacology and Toxicology , Michigan State University , East Lansing , MI , USA
| | - Abigail Jacobs
- b US Food and Drug Administration , Silver Spring , MD , USA
| | | | - Mirjam Luijten
- h Centre for Health Protection , National Institute for Public Health and the Environment (RIVM) , Bilthoven , The Netherlands
| | | | - Matthew Martin
- j Environmental Protection Agency , Washington , DC , USA
| | - Chihae Yang
- k Chemical and Biomolecular Engineering , The Ohio State University , Columbus , OH , USA.,l Molecular Networks GmbH , Nürnberg , Germany.,m Altamira LLC , Columbus , OH , USA
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18
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Douša M, Doubský J, Srbek J. Utilization of Photochemically Induced Fluorescence Detection for HPLC Determination of Genotoxic Impurities in the Vortioxetine Manufacturing Process. J Chromatogr Sci 2016; 54:1625-1630. [DOI: 10.1093/chromsci/bmw116] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 03/21/2016] [Indexed: 11/13/2022]
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19
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Recent developments in the risk assessment of chemicals in food and their potential impact on the safety assessment of substances used in food contact materials. EFSA J 2016. [DOI: 10.2903/j.efsa.2016.4357] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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20
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Criteria for the Research Institute for Fragrance Materials, Inc. (RIFM) safety evaluation process for fragrance ingredients. Food Chem Toxicol 2015; 82 Suppl:S1-S19. [DOI: 10.1016/j.fct.2014.11.014] [Citation(s) in RCA: 1123] [Impact Index Per Article: 124.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 11/13/2014] [Accepted: 11/17/2014] [Indexed: 11/24/2022]
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21
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Costigan S, Meredith C. An approach to ingredient screening and toxicological risk assessment of flavours in e-liquids. Regul Toxicol Pharmacol 2015; 72:361-9. [DOI: 10.1016/j.yrtph.2015.05.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/14/2015] [Accepted: 05/16/2015] [Indexed: 11/16/2022]
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22
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Bhatia S, Schultz T, Roberts D, Shen J, Kromidas L, Marie Api A. Comparison of Cramer classification between Toxtree, the OECD QSAR Toolbox and expert judgment. Regul Toxicol Pharmacol 2014; 71:52-62. [PMID: 25460032 DOI: 10.1016/j.yrtph.2014.11.005] [Citation(s) in RCA: 435] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 11/10/2014] [Accepted: 11/12/2014] [Indexed: 11/29/2022]
Abstract
The Threshold of Toxicological Concern (TTC) is a pragmatic approach in risk assessment. In the absence of data, it sets up levels of human exposure that are considered to have no appreciable risk to human health. The Cramer decision tree is used extensively to determine these exposure thresholds by categorizing non-carcinogenic chemicals into three different structural classes. Therefore, assigning an accurate Cramer class to a material is a crucial step to preserve the integrity of the risk assessment. In this study the Cramer class of over 1000 fragrance materials across diverse chemical classes were determined by using Toxtree (TT), the OECD QSAR Toolbox (TB), and expert judgment. Disconcordance was observed between TT and the TB. A total of 165 materials (16%) showed different results from the two programs. The overall concordance for Cramer classification between TT and expert judgment is 83%, while the concordance between the TB and expert judgment is 77%. Amines, lactones and heterocycles have the lowest percent agreement with expert judgment for TT and the TB. For amines, the expert judgment agreement is 45% for TT and 55% for the TB. For heterocycles, the expert judgment agreement is 55% for TT and the TB. For lactones, the expert judgment agreement is 56% for TT and 50% for the TB. Additional analyses were conducted to determine the concordance within various chemical classes. Critical checkpoints in the decision tree are identified. Strategies and guidance on determining the Cramer class for various chemical classes are discussed.
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Affiliation(s)
- Sneha Bhatia
- Research Institute for Fragrance Materials, Inc., 50 Tice Blvd., Woodcliff Lake, NJ 07677, USA
| | - Terry Schultz
- The University of Tennessee, College of Veterinary, 2407 River Dr., Knoxville, TN 37996, USA
| | - David Roberts
- Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Jie Shen
- Research Institute for Fragrance Materials, Inc., 50 Tice Blvd., Woodcliff Lake, NJ 07677, USA
| | - Lambros Kromidas
- Research Institute for Fragrance Materials, Inc., 50 Tice Blvd., Woodcliff Lake, NJ 07677, USA.
| | - Anne Marie Api
- Research Institute for Fragrance Materials, Inc., 50 Tice Blvd., Woodcliff Lake, NJ 07677, USA
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23
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Galloway SM, Vijayaraj Reddy M, McGettigan K, Gealy R, Bercu J. Potentially mutagenic impurities: Analysis of structural classes and carcinogenic potencies of chemical intermediates in pharmaceutical syntheses supports alternative methods to the default TTC for calculating safe levels of impurities. Regul Toxicol Pharmacol 2013; 66:326-35. [DOI: 10.1016/j.yrtph.2013.05.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/09/2013] [Accepted: 05/11/2013] [Indexed: 12/01/2022]
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24
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Mons MN, Heringa MB, van Genderen J, Puijker LM, Brand W, van Leeuwen CJ, Stoks P, van der Hoek JP, van der Kooij D. Use of the Threshold of Toxicological Concern (TTC) approach for deriving target values for drinking water contaminants. WATER RESEARCH 2013; 47:1666-1678. [PMID: 23312671 DOI: 10.1016/j.watres.2012.12.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 11/21/2012] [Accepted: 12/17/2012] [Indexed: 06/01/2023]
Abstract
Ongoing pollution and improving analytical techniques reveal more and more anthropogenic substances in drinking water sources, and incidentally in treated water as well. In fact, complete absence of any trace pollutant in treated drinking water is an illusion as current analytical techniques are capable of detecting very low concentrations. Most of the substances detected lack toxicity data to derive safe levels and have not yet been regulated. Although the concentrations in treated water usually do not have adverse health effects, their presence is still undesired because of customer perception. This leads to the question how sensitive analytical methods need to become for water quality screening, at what levels water suppliers need to take action and how effective treatment methods need to be designed to remove contaminants sufficiently. Therefore, in the Netherlands a clear and consistent approach called 'Drinking Water Quality for the 21st century (Q21)' has been developed within the joint research program of the drinking water companies. Target values for anthropogenic drinking water contaminants were derived by using the recently introduced Threshold of Toxicological Concern (TTC) approach. The target values for individual genotoxic and steroid endocrine chemicals were set at 0.01 μg/L. For all other organic chemicals the target values were set at 0.1 μg/L. The target value for the total sum of genotoxic chemicals, the total sum of steroid hormones and the total sum of all other organic compounds were set at 0.01, 0.01 and 1.0 μg/L, respectively. The Dutch Q21 approach is further supplemented by the standstill-principle and effect-directed testing. The approach is helpful in defining the goals and limits of future treatment process designs and of analytical methods to further improve and ensure the quality of drinking water, without going to unnecessary extents.
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Affiliation(s)
- M N Mons
- KWR Watercycle Research Institute, P.O. Box 1072, 3430 BB Nieuwegein, The Netherlands
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25
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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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26
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Canady R, Lane R, Paoli G, Wilson M, Bialk H, Hermansky S, Kobielush B, Lee JE, Llewellyn C, Scimeca J. Determining the applicability of threshold of toxicological concern approaches to substances found in foods. Crit Rev Food Sci Nutr 2013; 53:1239-49. [PMID: 24090142 PMCID: PMC3809586 DOI: 10.1080/10408398.2012.752341] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2022]
Abstract
Threshold of Toxicological Concern (TTC) decision-support methods present a pragmatic approach to using data from well-characterized chemicals and protective estimates of exposure in a stepwise fashion to inform decisions regarding low-level exposures to chemicals for which few data exist. It is based on structural and functional categorizations of chemicals derived from decades of animal testing with a wide variety of chemicals. Expertise is required to use the TTC methods, and there are situations in which its use is clearly inappropriate or not currently supported. To facilitate proper use of the TTC, this paper describes issues to be considered by risk managers when faced with the situation of an unexpected substance in food. Case studies are provided to illustrate the implementation of these considerations, demonstrating the steps taken in deciding whether it would be appropriate to apply the TTC approach in each case. By appropriately applying the methods, employing the appropriate scientific expertise, and combining use with the conservative assumptions embedded within the derivation of the thresholds, the TTC can realize its potential to protect public health and to contribute to efficient use of resources in food safety risk management.
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Affiliation(s)
- Richard Canady
- Center for Risk Science Innovation and Application (RSIA), ILSI Research Foundation, 1156 Fifteenth Street NW, Suite 200, Washington, DC 20005-1743, USA
| | - Richard Lane
- PepsiCo Inc., 350 Columbus Avenue, Valhalla, NY 10595, USA
| | - Greg Paoli
- Risk Sciences International (RSI), 325 Dalhousie Street, 10th Floor, Ottawa, ON K1N 7G2, Canada
| | - Margaret Wilson
- Risk Sciences International (RSI), 325 Dalhousie Street, 10th Floor, Ottawa, ON K1N 7G2, Canada
| | - Heidi Bialk
- PepsiCo Inc., 350 Columbus Avenue, Valhalla, NY 10595, USA
| | - Steven Hermansky
- Scientific and Regulatory Affairs and Toxicology, ConAgra Foods Inc., Six ConAgra Drive, Mail Stop 6-460, Omaha, NE 68102-5006, USA
| | - Brent Kobielush
- General Mills Inc., One General Mills Boulevard, W01-B, Minneapolis, MN 55426, USA
| | - Ji-Eun Lee
- Kellogg Co., 2 Hamblin Avenue E, Battle Creek, MI 49017, USA
| | - Craig Llewellyn
- Scientific and Regulatory Affairs, Coca-Cola Company North America, One Coca-Cola Plaza, PO Box Drawer 1734, Atlanta, GA 30301, USA
| | - Joseph Scimeca
- Cargill Inc., 15407 McGinty Road West, MS #56, Wayzata, MN 55391, USA
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27
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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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28
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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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29
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Scientific Opinion on Evaluation of the Toxicological Relevance of Pesticide Metabolites for Dietary Risk Assessment. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2799] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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30
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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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31
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Scientific Opinion on the criteria to be used for safety evaluation of a mechanical recycling process to produce recycled PET intended to be used for manufacture of materials and articles in contact with food. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2184] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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32
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Bassan A, Fioravanzo E, Pavan M, Stocchero M. Applicability of physicochemical data, QSARs and read‐across in Threshold of Toxicological Concern assessment. ACTA ACUST UNITED AC 2011. [DOI: 10.2903/sp.efsa.2011.en-159] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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33
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Giordani A, Kobel W, Gally HU. Overall impact of the regulatory requirements for genotoxic impurities on the drug development process. Eur J Pharm Sci 2011; 43:1-15. [PMID: 21420491 DOI: 10.1016/j.ejps.2011.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 01/18/2011] [Accepted: 03/05/2011] [Indexed: 11/19/2022]
Abstract
In the last decade a considerable effort has been made both by the regulators and the pharmaceutical industry to assess genotoxic impurities (GTI) in pharmaceutical products. Though the control of impurities in drug substances and products is a well established and consolidated procedure, its extension to GTI has given rise to a number of problems, both in terms of setting the limits and detecting these impurities in pharmaceutical products. Several papers have dealt with this issue, discussing available regulations, providing strategies to evaluate the genotoxic potential of chemical substances, and trying to address the analytical challenge of detecting GTI at trace levels. In this review we would like to discuss the available regulations, the toxicological background for establishing limits, as well as the analytical approaches used for GTI assessment. The final aim is that of providing a complete overview of the topic with updated available information, to address the overall GTI issue during the development of new drug substances.
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34
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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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35
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Safety of botanical ingredients in personal care products/cosmetics. Food Chem Toxicol 2010; 49:324-41. [PMID: 21111022 DOI: 10.1016/j.fct.2010.11.022] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 11/17/2010] [Accepted: 11/17/2010] [Indexed: 11/20/2022]
Abstract
The key issue of the safety assessment of botanical ingredients in personal care products (PCP) is the phytochemical characterisation of the plant source, data on contamination, adulteration and hazardous residues. The comparative approach used in the safety assessment of GM-plants may be applied to novel botanical PCP ingredients. Comparator(s) are the parent plant or varieties of the same species. Chemical grouping includes definition of chemical groups suitable for a read-across approach; it allows the estimation of toxicological endpoints on the basis of data from related substances (congeneric groups) with physical/chemical properties producing similar toxicities. The Threshold of Toxicological Concern (TTC) and Dermal Sensitisation Threshold (DST) are tools for the assessment of trace substances or minor ingredients. The evaluation of skin penetration of substances present in human food is unnecessary, whereas mixtures may be assessed on the basis of physical/chemical properties of individual substances. Adverse dermal effects of botanicals include irritation, sensitisation, phototoxicity and immediate-type allergy. The experience from dietary supplements or herbal medicines showed that being natural is not equivalent to being safe. Pragmatic approaches for quality and safety standards of botanical ingredients are needed; consumer safety should be the first objective of conventional and botanical PCP ingredients.
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36
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Santos ASF, Agnelli JAM, Manrich S. Evaluation of sub-critical water as an extraction fluid for model contaminants from recycled PET for reuse as food packaging material. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2010; 27:567-73. [PMID: 20063227 DOI: 10.1080/19440040903440372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Recycling of plastics for food-contact packaging is an important issue and research into meaningful and cost-effective solutions is in progress. In this paper, the use of sub-critical water was evaluated as an alternative way of purifying poly(ethylene terephthalate) (PET) flakes for direct food contact applications. The effects of temperature, pressure and flow rate were assessed on the extraction efficiency of two of the most challenging classes of contaminants (toluene and benzophenone) from PET by sub-critical water using a first-order fractional experimental design. Extraction yield was quantified using GC/FID. The most important parameter was flow rate, indicating that the decrease in sub-critical water polarity with temperature was insufficient to eliminate partition effects. Temperature was also important, but only for the optimization of toluene extraction. These results may be explained by the poor solubility of higher molar mass compounds in sub-critical water compared to lower molar mass compounds under the same conditions, and the small decrease in dielectric constant with temperature under the experimental conditions evaluated. As cleaning efficiency is low and PET is very susceptible to hydrolysis, which limits the use of higher temperatures vis-à-vis physical recycling, the proposed extraction is unsuitable for a standalone super-clean process but may be a step in the process.
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Affiliation(s)
- Amélia S F Santos
- Department of Materials Engineering (DEMa), Federal University of Sao Carlos (UFSCar), CP 676, 13565-905-Sao Carlos, SP, Brazil
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37
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Elder DP, Harvey JS. Is there a Real Case for Cumulative Control of Structurally Related Genotoxic Impurities? Org Process Res Dev 2010. [DOI: 10.1021/op900343g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David P. Elder
- Pre-Clinical Development, GlaxoSmithKline R&D, Park Road, Ware, Hertfordshire SG120DP, United Kingdom
| | - James S. Harvey
- Pre-Clinical Development, GlaxoSmithKline R&D, Park Road, Ware, Hertfordshire SG120DP, United Kingdom
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38
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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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39
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Bercu JP, Dobo KL, Gocke E, McGovern TJ. Overview of Genotoxic Impurities in Pharmaceutical Development. Int J Toxicol 2009; 28:468-78. [DOI: 10.1177/1091581809349195] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This symposium focuses on the management of genotoxic impurities in the synthesis of pharmaceuticals. Recent developments in both Europe and United States require sponsors of new drug applications to develop processes to control the risks of potential genotoxic impurities. Genotoxic impurities represent a special case relative to the International Conference on Harmonisation Q3A/Q3B guidances, because genotoxicity tests used to qualify the drug substance may not be sufficient to demonstrate safety of a potentially genotoxic impurity. The default risk management approach for a genotoxic impurity is the threshold of toxicological concern unless a more specific risk characterization is appropriate. The symposium includes descriptions of industry examples where impurities are introduced and managed in the synthesis of a pharmaceutical. It includes recent regulatory developments such as the “staged threshold of toxicological concern” when administration is of short duration (eg, during clinical trials).
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Affiliation(s)
| | | | - Elmar Gocke
- F. Hoffmann-La Roche Ltd, Basel, Switzerland
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40
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Felter S, Lane RW, Latulippe ME, Craig Llewellyn G, Olin SS, Scimeca JA, Trautman TD. Refining the threshold of toxicological concern (TTC) for risk prioritization of trace chemicals in food. Food Chem Toxicol 2009; 47:2236-45. [DOI: 10.1016/j.fct.2009.06.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2008] [Revised: 06/01/2009] [Accepted: 06/04/2009] [Indexed: 11/26/2022]
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41
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Expert Report: Making Decisions about the Risks of Chemicals in Foods with Limited Scientific Information. Compr Rev Food Sci Food Saf 2009; 8:269-303. [DOI: 10.1111/j.1541-4337.2009.00081.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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42
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Hardin BD, Robbins CA, Fallah P, Kelman BJ. The concentration of no toxicologic concern (CoNTC) and airborne mycotoxins. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:585-598. [PMID: 19296408 DOI: 10.1080/15287390802706389] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The threshold of toxicologic concern (TTC) concept was developed as a method to identify a chemical intake level that is predicted to be without adverse human health effects assuming daily intake over the course of a 70-yr life span. The TTC values are based on known structure-activity relationships and do not require chemical-specific toxicity data. This allows safety assessment (or prioritization for testing) of chemicals with known molecular structure but little or no toxicity data. Recently, the TTC concept was extended to inhaled substances by converting a TTC expressed in micrograms per person per day to an airborne concentration (ng/m(3)), making allowance for intake by routes in addition to inhalation and implicitly assuming 100% bioavailability of inhaled toxicants. The resulting concentration of no toxicologic concern (CoNTC), 30 ng/m(3), represents a generic airborne concentration that is expected to pose no hazard to humans exposed continuously throughout a 70-yr lifetime. Published data on the levels of mycotoxins in agricultural dusts or in fungal spores, along with measured levels of airborne mycotoxins, spores, or dust in various environments, were used to identify conditions under which mycotoxin exposures might reach the CoNTC. Data demonstrate that airborne concentrations of dusts and mold spores sometimes encountered in agricultural environments have the potential to produce mycotoxin concentrations greater than the CoNTC. On the other hand, these data suggest that common exposures to mycotoxins from airborne molds in daily life, including in the built indoor environment, are below the concentration of no toxicologic concern.
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43
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Dobbins LL, Brain RA, Brooks BW. Comparison of the sensitivities of common in vitro and in vivo assays of estrogenic activity: application of chemical toxicity distributions. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2008; 27:2608-2616. [PMID: 18699703 DOI: 10.1897/08-126.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Accepted: 07/02/2008] [Indexed: 05/26/2023]
Abstract
A number of contaminants in municipal effluent discharges are estrogen agonists to fish. Whereas several in vitro and in vivo techniques have been developed to assess the estrogenic activity of these compounds or ambient environmental samples, previous comparisons of the relative sensitivities of these approaches remain inconclusive. We employed a probabilistic hazard assessment approach using chemical toxicity distributions (CTDs) to perform a novel evaluation of relative sensitivities of six common in vitro and in vivo assays. We predicted that there was an 8.3% (human breast ademocarcinoma cell line, MCF-7, assay), 6.3% (yeast estrogen screen assay), or 1.9% (fish hepatocyte vitellogenin, VTG, assay) probability of detecting a compound in aquatic systems that will elicit an estrogenic response at concentrations at or below 0.1 microg/L, suggesting that the MCF-7 assay was the most sensitive in vitro assay evaluated in this study. The probabilities of eliciting the estrogenic response of VTG induction at a concentration less than 0.1 microg/L in rainbow trout, fathead minnow, and Japanese medaka were determined at 29.9, 26.2, and 18.8%, respectively. Thus, rainbow trout VTG induction was the most sensitive in vivo assay assessed. Subsequently, CTDs may provide a useful technique for hazard assessment of chemical classes for which exposure data are limited and for chemicals with common toxicological mechanisms and modes of action.
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Affiliation(s)
- Laura L Dobbins
- Department of Environmental Science, Institute of Biomedical Studies, Center for Reservoir and Aquatic Systems Research, Baylor University, One Bear Place No. 97266, Waco, Texas 76798, USA
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44
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Yuabova ZY, Holschlag DR, Rodriguez SA, Qin C, Papov VV, Qiu F, McCaffrey JF, Norwood DL. Genotoxic Impurities: A Quantitative Approach. J LIQ CHROMATOGR R T 2008. [DOI: 10.1080/10826070802281745] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Zhanna Y. Yuabova
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
| | - David R. Holschlag
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
| | | | - Cindy Qin
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
| | - Vladimir V. Papov
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
| | - Fenghe Qiu
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
| | - John F. McCaffrey
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
| | - Daniel L. Norwood
- a Boehringer Ingelheim Pharmaceuticals, Inc. , Ridgefield, Connecticut, USA
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45
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Munro IC, Renwick AG, Danielewska-Nikiel B. The Threshold of Toxicological Concern (TTC) in risk assessment. Toxicol Lett 2008; 180:151-6. [PMID: 18573621 DOI: 10.1016/j.toxlet.2008.05.006] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2008] [Revised: 05/12/2008] [Accepted: 05/14/2008] [Indexed: 11/29/2022]
Abstract
The Threshold of Toxicological Concern (TTC) is a level of human intake or exposure that is considered to be of negligible risk, despite the absence of chemical-specific toxicity data. The TTC approach is a form of risk characterisation in which uncertainties arising from the use of data on other compounds are balanced against the low level of exposure. The approach was initially developed by the FDA for packaging migrants, and used a single threshold value of 1.5 microg/day (called the threshold of regulation). Subsequent analyses of chronic toxicity data resulted in the development of TTC values for three structural classes with different potentials for toxicity (1,800, 540 and 90 microg/day). These TTC values have been incorporated into the procedure that is used internationally for the evaluation of flavouring substances. Further developments included additional TTC values for certain structural alerts for genotoxicity (0.15 microg/day), and for the presence of an organophosphate group (18 microg/day). All of these TTC values were incorporated into an extended decision tree for chemicals, such as contaminants, which might be present in human foods. The TTC approach has been shown to have potential applications to risk assessments of cosmetic ingredients, household products and impurities in therapeutic drugs.
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Affiliation(s)
- I C Munro
- CANTOX Health Sciences International, 2233 Argentia Road, Suite 308, Mississauga, Ontario, Canada, L5N 2X7
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46
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Safford RJ. The Dermal Sensitisation Threshold- a TTC approach for allergic contact dermatitis. Regul Toxicol Pharmacol 2008; 51:195-200. [PMID: 18406502 DOI: 10.1016/j.yrtph.2008.02.010] [Citation(s) in RCA: 381] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 02/06/2008] [Accepted: 02/27/2008] [Indexed: 10/22/2022]
Abstract
The Threshold of Toxicological Concern (TTC) is a useful concept that is becoming of increasing interest as an addition to the arsenal of tools used for characterising the toxicological risk of human exposure to chemicals. Traditionally used for low level indirect additives, flavours and contaminants in foods, the TTC obviates the need for toxicological testing of chemicals where human exposure is low. Proposals have recently been made for the use of the TTC for low level ingredients in cosmetic and personal care products. However, use of the TTC is only protective for systemic toxicity endpoints, and cannot be used for local endpoints such as contact sensitisation. In this paper a probabilistic analysis of available sensitisation data, similar to that used in the development of the TTC, is presented. The incidence of sensitisers in the world of chemicals was estimated using the ELINCS (European List of Notified Chemical Substances) data set, and a distribution for sensitisation potency was established using a recently published compilation of Local Lymph Node Assay data. From the analysis of these data sets it is concluded that a Dermal Sensitisation Threshold (DST) can be established below which there is no appreciable risk of sensitisation, even for an untested ingredient. Use of a DST would preclude the need for sensitisation testing of ingredients where dermal exposure is sufficiently low.
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Affiliation(s)
- R J Safford
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedford MK44 1LQ, UK.
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47
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Patlewicz G, Jeliazkova N, Safford RJ, Worth AP, Aleksiev B. An evaluation of the implementation of the Cramer classification scheme in the Toxtree software. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2008; 19:495-524. [PMID: 18853299 DOI: 10.1080/10629360802083871] [Citation(s) in RCA: 225] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Risk assessment for most human health effects is based on the threshold of a toxicological effect, usually derived from animal experiments. The Threshold of Toxicological Concern (TTC) is a concept that refers to the establishment of a level of exposure for all chemicals below which there would be no appreciable risk to human health. When carefully applied, the TTC concept can provide a means of waiving testing based on knowledge of exposure limits. Two main approaches exist; the first of these is a General Threshold of Toxicological Concern; the second approach is a TTC in relation to structural information and/or toxicological data of chemicals. The structural scheme most routinely used is that of Cramer and co-workers from 1978. Recently this scheme was encoded into a software program called Toxtree, specifically commissioned by the European Chemicals Bureau (ECB). Here we evaluate two published datasets using Toxtree to demonstrate its concordance and highlight potential software modifications. The results were promising with an overall good concordance between the reported classifications and those generated by Toxtree. Further evaluation of these results highlighted a number of inconsistencies which were examined in turn and rationalised as far as possible. Improvements for Toxtree were proposed where appropriate. Notable of these is a necessity to update the lists of common food components and normal body constituents as these accounted for the majority of false classifications observed. Overall Toxtree was found to be a useful tool in facilitating the systematic evaluation of compounds through the Cramer scheme.
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Affiliation(s)
- G Patlewicz
- European Commission, DG Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy.
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48
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Kroes R, Renwick AG, Feron V, Galli CL, Gibney M, Greim H, Guy RH, Lhuguenot JC, van de Sandt JJM. Application of the threshold of toxicological concern (TTC) to the safety evaluation of cosmetic ingredients. Food Chem Toxicol 2007; 45:2533-62. [PMID: 17664037 DOI: 10.1016/j.fct.2007.06.021] [Citation(s) in RCA: 1363] [Impact Index Per Article: 80.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 05/25/2007] [Accepted: 06/15/2007] [Indexed: 12/31/2022]
Abstract
The threshold of toxicological concern (TTC) has been used for the safety assessment of packaging migrants and flavouring agents that occur in food. The approach compares the estimated oral intake with a TTC value derived from chronic oral toxicity data for structurally-related compounds. Application of the TTC approach to cosmetic ingredients and impurities requires consideration of whether route-dependent differences in first-pass metabolism could affect the applicability of TTC values derived from oral data to the topical route. The physicochemical characteristics of the chemical and the pattern of cosmetic use would affect the long-term average internal dose that is compared with the relevant TTC value. Analysis has shown that the oral TTC values are valid for topical exposures and that the relationship between the external topical dose and the internal dose can be taken into account by conservative default adjustment factors. The TTC approach relates to systemic effects, and use of the proposed procedure would not provide an assessment of any local effects at the site of application. Overall the TTC approach provides a useful additional tool for the safety evaluation of cosmetic ingredients and impurities of known chemical structure in the absence of chemical-specific toxicology data.
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Affiliation(s)
- R Kroes
- Institute for Risk Assessment Sciences, Utrecht University, c/o Seminariehof 38, NL- 3768 EE Soest, The Netherlands
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Delaney EJ. An impact analysis of the application of the threshold of toxicological concern concept to pharmaceuticals. Regul Toxicol Pharmacol 2007; 49:107-24. [PMID: 17888551 DOI: 10.1016/j.yrtph.2007.06.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 06/12/2007] [Accepted: 06/13/2007] [Indexed: 11/29/2022]
Abstract
The recent application of the threshold of toxicological concern (TTC) concept to the regulation of pharmaceuticals in the European Union is analyzed. The derivation of TTC and the threshold of regulation that followed it were originally intended to provide makers of food contact materials greater flexibility with their products, while allowing the CFSAN branch of FDA to conserve its resources for more important issues. A reanalysis of the scientific data employed by EMEA regulators to rationalize its 1.5 mcg default genotoxic impurity limit is presented to demonstrate (a) that direct translation of conclusions relevant to food consumption are unduly influenced by many classes of potent carcinogens of historic concern which would be impossible to generate unknowingly as pharmaceutical impurities, and (b) that the majority of reactive chemicals that would be useful to synthetic chemists are among the least potent carcinogens in the underpinning supportive analyses. Evidence is further presented to show that implementation and acceptance of a 1.5 mcg TTC-based total limit on such impurities can be expected to impede pharmaceutical research and development efficiency while providing an insignificant cancer risk-avoidance benefit to patients who require pharmaceutical treatments. The conclusion drawn is that a significantly higher default limit can readily be defended that would be both in keeping with TTC principles and the best interest of patients.
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Affiliation(s)
- Edward J Delaney
- Bristol-Myers Squibb Company, One Squibb Drive, New Brunswick, NJ 08903, USA.
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50
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Drew R, Frangos J. The concentration of no toxicological concern (CoNTC): a risk assessment screening tool for air toxics. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1584-93. [PMID: 17763076 DOI: 10.1080/15287390701429539] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Although numerous chemicals might occur in ambient air as a result of natural or anthropogenic activity (primarily through vehicle exhaust and industrial emissions), not all are necessarily of concern for public health even if they are classified as hazardous. There are many minor components in emissions that are predicted to be present at small concentrations. For the majority of these chemicals a health-based guideline does not exist to facilitate risk assessment. Furthermore, there are no appropriate toxicological or health data to enable health-based guidelines to be established. Consequently in most risk assessments these substances are usually, and conveniently, ignored. The tacit justification is that concentrations in ambient air are small and thus insignificant. For many stakeholders this is an inadequate explanation, and the justifiable question of how it is known exposures are insignificant for health is often asked. The concept of a "concentration of no toxicological concern" (CoNTC) was developed for air toxics and can be applied as a risk assessment screening tool to legitimately dismiss substances whose ground-level concentrations are predicted to be trivial. The CoNTC helps define trivial and is grounded in regulatory and scientific deliberations of the U.S. Food and Drug Administration (FDA) and the European Commission for developing concentrations of no toxicological or regulatory concern for contaminants in food. The suggested conservative generic CoNTC value that can be applied to most organic chemicals in air is 0.03 microg/m3. The derivation of the CoNTC and its validation and limitations are discussed, and its utility as a screening tool is presented.
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Affiliation(s)
- Roger Drew
- Toxikos Pty Ltd, East Caulfield, Victoria, Australia.
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