Evaluation of Tebuconazole, Triclosan, Methylparaben and Ethylparaben According to the Danish Proposal for Criteria for Endocrine Disrupters
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Downloaded from orbit.dtu.dk on: Sep 26, 2021 Evaluation of tebuconazole, triclosan, methylparaben and ethylparaben according to the Danish proposal for criteria for endocrine disrupters Hass, Ulla; Christiansen, Sofie; Petersen, Marta Axelstad; Boberg, Julie; Andersson, Anna-Maria ; Skakkebæk, Niels Erik ; Bay, Katrine ; Holbech, Henrik ; Lund Kinnberg, Karin ; Bjerregaard, Poul Publication date: 2012 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Hass, U., Christiansen, S., Petersen, M. A., Boberg, J., Andersson, A-M., Skakkebæk, N. E., Bay, K., Holbech, H., Lund Kinnberg, K., & Bjerregaard, P. (2012). Evaluation of tebuconazole, triclosan, methylparaben and ethylparaben according to the Danish proposal for criteria for endocrine disrupters. Danish Centre on Endocrine Disrupters. 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Page 1 Evaluation of tebuconazole, triclosan, methylparaben and ethylparaben according to the Danish proposal for criteria for endocrine disrupters, May 2012 Evaluation of tebuconazole, triclosan, methylparaben and ethylparaben according to the Danish proposal for criteria for endocrine disrupters DANISH CENTRE ON ENDOCRINE DISRUPTERS Ulla Hass, Sofie Christiansen, Marta Axelstad, and Julie Boberg Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark Anna-Maria Andersson, Niels Erik Skakkebæk and Katrine Bay Department of Growth and Reproduction, Copenhagen University Hospital Henrik Holbech, Karin Lund Kinnberg and Poul Bjerregaard Institute of Biology, University of Southern Denmark Page 2 Terms of reference and scope This report has been prepared by the Danish Centre on Endocrine Disrupters (CEHOS) as a project contracted by the Danish Environmental Protection Agency. The Danish Centre on Endocrine Disrupters is an interdisciplinary scientific network without walls. The main purpose of the Centre is to build and gather new knowledge on endocrine disrupters with the focus on providing information requested for the preventive work of the regulatory authorities. The Centre is financed by the Ministry of the Environment and the scientific work programme is followed by an international scientific advisory board. The overall scope of this project is to provide a science based evaluation of tebuconazole, triclosan, methylparaben and ethylparaben and their endocrine disrupting properties. 1. Background and aim During the last years Denmark has been focusing the work under the national strategy on endocrine disruptors on regulatory measures with the aim to reduce human and environmental exposure to endocrine disruptors. As a first step towards more systematic regulation of endocrine disruptors the Danish Environmental Protection Agency contributed to the ongoing EU-process on criteria setting for endocrine disruptors by submitting the report: Establishment of Criteria for Endocrine Disruptors and Options for Regulation in May 2011 (Danish EPA, 2011). In relation to this work and the REACH process the DK-EPA has asked the Danish Centre on Endocrine Disrupters to conduct a project which is to evaluate tebuconazole, triclosan, methyl paraben and ethyl paraben. The overall aim is to categorize the 4 substances on the basis of the Danish proposal for criteria for endocrine disrupters which is scientifically justified by a report (Hass et al., 2011). This means that the evaluation is based on results from both human health, in vitro/vivo studies and studies in the environment. Furthermore, the 4 substances are evaluated according to the Joint British-German Position Paper: Regulatory Definition of an Endocrine Disrupter in relation to Potential Threat to Human Health that is based on a potency cut-off criteria (DE-UK, 2011). The substances and their main use(s) are shown in table 1. Page 3 Evaluation of tebuconazole, triclosan, methylparaben and ethylparaben according to the Danish proposal for criteria for endocrine disrupters, May 2012 Table 1. The evaluated substances and their main use(s) according to SIN list document Substance Use(s) Tebuconazole A triazole fungicide used agriculturally to treat against plant pathogenic fungi and as biocide (film, wood, masonry fibre, leather, rubber and polymerised material preservation). Triclosan A biocide used as an antibacterial and antifungal agent. Methylparaben Antifungal agent often used in a variety of cosmetics and personal-care products. As a food additive, it has E number E218 Ethylparaben An antifungal preservative used in personal care-products and as a food additive. As a food additive, it has E number E214 1.1 Danish Criteria for identification of ED The Danish proposal for criteria for EDs (Endocrine Disrupters) are described in detail in a previous report from CEHOS (Hass et al 2011) and will only be briefly described here. The criteria include 3 categories, i.e. ED (category 1), suspected ED (category 2a) and indicated ED (category 2b). The definitions of the categories are: An endocrine disrupter is an exogenous substance or mixture that alters function(s) of the endocrine system and causes adverse health effects in an intact organism, or its progeny, or (sub)populations." Potential endocrine disrupter: A suspected endocrine disrupter is an exogenous substance or mixture that may alter function(s) of the endocrine system and consequently may cause adverse health effects in an intact organism, or its progeny, or (sub)populations." A substance with indication of endocrine disrupting properties (called indicated ED) is an exogenous substance or mixture that possesses properties that might be expected to lead to endocrine disruption in an intact organism, or its progeny, or (sub)populations. The definition of EDs and suspected EDs both include the term “adverse”. The WHO/IPCS definition of the term “adversity” is used: “A change in morphology, physiology, growth, reproduction, development or lifespan of an organism which results in impairment of functional capacity or impairment of capacity to compensate for additional stress or increased susceptibility to the harmful effects of other environmental influences.” (WHO/IPCS 2004) In table 2 the criteria for placing substances in each of the three categories are presented. Page 4 Table 2 Proposed criteria for EDs Category 1- Endocrine disrupter Substances are placed in category 1 when they are known to have produced ED adverse effects in humans or animal species living in the environment or when there is evidence from animal studies, possibly supplemented with other information, to provide a strong presumption that the substance has the capacity to cause ED effects in humans or animals living in the environment. The animal studies shall provide clear evidence of ED effect in the absence of other toxic effects, or if occurring together with other toxic effects, the ED effects should be considered not to be a secondary non-specific consequence of other toxic effects. However, when there is e.g. mechanistic information that raises doubt about the relevance of the adverse effect for humans or the environment, Category 2a may be more appropriate. Substances can be allocated to this category based on: - Adverse in vivo effects where an ED mode of action is highly plausible - ED mode of action in vivo that is clearly linked to adverse in vivo effects (by e.g. read- across) Category 2a - Suspected ED Substances are placed in Category 2a when there is some evidence from humans or experimental animals, and where the evidence is not sufficiently convincing to place the substance in Category 1. If for example limitations in the study (or studies) make the quality of evidence less convincing, Category 2a could be more appropriate. Such effects should be observed in the absence of other toxic effects, or if occurring together with other toxic effects, the ED effect should be considered not to be a secondary non-specific consequence of other toxic effects. Substances can be allocated to this category based on: - Adverse effects in vivo where an ED mode of action is suspected - ED mode of action in vivo that is suspected to be linked to adverse effects in vivo - ED mode of action in vitro combined with toxicokinetic in vivo data (and relevant non test information such as read across, chemical categorisation and QSAR predictions) Category 2b – Substances with indications of ED properties (indicated ED) Substances are placed in Category 2b when there is in vitro/in silico evidence indicating potential for endocrine disruption in intact organisms. Evidence could also be observed effects in vivo that could be ED-mediated. A substance can be considered an ED (category 1) based on data from: • In vivo assays providing data on effects clearly linked to endocrine mechanisms (OECD, conceptual Framework (CF) level