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1.
Regul Toxicol Pharmacol ; 82: 156, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27825833

RESUMEN

The SCCS considers 2-phenoxyethanol safe for use as a preservative with a maximum concentration of 1.0%, taking into account the information provided. The toxicokinetics default factor of 4.0 can be reduced to 1.0 yielding a minimum Margin of Safety (MoS) of 25 instead of 100 for the safety assessment of 2-phenoxyethanol. Therefore, the MoS of about 50 for children also covers this specific age group who might be higher exposed to 2-phenoxyethanol than adults. This Opinion does not take into account exposure from sources other than cosmetics.


Asunto(s)
Seguridad de Productos para el Consumidor , Cosméticos/efectos adversos , Glicoles de Etileno/efectos adversos , Conservadores Farmacéuticos/efectos adversos , Pruebas de Toxicidad/métodos , Factores de Edad , Animales , Preescolar , Relación Dosis-Respuesta a Droga , Humanos , Medición de Riesgo , Factores de Riesgo , Toxicocinética
2.
Environ Health Perspect ; 123(12): 1232-40, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25956009

RESUMEN

BACKGROUND: Safety assessment for repeated dose toxicity is one of the largest challenges in the process to replace animal testing. This is also one of the proof of concept ambitions of SEURAT-1, the largest ever European Union research initiative on alternative testing, co-funded by the European Commission and Cosmetics Europe. This review is based on the discussion and outcome of a workshop organized on initiative of the SEURAT-1 consortium joined by a group of international experts with complementary knowledge to further develop traditional read-across and include new approach data. OBJECTIVES: The aim of the suggested strategy for chemical read-across is to show how a traditional read-across based on structural similarities between source and target substance can be strengthened with additional evidence from new approach data--for example, information from in vitro molecular screening, "-omics" assays and computational models--to reach regulatory acceptance. METHODS: We identified four read-across scenarios that cover typical human health assessment situations. For each such decision context, we suggested several chemical groups as examples to prove when read-across between group members is possible, considering both chemical and biological similarities. CONCLUSIONS: We agreed to carry out the complete read-across exercise for at least one chemical category per read-across scenario in the context of SEURAT-1, and the results of this exercise will be completed and presented by the end of the research initiative in December 2015.


Asunto(s)
Alternativas a las Pruebas en Animales , Pruebas de Toxicidad/métodos , Seguridad Química , Simulación por Computador , Toma de Decisiones , Unión Europea , Humanos , Relación Estructura-Actividad Cuantitativa , Pruebas de Toxicidad/normas
4.
Arch Toxicol ; 88(12): 2191-211, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25326817

RESUMEN

Nanotechnology offers enormous potential for technological progress. Fortunately, early and intensive efforts have been invested in investigating toxicology and safety aspects of this new technology. However, despite there being more than 6,000 publications on nanotoxicology, some key questions still have to be answered and paradigms need to be challenged. Here, we present a view on the field of nanotoxicology to stimulate the discussion on major knowledge gaps and the critical appraisal of concepts or dogma. First, in the ongoing debate as to whether nanoparticles may harbour a specific toxicity due to their size, we support the view that there is at present no evidence of 'nanospecific' mechanisms of action; no step-change in hazard was observed so far for particles below 100 nm in one dimension. Therefore, it seems unjustified to consider all consumer products containing nanoparticles a priori as hazardous. Second, there is no evidence so far that fundamentally different biokinetics of nanoparticles would trigger toxicity. However, data are sparse whether nanoparticles may accumulate to an extent high enough to cause chronic adverse effects. To facilitate hazard assessment, we propose to group nanomaterials into three categories according to the route of exposure and mode of action, respectively: Category 1 comprises nanomaterials for which toxicity is mediated by the specific chemical properties of its components, such as released ions or functional groups on the surface. Nanomaterials belonging to this category have to be evaluated on a case-by-case basis, depending on their chemical identity. Category 2 focuses on rigid biopersistent respirable fibrous nanomaterials with a specific geometry and high aspect ratio (so-called WHO fibres). For these fibres, hazard assessment can be based on the experiences with asbestos. Category 3 focuses on respirable granular biodurable particles (GBP) which, after inhalation, may cause inflammation and secondary mutagenicity that may finally lead to lung cancer. After intravenous, oral or dermal exposure, nanoscaled GBPs investigated apparently did not show 'nanospecific' effects so far. Hazard assessment of GBPs may be based on the knowledge available for granular particles. In conclusion, we believe the proposed categorization system will facilitate future hazard assessments.


Asunto(s)
Sustancias Peligrosas/química , Sustancias Peligrosas/toxicidad , Nanoestructuras/química , Nanoestructuras/toxicidad , Toxicología/métodos , Animales , Humanos , Tamaño de la Partícula , Medición de Riesgo , Solubilidad , Propiedades de Superficie , Pruebas de Toxicidad
5.
Toxicol Lett ; 231(3): 378-86, 2014 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-25072144

RESUMEN

On September 9th, 2002, two goods trains collided in Bad Münder, Lower Saxony, causing the release of more than 40 metric tonnes of epichlorohydrin (1-chloro-2,3-epoxypropane) into the environment. A human biomonitoring study was performed to evaluate the accidental exposure to epichlorohydrin and to assess the possible long-term, i.e. carcinogenic health effects. This was done on the basis of a biochemical effect monitoring using the N-(3-chloro-2-hydroxypropyl)valine and the N-(2,3-dihydroxypropyl)valine haemoglobin adducts of epichlorohydrin in blood to respond to missing ambient monitoring immediately after the crash. N-(3-chloro-2-hydroxypropyl)valine adduct levels above the LOQ (25 pmol/g globin) ranged from 32.0 to 116.4 pmol/g globin in 6 out of 628 samples. The N-(2,3-dihydroxypropyl)valine adduct was not detected above the LOD (10 pmol/g globin) in any of the blood samples. Based on the quantified N-(3-chloro-2-hydroxypropyl)valine adduct values, the body doses after two days of exposure were estimated to be in the range of 1.7-6.2 nmol/kg body weight. The reverse estimation of the external exposure leads to cumulative additional lifetime cancer risks ranging from 2.61×10(-8) to 9.48×10(-8). The estimated excess lifetime cancer risks have to be assessed as extremely low. Our biomonitoring study facilitated the dialogue between individuals and groups concerned and authorities, because suspected or occurred exposures and risks to human health could be quantified and interpreted in a sound manner.


Asunto(s)
Liberación de Peligros Químicos , Monitoreo del Ambiente/métodos , Epiclorhidrina/sangre , Epiclorhidrina/envenenamiento , Hemoglobinas/metabolismo , Exposición por Inhalación/efectos adversos , Socorristas , Alemania , Humanos , Riesgo , Valina/análogos & derivados , Valina/sangre
6.
Artículo en Alemán | MEDLINE | ID: mdl-19137219

RESUMEN

Alternative methods to safety studies using laboratory animals have been accepted by the OECD in areas such as local toxicity and mutagenicity. In more complex important fields, such as systemic single and repeated dose toxicity, toxicokinetics, sensitisation, reproductive toxicity and carcinogenicity, it is expected that the development and validation of computerised methods, testing batteries (in vitro and in silico) and tiered testing systems will need many years and have to overcome many scientific and regulatory obstacles, which makes it extremely difficult to predict the outcome and the time needed. Therefore, the validated alternative methods available will only have a limited impact on reducing the numbers of animals required under REACH. In the midterm, the strategy should be more directed towards the refinement or reduction of in vivo testing because the replacement concerning complex toxicological endpoints is at present not in sight.


Asunto(s)
Seguridad de Productos para el Consumidor/legislación & jurisprudencia , Programas de Gobierno/métodos , Sustancias Peligrosas/toxicidad , Medición de Riesgo/legislación & jurisprudencia , Medición de Riesgo/organización & administración , Pruebas de Toxicidad/métodos , Toxicología/métodos , Animales , Unión Europea , Sustancias Peligrosas/clasificación , Sustancias Peligrosas/normas , Factores de Riesgo
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