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Sebastian Hoffmann

Sebastian Hoffmann
seh consulting + services · -

PhD

About

140
Publications
55,515
Reads
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4,551
Citations
Additional affiliations
May 2003 - September 2008
European Commission
Position
  • Biostatistician and project manager
January 2001 - April 2003
Universität Konstanz
Position
  • PhD Student
Education
October 1993 - August 2000
Technische Universität Dortmund
Field of study
  • Statistics

Publications

Publications (140)
Article
Full-text available
Evaluation of the reliability of toxicological data is of key importance for regulatory decision-making. In particular, the new EU Regulations concerning the registration, evaluation, authorisation and restriction of chemicals (REACH) and classification, labelling and packaging (CLP) according to the new globally harmonised system (GHS) rely on the...
Article
Full-text available
The development of non-animal skin sensitization test methods and strategies is quickly progressing. Either individually or in combination, the predictive capacity is usually described in comparison to local lymph node assay (LLNA) results. In this process the important lesson from other endpoints, such as skin or eye irritation, to account for var...
Article
Full-text available
Systematic reviews, pioneered in the clinical field, provide a transparent, methodologically rigorous and reproducible means of summarizing the available evidence on a precisely framed research question. Having matured to a well-established approach in many research fields, systematic reviews are receiving increasing attention as a potential tool f...
Article
Full-text available
Cosmetics Europe, the European Trade Association for the cosmetics and personal care industry, is conducting a multi-phase program to develop regulatory accepted, animal-free testing strategies enabling the cosmetics industry to conduct safety assessments. Based on a systematic evaluation of test methods for skin sensitization, five non-animal test...
Article
Full-text available
Originally developed to inform the acute toxicity of chemicals on fish, the zebrafish embryotoxicity test (ZET) has also been proposed for assessing the prenatal developmental toxicity of chemicals, potentially replacing mammalian studies. While extensively evaluated in primary studies, a comprehensive review summarizing the available evidence for...
Article
Irritation testing is an integral part of the biocompatibility assessment of medical devices and has historically been conducted on animals, either by direct contact or with polar and non-polar solvent extracts. In 2018 an ISO-sponsored interlaboratory validation study demonstrated that two reconstituted human epidermis (RhE) based assays, which we...
Article
Background “Biological plausibility” is a concept frequently referred to in environmental and public health when researchers are evaluating how confident they are in the results and inferences of a study or evidence review. Biological plausibility is not, however, a domain of one of the most widely-used approaches for assessing the certainty of evi...
Article
The assessment of skin sensitisation is a key requirement in all regulated sectors, with the European Union's regulation of cosmetic ingredients being most challenging, since it requires quantitative skin sensitisation assessment based on new approach methodologies (NAMs). To address this challenge, an in-depth and harmonised understanding of NAMs...
Poster
Irritation testing is an integral part of the biocompatibility assessment of medical devices and has historically been conducted on animals, either by direct contact or with polar and non-polar solvent extracts. In 2018 an ISO-sponsored interlaboratory validation study demonstrated that two reconstituted human epidermis (RhE) assays, which were ada...
Article
Full-text available
The workshop titled "Application of evidence-based methods to construct mechanism-driven chemical assessment frameworks" was co-organized by the Evidence-based Toxicology Collaboration and the European Food Safety Authority (EFSA), and hosted by EFSA at its headquarters in Parma, Italy on October 2 and 3, 2019. The goal was to explore integration o...
Article
Full-text available
Background “Biological plausibility” is a concept frequently referred to in environmental and public health when researchers are evaluating how confident they are in the results and inferences of a study or evidence review. Biological plausibility is not, however, a domain of one of the most widely-used approaches for assessing the certainty of evi...
Article
Evidence-based methodology, in particular systematic review, is increasingly being applied in environmental, public and occupational health in order to increase the transparency, comprehensiveness and objectivity of the processes by which existing evidence is gathered, assessed and synthesized in answering research questions. This development is al...
Article
Reproductive toxicity chemical safety assessment involves extensive use of vertebrate animals for regulatory testing purposes. Although alternative methods such as the zebrafish embryo teratogenicity assay (identified in the present manuscript by the acronym ZETA) are promising for replacing tests with mammals, challenges to regulatory application...
Article
Full-text available
Background: Nitrous oxide (N2O) is a common inhalation anaesthetic used in medical, paramedical, and veterinary practice. Since the mid 1950's, concerns have been raised regarding occupational exposure to N2O, leading to many epidemiological and experimental animal studies. Previous evaluations resulted in the classification of N2O as a possible ri...
Article
Full-text available
The workshop "Application of evidence-based methods to construct mechanistic frameworks for the development and use of non-animal toxicity tests" was organized by the Evidence-based Toxicology Collaboration and hosted by the Grading of Recommendations Assessment, Development and Evaluation Working Group on June 12, 2019. The purpose of the workshop...
Article
Full-text available
Device manufacturers and regulatory agencies currently utilize expensive and often inconclusive in vivo vascular implant models to assess implant material thrombogenicity. We report an in vitro thrombogenicity assessment methodology where test materials (polyethylene, Elasthane™ 80A polyurethane, Pebax®), alongside positive (borosilicate glass) and...
Article
Full-text available
In vitro test batteries have become the standard approach to determine the genotoxic potential of substances of interest across industry sectors. While useful for hazard identification, standard in vitro genotoxicity assays in 2D cell cultures have limited capability to predict in vivo outcomes and may trigger unnecessary follow-up animal studies o...
Article
Full-text available
Background There are several standards that offer explicit guidance on good practice in systematic reviews (SRs) for the medical sciences; however, no similarly comprehensive set of recommendations has been published for SRs that focus on human health risks posed by exposure to environmental challenges, chemical or otherwise. Objectives To develop...
Article
Full-text available
The purpose of this project report is to introduce the European “GOLIATH” project, a new research project which addresses one of the most urgent regulatory needs in the testing of endocrine-disrupting chemicals (EDCs), namely the lack of methods for testing EDCs that disrupt metabolism and metabolic functions. These chemicals collectively referred...
Article
Nitrous oxide (N2O) is widely used as inhalation analgesic and anaesthetic in medical, paramedical, and veterinary practice. Previous evaluations resulted in classification of N2O as a possible risk factor for adverse reproductive health outcomes based on evidence from animal data. Available human data were considered inadequate, partly due to the...
Article
In vivo experiments are still widely used for the testing of lung toxicity but there is an ethical and legal obligation to replace, reduce and refine animal testing. Lung A549 cells could serve as an in vitro indicator for acute lung toxicity but little data about the correlation of the cytotoxicity in A549 cells and data leading to CLP classificat...
Article
Full-text available
Systematic review methodology is a means of addressing specific questions through structured, consistent, and transparent examinations of the relevant scientific evidence. This methodology has been used to advantage in clinical medicine, and is being adapted for use in other disciplines. While some applications to toxicology have been explored, esp...
Preprint
Full-text available
The Cocultured Activation Test (COCAT) consists of cocultured HaCaT (human keratinocyte cell line) and THP-1 cells (surrogate of antigen presenting cells). Individually, these cell lines are used to address key event 2 and 3 of the skin sensitization Adverse Outcome Pathway (AOP). Their exposure in coculture was found to have the potential to incre...
Article
The CULTEX® Radial Flow System (RFS) is a modular in vitro system for the homogenous exposure of cells to airborne particles at the air-liquid interface (ALI). A former pre-validation study successfully demonstrated the general applicability of the CULTEX® RFS and its transferability, stability and reproducibility. Based on these results, the metho...
Article
Full-text available
A good experiment reported badly is worthless. Meaningful contributions to the body of science are made by sharing the full methodology and results so that they can be evaluated and reproduced by peers. Erroneous and incomplete reporting does not do justice to the resources spent on conducting the experiment and the time peers spend reading the art...
Article
Full-text available
Skin sensitization is a toxicity endpoint of widespread concern, for which the mechanistic understanding and concurrent necessity for non-animal testing approaches have evolved to a critical juncture, with many available options for predicting sensitization without using animals. Cosmetics Europe and the National Toxicology Program Interagency Cent...
Article
Full-text available
Recently revised OECD Testing Guidelines highlight the importance of considering the first site-of-contact when investigating genotoxic hazard. Thus far, only in vivo approaches are available to address the dermal route of exposure. The 3D Skin Comet and Reconstructed Skin Micronucleus (RSMN) assays intend to close this gap in the in vitro genotoxi...
Article
Assessment of skin irritation is an essential component of the safety evaluation of medical devices. OECD Test Guideline 439 describes the use of reconstructed human epidermis (RhE) as an in vitro test system for classification of skin irritation by neat chemicals. An international round robin study was conducted to evaluate the RhE method for dete...
Poster
Assessment of dermal irritation is an essential component of the safety evaluation of medical devices. A protocol employing RhE EpiDerm (MatTek), according to OECD 439 used for neat chemicals, was optimized in 2013 using liquid irritants spiked into polymer extracts (Casas et al., TIV, 2013) and in 2014 with another RhE, SkinEthic RHE (EPISKIN SA)....
Book
Full-text available
RECOMMENDATION FROM THE SCIENTIFIC COMMITTEE ON OCCUPATIONAL EXPOSURE LIMITS FOR 2-NITROPROPANE 8-hour TWA: not assigned STEL: not assigned BLV: not assigned Additional categorisation: SCOEL carcinogen group A (DNA-reactive genotoxic carcinogen without a threshold) Notation: skin The present Recommendation was adopted by SCOEL on 2017-02-08. Outcom...
Poster
On the road to animal-free skin sensitisation risk assessment: Cosmetics Europe’s assessment of testing strategies
Chapter
Evidence-based toxicology (EBT) was introduced independently by two groups in 2005, in the context of toxicological risk assessment and causation as well as based on parallels between the evaluation of test methods in toxicology and evidence-based assessment of diagnostics tests in medicine. The role model of evidence-based medicine (EBM) motivated...
Article
Full-text available
To replace the Draize skin irritation assay (OECD guideline 404) several test methods based on reconstructed human epidermis (RHE) have been developed and were adopted in the OECD test guideline 439. However, all validated test methods in the guideline are linked to RHE provided by only three companies. Thus, the availability of these test models i...
Article
Full-text available
The Evidence-based Toxicology Collaboration hosted a workshop on “The Emergence of Systematic Review and Related Evidence-based Approaches in Toxicology,” on November 21, 2014 in Baltimore, Maryland. The workshop featured speakers from agencies and organizations applying systematic review approaches to questions in toxicology, speakers with experie...
Book
Full-text available
RECOMMENDATION FROM THE SCIENTIFIC COMMITTEE ON OCCUPATIONAL EXPOSURE LIMITS FOR N-METHYL-2-PYRROLIDONE 8-hour TWA: 10 ppm (40 mg/m3) STEL: 20 ppm (80 mg/m3) BLV: 20 mg/g creatinine 2-hydroxy-N-methylsuccinimide (2-HMSI) in urine, monitored morning-after-shift (18 h), or 70 mg/g creatinine 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) in urine, monito...
Article
Full-text available
Assessments of methodological and reporting quality are critical to adequately judging the credibility of a study's conclusions and to gauging its potential reproducibility. To aid those seeking to assess the methodological or reporting quality of studies relevant to toxicology, we conducted a scoping review of the available guidance with respect t...
Article
Full-text available
Several non-animal methods are now available to address the key events leading to skin sensitization as defined by the adverse outcome pathway. The KeratinoSens™ assay addresses the cellular event of keratinocyte activation and is a method accepted under OECD TG 442D. In this study, the results of an inter-laboratory evaluation of the “me-too” LuSe...
Article
Full-text available
Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bias when summarising the body of research evidence relevant to a specific scientific question. Taking as a comparator the use of SR in synthesising research in healthcare, we argue that SR methods could also pave the way for a “step change” in the transpa...
Poster
Currently used in vitro cytogenetic assays show a high rate of false positive results. In order to improve the in vitro prediction, we adapted the Comet assay procedure to 3D skin models that mimic exposure route and potential metabolism of cosmetic ingredients 1.  The assay reflects now the first‐site‐of‐contact for dermally applied ingredients a...
Article
Full-text available
During surgical procedures, abdominal swabs are routinely used to adsorb blood from the operation field and for the retention of tissues and organs. Due to the material characteristics, abdominal swabs exhibit a slight procoagulant activity, which is usually desirable and mostly harmless. However, during cardiac surgery with heart–lung machine (HLM...
Chapter
Evidence-based toxicology attempts to translate concepts of evidence-based medicine to toxicology. The objective and transparent assessment of methods has served clinical medicine well over the last two decades, providing practitioners with best available evidence in quality-assured way. Tools such as systematic reviews, quality appraisal, and meta...
Article
Full-text available
Integrated testing strategies (ITS), as opposed to single definitive tests or fixed batteries of tests, are expected to efficiently combine different information sources in a quantifiable fashion to satisfy an information need, in this case for regulatory safety assessments. With increasing awareness of the limitations of each individual tool and t...