Exposure Assessment of Toxicologically Relevant Volatile Organic Compounds Emitted from Polymer-Based Costume Masks.

Plastic costume masks regularly exhibit unpleasant odors that may be associated with the emissions of volatile organic compounds (VOCs). Upon inhalation, VOCs might adversely affect the wearer's health if the exposure exceeds regulatory threshold values. The VOCs emitted from a selection of costume masks (n = 12) were characterized semiquantitatively with a screening method based on GC/MS measurements in dynamic headspace sampling mode. Furthermore, odors associated with the masks were evaluated by a sensory panel. Two masks emitted particularly high concentrations of ethylbenzene, xylenes, and cyclohexanone and exhibited the most intense and unpleasant odors, which were described as rubber-like, pungent, and leather-like. To simulate and assess the inhalation exposures for wearers of these masks, an innovative experimental setup based on a doll's head was developed, with sampling of emitted volatiles on adsorption material and subsequent analysis by thermal desorption-GC/MS. The measured inhalable concentrations of cyclohexanone exceeded the derived no-effect level (DNEL) for systemic effects on the general population over several hours of wearing, and also after repeated use. Importantly, the cyclohexanone DNEL was reevaluated in relation to a recent study on inhalation toxicity in rodents and was found to be significantly lower (1.4 mg·m-3) compared to the industry-derived values (10-20 mg·m-3), thus aggravating the health risks associated with inhalation exposure from some of the costume masks tested. Finally, a comparison of the inhalable concentrations derived from the simulated exposure assessments with those derived from measurements in miniaturized emission test chambers indicate that microchambers represent a useful tool for high-throughput analysis. The influences of temperature and inhalation/exhalation flow rates on VOC exposures were also studied.

The German REACH Congress 2016: a workshop report.

In October 2016, the German REACH Congress was held at the German Federal Institute for Risk Assessment (BfR) in Berlin. Here, the associated improvement made in the fields of consumer protection and the progress in and experiences gained from the implementation of the authorisation procedure were discussed. Several speakers from EU institutions, German authorities, industry, and civil society organisations were invited to present their views. There was a shared consensus that REACH contributes to the advancement of consumer protection against chemical risks, mainly because more and higher quality information on substance-related hazards and potential exposures becomes available. In addition, risk management measures, particularly regarding restrictions on uses, scale down consumer exposures to chemicals. Opportunities for improvements identified at the congress include the quality of registration dossiers and the management of and communication on substances of very high concern (SVHC) that may be present in consumer articles. Although regarded as being in an early implementation phase, the authorisation process was generally found to be operational and progressing well. Criticism was expressed with regard to the consistency of authorisation decisions and the costs and uncertainties related to authorisation applications. Consumer protection legislation consists of several legal provisions which are interlinked. The congress participants agreed that REACH is an important element of this legal framework as it enhances and complements other legal provisions.

Characterizing "Adversity" of Pathology Findings in Nonclinical Toxicity Studies: Results from the 4th ESTP International Expert Workshop.

The identification of adverse health effects has a central role in the development and risk/safety assessment of chemical entities and pharmaceuticals. There is currently a need for better alignment regarding how nonclinical adversity is determined and characterized. The European Society of Toxicologic Pathology (ESTP) therefore coordinated a workshop to review available definitions of adversity, weigh determining and qualifying factors of adversity based on case examples, and recommend a practical approach to define and characterize adversity in toxicology reports, to serve as a valuable prerequisite for future organ- or lesion-specific workshops planned by the ESTP.

The carcinogenic potential of nanomaterials, their release from products and options for regulating them.

A summary of a critical review by a working group of the German Federal Environment Agency and the German Federal Institute for Risk Assessment on the carcinogenic potential of nanomaterials is presented. After a critical review of the available data, we conclude that the potential carcinogenic risk of nanomaterials can currently be assessed only on a case-by-case basis. There is certain evidence that different forms of CNTs (carbon nanotubes) and nanoscale TiO(2) particles may induce tumours in sensitive animal models. It is assumed that the mode of action of the inhalation toxicity of asbestos-like fibres and of inhalable fractions of biopersistent fine dusts of low toxicity (nano-TiO(2)) is linked to chronic inflammatory processes. Existing epidemiological studies on carcinogenicity for these manufactured nanomaterials are not sufficiently conclusive. Generally speaking, the database is not adequate for an assessment of the carcinogenic potential of nanomaterials. Whereas a number of studies provide evidence of a nano-specific potential to induce tumours, other studies did not. This is possibly due to insufficient characterisation of the test material, difference in the experimental design, the use of different animal models and species and/or differences in dosimetry (both with regard to the appropriate dose metric and the estimated effective dose quantities). An assessment of the carcinogenic potential and its relevance for humans are currently fraught with uncertainty. Furthermore, the nano-specificity of the carcinogenic effects observed cannot be conclusively evaluated. Specific carcinogenic effects of nanomaterials may be both quantitative and qualitative. In quantitative terms, the carcinogenic effects of nanoparticles are thought to be simply more pronounced compared to the corresponding bulk material (due, for example, to the considerably larger surface area and higher number of particles relative to the mass concentration). On the other hand, certain nano-properties such as small size, shape and reactivity, retention time and distribution in the body after overcoming biological barriers, as well as subcellular and molecular interactions may play a role in determining the toxicity in qualitative terms, i.e. the carcinogenic potential of the nanomaterial and the non-nanoscale comparison substance may be fundamentally different. All of these factors leave no doubt about the fact that there is a great need for research in this area and that new standardised test methods need to be developed or existing ones adapted at the very least to achieve valid answers regarding the carcinogenic potential of nanomaterials. Global production of nanomaterials is set to increase in the years to come, and new materials with new properties will be developed, so that greater human exposure to them must be anticipated. No reliable conclusions can currently be drawn about exposure to nanoparticles and their release from products. Firstly, there are substantial deficits in information about the processing of nanomaterials in products and preparations. Secondly, there are only a small number of studies on nanoparticle release, and reliable techniques for measuring and monitoring nanomaterials in different environmental media are still being developed which is both complex and costly. Despite the uncertainties, the findings to date on the carcinogenic potential of nanomaterials must be taken seriously, and precautionary measures to minimise exposure should go hand in hand with the development of a comprehensive and conclusive toxicological methodology and testing procedure for nanostructured materials that includes all possible exposure routes. With regard to possible legal classification of nanomaterials and the transferability of classifications of their non-nanomaterial counterparts, we believe it is necessary to have separate procedures for nano and non-nano forms. Furthermore, criteria for evaluating nano-specific carcinogenic properties should be constantly updated and adapted to the state of knowledge. There is a need here for amendments to be made to EU legislation, as currently nanoforms do not represent a separate category of substance in their own right.

1st international ESTP expert workshop: "Larynx squamous metaplasia". A re-consideration of morphology and diagnostic approaches in rodent studies and its relevance for human risk assessment.

Invited international experts participated in a 2-day workshop organized by the European Society of Toxicologic Pathology (ESTP) to evaluate and discuss spontaneous and induced laryngeal lesions in rodents. The main purpose of the workshop was to agree upon the terminology and relevance of a range of laryngeal changes that varied from very subtle epithelial alterations up to severe metaplastic or neoplastic lesions. The workshop experts concluded that minimal, focal epithelial changes of the laryngeal epithelium, predominantly occurring at the base of the epiglottis, should be given the descriptive term of "epithelial alteration" and assessed as "non-adverse". Although observed as induced effects they may also occur in non-treated animals and were not considered to have a potential for a laryngeal dysfunction. Also, cases of minimal to slight laryngeal squamous metaplasia that are not observed diffusely could occur spontaneously or as treatment-induced lesions and should be assessed as "non-adverse". Cases of moderate to severe laryngeal squamous metaplasia observed diffusely in multiple levels should be regarded as "adverse", as there is a potential for dysfunction of the larynx. The occurrence of dysplasia or cellular atypia linked to laryngeal squamous metaplasia should always be reported separately and described in detail. In the evaluation of treatment-related effects of the larynx in studies utilizing aged animals, it has to be considered that moderate or even severe cases of focal laryngeal squamous metaplasia may occasionally be found as age-related, spontaneous lesions. Although inhalation exposure of rodents to non-genotoxic compounds may cause laryngeal squamous metaplasia, none of the workshop experts were aware of any reported cases of tumor induction in the larynx with a non-genotoxic compound. Therefore, for non-genotoxic compounds, the workshop experts did not regard laryngeal squamous metaplasia by itself as a precancerous lesion.

Hazard classification of chemicals inducing haemolytic anaemia: An EU regulatory perspective.

Haemolytic anaemia is often induced following prolonged exposure to chemical substances. Currently, under EU Council Directive 67/548/EEC, substances which induce such effects are classified as dangerous and assigned the risk phrase R48 'Danger of serious damage to health by prolonged exposure.' Whilst the general classification criteria for this endpoint are outlined in Annex VI of this Directive, they do not provide specific information to assess haemolytic anaemia. This review produced by the EU Working Group on Haemolytic Anaemia provides a toxicological assessment of haemolytic anaemia and proposes criteria that can be used in the assessment for classification of substances which induce such effects. An overview of the primary and secondary effects of haemolytic anaemia which can occur in rodent repeated dose toxicity studies is given. A detailed analysis of the toxicological significance of such effects is then performed and correlated with the general classification criteria used for this endpoint. This review intends to give guidance when carrying out an assessment for classification for this endpoint and to allow for better transparency in the decision-making process on when to classify based on the presence of haemolytic anaemia in repeated dose toxicity studies. The extended classification criteria for haemolytic anaemia outlined in this review were accepted by the EU Commission Working Group on the Classification and Labelling of Dangerous Substances in September 2004.

Regulatory aspects of immunotoxicology.

Since years, differences among the regulatory requirements on preclinical immunotoxicity testing for pharmaceuticals in the EU, Japan and US indicated a need for an internationally accepted approach. Requests for immunotoxicity investigations are also addressed by guidelines in non-drug areas. While some contain more detailed information in their requirements, other regulations comprise only vague descriptions for consideration of (non-intended) effects on the immune effects. Since 2002, the International Conference on Harmonisation (ICH) of Technical Requirements for Registration of Pharmaceuticals for Human Use put effort in the development of a harmonised approach for testing of immunosuppression and immunoenhancement. Consensus on the ICH S8 guideline on immunotoxicity testing for pharmaceuticals was achieved which now can be implemented into national regulations. The new concept contains in-depth testing, e.g., by functional tests in a concern/weight of evidence approach if the standard toxicity studies or other causes of concern give evidence of an immunotoxic potential or when the target populations are specifically vulnerable. It is expected that the progress on immunotoxicity testing reached by the ICH process will also have an impact on other regulatory areas. Additionally, the regulatory differences in testing requirements on immunotoxicity in other pharmaceutical areas including biotechnology-derived drugs, medicinal products and vaccines and in non-drug areas consisting of chemicals, agrochemicals or food additives are briefly highlighted.

Animal testing and alternative approaches for the human health risk assessment under the proposed new European chemicals regulation.

During the past 20 years the EU legislation for the notification of chemicals has focussed on new chemicals and at the same time failed to cover the evaluation of existing chemicals in Europe. Therefore, in a new EU chemicals policy (REACH, Registration, Evaluation and Authorization of Chemicals) the European Commission proposes to evaluate 30,000 chemicals within a period of 15 years. We are providing estimates of the testing requirements based on our personal experiences during the past 20 years. A realistic scenario based on an in-depth discussion of potential toxicological developments and an optimised "tailor-made" testing strategy shows that to meet the goals of the REACH policy, animal numbers may be significantly reduced below 10 million if industry would use in-house data from toxicity testing, which are confidential, if non-animal tests would be used, and if information from quantitative structure activity relationships (QSARs) would be applied in substance-tailored testing schemes. The procedures for evaluating the reproductive toxicity of chemicals have the strongest impact on the total number of animals bred for testing under REACH. We are assuming both an active collaboration with our colleagues in industry and substantial funding of the development and validation of advanced non-animal methods by the EU Commission, specifically in reproductive and developmental toxicity.

Two immunotoxicity ring studies according to OECD TG 407-comparison of data on cyclosporin A and hexachlorobenzene.

Two international ring studies were performed to develop appropriate parameters within standard toxicology study for screening of immunotoxicological potential of unknown substances. These studies followed OECD TG 407 and included a number of additional examinations. CSA was selected as model for its immunosuppressive and HCB as model for its immunostimulating effects. Reproducibility of data was defined by significant findings in at least 50% of participating laboratories. In-life clinical observations, values for WBC parameters, and changes of lymphoid organ weights suggested immune effects. Elevated IgM titers indicated increased antibody formation in HCB-exposed rats. Cellularity of T-cell compartments in thymus (medulla), spleen (PALS), and lymph nodes (paracortical zone of mesenteric and popliteal LN) were dose dependently decreased in CSA-treated rats. The numbers of follicular germinal centers were reduced in LN. HCB induced cellular proliferation in spleen marginal zones and endothelial activation in HEV of mesenteric and popliteal LN and GALT and in small pulmonary venules. Data obtained by specific immune parameters indicated immune effects; however, statistical inference was limited to low numbers of participating laboratories. In spleen, both substances decreased lymphoblast proliferation after ConA mitogen stimulation. Reduced numbers of antibody-forming cells in PFC assay indicated impaired T-cell-dependent humoral immunity by CSA, which was not seen for HCB. Altered fractions for B- and T-cell subpopulations were identified in spleen for both substances. In order to predict immunomodulatory effects of CSA or HCB, histomorphologic examination of lymphoid tissues resulted in the most reliable and sensitive data to distinguish immunosuppression and -stimulation.