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Exposure models are essential for a range of contexts involving exposure science. The Exposure Models Working Group, established under ISES Europe, identified that to improve model use, suitable training and education is required. However, there is currently no formal educational training programme for exposure modelling in Europe. We present results from an online survey disseminated to the European exposure science community to identify modelling training needs. The questionnaire had three sections: background information about the respondents and interests in exposure science, previous attendance of exposure modelling courses, interest in future training and education in exposure modelling and their coverage and format.A total of 88 survey recipients completed the survey. Most respondents were from governmental organizations (36 %), with 50 % of all respondents having less than 10 years of experience. About two-thirds of the respondents stated that they had previously attended exposure modelling courses. These were mostly focused on specific models, up to one day in duration and took place in-person. Two thirds of respondents expressed interest in attending future exposure modelling training modules, with the most important topics being interpretation of model results and use of models to meet regulatory standards/requirements. Preferred attendance of training courses was virtual or blended. Costs and certificates of attendance seemed less influential when selecting a training course. Our survey suggests that there is a demand for training in exposure modelling and provides insight to inform the development of training modules that are suitable to fulfil the training needs of exposure scientists and practitioners.

Objectives: To study work exposure and respiratory symptoms in New Zealand plywood mill workers. Methods: Personal inhalable dust (n = 57), bacterial endotoxin (n = 20), abietic acid (n = 20), terpene (n = 20) and formaldehyde (n = 22) measurements were taken and a respiratory health questionnaire was administered to 112 plywood mill workers. Results: Twenty-six percent of the dust exposures exceeded 1 mg/m3, however, none of the samples exceeded the legal limit of 5 mg/m3 [geometric mean (GM) = 0.7 mg/m3, geometric standard deviation (GSD) = 1.9]. Workers in the composer area (where broken sheets are joined together) were significantly (P < 0.01) more highly exposed. Endotoxin levels were low to moderate (GM = 23.0 EU/m3, GSD = 2.8). Abietic acid levels ranged from 0.3 to 2.4 µg/m3 (GM = 0.7 µg/m3, GSD = 1.8) and were significantly (P < 0.05) higher for workers in the composer area of the process. Geometric mean levels of α-pinene, β-pinene and Δ3-carene were 1.0 (GSD = 2.7), 1.5 (GSD = 2.8) and 0.1 (GSD = 1.4), respectively, and α-pinene and β-pinene levels were significantly (P < 0.001) higher for workers in the ''green end'' of the process, up to and including the veneer dryers. Formaldehyde levels ranged from 0.01 to 0.74 mg/m3 [GM = 0.08 mg/m3 (= 0.06 p.p.m.), GSD = 3.0]. Asthma symptoms were more common in plywood mill workers (20.5%, n = 112) than in the general population [12.8%, n = 415, adjusted OR (95% CI) = 1.5 (0.9-2.8)]. Asthma symptoms were associated with duration of employment and were reported to lessen or disappear during holidays. No clear association with any of the measured exposures was found, with the exception of formaldehyde, where workers with high exposure reported more asthma symptoms (36.4%) than low exposed workers [7.9%, adjusted OR (95% CI) = 4.3 (0.7-27.7)]. Conclusions: Plywood mill workers are exposed to inhalable dust, bacterial endotoxin, abietic acid, terpenes and formaldehyde, and they appear to have an increased risk of developing work-related respiratory symptoms. These symptoms may be due to formaldehyde exposure, although a potential causal role for other exposures cannot be excluded. [ABSTRACT FROM AUTHOR]

Exposure to manufactured nanomaterials (MNs) is a growing concern for occupational health and safety. Reliable methods for assessing and predicting MN exposure are essential to mitigate associated risks. This study presents the development of the Nano Exposure Quantifier (NEQ), a mechanistic model designed to assess airborne MN exposure in the workplace. By utilizing a dataset of 128 MN measurements from existing exposure studies, the model demonstrates its effectiveness in estimating MN exposure levels for particles smaller than 10 µm. The NEQ provides estimates in terms of particle number concentration accompanied by a 95% confidence interval (CI), enabling a comprehensive assessment of MN exposure. The NEQ includes 2 quantitative models: a simplified tier 1 model and a more comprehensive tier 2 model. Both tier 1 and tier 2 models exhibit robust performance, with correlation coefficients (r) of 0.57 and 0.62, respectively. The models exhibit a moderate level of error, as indicated by residuals' standard deviation of 4.10 for tier 1 and 3.90 for tier 2. The tier 1 model demonstrates a slightly higher overestimation bias (1.15) compared to the tier 2 model (0.54). Overall, the NEQ offers a practical and reliable approach for estimating MN exposure in occupational settings. Future validation studies will investigate the impact of initial calibration efforts, heteroscedasticity, and further refine the model's accuracy., (© The Author(s) 2025. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

This article describes the development of a Safe-by-Design (SbD) module and its integration into an easy-to-use tool, named the Nano Exposure Quantifier-Safe-by-Design (NEQ-SbD) tool. The NEQ-SbD tool guides its user to lower the exposure to nanomaterials at the worksite where nanomaterials are manipulated or handled during a wide range of activities. This allows the tool user with an informed decision to assess airborne exposure and to select, compare, and identify appropriate risk management measures (RMM). The SbD module was developed using various information sources that can support and guide the SbD process, including the (i) RMM effectiveness based on analyses of an Exposure Control Efficacy Library (ECEL), (ii) RMM performance using a Computational Fluid Dynamics (CFD) model, (iii) e-cards based on a qualitative analysis of RMM information sources, and (iv) guidance for SbD strategy using an exposure directionality assessment. This information has been integrated in the user interface of the SbD module and NEQ-SbD tool to facilitate the SbD decision-making process. The SbD concept applied in the integrated NEQ-SbD tool introduces a comparison between a baseline exposure assessment and an (improved) SbD exposure assessment. The integrated NEQ-SbD tool consists of 4 modules including (i) a baseline exposure assessment, (ii) baseline results, (iii) SbD assessment, and (iv) SbD comparative results. The main purpose of the SbD module lies in guiding the user to the most sensitive (exposure) parameters and allowing a side-by-side comparison of potentially suitable RMMs. The integrated NEQ-SbD tool also offers a tiered approach and seamlessly shifts from a tier-1 to tier-2 uncertainty of an exposure assessment. The SbD module is illustrated using a worked example for the transfer of nano powders, showing the possibility of identifying SbD solutions for both safe-by-process and safe-by-material design purposes. The NEQ-SbD tool is a valuable tool for the SbD of nanomaterials and as a decision-making tool to support SbD risk management strategies that lead to minimizing health risks associated with occupational exposures., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Occupational Hygiene Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This manuscript discusses the challenges of applying New Approach Methodologies (NAMs) for safe by design and regulatory risk assessment of advanced nanomaterials (AdNMs). The authors propose a framework for Next Generation Risk Assessment of AdNMs involving NAMs that is aligned to the conventional risk assessment paradigm. This framework is exposure-driven, endpoint-specific, makes best use of pre-existing information, and can be implemented in tiers of increasing specificity and complexity of the adopted NAMs. The tiered structure of the approach, which effectively combines the use of existing data with targeted testing will allow safety to be assessed cost-effectively and as far as possible with even more limited use of vertebrates. The regulatory readiness of state-of-the-art emerging NAMs is assessed in terms of Transparency, Reliability, Accessibility, Applicability, Relevance and Completeness, and their appropriateness for AdNMs is discussed in relation to each step of the risk assessment paradigm along with providing perspectives for future developments in the respective scientific and regulatory areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The past few decades of managing the uncertain risks associated with nanomaterials have provided valuable insights (knowledge gaps, tools, methods, etc.) that are equally important to promote safe and sustainable development and use of advanced materials. Based on these insights, the current paper proposes several actions to optimize the risk and sustainability governance of advanced materials. We emphasise the importance of establishing a European approach for risk and sustainability governance of advanced materials as soon as possible to keep up with the pace of innovation and to manage uncertainty among regulators, industry, SMEs and the public, regarding potential risks and impacts of advanced materials. Coordination of safe and sustainable advanced material research efforts, and data management according to the Findable, Accessible, Interoperable and Reusable (FAIR) principles will enhance the generation of regulatory-relevant knowledge. This knowledge is crucial to identify whether current regulatory standardised and harmonised test methods are adequate to assess advanced materials. At the same time, there is urgent need for responsible innovation beyond regulatory compliance which can be promoted through the Safe and Sustainable Innovation Approach. that combines the Safe and Sustainable by Design concept with Regulatory Preparedness, supported by a trusted environment. We further recommend consolidating all efforts and networks related to the risk and sustainability governance of advanced materials in a single, easy-to-use digital portal. Given the anticipated complexity and tremendous efforts required, we identified the need of establishing an organisational structure dedicated to aligning the fast technological developments in advanced materials with proper risk and sustainability governance. Involvement of multiple stakeholders in a trusted environment ensures a coordinated effort towards the safe and sustainable development, production, and use of advanced materials. The existing infrastructures and network of experts involved in the governance of nanomaterials would form a solid foundation for such an organisational structure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background and Objectives: This paper describes an evaluation and analysis of an updated version of ECEL v3.0-an integrated risk management measure (RMM) library developed as part of a CEFIC LRI initiative. The occupational module contains extensive data on the quantitative effectiveness of RMMs to control inhalation and dermal exposure in the workplace. The objective was to investigate the effectiveness and variability in effectiveness of RMM and to explore the difference between optimal and non-optimal RMM applications in the workplace., Methods: A new database structure and interface were developed and the content of the database was updated with a systematic literature review and integration with other databases (totalling 3373 records from 548 studies). To analyse the data, Bayesian linear mixed models were constructed with the study as a random effect and various study characteristics and RMM categories as fixed effects individually in separate models. A multivariate mixed model was used on a stratified dataset to test (amongst others) the conditions of RMM use., Results: Analyses of the data indicated effectiveness values for each RMM category (for example ~87% for technical emission controls compared with ~60% for technical dispersion controls). Substantial variability in effectiveness was observed within and between different types of RMM. Seven study characteristics (covariables) were included in the analyses, which indicated a pronounced difference in as-built (optimal/experimental) and as-used (workplace) conditions of RMM use (93.3% and 74.6%, respectively)., Conclusions: This library provides a reliable evidence base to derive base estimates of RMM effectiveness-beneficial for both registrant and downstream users. It stresses the importance of optimal use of RMMs in the workplace (technical design/functioning, use, and maintenance). Various challenges are foreseen to further update ECEL to improve guidance, for deriving improved estimates and ensure user-friendliness of the library., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Occupational Hygiene Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Several exposure assessment models use dustiness as an input parameter for scaling or estimating exposure during powder handling. Use of different dustiness methods will result in considerable differences in the dustiness values as they are based on different emission generation principles. EN17199:2019 offers 4 different dustiness test methods considering different dust release scenarios (e.g. powder pouring, mixing and gentle agitation, and vibration). Conceptually, the dustiness value by a given method can be multiplied with a scenario-specific modifier, called a handling energy factor (Hi), that allows conversion of a dustiness value to a release constant. Therefore, a Hi, scaling the effective mechanical energy in the process to the energy supplied in the specific dustiness test, needs to be applied. To improve the accuracy in predictive exposure modelling, we derived experimental Hi to be used in exposure algorithms considering both the mass- and number-based dust release fraction determined by the EN17199-3 continuous drop (CD) and the EN17199-4 small rotating drum (SRD) test methods. Three materials were used to evaluate the relationship between dustiness and dust levels during pouring powder from different heights in a controlled environment. The results showed increasing scatter and difference between the Hi derived for the 2 test methods with increasing pouring height. Nearly all the Hi values obtained for both SRD and CD were <1 indicating that the dustiness tests involved more energy input than the simulated pouring activity and consequently de-agglomeration and dust generation were higher. This effect was most pronounced in CD method showing that SRD mechanistically resembles more closely the powder pouring., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Biobanks are important in biomedical and public health research, and future healthcare research relies on their strength and capacity. However, there are financial challenges related to the operation of commercial biobanks and concerns around the commercialization of biobanks. Non-commercial biobanks depend on grant funding to operate and could be valuable to researchers if they can enable access to quality specimens at lower costs. The objective of this study is to estimate the value of specific biobank attributes. We used a rating-based conjoint experiment approach to study how researchers valued handling fee, access, quality, characterization, breadth of consent, access to key endemics, and time taken to fulfil requests. We found that researchers placed the greatest relative importance on the quality of specimens (26%), followed by the characterization of specimens (21%). Researchers with prior experience purchasing biological samples also valued access to key endemic in-country sites (11.6%) and low handling fees (5.5%) in biobanks., (© 2023. The Author(s).)

A roadmap was developed to strengthen standardisation activities for risk governance of nanotechnology. Its baseline is the available standardised and harmonised methods for nanotechnology developed by the International Organization for Standardization (ISO), the European Committee for Standardization (CEN), and the Organisation for Economic Co-operation and Development (OECD). In order to identify improvements and needs for new themes in standardisation work, an analysis of the state-of-the-art concepts and interpretations of risk governance of nanotechnology was performed. Eleven overall areas of action were identified, each including a subset of specific topics. Themes addressed include physical chemical characterisation, assessment of hazard, exposure, risk and socio-economic factors, as well as education & training and social dialogue. This has been visualised in a standardisation roadmap spanning a timeframe of ten years and including key outcomes and highlights of the analysis. Furthermore, the roadmap indicates potential areas of action for harmonisation and standardisation (H&S) for nanomaterials and nanotechnology. It also includes an evaluation of the current level (limited, moderate, intense) of ongoing H&S activities and indicates the time horizon for the different areas of action. As the identified areas differ in their state of development, the number and type of actions varied widely amongst the different actions towards achieving standardisation. Thus, priority areas were also identified. The overall objective of these actions is to strengthen risk governance towards a safe use of nanomaterials and nano-related products. Though not explicitly addressed, risk-based legislation and policies are supported via the proposed H&S actions., Competing Interests: Declaration of Competing Interest The authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

There has been an increasing use of advanced materials, particularly manufactured nanomaterials, in industrial applications and consumer products in the last two decades. It has instigated concerns about the sustainability, in particular, risks and uncertainties regarding the interactions of the manufactured nanomaterials with humans and the environment. Consequently, significant resources in Europe and beyond have been invested into the development of tools and methods to support risk mitigation and risk management, and thus facilitate the research and innovation process of manufactured nanomaterials. The level of risk analysis is increasing, including assessment of socio-economic impacts, and sustainability aspects, moving from a conventional risk-based approach to a wider safety-and-sustainability-by-design perspective. Despite these efforts on tools and methods development, the level of awareness and use of most of such tools and methods by stakeholders is still limited. Issues of regulatory compliance and acceptance, reliability and trust, user-friendliness and compatibility with the users' needs are some of the factors which have been traditionally known to hinder their widespread use. Therefore, a framework is presented to quantify the readiness of different tools and methods towards their wider regulatory acceptance and downstream use by different stakeholders. The framework diagnoses barriers which hinder regulatory acceptance and wider usability of a tool/method based on their Transparency, Reliability, Accessibility, Applicability and Completeness (TRAAC framework). Each TRAAC pillar consists of criteria which help in evaluating the overall quality of the tools and methods for their (i) compatibility with regulatory frameworks and (ii) usefulness and usability for end-users, through a calculated TRAAC score based on the assessment. Fourteen tools and methods were assessed using the TRAAC framework as proof-of-concept and for user variability testing. The results provide insights into any gaps, opportunities, and challenges in the context of each of the 5 pillars of the TRAAC framework. The framework could be, in principle, adapted and extended to the evaluation of other type of tools & methods, even beyond the case of nanomaterials., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: Within the chemical legislation, REACH was implemented in order to improve safe working conditions with hazardous substances. Literature and real-life experiences by those concerned have shown that there are still gaps with a need for improved risk communication. This study elaborated on how information provided by REACH is understood and acted on by down- and upstream users, and how it can be further improved., Methods: An extensive literature study including 21 studies and 13 tools was carried out. The outcomes were discussed and further supplemented by means of 18 interviews concerning 37 internal safety and REACH documents to build six different use cases representing different Dutch downstream companies. For the upstream perspective also 2 sector organizations and 2 registrants were interviewed. Three online workshops were organized in order to share insights and gather input on international recognition, potential suggestions and further recommendations with 30 participants from nine different EU countries., Results: Although the methods to collect the data differed between the different stages of the study, the general results from all three stages elucidated similar themes in the data and each of the stages used the results from the previous stage as a starting point. Recurring themes concerned the (i) complexity of documents, (ii) deficiencies as experienced by SMEs in REACH, (iii) feedback and responsibilities in the supply chain, and (iv) the cooperation between REACH and OSH., Discussion: The study at hand revealed that even though there are currently several activities to improve communication on safe-use of chemicals, communication on safe-use in the scope of REACH should be improved. This includes e.g. the future involvement of actual end-users in activities and development related to communication of safe-use information in the scope of REACH including feedback, less complicated and complex documents and clear communication concerning legislations and updates of documents. Furthermore, the issues recognized in the Netherlands are mostly also recognized by international workshop participants, thereby indicating international benefits in various areas by means of improved communication., Conclusions: The study confirmed that many of our generic conclusions were already part of the shared knowledge in the REACH community, but that it is very valuable that this knowledge has been explicated, validated and reported in a structured way in the present project. Besides uncovering some crucial aspects that offer potential improvements regarding risk communication, this study offers possible solutions and next steps to be taken., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Exposure models are essential in almost all relevant contexts for exposure science. To address the numerous challenges and gaps that exist, exposure modelling is one of the priority areas of the European Exposure Science Strategy developed by the European Chapter of the International Society of Exposure Science (ISES Europe). A strategy was developed for the priority area of exposure modelling in Europe with four strategic objectives. These objectives are (1) improvement of models and tools, (2) development of new methodologies and support for understudied fields, (3) improvement of model use and (4) regulatory needs for modelling. In a bottom-up approach, exposure modellers from different European countries and institutions who are active in the fields of occupational, population and environmental exposure science pooled their expertise under the umbrella of the ISES Europe Working Group on exposure models. This working group assessed the state-of-the-art of exposure modelling in Europe by developing an inventory of exposure models used in Europe and reviewing the existing literature on pitfalls for exposure modelling, in order to identify crucial modelling-related strategy elements. Decisive actions were defined for ISES Europe stakeholders, including collecting available models and accompanying information in a living document curated and published by ISES Europe, as well as a long-term goal of developing a best-practices handbook. Alongside these actions, recommendations were developed and addressed to stakeholders outside of ISES Europe. Four strategic objectives were identified with an associated action plan and roadmap for the implementation of the European Exposure Science Strategy for exposure modelling. This strategic plan will foster a common understanding of modelling-related methodology, terminology and future research in Europe, and have a broader impact on strategic considerations globally., (© 2022. The Author(s).)

On 20 October 2020, the Working Group "Exposure Models" of the Europe Regional Chapter of the International Society of Exposure Science (ISES Europe) organised an online workshop to discuss the theoretical background of models for the assessment of occupational exposure to chemicals. In this report, participants of the workshop with an active role before and during the workshop summarise the most relevant discussion points and conclusions of this well-attended workshop. ISES Europe has identified exposure modelling as one priority area for the strategic development of exposure science in Europe in the coming years. This specific workshop aimed to discuss the main challenges in developing, validating, and using occupational-exposure models for regulatory purposes. The theoretical background, application domain, and limitations of different modelling approaches were presented and discussed, focusing on empirical "modifying-factor" or "mass-balance-based" approaches. During the discussions, these approaches were compared and analysed. Possibilities to address the discussed challenges could be a validation study involving alternative modelling approaches. The wider discussion touched upon the close relationship between modelling and monitoring and the need for better linkage of the methods and the need for common monitoring databases that include data on model parameters.

Introduction: Oil and gas workers have been shown to be at increased risk of chronic diseases including cancer, asthma, chronic obstructive pulmonary disease, and hearing loss, among others. Technological advances may be used to assess the external (e.g. personal sensors, smartphone apps and online platforms, exposure models) and internal exposome (e.g. physiologically based kinetic modeling (PBK), biomonitoring, omics), offering numerous possibilities for chronic disease prevention strategies and risk management measures. The objective of this study was to review the literature on these technologies, by focusing on: (i) evaluating their applicability for exposome research in the oil and gas industry, and (ii) identifying key challenges that may hamper the successful application of such technologies in the oil and gas industry., Method: A scoping review was conducted by identifying peer-reviewed literature with searches in MEDLINE/PubMed and SciVerse Scopus. Two assessors trained on the search strategy screened retrieved articles on title and abstract. The inclusion criteria used for this review were: application of the aforementioned technologies at a workplace in the oil and gas industry or, application of these technologies for an exposure relevant to the oil and gas industry but in another occupational sector, English language and publication period 2005-end of 2019., Results: In total, 72 articles were included in this scoping review with most articles focused on omics and bioinformatics (N = 22), followed by biomonitoring and biomarkers (N = 20), external exposure modeling (N = 11), PBK modeling (N = 10), and personal sensors (N = 9). Several studies were identified in the oil and gas industry on the application of PBK models and biomarkers, mainly focusing on workers exposed to benzene. The application of personal sensors, new types of exposure models, and omics technology are still in their infancy with respect to the oil and gas industry. Nevertheless, applications of these technologies in other occupational sectors showed the potential for application in this sector., Discussion and Conclusion: New exposome technologies offer great promise for personal monitoring of workers in the oil and gas industry, but more applied research is needed in collaboration with the industry. Current challenges hindering a successful application of such technologies include (i) the technological readiness of sensors, (ii) the availability of data, (iii) the absence of standardized and validated methods, and (iv) the need for new study designs to study the development of disease during working life., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Driven by the concept of the 'four generations of nanomaterials', the current state of the knowledge on risk assessment of future generation is explored for active nanomaterials. Through case studies, we identify challenges and evaluate the preparedness of characterization methods, available risk assessment modeling tools, and analytical instrumentation for such future generation active nanomaterials with dynamic hybrid structures of biotic-abiotic and organic-inorganic combinations. Currently available risk assessment tools and analytical instrumentation were found to be lacking the risk preparedness and characterization readiness for active nanomaterials, respectively. Potential future developments in risk assessment modeling tools and analytical techniques can be based upon this work which shall ensure long-term safety of the next generation of nanomaterials., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

This commentary explores the use of high-resolution data from new, miniature sensors to enrich models that predict exposures to chemical substances in the workplace. To optimally apply these sensors, one can expect an increased need for new models that will facilitate the interpretation and extrapolation of the acquired time-resolved data. We identified three key modelling approaches in the context of sensor data, namely (i) enrichment of existing time-integrated exposure models, (ii) (new) high-resolution (in time and space) empirical models, and (iii) new 'occupational dispersion' models. Each approach was evaluated in terms of their application in research, practice, and for policy purposes. It is expected that substance-specific sensor data will have the potential to transform workplace modelling by re-calibrating, refining, and validating existing (time-integrated) models. An increased shift towards 'sensor-driven' models is expected. It will allow for high-resolution modelling in time and space to identify peak exposures and will be beneficial for more individualized exposure assessment and real-time risk management. New 'occupational dispersion models' such as interpolation, computational fluid dynamic models, and assimilation techniques, together with sensor data, will be specifically useful. These techniques can be applied to develop site-specific concentration maps which calculate personal exposures and mitigate worker exposure through early warning systems, source finding and improved control design and control strategies. Critical development and investment needs for sensor data linked to (new) model development were identified such as (i) the generation of more sensor data with reliable sensor technologies (achieved by improved specificity, sensitivity, and accuracy of sensors), (ii) investing in statistical and new model developments, (iii) ensuring that we comply with privacy and security issues of concern, and (iv) acceptance by relevant target groups (such as employers and employees) and stimulation of these new technologies by policymakers and technology developers., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

For many work situations only insufficient exposure data are available to perform proper risk assessment. Because measuring worker exposure can be time consuming and resource intense, the availability of reliable exposure models is important when performing risk assessments. However, the development and improvement of exposure models are hampered by scarcity of sound exposure data as well as by lack of information on relevant exposure factors and conditions of exposure. This paper describes a study where inhalation and dermal exposure data were collected under defined conditions. Exposure scenarios examined included tasks that have not been investigated in previous validation studies. The results of these measurements were compared with ECETOC TRA model version 3.1 predictions. In this study, five exposure scenarios were selected, namely 'use in a closed batch process' (PROC 4), 'mixing or blending in a partly open batch process' (PROC 5), 'rolling' (PROC 10), 'immersion' (PROC 13), and 'stirring' (PROC 19). These PROCs stem from the descriptors that Registration, Evaluation and Authorization of Chemicals has established to depict the identified uses of chemical substances. These exposure scenarios were selected mainly because little or no data are available for these situations, or ECETOC TRA is likely to underestimate exposure for these situations. Experiments were performed by volunteers for the selected exposure scenarios, in which tasks were performed aiming to represent real workplace situations. In total 70 experiments were performed, during which 70 dermal exposure measurements (5 volunteers × 2 repeats × 7 scenarios) and 32 inhalation exposure measurements (4 volunteers × 2 repeats × 4 scenarios) were collected. Two formulations were used, namely pure Tinopal SWN powder (solid product, a fluorescent tracer) and 0.5% Tinopal SWN dissolved in 1,2-dichloroethane (1,2-DCE). DCE is considered a moderate volatile liquid. For exposure scenarios using the liquid formulation, both inhalation and dermal measurements were performed, while for exposure scenarios using the pure powder only dermal exposure measurements were performed. In addition, photographs were taken under ultraviolet light to qualitatively assess exposure patterns on hands and body. Volunteers repeatedly performed a selection of tasks under standardized conditions in a test chamber for each exposure scenario. Results show that ECETOC TRA overestimated dermal hand exposure for all PROCs included in the study, and was considered to be conservative. Additionally, ECETOC TRA overestimated inhalation exposure for closed and partially closed processes, but underestimated inhalation exposure for rolling and handling of immersed objects. Qualitative assessment of the hands and body showed mainly the hands were exposed for tasks involving closed and partially closed processes and when handling of immersed objects. Exposure to other body segments were also observed for rolling and stirring. In conclusion, this study gave insights into dermal and inhalation exposure levels during selected task scenarios, and showed that ECETOC TRA is conservative when dermal exposure is estimated. Inhalation exposure estimates for PROCs 10 and 13 tasks with the moderate volatility liquid were underestimated in this study. It may be therefore necessary to re-evaluate base model predictions for these scenarios when medium fugacity liquids are involved., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Measured data are generally preferred to modelled estimates of exposure. Grouping and read-across is already widely used and accepted approach in toxicology, but an appropriate approach and guidance on how to use existing exposure measurement data on one substance and work situation for another substance and/or work situation is currently not available. This study presents a framework for an extensive read-across of existing worker inhalable exposure measurement data. This framework enables the calculation of read-across factors based on another substance and/or work situation by first evaluating the quality of the existing measurement data and then mapping its similarity or difference with another substance and/or work situation. The system of read-across factors was largely based on the determinants in ECETOC TRA and ART exposure models. The applicability of the framework and its proof of principle were demonstrated by using five case studies. In these case studies, either the 75th percentiles of measured exposure data was observed to lie within the estimated 90% confidence intervals from the read-across approach or at least with the increase in the geometric mean of measured exposure, geometric mean of estimated exposure also increased. Testing and re-evaluation of the present framework by experts in exposure assessment and statistics is recommended to develop it further into a tool that can be widely used in exposure assessment and regulatory practices., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Advanced material development, including at the nanoscale, comprises costly and complex challenges coupled to ensuring human and environmental safety. Governmental agencies regulating safety have announced interest toward acceptance of safety data generated under the collective term New Approach Methodologies (NAMs), as such technologies/approaches offer marked potential to progress the integration of safety testing measures during innovation from idea to product launch of nanomaterials. Divided in overall eight main categories, searchable databases for grouping and read across purposes, exposure assessment and modeling, in silico modeling of physicochemical structure and hazard data, in vitro high-throughput and high-content screening assays, dose-response assessments and modeling, analyses of biological processes and toxicity pathways, kinetics and dose extrapolation, consideration of relevant exposure levels and biomarker endpoints typify such useful NAMs. Their application generally agrees with articulated stakeholder needs for improvement of safety testing procedures. They further fit for inclusion and add value in nanomaterials risk assessment tools. Overall 37 of 50 evaluated NAMs and tiered workflows applying NAMs are recommended for considering safer-by-design innovation, including guidance to the selection of specific NAMs in the eight categories. An innovation funnel enriched with safety methods is ultimately proposed under the central aim of promoting rigorous nanomaterials innovation., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Model tools for estimating hazardous substance exposure are an accepted part of regulatory risk assessments in Europe, and models underpin control banding tools used to help manage chemicals in workplaces. Of necessity the models are simplified abstractions of real-life working situations that aim to capture the essence of the scenario to give estimates of actual exposures with an appropriate margin of safety. The basis for existing inhalation exposure assessment tools has recently been discussed by some scientists who have argued for the use of more complex models. In our opinion, the currently accepted tools are documented to be the most robust way for workplace health and safety practitioners and others to estimate inhalation exposure. However, we recognise that it is important to continue the scientific development of exposure modelling to further elaborate and improve the existing methodologies.

Dustiness is not an intrinsic physically defined property of a powder, but the tendency of particles to become airborne in response to mechanical and/or aerodynamic stimuli. The present study considers a set of 10 physical properties to which the powder dustiness can be attributed. Through a preliminary investigation of a standardized continuous drop test scenario, we present first set of results on the varying degrees or weights of influence of these properties on the aerosolization tendency of powder particles. The inter-particle distance is found to be the most dominant property controlling the particle aerosolization, followed by the ability of powder particles to get electrostatically charged. We observe the kinetics involved during powder aerosolization to be governed by two ratios: drag force/cohesive force and drag force/gravitational force. The converging tendencies in these initial results indicate that these physical properties can be used to model dustiness of falling powder, which can eventually be used in risk assessment tools for an efficient exposure estimation of the powders., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

The widespread use of engineered nanomaterials (ENMs) in consumer products and the overwhelming uncertainties in their ecological and human health risks have raised concerns regarding their safety among industries and regulators. There has been an ongoing debate over the past few decades on ways to overcome the challenges in assessing and mitigating nano-related risks, which has reached a phase of general consensus that nanotechnology innovation should be accompanied by the application of the precautionary principle and best practice risk management, even if the risk assessment uncertainties are large. We propose a quantitative methodology for selecting the optimal risk control strategy based on information about human health and ecological risks, efficacy of risk mitigation measures, cost and other contextual factors. The risk control (RC) methodology was developed in the European FP7 research project SUN and successfully demonstrated in two case studies involving real industrial nano-enabled products (NEPs): nano-scale copper oxide (CuO) and basic copper carbonate (Cu 2 (OH) 2 CO 3 ) used as antimicrobial and antifungal coatings and impregnations for the preservation of treated wood, and two nanoscale pigments used for colouring plastic automotive parts (i.e. red organic pigment and carbon black). The application of RC for human health risks showed that although nano-related risks could easily be controlled in automotive plastics case study with modifications in production technology or specific type of engineering controls, nano-related risks due to sanding and sawing copper oxide painted wood were non-acceptable in the use lifecycle stage and would need the identification of a more effective risk control strategy., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

A particle exposure experiment inside a large climate-controlled chamber was conducted. Data on spatial and temporal distribution of nanoscale and fine aerosols in the range of mobility diameters 8-600 nm were collected with high resolution, for sodium chloride, fluorescein sodium, and silica particles. Exposure scenarios studied included constant and intermittent source emissions, different aggregation conditions, high (10 h -1 ) and low (3.5 h -1 ) air exchange rates (AERs) corresponding to chamber Reynolds number, respectively, equal to 1 × 10 5 and 3 × 10 4 . Results are presented and analyzed to highlight the main determinants of exposure and to determine whether the assumptions underlying two-box models hold under various scenarios. The main determinants of exposure found were the source generation rate and the ventilation rate. The effect of particles nature was indiscernible, and the decrease of airborne total number concentrations attributable to surface deposition was estimated lower than 2% when the source was active. A near-field/far-field structure of aerosol concentration was always observed for the AER = 10 h -1 but for AER = 3.5 h -1 , a single-field structure was found. The particle size distribution was always homogeneous in space but a general shift of particle diameter (-8% to +16%) was observed between scenarios in correlation with the AER and with the source position, presumably largely attributable to aggregation., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This article describes the development of a mechanistic model for underpinning the dermal Advanced REACH Tool (dART), an extension of the existing ART model and its software platform. It was developed for hand exposure to low volatile liquids (vapour pressure ≤ 10 Pa at 20°C) including solids-in-liquid products. The model is based on an existing conceptual dermal source-receptor model that has been integrated into the ART framework. A structured taxonomy of workplace activities referred to as activity classes are adopted from ART.  Three key processes involved in mass transport associated with dermal exposure are applied, i.e. deposition, direct emission and contact, and transfer. For deposition, the model adopts all the relevant modifying factors (MFs) applied in ART. In terms of direct emission and contact (e.g. splashes) and transfer (e.g. hand-surface contacts), the model defines independent principal MFs, i.e. substance-related factors, activity-related factors, localized- and dispersion control and exposed surface area of the hands. To address event-based exposures as much as possible, the model includes crucial events during an activity (e.g. hand immersions) and translates objective information on tools and equipment (manual or automated) to probable events (e.g. splashes) and worker behaviours (e.g. surface contacts). Based on an extensive review of peer-reviewed literature and unpublished field studies, multipliers were assigned to each determinant and provide an approximated (dimensionless) numerical value. In the absence of (sufficient) evidence, multipliers were assigned to determinants based on assumptions made during discussions by experts in the consortium. A worked example is presented to illustrate the calculation of hand exposure for a specific scenario. The dART model is not yet implemented in the ART software platform, and a robust validation of the model is necessary to determine its predictive ability. With advancing knowledge on dermal exposure and its determinants, this model will require periodic updates and refinements, in addition to further expansion of the applicability domain of the model., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Introduction: Knowledge on the exposure characteristics, including release of nanomaterials, is especially needed in the later stages of nano-enabled products' life cycles to perform better occupational risk assessments. The objective of this study was to assess the concentrations during sawing and drilling in car bumpers containing multi-walled carbon nanotubes (MWCNTs) and nanosized organic pigment (OP) under variable realistic workplace situations related to the ventilation in the room and machine settings., Methods: Twelve different experiments were performed in triplicate (N = 36) using tools powered by induction engines that allow interference-free particle measurements. A DiSCmini was used to measure particle number concentrations, whereas particle size distributions were measured using Aerodynamic Particle Sizer (TSI), Scanning Mobility Particle Sizer (TSI), and Electrical Low Pressure Impactor (Dekati). In addition, inhalable particles were sampled using IOM samplers on filters for scanning electron microscope/energy-dispersive X-ray spectrometry (SEM/EDX) analyses. Data were analysed to estimate the effects of individual exposure determinants, in a two-stage modelling strategy using Autoregressive Integrated Moving Average models (stage 1) and subsequently combining first stage results in simulations using multiple linear regression models (stage 2)., Results: In sawing experiments, partly melted carbon-rich particles (mainly ~2 to ~8 µm) were identified with SEM/EDX, whereas drilling experiments revealed no activity-related particles. In addition, no pristine engineered nanoparticles (MWCNTs and OP) were observed to be liberated from the matrix. Statistical analyses showed significant effects of a higher sawing speed, a reduction in air concentration due to mechanical ventilation, and less exposure during sawing of car bumpers containing MWCNTs compared to bumpers containing OP., Conclusion: The experiments in this study give an indication of the effects of different abrasive activities (sawing, drilling), machine settings (sawing speed, drill size), mechanical ventilation, and material characteristics on the manufactured nano-objects, their agglomerates, and aggregates concentration levels., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

This review describes an evaluation of the effectiveness of Risk Management Measures (RMM) for nanomaterials in the workplace. Our aim was to review the effectiveness of workplace RMM for nanomaterials and to determine whether established effectiveness values of conventional chemical substances applied for modelling purposes should be adopted or revised based on available evidence. A literature review was conducted to collate nano-specific data on workplace RMM. Besides the quantitative efficacy values, the library was populated with important covariables such as the study design, measurement type, size of particles or agglomerates/aggregates, and metrics applied. In total 770 records were retrieved from 41 studies for three general types of RMM (engineering controls, respiratory equipment and skin protective equipment: gloves and clothing). Records were found for various sub-categories of the different types of RMM although the number of records for each was generally limited. Significant variation in efficacy values was observed within RMM categories while also considering the respective covariables. Based on a comparative evaluation with efficacy values applied for conventional substances, adapted efficacy values are proposed for various RMM sub-categories (e.g. containment, fume cupboards, FFP2 respirators). It is concluded that RMM efficacy data for nanomaterials are limited and often inconclusive to propose effectiveness values. This review also shed some light on the current knowledge gaps for nanomaterials related to RMM effectiveness (e.g. ventilated walk-in enclosures and clean rooms) and the challenges foreseen to derive reliable RMM efficacy values from aggregated data in the future.

The use of nano-scale copper oxide (CuO) and basic copper carbonate (Cu 2 (OH) 2 CO 3 ) in both ionic and micronized wood preservatives has raised concerns about the potential of these substances to cause adverse humans health effects. To address these concerns, we performed quantitative (probabilistic) human health risk assessment (HHRA) along the lifecycles of these formulations used in antibacterial and antifungal wood coatings and impregnations by means of the EU FP7 SUN project's Decision Support System (SUNDS, www.sunds.gd). The results from the risk analysis revealed inhalation risks from CuO in exposure scenarios involving workers handling dry powders and performing sanding operations as well as potential ingestion risks for children exposed to nano Cu 2 (OH) 2 CO 3 in a scenario involving hand-to-mouth transfer of the substance released from impregnated wood. There are, however, substantial uncertainties in these results, so some of the identified risks may stem from the safety margin of extrapolation to fill data gaps and might be resolved by additional testing. Our stochastic approach successfully communicated the contribution of different sources of uncertainty in the risk assessment. The main source of uncertainty was the extrapolation from short to long-term exposure, which was necessary due to the lack of (sub)chronic in vivo studies with CuO and Cu 2 (OH) 2 CO 3 . Considerable uncertainties also stemmed from the use of default inter- and intra-species extrapolation factors.

Nanoscale TiO 2 (nTiO 2 ) is manufactured in high volumes and is of potential concern in occupational health. Here, we measured workers exposure levels while ceramic honeycombs were dip coated with liquid photoactive nanoparticle suspension and dried with an air blade. The measured nTiO 2 concentration levels were used to assess process specific emission rates using a convolution theorem and to calculate inhalation dose rates of deposited nTiO 2 particles. Dip coating did not result in detectable release of particles but air blade drying released fine-sized TiO 2 and nTiO 2 particles. nTiO 2 was found in pure nTiO 2 agglomerates and as individual particles deposited onto background particles. Total particle emission rates were 420×10 9 min -1 , 1.33×10 9 μm 2 min -1 , and 3.5mgmin -1 respirable mass. During a continued repeated process, the average exposure level was 2.5×10 4 cm -3 , 30.3μm 2 cm -3 , <116μgm -3 for particulate matter. The TiO 2 average exposure level was 4.2μgm -3 , which is well below the maximum recommended exposure limit of 300μgm -3 for nTiO 2 proposed by the US National Institute for Occupational Safety and Health. During an 8-hour exposure, the observed concentrations would result in a lung deposited surface area of 4.3×10 -3 cm 2 g -1 of lung tissue and 13μg of TiO 2 to the trachea-bronchi, and alveolar regions. The dose levels were well below the one hundredth of the no observed effect level (NOEL 1/100 ) of 0.11cm 2 g -1 for granular biodurable particles and a daily no significant risk dose level of 44μgday -1 . These emission rates can be used in a mass flow model to predict the impact of process emissions on personal and environmental exposure levels., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Fume hoods are one of the most common types of equipment applied to reduce the potential of particle exposure in laboratory environments. A number of previous studies have shown particle release during work with nanomaterials under fume hoods. Here, we assessed laboratory workers' inhalation exposure during synthesis and handling of CuO, TiO 2 and ZnO in a fume hood. In addition, we tested the capacity of a fume hood to prevent particle release to laboratory air during simulated spillage of different powders (silica fume, zirconia TZ-3Y and TiO 2 ). Airborne particle concentrations were measured in near field, far field, and in the breathing zone of the worker. Handling CuO nanoparticles increased the concentration of small particles (< 58 nm) inside the fume hood (up to 1 × 10 5  cm -3 ). Synthesis, handling and packaging of ZnO and TiO 2 nanoparticles did not result in detectable particle release to the laboratory air. Simulated powder spills showed a systematic increase in the particle concentrations inside the fume hood with increasing amount of material and drop height. Despite powder spills were sometimes observed to eject into the laboratory room, the spill events were rarely associated with notable release of particles from the fume hood. Overall, this study shows that a fume hood generally offers sufficient exposure control during synthesis and handling of nanomaterials. An appropriate fume hood with adequate sash height and face velocity prevents 98.3% of particles release into the surrounding environment. Care should still be made to consider spills and high cleanliness to prevent exposure via resuspension and inadvertent exposure by secondary routes., Competing Interests: Compliance with ethical standardsThe authors declare that they have no conflict of interest.

The ECETOC TRA model (presently version 3.1) is often used to estimate worker inhalation and dermal exposure in regulatory risk assessment. The dermal model in ECETOC TRA has not yet been validated by comparison with independent measured exposure levels. This was the goal of the present study. Measured exposure levels and relevant contextual information were gathered via literature search, websites of relevant occupational health institutes and direct requests for data to industry. Exposure data were clustered in so-called exposure cases, which are sets of data from one data source that are expected to have the same values for input parameters in the ECETOC TRA dermal exposure model. For each exposure case, the 75th percentile of measured values was calculated, because the model intends to estimate these values. The input values for the parameters in ECETOC TRA were assigned by an expert elicitation and consensus building process, based on descriptions of relevant contextual information.From more than 35 data sources, 106 useful exposure cases were derived, that were used for direct comparison with the model estimates. The exposure cases covered a large part of the ECETOC TRA dermal exposure model. The model explained 37% of the variance in the 75th percentiles of measured values. In around 80% of the exposure cases, the model estimate was higher than the 75th percentile of measured values. In the remaining exposure cases, the model estimate may not be sufficiently conservative.The model was shown to have a clear bias towards (severe) overestimation of dermal exposure at low measured exposure values, while all cases of apparent underestimation by the ECETOC TRA dermal exposure model occurred at high measured exposure values. This can be partly explained by a built-in bias in the effect of concentration of substance in product used, duration of exposure and the use of protective gloves in the model. The effect of protective gloves was calculated to be on average a factor of 34 in this data set, while factors of five to ten were used in the model estimations. There was also an effect of the sampling method in the measured data on the exposure levels. Exposure cases where sampling was done via an interception method, such as gloves, on average showed a factor of six higher 75th percentiles of measured values than exposure cases where sampling was done via a removal method, such as hand washing. This may partly be responsible for the apparent underestimation of dermal exposure by the model at high exposure values. However, there also appeared to be a relation between expected exposure level (as indicated by the model estimate) and the choice of sampling method.In this study, solid substances used in liquid products were treated as liquids with negligible volatility. The results indicate that the ECETOC TRA dermal exposure model performs equally well for these substances as for liquids. There were suggestions of a difference in performance of the model between solids and liquids.For several parts of the ECETOC TRA dermal model, no or hardly any measured dermal exposure data were available. Therefore, gathering of more dermal exposure levels is recommended, specifically for situations not yet sufficiently covered in the present data set., (© The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

For safe innovation, knowledge on potential human health impacts is essential. Ideally, these impacts are considered within a larger life-cycle-based context to support sustainable development of new applications and products. A methodological framework that accounts for human health impacts caused by inhalation of engineered nanomaterials (ENMs) in an indoor air environment has been previously developed. The objectives of this study are as follows: (i) evaluate the feasibility of applying the CF framework for NP exposure in the workplace based on currently available data; and (ii) supplement any resulting knowledge gaps with methods and data from the life cycle approach and human risk assessment (LICARA) project to develop a modified case-specific version of the framework that will enable near-term inclusion of NP human health impacts in life cycle assessment (LCA) using a case study involving nanoscale titanium dioxide (nanoTiO 2 ). The intent is to enhance typical LCA with elements of regulatory risk assessment, including its more detailed measure of uncertainty. The proof-of-principle demonstration of the framework highlighted the lack of available data for both the workplace emissions and human health effects of ENMs that is needed to calculate generalizable characterization factors using common human health impact assessment practices in LCA. The alternative approach of using intake fractions derived from workplace air concentration measurements and effect factors based on best-available toxicity data supported the current case-by-case approach for assessing the human health life cycle impacts of ENMs. Ultimately, the proposed framework and calculations demonstrate the potential utility of integrating elements of risk assessment with LCA for ENMs once the data are available., (© 2016 Society for Risk Analysis.)

Exposure assessment for nano-objects, and their aggregates and agglomerates (NOAA), has evolved from explorative research toward more comprehensive exposure assessment, providing data to further develop currently used conservative control banding (CB) tools for risk assessment. This study aims to provide an overview of current knowledge on emission potential of NOAA across the occupational life cycle stages by a systematic review and subsequently use the results in a data analysis. Relevant parameters that influence emission were collected from peer-reviewed literature with a focus on the four source domains (SD) in the source-receptor conceptual framework for NOAA. To make the reviewed exposure data comparable, we applied an approach to normalize for workplace circumstances and measurement location, resulting in comparable "surrogate" emission levels. Finally, descriptive statistics were performed. During the synthesis of nanoparticles (SD1), mechanical reduction and gas phase synthesis resulted in the highest emission compared to wet chemistry and chemical vapor condensation. For the handling and transfer of bulk manufactured nanomaterial powders (SD2) the emission could be differentiated for five activity classes: (1) harvesting; (2) dumping; (3); mixing; (4) cleaning of a reactor; and (5) transferring. Additionally, SD2 was subdivided by the handled amount with cleaning further subdivided by energy level. Harvesting and dumping resulted in the highest emissions. Regarding processes with liquids (SD3b), it was possible to distinguish emissions for spraying (propellant gas, (high) pressure and pump), sonication and brushing/rolling. The highest emissions observed in SD3b were for propellant gas spraying and pressure spraying. The highest emissions for the handling of nano-articles (SD4) were found to nano-sized particles (including NOAA) for grinding. This study provides a valuable overview of emission assessments performed in the workplace during the occupational handling of NOAA. Analyses were made per source domain to derive emission levels which can be used for models to quantitatively predict the exposure.

Background: Nano-specific inhalation exposure models could potentially be effective tools to assess and control worker exposure to nano-objects, and their aggregates and agglomerates (NOAA). However, due to the lack of reliable and consistent collected NOAA exposure data, the scientific basis for validation of the existing NOAA exposure models is missing or limited. The main objective of this study was to gain more insight into the effect of various determinants underlying the potential on the concentration of airborne NOAA close to the source with the purpose of providing a scientific basis for existing and future exposure inhalation models., Method: Four experimental studies were conducted to investigate the effect of 11 determinants of emission on the concentration airborne NOAA close to the source during dumping of ~100% nanopowders. Determinants under study were: nanomaterial, particle size, dump mass, height, rate, ventilation rate, mixing speed, containment, particle surface coating, moisture content of the powder, and receiving surface. The experiments were conducted in an experimental room (19.5 m3) with well-controlled environmental and ventilation conditions. Particle number concentration and size distribution were measured using real-time measurement devices., Results: Dumping of nanopowders resulted in a higher number concentration and larger particles than dumping their reference microsized powder (P < 0.05). Statistically significant more and larger particles were also found during dumping of SiO2 nanopowder compared to TiO2/Al2O3 nanopowders. Particle surface coating did not affect the number concentration but on average larger particles were found during dumping of coated nanopowders. An increase of the powder's moisture content resulted in less and smaller particles in the air. Furthermore, the results indicate that particle number concentration increases with increasing dump height, rate, and mass and decreases when ventilation is turned on., Discussion: These results give an indication of the direction and magnitude of the effect of the studied determinants on concentrations close to the source and provide a scientific basis for (further) development of existing and future NOAA inhalation exposure models., (© The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Background: Control banding can be used as a first-tier assessment to control worker exposure to nano-objects and their aggregates and agglomerates (NOAA). In a second tier, more advanced modelling approaches are needed to produce quantitative exposure estimates. As currently no general quantitative nano-specific exposure models are available, this study evaluated the validity and applicability of using a generic exposure assessment model (the Advanced REACH Tool-ART) for occupational exposure to NOAA., Method: The predictive capability of ART for occupational exposure to NOAA was tested by calculating the relative bias and correlations (Pearson) between the model estimates and measured concentrations using a dataset of 102 NOAA exposure measurements collected during experimental and workplace exposure studies., Results: Moderate to (very) strong correlations between the ART estimates and measured concentrations were found. Estimates correlated better to measured concentration levels of dust (r = 0.76, P < 0.01) than liquid aerosols (r = 0.51, P = 0.19). However, ART overestimated the measured NOAA concentrations for both the experimental and field measurements (factor 2-127). Overestimation was highest at low concentrations and decreased with increasing concentration. Correlations seemed to be better when looking at the nanomaterials individually compared to combined scenarios, indicating that nanomaterial-specific characteristics are not well captured within the mechanistic model of the ART., Discussion: Although ART in its current state is not capable to estimate occupational exposure to NOAA, the strong correlations for the individual nanomaterials indicate that the ART (and potentially other generic exposure models) have the potential to be extended or adapted for exposure to NOAA. In the future, studies investigating the potential to estimate exposure to NOAA should incorporate more explicitly nanomaterial-specific characteristics in their models., (© The Author 2016. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

An important step in building a computational model is its documentation; a comprehensive and structured documentation can improve the model applicability and transparency in science/research and for regulatory purposes. This is particularly crucial and challenging for environmental and/or human exposure models that aim to establish quantitative relationships between personal exposure levels and their determinants. Exposure models simulate the transport and fate of a contaminant from the source to the receptor and may involve a large set of entities (e.g. all the media the contaminants may pass though). Such complex models are difficult to be described in a comprehensive, unambiguous and accessible way. Bad communication of assumptions, theory, structure and/or parameterization can lead to lack of confidence by the user and it may be source of errors. The goal of this paper is to propose a standard documentation protocol (SDP) for exposure models, i.e. a generic format and a standard structure by which all exposure models could be documented. For this purpose, a CEN (European Committee for Standardisation) workshop was set up with objective to agree on minimum requirements for the amount and type of information to be provided on exposure models documentation along with guidelines for the structure and presentation of the information. The resulting CEN workshop agreement (CWA) was expected to facilitate a more rigorous formulation of exposure models description and the understanding by users. This paper intends to describe the process followed for defining the SDP, the standardisation approach, as well as the main components of the SDP resulting from a wide consultation of interested stakeholders. The main outcome is a CEN CWA which establishes terms and definitions for exposure models and their elements, specifies minimum requirements for the amount and type of information to be documented, and proposes a structure for communicating the documentation to different users., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Tiered or stepwise approaches to assess occupational exposure to nano-objects, and their agglomerates and aggregates have been proposed, which require decision rules (DRs) to move to a next tier, or terminate the assessment. In a desk study the performance of a number of DRs based on the evaluation of results from direct reading instruments was investigated by both statistical simulations and the application of the DRs to real workplace data sets. A statistical model that accounts for autocorrelation patterns in time-series, i.e. autoregressive integrated moving average (ARIMA), was used as 'gold' standard. The simulations showed that none of the proposed DRs covered the entire range of simulated scenarios with respect to the ARIMA model parameters, however, a combined DR showed a slightly better agreement. Application of the DRs to real workplace datasets (n = 117) revealed sensitivity up to 0.72, whereas the lowest observed specificity was 0.95. The selection of the most appropriate DR is very much dependent on the consequences of the decision, i.e. ruling in or ruling out of scenarios for further evaluation. Since a basic assessment may also comprise of other type of measurements and information, an evaluation logic was proposed which embeds the DRs, but furthermore supports decision making in view of a tiered-approach exposure assessment., (© The Author 2016. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Increasing production and applications of manufactured nano objects (MNOs) have become a source for human exposure and therefore raise concerns and questions about the possible health effects. In this study, the potential release of nano objects, their agglomerates, and aggregates (NOAA) as a result of sanding of hardwood treated with MNOs-containing coating was examined. Two types of MNO-containing coating were compared with untreated hardwood that allowed the evaluation of the influence of the chemical composition on the release of particles. Furthermore, the rotation speed of the sander and the grit size of the sanding paper were varied in order to assess their influence on the release of particles.Measurements were conducted in a gas-tight chamber with a volume of 19.5 m(3) in which ventilation was minimized during experiments. Particle size distributions were assessed by scanning mobility particle sizer , aerodynamic particle sizer, and electrical low pressure impactor. Furthermore, aerosol number concentrations (Nanotracer), active surface area (LQ1), and fractionated mass (Cascade Impactor) were measured before, during, and after sanding. Scanning electron microscope/energy dispersive X-ray (SEM/EDX) analysis was performed to adequately characterize the morphology, size, and chemical composition of released particles.SEM/EDX analysis indicated that sanding surfaces treated with MNO-containing coating did not release the designated MNO as free primary particles. In both coatings, clusters of MNO were perceived embedded in and attached to micro-sized wood and/or coating particles created by sanding the coated surface. Real-time measurements indicated a lower release of micro-sized particles from sanding of surfaces treated with Coating I than from sanding untreated surfaces or surfaces treated with Coating II. A substantial increase in nanosized and a slight increase in micro-sized particles was perceived as the rotation speed of the sander increased. However, most nanosized particles were most likely emitted by the sanding machine. No effect of the grit size on the release of particles was detected., (© The Author 2016. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

The fast penetration of nanoproducts on the market under conditions of significant uncertainty of their environmental properties and risks to humans creates a need for companies to assess sustainability of their products. Evaluation of the potential benefits and risks to build a coherent story for communication with clients, authorities, consumers, and other stakeholders is getting to be increasingly important, but SMEs often lack the knowledge and expertise to assess risks and communicate them appropriately. This paper introduces LICARA nanoSCAN, a modular web based tool that supports SMEs in assessing benefits and risks associated with new or existing nanoproducts. This tool is unique because it is scanning both the benefits and risks over the nanoproducts life cycle in comparison to a reference product with a similar functionality in order to enable the development of sustainable and competitive nanoproducts. SMEs can use data and expert judgment to answer mainly qualitative and semi-quantitative questions as a part of tool application. Risks to public, workers and consumers are assessed, while the benefits are evaluated for economic, environmental and societal opportunities associated with the product use. The tool provides an easy way to visualize results as well as to identify gaps, missing data and associated uncertainties. The LICARA nanoSCAN has been positively evaluated by several companies and was tested in a number of case studies. The tool helps to develop a consistent and comprehensive argument on the weaknesses and strengths of a nanoproduct that may be valuable for the communication with authorities, clients and among stakeholders in the value chain. LICARA nanoSCAN identifies areas for more detailed assessments, product design improvement or application of risk mitigation measures., (Copyright © 2016 Elsevier Ltd. All rights reserved.)