Application of a pilot control banding tool for risk level assessment and control of nanoparticle exposures

An analysis on control banding-based methods used for occupational risk assessment of nanomaterials

Despite all benefits of nanomaterials, their unique characteristics made them an emerging hazard in workplaces, which need to be assessed for their potential risks. So, the aim of this study was to review all the studies conducted on the risk assessment of activities involving nanomaterials with CB-based methods.This study is based on a literature review on databases including Web of science, Scopus, PubMed, and SID. After reviewing and screening studies according to PRISMA, the collected data were meta-analyzed by Comprehensive Meta-Analysis Software. Also, Newcastle-Ottawa checklist was used for quality assessment of the studies. To determine similarity of methods, Cohen's Kappa was used. Sensitivity analysis was used to determine the role of each factor in the risk assessment by using the Crystal Ball tool.There are eight validated methods for risk assessment. Also, some authors used a self-deigned tool based on CB approach. The results of meta-analysis showed that the odds ratio for the risk of activities involved with nanomaterials was 0.654 (high risk). Results of simulation for Nanotool showed that the mean risk level of activities involved with nanomaterials, with a certainty of 95.07%, is moderate (RL3). Moreover, sensitivity analysis showed that the risk was depended on "Hazard band" in all methods except ISO method.The obtained results can be useful in improving existing methods and suggesting new methods. Also, there is a need to design and propose specific methods for risk assessment of incidental and natural nanomaterials.

Control Banding and the Global Rise of Qualitative Risk Assessment Strategies

PURPOSE OF REVIEW

Control banding (CB) is a risk assessment strategy that has been applied globally to a variety of occupational hazards. This article describes how this method can be applied, recent developments in the CB literature, an example of how it is utilized for a large, diverse worksite, and where the future of CB is headed.

RECENT FINDINGS

Over the past several years, the applications of CB have widened significantly and have accordingly helped bolster the public and occupational safety, health, and hygiene (OSHH) professionals' understanding of occupational exposure to various hazards. The fields of workplace chemicals, nanomaterials, and airborne pathogens (i.e., COVID-19), specifically have seen remarkable increases in the development of CB tools. Extensive CB tool validation efforts have also lent increasing credibility to this alternative approach. CB is a simplified strategy of assessing occupational exposures and providing commensurate controls and solutions to reduce workplace risks. CB can be used as a primary or tiered risk assessment and risk management approach which can be utilized by both OSHH professionals and nonexperts alike to identify solutions for reducing work-related exposures. The need for health and safety expertise will continue to grow as technological advancements, environmental changes, and economic forces increase workplace hazard complexity, and CB will continue to be a useful tool for those performing risk assessments.

NanoSafe III: A User Friendly Safety Management System for Nanomaterials in Laboratories and Small Facilities

Research in nanoscience continues to bring forward a steady stream of new nanomaterials and processes that are being developed and marketed. While scientific committees and expert groups deal with the harmonization of terminology and legal challenges, risk assessors in research labs continue to have to deal with the gap between regulations and rapidly developing information. The risk assessment of nanomaterial processes is currently slow and tedious because it is performed on a material-by-material basis. Safety data sheets are rarely available for (new) nanomaterials, and even when they are, they often lack nano-specific information. Exposure estimations or measurements are difficult to perform and require sophisticated and expensive equipment and personal expertise. The use of banding-based risk assessment tools for laboratory environments is an efficient way to evaluate the occupational risks associated with nanomaterials. Herein, we present an updated version of our risk assessment tool for working with nanomaterials based on a three-step control banding approach and the precautionary principle. The first step is to determine the hazard band of the nanomaterial. A decision tree allows the assignment of the material to one of three bands based on known or expected effects on human health. In the second step, the work exposure is evaluated and the processes are classified into three "nano" levels for each specific hazard band. The work exposure is estimated using a laboratory exposure model. The result of this calculation in combination with recommended occupational exposure limits (rOEL) for nanomaterials and an additional safety factor gives the final "nano" level. Finally, we update the technical, organizational, and personal protective measures to allow nanomaterial processes to be established in research environments.

Risk Assessment of Nano-Flame Retardants Coating in the Selected Construction Industry of Iran by Control Banding Approach

Background:

There is a wide range of challenges through the use of nano-material in buildings. By developing construction industries the use of flame retardant nano-materials is a hurdle for human health. However occupational exposure measurement is not applicable for nano-particles monitoring. Risk assessment is an alternative method for industrial hygiene strategies. In this study, we use the control banding approach for risk assessment of 3 nano-fire retardant (NFR) in the building industry.

Methods:

We used control banding as a risk assessment approach for decision making about nano-materials in the building industry. The risk of nano-fire retardants such as monokote accelerator, monokote Z-106 G and monokote Z-106 HY in the construction industry was studied. The level of risk was evaluated by the matrix of hazard severity and probability score. Hazard severity was scored by toxicological information. The probability score was estimated by the state work operation.

Results:

A score of hazard severity in monokot Z-106 HY was higher than other nano-materials. The probability score of spraying tasks was lower than mixing and transportation tasks. The results show the application of all nano-materials had the higher risk level in transportation and mixing tasks. The risk level of monokote accelerator and monokote Z-106 G in spraying task is lower than monokot Z-106 HY.

Conclusions:

There is a high risk level for studied nano-materials in the coating tasks of the construction industry. In conclusion, powerful controlling strategies such as the substitution of nano-materials was suggested to decrease the risk of nano-fire retardants.

Occupational Exposure to Ultrafine Particles in Metal Additive Manufacturing: A Qualitative and Quantitative Risk Assessment

Ultrafine particles (UFPs) can be released unintentionally during metal additive manufacturing (AM). Experts agree on the urgent need to increase the knowledge of the emerging risk of exposure to nanoparticles, although different points of view have arisen on how to do so. This article presents a case study conducted on a metal AM facility, focused on studying the exposure to incidental metallic UFP. It intends to serve as a pilot study on the application of different methodologies to manage this occupational risk, using qualitative and quantitative approaches that have been used to study exposure to engineered nanoparticles. Quantitative data were collected using a condensation particle counter (CPC), showing the maximum particle number concentration in manual cleaning tasks. Additionally, scanning electron microscopy (SEM) and energy dispersive X-ray analyzer (EDS) measurements were performed, showing no significant change in the particles’ chemical composition, size, or surface (rugosity) after printing. A qualitative approach was fulfilled using Control Banding Nanotool 2.0, which revealed different risk bands depending on the tasks performed. This article culminates in a critical analysis regarding the application of these two approaches in order to manage the occupational risk of exposure to incidental nanoparticles, raising the potential of combining both.

New Tools to Support the Risk Assessment Process of Nanomaterials in the Insurance Sector

During the last decade, the use of nanomaterials, due to their multiple utilities, has exponentially increased. Nanomaterials have unique properties such as a larger specific surface area and surface activity, which may result in health and environmental hazards different from those demonstrated by the same materials in bulk form. Besides, due to their small size, they can easily penetrate through the environmental and biological barriers. In terms of exposure potential, the vast majority of studies are focused on workplace areas, where inhalation is the most common route of exposure. The main route of entry into the environment is due to indirect emissions of nanomaterials from industrial settings, as well as uncontrollable releases into the environment during the use, recycling and disposal of nano-enabled products. Accidental spills during production or later transport of nanomaterials and release from wear and tear of materials containing nanomaterials may lead to potential exposure. In this sense, a proper understanding of all significant risks due to the exposure to nanomaterials that might result in a liability claim has been proved to be necessary. In this paper, the utility of an application for smartphones developed for the insurance sector has been validated as a solution for the analysis and evaluation of the emerging risk of the application of nanotechnology in the market. Different exposure scenarios for nanomaterials have been simulated with this application. The results obtained have been compared with real scenarios, corroborating that the use of novel tools can be used by companies that offer risk management in the form of insurance contracts.

Comparison of the Qualitative and the Quantitative Risk Assessment of Hazardous Substances Requiring Management under the Occupational Safety and Health Act in South Korea

The risk assessment of hazardous substances has become increasingly important for the efficient prevention and management of various diseases or accidents caused by increased amounts of hazardous substances in the workplace. In this study, risk assessment was conducted for 36 kinds of hazardous substances requiring management by using qualitative and quantitative risk assessments. Qualitative risk assessment was performed by multiplying the exposure level class by the hazard class according to the Korea Occupational Safety and Health Agency’s (KOSHA) Chemical Hazard Risk Management (CHARM). The quantitative risk assessment was followed by a four-step risk assessment system presented in the Guidelines for Hazard Risk Assessment of Chemicals (KOSHA GUIDE W-6-2016). In the quantitative assessments, we presented a new method of classifying risk levels into four steps, much like qualitative assessments. In this study, the quantitative risk assessment was considered difficult to predict through qualitative risk assessment. Therefore, it is necessary to perform a quantitative risk assessment after a qualitative risk assessment for a higher level of risk assessment.

Management of Occupational Risk Prevention of Nanomaterials Manufactured in Construction Sites in the EU

Currently, nanotechnology plays a key role for technological innovation, including the construction sector. An exponential increase is expected in its application, although this has been hampered by the current degree of uncertainty regarding the potential effects of nanomaterials on both human health and the environment. The accidents, illnesses, and disease related to the use of nanoproducts in the construction sector are difficult to identify. For this purpose, this work analyzes in depth the products included in recognized inventories and the safety data sheets of these construction products. Based on this analysis, a review of the recommendations on the use of manufactured nanomaterials at construction sites is performed. Finally, a protocol is proposed with the aim of it serving as a tool for technicians in decision-making management at construction sites related to the use of manufactured nanomaterials. This proposed protocol should be an adaptive and flexible tool while the manufactured nanomaterials-based work continues to be considered as an "emerging risk," despite the expectation that the protocol will be useful for the development of new laws and recommendations for occupational risk prevention management.

Probabilistic model for assessing occupational risk during the handling of nanomaterials

Exposure to nanomaterials (NMs) can be considered as human, occupational or environmental. Occupational exposure may be experienced by the workers and/or researchers who develop and produce these products and the hazards inherent to exposure are not yet fully known. Quantitative and qualitative methods are available to estimate the occupational risks associated with the handling of NMs, however, both have limitations. In this context, the objective of this study was to create a Bayesian network (BN) that will allow an assessment of the occupational risk associated with the handling of NMs in research laboratories. The BN was developed considered variables related to exposure, the hazards associated with NMs and also the existing control measures in the work environment, such as collective protection equipment (CPE), administrative measures and personal protection equipment (PPE). In addition to assessing the occupational risk, simulations were carried out by the laboratory manager to obtain information on which actions should be taken to reduce the risk. The development of a BN to assess the occupational risk associated with the handling of NMs is a novel aspect of this study. As a distinctive feature, the BN has measurement control variables in addition to considering CPE, administrative measures and PPE. An advantage of this network in relation to other risk assessment models is that it allows the easy execution of simulations and provides a guide for a decision making by identifying which actions should be taken to minimize the risk.

Assessing the risk of main activities of nanotechnology companies by the NanoTool method

Purpose. Nanotechnology can be considered one of the greatest developments over the past few decades. Despite many applications of nanomaterials in various fields, there are concerns about their effects on humans and the environment. Therefore, this study was conducted to assess the risk level of activities involving nanomaterials in nanotechnology companies in Tehran, Iran. Materials and methods. After identifying the main activities of 18 nanotechnology companies, these activities were assessed using the NanoTool method, which is a method for assessing risks of activities involving nanomaterials. Data were analyzed using SPSS version 22. Results. The results showed that in six activities (33.30%) the risk level was 4 (RL4), in eight activities (44.40%) the risk level was 3 (RL3) and four activities (22.30%) had risk level 2 (RL2). Also, it was found that 78.88% of the controls used by these companies were not enough to reduce the risks of nanomaterials and need to be upgraded. Conclusions. The high level of risk in the activities involving nanomaterials shows that there are serious problems regarding the safety of nanomaterials in the nanotechnology companies in Tehran, Iran.

Risk Governance of Nanomaterials: Review of Criteria and Tools for Risk Communication, Evaluation, and Mitigation

Nanotechnologies have been increasingly used in industrial applications and consumer products across several sectors, including construction, transportation, energy, and healthcare. The widespread application of these technologies has raised concerns regarding their environmental, health, societal, and economic impacts. This has led to the investment of enormous resources in Europe and beyond into the development of tools to facilitate the risk assessment and management of nanomaterials, and to inform more robust risk governance process. In this context, several risk governance frameworks have been developed. In our study, we present and review those, and identify a set of criteria and tools for risk evaluation, mitigation, and communication, the implementation of which can inform better risk management decision-making by various stakeholders from e.g., industry, regulators, and the civil society. Based on our analysis, we recommend specific methods from decision science and information technologies that can improve the existing risk governance tools so that they can communicate, evaluate, and mitigate risks more transparently, taking stakeholder perspectives and expert opinion into account, and considering all relevant criteria in establishing the risk-benefit balance of these emerging technologies to enable more robust decisions about the governance of their risks.

Control Banding Tools for Engineered Nanoparticles: What the Practitioner Needs to Know

Control banding (CB) has been widely recommended for the selection of exposure controls for engineered nanomaterials (ENMs) in the absence of ENM-specific occupational exposure limits (OELs). Several ENM-specific CB strategies have been developed but have not been systematically evaluated. In this article, we identify the data inputs and compare the guidance provided by eight CB tools, evaluated on six ENMs, and assuming a constant handling/use scenario. The ENMs evaluated include nanoscale silica, titanium dioxide, silver, carbon nanotubes, graphene, and cellulose. Several of the tools recommended the highest level of exposure control for each of the ENMs in the evaluation, which was driven largely by the hazard banding. Dustiness was a factor in determining the exposure band in many tools, although most tools did not provide explicit guidance on how to classify the dustiness (high, medium, low), and published data are limited on this topic. The CB tools that recommended more diverse control options based on ENM hazard and dustiness data appear to be better equipped to utilize the available information, although further validation is needed by comparison to exposure measurements and OELs for a variety of ENMs. In all CB tools, local exhaust ventilation was recommended at a minimum to control exposures to ENMs in the workplace. Generally, the same or more stringent control levels were recommended by these tools compared with the OELs proposed for these ENMs, suggesting that these CB tools would generally provide prudent exposure control guidance, including when data are limited.

Needs and challenges for assessing the environmental impacts of engineered nanomaterials (ENMs)

The potential environmental impact of nanomaterials is a critical concern and the ability to assess these potential impacts is top priority for the progress of sustainable nanotechnology. Risk assessment tools are needed to enable decision makers to rapidly assess the potential risks that may be imposed by engineered nanomaterials (ENMs), particularly when confronted by the reality of limited hazard or exposure data. In this review, we examine a range of available risk assessment frameworks considering the contexts in which different stakeholders may need to assess the potential environmental impacts of ENMs. Assessment frameworks and tools that are suitable for the different decision analysis scenarios are then identified. In addition, we identify the gaps that currently exist between the needs of decision makers, for a range of decision scenarios, and the abilities of present frameworks and tools to meet those needs.

A comparison of control banding tools for nanomaterials

Control banding (CB) is a useful approach to evaluate and control the risk of exposure to nanomaterials (NM) due to uncertainty surrounding their toxicity and challenges associated with their measurement. Four CB tools specifically developed for NMs (NanoSafer, Stoffenmanager-Nano, NanoTool, and the Precautionary matrix) have been evaluated for their changes to differences in hazard and exposure input data. The hazard and exposure classification were also compared with experimental data. The tools provided different hazard and emission/exposure outputs when compared with each other and with experimental data. For some of the tools the information required to estimate the hazard is not always available in the Safety Data Sheet and it requires expert judgement. The tools have the potential to be valuable starting points to assess areas of high priority, although outputs should be interpreted with care. Further work should be done to improve their estimates, especially the inclusion of modifiers that account for the effectiveness of the ventilation and the effect of high temperatures during the process.

Systematic Review of Screening and Surveillance Programs to Protect Workers from Nanomaterials

Background

Screening and surveillance approaches for workers exposed to nanomaterials could aid in early detection of health effects, provide data for epidemiological studies and inform action to decrease exposure. The aim of this review is to identify such screening and surveillance approaches, in order to extract available data regarding (i) the studies that have successfully been implemented in present day, (ii) identification of the most common and/or toxic nano-related health hazards for workers and (iii) possible exposure surveillance markers. This review contributes to the current understanding of the risk associated with nanomaterials by determining the knowledge gap and making recommendations based on current findings.

Methods

A systematic review was conducted. PubMed and Embase were searched to identify articles reporting on any surveillance-related study that described both exposure to nanomaterials and the health indicators that were measured. Four reviewers worked in pairs to independently assess the eligibility of studies and risk of bias before extraction of data. Studies were categorised according to the type of study and the medical surveillance performed, which included the type of nanomaterial, any exposure details provided, as well as health indicators and biomarkers tested.

Results

Initially 92 studies were identified, from which 84 full texts were assessed for eligibility. Seven studies met all the inclusion criteria, i.e. those performed in Taiwan, Korea, Czech Republic and the US. Of these, six compared health indicators between exposed and unexposed workers and one study described a surveillance program. All studies were at a high risk of bias. Workers were exposed to a mix of nanomaterials in three studies, carbon-based nanomaterials in two studies, nano-silver in one study and nano-titanium oxide in the other study. Two studies did not find a difference in biomarkers between exposed and unexposed workers. In addition, differences in early effects on pulmonary function or neurobehavioral tests were not observed. One study found an increased prevalence of allergic dermatitis and “sneezing” in the exposed group.

Conclusions

This review of recently published data on surveillance studies proves that there is a gap in the current knowledge, where most of the surveillance-related studies reported do not follow a set format that provides the required information on ENM characterisation, the type of exposure and the measured indicators/biomarkers. Hence, there is very low quality evidence that screening and surveillance might detect adverse health effects associated with workplace exposure. This systematic review is relevant because it proves that, although surveillance programs have been initiated and preliminary results are being published, the current studies are actually not answering the important questions or solving the overall problem regarding what the potential health hazards are among workers either handling or potentially exposed to ENMs. The recommendations, thus proposed, are based on an obvious need for (i) exposure registries, where longitudinal follow-up studies should inform surveillance, (ii) known exposure measurements or summary indices for ENMs as a reference (iii) validation of candidate biomarkers and (iv) studies that compare the effects of these surveillance approaches to usual care, e.g. those commonly followed for bulk-size hazardous materials.

Review of Research Trends and Methods in Nano Environmental, Health, and Safety Risk Analysis

Despite the many touted benefits of nanomaterials, concerns remain about their possible environmental, health, and safety (EHS) risks in terms of their toxicity, long-term accumulation effects, or dose-response relationships. The published studies on EHS risks of nanomaterials have increased significantly over the past decade and half, with most focused on nanotoxicology. Researchers are still learning about health consequences of nanomaterials and how to make environmentally responsible decisions regarding their production. This article characterizes the scientific literature on nano-EHS risk analysis to map the state-of-the-art developments in this field and chart guidance for the future directions. First, an analysis of keyword co-occurrence networks is investigated for nano-EHS literature published in the past decade to identify the intellectual turning points and research trends in nanorisk analysis studies. The exposure groups targeted in emerging nano-EHS studies are also assessed. System engineering methods for risk, safety, uncertainty, and system reliability analysis are reviewed, followed by detailed descriptions where applications of these methods are utilized to analyze nanomaterial EHS risks. Finally, the trends, methods, future directions, and opportunities of system engineering methods in nano-EHS research are discussed. The analysis of nano-EHS literature presented in this article provides important insights on risk assessment and risk management tools associated with nanotechnology, nanomanufacturing, and nano-enabled products.

Taking stock of the occupational safety and health challenges of nanotechnology: 2000-2015

Engineered nanomaterials significantly entered commerce at the beginning of the 21st century. Concerns about serious potential health effects of nanomaterials were widespread. Now, approximately 15 years later, it is worthwhile to take stock of research and efforts to protect nanomaterial workers from potential risks of adverse health effects. This article provides and examines timelines for major functional areas (toxicology, metrology, exposure assessment, engineering controls and personal protective equipment, risk assessment, risk management, medical surveillance, and epidemiology) to identify significant contributions to worker safety and health. The occupational safety and health field has responded effectively to identify gaps in knowledge and practice, but further research is warranted and is described. There is now a greater, if imperfect, understanding of the mechanisms underlying nanoparticle toxicology, hazards to workers, and appropriate controls for nanomaterials, but unified analytical standards and exposure characterization methods are still lacking. The development of control-banding and similar strategies has compensated for incomplete data on exposure and risk, but it is unknown how widely such approaches are being adopted. Although the importance of epidemiologic studies and medical surveillance is recognized, implementation has been slowed by logistical issues. Responsible development of nanotechnology requires protection of workers at all stages of the technological life cycle. In each of the functional areas assessed, progress has been made, but more is required.

Engineered nanomaterials: toward effective safety management in research laboratories

BACKGROUND

It is still unknown which types of nanomaterials and associated doses represent an actual danger to humans and environment. Meanwhile, there is consensus on applying the precautionary principle to these novel materials until more information is available. To deal with the rapid evolution of research, including the fast turnover of collaborators, a user-friendly and easy-to-apply risk assessment tool offering adequate preventive and protective measures has to be provided.

RESULTS

Based on new information concerning the hazards of engineered nanomaterials, we improved a previously developed risk assessment tool by following a simple scheme to gain in efficiency. In the first step, using a logical decision tree, one of the three hazard levels, from H1 to H3, is assigned to the nanomaterial. Using a combination of decision trees and matrices, the second step links the hazard with the emission and exposure potential to assign one of the three nanorisk levels (Nano 3 highest risk; Nano 1 lowest risk) to the activity. These operations are repeated at each process step, leading to the laboratory classification. The third step provides detailed preventive and protective measures for the determined level of nanorisk.

CONCLUSIONS

We developed an adapted simple and intuitive method for nanomaterial risk management in research laboratories. It allows classifying the nanoactivities into three levels, additionally proposing concrete preventive and protective measures and associated actions. This method is a valuable tool for all the participants in nanomaterial safety. The users experience an essential learning opportunity and increase their safety awareness. Laboratory managers have a reliable tool to obtain an overview of the operations involving nanomaterials in their laboratories; this is essential, as they are responsible for the employee safety, but are sometimes unaware of the works performed. Bringing this risk to a three-band scale (like other types of risks such as biological, radiation, chemical, etc.) facilitates the management for occupational health and safety specialists. Institutes and school managers can obtain the necessary information to implement an adequate safety management system. Having an easy-to-use tool enables a dialog between all these partners, whose semantic and priorities in terms of safety are often different.

Green Jobs: Definition and Method of Appraisal of Chemical and Biological Risks

In the wake of sustainable development, green jobs are developing rapidly, changing the work environment. However a green job is not automatically a safe job. The aim of the study was to define green jobs, and to establish a preliminary risk assessment of chemical substances and biological agents for workers in Quebec. An operational definition was developed, along with criteria and sustainable development principles to discriminate green jobs from regular jobs. The potential toxicity or hazard associated with their chemical and biological exposures was assessed, and the workers' exposure appraised using an expert assessment method. A control banding approach was then used to assess risks for workers in selected green jobs. A double entry model allowed us to set priorities in terms of chemical or biological risk. Among jobs that present the highest risk potential, several are related to waste management. The developed method is flexible and could be adapted to better appraise the risks that workers are facing or to propose control measures.

Can Control Banding be Useful for the Safe Handling of Nanomaterials? A Systematic Review

OBJECTIVES

Control banding (CB) is a risk management strategy that has been used to identify and recommend exposure control measures to potentially hazardous substances for which toxicological information is limited. The application of CB and level of expertise required for implementation and management can differ depending on knowledge of the hazard potential, the likelihood of exposure, and the ability to verify the effectiveness of exposure control measures. A number of different strategies have been proposed for using CB in workplaces where exposure to engineered nanomaterials (ENMs) can occur. However, it is unclear if the use of CB can effectively reduce worker exposure to nanomaterials. A systematic review of studies was conducted to answer the question "can control banding be useful to ensure adequate controls for the safe handling of nanomaterials."

METHODS

A variety of databases were searched to identify relevant studies pertaining to CB. Database search terms included 'control', 'hazard', 'exposure' and 'risk' banding as well as the use of these terms in the context of nanotechnology or nanomaterials. Other potentially relevant studies were identified during the review of articles obtained in the systematic review process. Identification of studies and the extraction of data were independently conducted by the reviewers. Quality of the studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS). The quality of the evidence was evaluated using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

A total of 235 records were identified in the database search in which 70 records were determined to be eligible for full-text review. Only two studies were identified that met the inclusion criteria. These studies evaluated the application of the CB Nanotool in workplaces where ENMs were being handled. A total of 32 different nanomaterial handling activities were evaluated in these studies by comparing the recommended exposure controls using CB to existing exposure controls previously recommended by an industrial hygienist. It was determined that the selection of exposure controls using CB were consistent with those recommended by an industrial hygienist for 19 out of 32 (59.4%) job activities. A higher level of exposure control was recommended for nine out of 32 (28.1%) job activities using CB while four out of 32 (12.5%) job activities had in place exposure controls that were more stringent than those recommended using CB. After evaluation using GRADE, evidence indicated that the use of CB Nanotool can recommend exposure controls for many ENM job activities that would be consistent with those recommended by an experienced industrial hygienist.

CONCLUSION

The use of CB for reducing exposures to ENMs has the potential to be an effective risk management strategy when information is limited on the health risk to the nanomaterial and/or there is an absence of an occupational exposure limit (OEL). However, there remains a lack of evidence to conclude that the use of CB can provide adequate exposure control in all work environments. Additional validation work is needed to provide more data to support the use of CB for the safe handling of ENMs.

Impact and effectiveness of risk mitigation strategies on the insurability of nanomaterial production: evidences from industrial case studies

Workers involved in producing nanomaterials or using nanomaterials in manufacturing plants are likely to have earlier and higher exposure to manufactured/engineered nanomaterials (ENM) than the general population. This is because both the volume handled and the probability of the effluence of 'free' nanoparticles from the handled volume are much higher during a production process than at any other stage in the lifecycle of nanomaterials and nanotechnology-enabled products. Risk assessment (RA) techniques using control banding (CB) as a framework for risk transfer represents a robust theory but further progress on implementing the model is required so that risk can be transferred to insurance companies. Following a review of RA in general and hazard measurement in particular, we subject a Structural Alert Scheme methodology to three industrial case studies using ZrO2 , TiO2 , and multi-walled carbon nanotubes (MWCNT). The materials are tested in a pristine state and in a remediated (coated) state, and the respective emission and hazard rates are tested alongside the material performance as originally designed. To our knowledge, this is the first such implementation of a CB RA in conjunction with an ENM performance test and offers both manufacturers and underwriters an insight into future applications.

Assessing the first wave of epidemiological studies of nanomaterial workers

The results of early animal studies of engineered nanomaterials (ENMs) and air pollution epidemiology suggest that it is important to assess the health of ENM workers. Initial epidemiological studies of workers' exposure to ENMs (<100 nm) are reviewed and characterized for their study designs, findings, and limitations. Of the 15 studies, 11 were cross-sectional, 4 were longitudinal (1 was both cross-sectional and longitudinal in design), and 1 was a descriptive pilot study. Generally, the studies used biologic markers as the dependent variables. All 11 cross-sectional studies showed a positive relationship between various biomarkers and ENM exposures. Three of the four longitudinal studies showed a negative relationship; the fourth showed positive findings after a 1-year follow-up. Each study considered exposure to ENMs as the independent variable. Exposure was assessed by mass concentration in 10 studies and by particle count in six studies. Six of them assessed both mass and particle concentrations. Some of the studies had limited exposure data because of inadequate exposure assessment. Generally, exposure levels were not very high in comparison to those in human inhalation chamber studies, but there were some exceptions. Most studies involved a small sample size, from 2 to 258 exposed workers. These studies represent the first wave of epidemiological studies of ENM workers. They are limited by small numbers of participants, inconsistent (and in some cases inadequate) exposure assessments, generally low exposures, and short intervals between exposure and effect. Still, these studies are a foundation for future work; they provide insight into where ENM workers are experiencing potentially adverse effects that might be related to ENM exposures.

Size and site dependent biological hazard potential of particulate matters collected from different heights at the vicinity of a building construction

Although building constructions are a recurring part of urbanization, the health risk of particulate matters (PM) originating from such activities have seldom been subjected to detailed studies. We sought to characterize the relative risk of air borne PM collected from different heights (ground and top floor) of a building adjacent to a building under early phase of construction. We determined the physico-chemical properties such as size and shape, elemental composition and surface charge of the PM. The oxidative stress dependent cytotoxic and pro-inflammatory responses were assessed in BEAS-2B and RAW 264.7 cell lines using high-content-screening platforms. In comparison to top floor, the total mass of PM collected from ground floor was two-three folds higher and the mass fraction was dominated by PM20-35. Elemental analysis showed abundance of Si, Al, K, Ca and Fe in bigger PM while for PM0.25-0.5 it was mostly constituted by C and crystals rich in S and K. PM caused NFκB activation, secretion of pro-inflammatory cytokines and cytotoxicity wherein PM0.25-0.5 was the most potent among the tested PM. Estimated exposure level and lung burden together with the data on hazard potential were used for developing a MATLAB based risk-assessment model which suggested that the potential for health risk is relatively higher at the ground floor. Our studies demonstrated differences in, relative abundance of PM, their physicochemical and biological properties collected from different heights adjacent to a construction site and showed that relative health risk is higher at the ground floor.

Achieving Control of Occupational Exposures to Engineered Nanomaterials

Occupational exposures resulting from Engineered Nanomaterials (ENMs) can pose a challenge for applying traditional risk assessment, control, or evaluation standards. This article discusses the limitations in traditional risk management approaches when it comes to ENM exposures, reviews current monitoring options, and suggests an interim management framework until research can meet the standard of evidence required by legislators. The proposed Nanomaterial Occupational Exposure Management Model (NOEM) offers a pragmatic approach that integrates resources from current academic research to provide a framework that can be applied by both industry and regulators. The NOEM Model focuses on addressing three concerns to exposure management: Risk Assessment, Exposure Control, and Exposure Monitoring. The resources supported for meeting these three components involve the integration of the Control Banding Nanotool and Nano Reference Values, both of which have been piloted and accepted through peer-reviewed processes and industry consultation.

Proposal of a new risk assessment method for the handling of powders and nanomaterials

A new approach to assess the risks inherent in the implementation of powders, including nanomaterials, has been developed, based on the OHB (Occupational Hazard Band) method which is widely spread in the chemical industry. Hazard classification has not been modified; only the control of exposure has been worked at. The method applies essentially to the prevention of the exposures to airborne materials, whatever their particle size. The method considers exposure based on seven parameters which take into account the characteristics of the materials used, their emission potential, the conditions of use, as well as classic parameters of exposure characterization like duration and frequency. The method is a pragmatic exploitation of the state-of-art and of available data, bearing in mind that a lot of them are not easily accessible to factory operators. The result of the reflection is then positioned on a hazard versus exposure matrix from which 4 levels of priority of action are defined, as in the classical OHB method used to manage pure chemical risk. This approach fills a gap in terms of risk assessment and avoids jeopardizing all that has been set up for years, while introducing new elements of decision making accessible to all operators.

Workshop report: strategies for setting occupational exposure limits for engineered nanomaterials

Occupational exposure limits (OELs) are important tools for managing worker exposures to chemicals; however, hazard data for many engineered nanomaterials (ENMs) are insufficient for deriving OELs by traditional methods. Technical challenges and questions about how best to measure worker exposures to ENMs also pose barriers to implementing OELs. New varieties of ENMs are being developed and introduced into commerce at a rapid pace, further compounding the issue of OEL development for ENMs. A Workshop on Strategies for Setting Occupational Exposure Limits for Engineered Nanomaterials, held in September 2012, provided an opportunity for occupational health experts from various stakeholder groups to discuss possible alternative approaches for setting OELs for ENMs and issues related to their implementation. This report summarizes the workshop proceedings and findings, identifies areas for additional research, and suggests potential avenues for further progress on this important topic.

Effect of nanoparticles exposure on fractional exhaled nitric oxide (FENO) in workers exposed to nanomaterials

Fractional exhaled nitric oxide (FENO) measurement is a useful diagnostic test of airway inflammation. However, there have been few studies of FENO in workers exposed to nanomaterials. The purpose of this study was to examine the effect of nanoparticle (NP) exposure on FENO and to assess whether the FENO is increased in workers exposed to nanomaterials (NM). In this study, both exposed workers and non-exposed controls were recruited from NM handling plants in Taiwan. A total of 437 subjects (exposed group = 241, non-exposed group = 196) completed the FENO and spirometric measurements from 2009–2011. The authors used a control-banding (CB) matrix to categorize the risk level of each participant. In a multivariate linear regression analysis, this study found a significant association between risk level 2 of NP exposure and FENO. Furthermore, asthma, allergic rhinitis, peak expiratory flow rate (PEFR), and NF-κB were also significantly associated with FENO. When the multivariate logistic regression model was adjusted for confounders, nano-TiO₂ in all of the NM exposed categories had a significantly increased risk in FENO > 35 ppb. This study found associations between the risk level of NP exposure and FENO (particularly noteworthy for Nano-TiO₂). Monitoring FENO in the lung could open up a window into the role nitric oxide (NO) may play in pathogenesis.

Exposure assessment of four pharmaceutical powders based on dustiness and evaluation of damaged HEPA filters

In this study, we show the different dustiness characteristics of four molecular pharmaceutical powder candidates and evaluate the performance of HEPA filters damaged with three different pinhole sizes and exposed to dust using real industrial powders in a miniaturized EN15051 rotating drum dustiness tester. We then demonstrate the potential use of such data using first-order exposure modeling to assess the potential worker exposure and transmission of active powder ingredients into ventilation systems. The four powders had highly variable inhalable dustiness indices (1,036 - 14,501 mg/kg). Dust particle size-distributions were characterized by three peaks; the first occurred around 60-80 nm, the second around 250 nm, and the third at 2-3 μm. The second and third peaks are often observed in dustiness test studies, but peaks in the 60-80 nm range have not been previously reported. Exposure modeling in a 5 times 20 kg powder pouring scenario, suggests that excessive dust concentrations may be reached during use of powders with the highest dustiness levels. By number, filter-damage by three pinhole sizes resulted in damage-dependent penetration of 70-80 nm-size particles, but by volume and mass the penetration is still dominated by particles larger than 100 nm. Whereas the exposure potential was evident, the potential dust concentrations in air ducts following the pouring scenario above were at pg/m(3) levels. Hence, filter penetration at these damage levels was assumed to be only critical, if the active ingredients were associated with high hazard or unique product purity is required. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: An example of a typical particle number time-series of a complete dustiness test. It provides information on the HEPA-filter used including a scanning electron microscopy image of it. It also provides APS-measurements of particles penetrating the damaged HEPA-filter.].

Occupational safety and health criteria for responsible development of nanotechnology

Organizations around the world have called for the responsible development of nanotechnology. The goals of this approach are to emphasize the importance of considering and controlling the potential adverse impacts of nanotechnology in order to develop its capabilities and benefits. A primary area of concern is the potential adverse impact on workers, since they are the first people in society who are exposed to the potential hazards of nanotechnology. Occupational safety and health criteria for defining what constitutes responsible development of nanotechnology are needed. This article presents five criterion actions that should be practiced by decision-makers at the business and societal levels-if nanotechnology is to be developed responsibly. These include (1) anticipate, identify, and track potentially hazardous nanomaterials in the workplace; (2) assess workers' exposures to nanomaterials; (3) assess and communicate hazards and risks to workers; (4) manage occupational safety and health risks; and (5) foster the safe development of nanotechnology and realization of its societal and commercial benefits. All these criteria are necessary for responsible development to occur. Since it is early in the commercialization of nanotechnology, there are still many unknowns and concerns about nanomaterials. Therefore, it is prudent to treat them as potentially hazardous until sufficient toxicology, and exposure data are gathered for nanomaterial-specific hazard and risk assessments. In this emergent period, it is necessary to be clear about the extent of uncertainty and the need for prudent actions.

Developing a semi-quantitative occupational risk prediction model for chemical exposures and its application to a national chemical exposure databank

In this study, a semi-quantitative occupational chemical exposure risk prediction model, based on the calculation of exposure hazard indexes, was proposed, corrected, and applied to a national chemical exposure databank. The model comprises one factor used to describe toxicity (i.e., the toxicity index), and two factors used to reflect the exposure potential (i.e., the exposure index and protection deficiency index) of workers exposed to chemicals. An expert system was used to correct the above proposed model. By applying the corrected model to data obtained from a national occupational chemical hazard survey program, chemical exposure risks of various manufacturing industries were determined and a national control strategy for the abatement of occupational chemical exposures was proposed. The results of the present study would provide useful information for governmental agencies to allocate their limited resources effectively for reducing chemical exposures of workers.

Dustiness of fine and nanoscale powders

Dustiness may be defined as the propensity of a powder to form airborne dust by a prescribed mechanical stimulus; dustiness testing is typically intended to replicate mechanisms of dust generation encountered in workplaces. A novel dustiness testing device, developed for pharmaceutical application, was evaluated in the dustiness investigation of 27 fine and nanoscale powders. The device efficiently dispersed small (mg) quantities of a wide variety of fine and nanoscale powders, into a small sampling chamber. Measurements consisted of gravimetrically determined total and respirable dustiness. The following materials were studied: single and multiwalled carbon nanotubes, carbon nanofibers, and carbon blacks; fumed oxides of titanium, aluminum, silicon, and cerium; metallic nanoparticles (nickel, cobalt, manganese, and silver) silicon carbide, Arizona road dust; nanoclays; and lithium titanate. Both the total and respirable dustiness spanned two orders of magnitude (0.3-37.9% and 0.1-31.8% of the predispersed test powders, respectively). For many powders, a significant respirable dustiness was observed. For most powders studied, the respirable dustiness accounted for approximately one-third of the total dustiness. It is believed that this relationship holds for many fine and nanoscale test powders (i.e. those primarily selected for this study), but may not hold for coarse powders. Neither total nor respirable dustiness was found to be correlated with BET surface area, therefore dustiness is not determined by primary particle size. For a subset of test powders, aerodynamic particle size distributions by number were measured (with an electrical low-pressure impactor and an aerodynamic particle sizer). Particle size modes ranged from approximately 300 nm to several micrometers, but no modes below 100 nm, were observed. It is therefore unlikely that these materials would exhibit a substantial sub-100 nm particle contribution in a workplace.

Application of a quantitative weight of evidence approach for ranking and prioritising occupational exposure scenarios for titanium dioxide and carbon nanomaterials

Substantial limitations and uncertainties hinder the exposure assessment of engineered nanomaterials (ENMs). The present deficit of reliable measurements and models will inevitably lead in the near term to qualitative and uncertain exposure estimations, which may fail to support adequate risk assessment and management. Therefore it is necessary to complement the current toolset with user-friendly methods for near-term nanosafety evaluation. This paper proposes an approach for relative exposure screening of ENMs. For the first time, an exposure model explicitly implements quantitative weight of evidence (WoE) methods and utilises expert judgement for filling data gaps in the available evidence-base. Application of the framework is illustrated for screening of exposure scenarios for nanoscale titanium dioxide, carbon nanotubes and fullerenes, but it is applicable to other nanomaterials as well. The results show that the WoE-based model overestimates exposure for scenarios where expert judgement was substantially used to fill data gaps, which suggests its conservative nature. In order to test how variations in input data influence the obtained results, probabilistic Monte Carlo sensitivity analysis was applied to demonstrate that the model performs in stable manner.

The hierarchy of environmental health and safety practices in the U.S. nanotechnology workplace

Manufacturing of nanoscale materials (nanomaterials) is a major outcome of nanotechnology. However, the potential adverse human health effects of manufactured nanomaterial exposure are not yet fully understood, and exposures in humans are mostly uncharacterized. Appropriate exposure control strategies to protect workers are still being developed and evaluated, and regulatory approaches rely largely on industry self-regulation and self-reporting. In this context of soft regulation, the authors sought to: 1) assess current company-reported environmental health and safety practices in the United States throughout the product life cycle, 2) consider their implications for the manufactured nanomaterial workforce, and 3) identify the needs of manufactured nanomaterial companies in developing nano-protective environmental health and safety practices. Analysis was based on the responses of 45 U.S.-based company participants in a 2009-2010 international survey of private companies that use and/or produce nanomaterials. Companies reported practices that span all aspects of the current government-recommended hierarchical approach to manufactured nanomaterials' exposure controls. However, practices that were tailored to current manufactured nanomaterials' hazard and exposure knowledge, whether within or outside the hierarchical approach, were reported less frequently than general chemical hygiene practices. Product stewardship and waste management practices-the influences of which are substantially downstream-were reported less frequently than most other environmental health and safety practices. Larger companies had more workers handling nanomaterials, but smaller companies had proportionally more employees handling nanomaterials and more frequently identified impediments to implementing nano-protective practices. Company-reported environmental health and safety practices suggest more attention to environmental health and safety is necessary, especially with regard to practices that can cause external effects. Given reported impediments, smaller companies may especially benefit from more attention. However, the manufactured nanomaterial workforce within smaller companies is particularly difficult to identify and hence locate, posing challenges to developing and enforcing appropriate workplace environmental health and safety. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a file containing Survey of Current Health and Safety Practices in the Nanomaterial Industry and a file containing figures.].

Risk management strategy to increase the safety of workers in the nanomaterials industry

In recent years, many engineered nanomaterials (NMs) have been produced, but increasing research has revealed that these may have toxicities far greater than conventional materials and cause significant adverse health effects. At present, there is insufficient data to determine the permissible concentrations of NMs in the workplace. There is also a lack of toxicity data and environmental monitoring results relating to complete health risk assessment. In view of this, we believe that workers in the NMs industry should be provided with simple and practical risk management strategy to ensure occupational health and safety. In this study, we developed a risk management strategy based on the precautionary risk management (PRM). The risk of the engineered NMs manufacturing plants can be divided into three levels based on aspect identification, solubility tests, dermal absorption, and cytotoxic analyses. The risk management strategies include aspects relating to technology control, engineering control, personal protective equipment, and monitoring of the working environment for each level. Here we report the first case in which a simple and practical risk management strategy applying in specific engineered NMs manufacturing plants. We are confident that our risk management strategy can be effectively reduced engineered NM industries risks for workers.

Man-made mineral fibers and the respiratory tract

Man-made mineral fibers are produced using inorganic materials and are widely used as thermal and acoustic insulation. These basically include continuous fiberglass filaments, glass wool (fiberglass insulation), stone wool, slag wool and refractory ceramic fibers. Likewise, in the last two decades nanoscale fibers have also been developed, among these being carbon nanotubes with their high electrical conductivity, mechanical resistance and thermal stability. Both man-made mineral fibers and carbon nanotubes have properties that make them inhalable and potentially harmful, which have led to studies to assess their pathogenicity. The aim of this review is to analyze the knowledge that currently exists about the ability of these fibers to produce respiratory diseases.