The Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST) announced on August 9, 2021, publication of a study entitled Characterization of Unintentionally Released Nanometric Particles in Various Workplaces. The study characterizes unintentionally released nanoparticles (URNP) found in six workplaces — an underground mine, a truck repair shop, an underground transportation network, a foundry, a machine shop, and a wax casting shop — on the basis of a broad range of indicators. IRSST assessed concentrations according to numerical and mass metrics, using an array of direct reading instruments. IRSST also took time-averaged measurements, based on the type of contaminant specific to each workplace. In parallel, IRSST took measurements for microscopy characterization in the same six workplaces. According to IRSST, workers exposed to diesel exhaust fumes (an underground mine, truck repair shop, and underground transportation network) “are exposed to mostly nanometric-size airborne particles whose mass concentration is largely in the submicron fraction.” In the presence of foundry fumes, IRSST states that “workers are exposed to airborne particles that are mostly nanometric in size and whose mass concentration is chiefly in the submicron fraction for chromium, cobalt, copper, iron, manganese, lead, vanadium and zinc.” The workers in the machine shop are exposed to fumes and dust particles from machining, most of which are nanometric in size, but IRSST notes that “some of the processes they use generate larger, micrometric particles. The contribution of larger particles to the mass concentration is significant in this environment and, as a result, the mass concentration is to be found in the inhalable fraction, especially for chromium, copper, iron and nickel.” Workers in the wax shop are exposed to fumes that are chiefly nanometric in size and whose mass concentration is mostly in the submicron fraction. IRSST states that its “innovative strategy” enabled it to characterize the URNPs released in the different workplaces with respect to both numerical and mass concentrations. IRSST used microscopy studies on particle samples from the microscope grid taken with a Mini Particle Sampler® to characterize the particles collected based on their morphology and chemical composition.
On September 7, 2021, the European Commission (EC) Scientific Committee on Health, Environmental and Emerging Risks (SCHEER) posted a preliminary opinion on “Draft Environmental Quality Standards for Priority Substances under the Water Framework Directive” for silver and its compounds. The Water Framework Directive requires the EC to identify priority substances among those presenting significant risk to or via the aquatic environment and to set environmental quality standards (EQS) for those substances in water, sediment, and/or biota. The Directorate-General for Environment (DG Environment) asked SCHEER to review the draft EQSs for proposed priority substances, including silver and its compounds. According to SCHEER, the issues that need to be revised include whether silver nanomaterials should “be considered as silver compounds or should nanomaterials, of any origin, be considered as particular compounds to be assessed separately?” SCHEER notes that the health and environmental effects of nanosilver, including the role in antimicrobial resistance, were evaluated in two Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR, 2014) and Scientific Committee on Consumer Safety (SCCS, 2018) opinions. SCHEER states that “this is a relevant issue that should be at least mentioned in the dossier.” Comments on the preliminary opinion are due October 7, 2021.
Registration has opened for a September 22, 2021, webinar held by the National Nanotechnology Coordination Office (NNCO) on “What We Know about NanoEHS: Measurement and Characterization.” The webinar’s speakers will explore the impact of advances in nanomaterial measurement and characterization on the safe and responsible development of nanotechnology. Vincent Hackley, Research Chemist, National Institute of Standards and Technology (NIST), will moderate. The panel will include:
- Jo Anne Shatkin, President and Founder, Vireo Advisors; and
- Wendel Wohlleben, Senior Principal Scientist, BASF.
NNCO held the following technical webinars in 2021 on the environmental, health, and safety implications of nanomaterials (nanoEHS):
- What We Know about NanoEHS: Human Health, June 8, 2021, Video with Closed Captioning;
- What We Know about NanoEHS: Environment, April 27, 2021, Video with Closed Captioning;
- What We Know about NanoEHS: Human Exposure, March 23, 2021, Video with Closed Captioning; and
- What We Know about NanoEHS: How It All Began, February 9, 2021, Video with Closed Captioning.
As reported in our May 7, 2021, blog item, the European Commission (EC) held a targeted stakeholder consultation as part of its review of the Recommendation on the definition of a nanomaterial. The EC held the consultation to update, test, and verify the preliminary findings of its review, gathering further evidence and feedback from a wide range of stakeholders who have a role in application of the harmonized regulatory definition of nanomaterial in the European Union (EU). The EC compiled the 136 non-duplicated replies in an XLS spreadsheet. The EC has posted an additional contribution by the French authorities, as well as supplemental information provided by the Industrial Minerals Association Europe (IMA-Europe) and the German Federal Institute for Risk Assessment (BfR). The EC is currently analyzing the responses in detail to help conclude its review. The EC states that it will publish the outcome of the review, including a summary of the feedback and statistical analysis of the responses, as an EC Staff Working document in 2021. At that time, the EC “will also indicate the plans for potential revision or replacement of the Recommendation 20122/696/EU.”
According to Australia, after the first year of operation of the Australian Industrial Chemicals Introduction Scheme (AICIS), the regulated industry and staff within the Office of Chemical Safety have identified “minor operational issues” that require amendments to the details set out in the Ministerial Rules. Australia is proposing targeted amendments to the Industrial Chemicals (General Rules) 2019 and the Industrial Chemicals (Consequential Amendments and Transitional Provisions) Rules 2019 that are intended to clarify the operation of the Ministerial Rules within existing policy. The proposed amendments address the following issues:
- Clarifying criteria for industrial chemicals introduced at the nanoscale;
- Declarations about data ownership;
- Annual declarations;
- Clarifying recordkeeping for listed introductions, specified classes, designated releases to the environment, and “internationally-assessed”;
- The authorization process for movement of industrial chemicals into or out of Australia that are subject to the Rotterdam Convention; and
- Transitional provisions.
The consultation paper lists the following amendments regarding the requirements for industrial chemicals introduced at the nanoscale:
- Schedule 1, Clause 1 of the Exposure Draft: The proposed amendments are to the definition of specified classes of introductions, in particular to the criteria for introductions at the nanoscale. They would improve clarity for introducers on how these criteria apply in practice. (There is no actual change to criteria proposed.)
- Schedule 1, Clauses 2, 3, and 4 of the Exposure Draft: These proposed amendments are for research and development (R&D) introductions (nanoscale) in the exempted introduction category. They would improve clarity for introducers on how these criteria apply in practice. (There is no actual change to criteria proposed.)
- Schedule 1, Clause 5 of the Exposure Draft: These proposed amendments relate to non-functionalized surface treatment of listed chemicals in the exempted introduction category.
- Schedule 1, Clauses 6 and 7 of the Exposure Draft: The proposed amendments are for industrial chemicals introduced at a low volume solely for R&D in the reported introduction category.
- Schedule 1, Clauses 8, 9, and 10 of the Exposure Draft: The proposed amendments are for industrial chemicals introduced for R&D (other than nanoscale) in the reported introduction category.
- Schedule 1, Clauses 11 and 12 of the Exposure Draft: The proposed amendments clarify the nanoscale criteria for determining the indicative human health risk of an introduction.
- Schedule 1, Clauses 13 and 14 of the Exposure Draft: The proposed amendments clarify the nanoscale criteria for determining the indicative environmental risk of an introduction.
- Schedule 1, Clauses 15 and 16 of the Exposure Draft: The proposed amendments clarify the recordkeeping requirements related to the nanoscale criteria for exempted introductions introduced solely for R&D.
- Schedule 1, Clauses 15 and 16 of the Exposure Draft: The proposed amendments clarify the recordkeeping requirements related to the nanoscale criteria for reported introductions introduced solely for R&D.
The consultation paper lists the following amendments regarding the pre-introduction reporting requirements for industrial chemicals introduced at the nanoscale:
- Schedule 1, Clause 20 of the Exposure Draft: The proposed amendments clarify the pre-introduction reporting requirements related to the nanoscale criteria for reported introductions introduced solely for R&D.
- Schedule 1, Clause 21 of the Exposure Draft: The proposed amendments clarify the pre-introduction reporting requirements related to the nanoscale criteria for reported introductions where the highest indicative risk is low risk.
Comments are due September 17, 2021.
ASTM recently announced that it published a standard, E3275, that seeks to familiarize laboratory scientists with background information and technical content necessary to image and identify engineered nanomaterials in cellular and noncellular samples. According to ASTM, the standard is specific to the use of the darkfield microscopy/hyperspectral imaging analysis technique. ASTM states that in this technique, the resulting sample analysis allows for direct visualization and identification of the nanomaterials based on comparison to the spectral profiles of well-characterized reference nanomaterials.
On August 18, 2021, the U.S. Environmental Protection Agency (EPA) issued several significant new use rules (SNUR) under the Toxic Substances Control Act (TSCA) for chemical substances that were the subject of premanufacture notices (PMN), including the chemical substance identified generically as multiwalled carbon nanotubes (PMN P-18-182). 86 Fed. Reg. 46133. The SNUR requires persons who intend to manufacture (defined by statute to include import) or process multiwalled carbon nanotubes (PMN P-18-182) for an activity that is designated as a significant new use to notify EPA at least 90 days before commencing that activity. The requirements of the SNUR do not apply to quantities of the substance that have been:
- Embedded or incorporated into a polymer matrix that itself has been reacted (cured);
- Embedded in a permanent solid/polymer form that is not intended to undergo further processing, except mechanical processing; or
- Incorporated into an article as defined at 40 C.F.R. Section 720.3(c).
Under the SNUR, it is a significant new use to use an application method that generates a dust, mist, or aerosol, unless such application method occurs in an enclosed process. It is a significant new use to use the substance other than for heat transfer, heat storage, thermal emission, and general temperature management in heat-generating systems such as electronics, to improve mechanical properties or electrical conductivities of other materials or products, and for light absorption properties. The SNUR will be effective on October 18, 2021.
The European Food Safety Authority (EFSA) published a Scientific Opinion entitled “Safety assessment of the substance silver nanoparticles for use in food contact materials.” The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the additive silver nanoparticles intended to be used in plastics. All the silver particles were in the size range of 1-100 nanometers (nm), with about 15 nm mean diameter and 99% by number of particles below 20 nm. The abstract states that the additive “is intended to be used as a surface biocide at up to 0.025% w/w in non‐polar plastics for contact with a wide variety of foods, times, temperatures and food contact surface/mass of food ratios.” According to the abstract, “[t]he data and information on theoretical considerations, on specific migration and abrasion tests show that, under the intended and tested conditions of uses, the silver nanoparticles stay embedded in the polymer, do not migrate and resist release by abrasion, thus, do not give rise to exposure via food and to toxicological concern.” The abstract notes that there is migration of silver in soluble ionic form up to 6 microgram (μg) silver per kilogram (kg) food from the surface of the additive particles, which is below the group restriction of 50 μg silver/kg food proposed by the Scientific Panel on Food Additives, Flavorings, Processing Aids and Materials in Contact with Food in 2004 and would lead to a maximum exposure from food contact materials (FCM) that would be below the acceptable daily intake (ADI) of 0.9 μg silver ions/kg body weight (bw) per day established by the European Chemicals Agency (ECHA). Therefore, the abstract states, “the Panel concluded that the substance does not raise safety concern for the consumer if used as an additive at up to 0.025% w/w in polymers, such as polyolefins, polyesters and styrenics, that do not swell in contact with aqueous foods and food simulants. The Panel noted, however, that exposure to silver from other sources of dietary exposure may exceed the ADI set by ECHA.”
The International Organization for Standardization (ISO) recently published two standards for nanomaterials. ISO/TS 21633:2021, “Label-free impedance technology to assess the toxicity of nanomaterials in vitro,” describes a methodology of a label-free and real-time detection for non-invasive monitoring of cell-based assays to assess toxicity of nanomaterials to eukaryotic and prokaryotic cells. ISO/TS 23034:2021, “Nanotechnologies — Method to estimate cellular uptake of carbon nanomaterials using optical absorption,” describes a near-infrared optical absorption method to estimate the in vitro cellular uptake of carbon nanomaterials, including both internalized and/or tightly adhered to the cell membrane from liquid dispersions. ISO states that “[t]his is a simple method to screen carbon nanomaterials uptake; additional analysis using a different technique can be required if quantification is desired.”
The European Food Safety Authority (EFSA) has updated its “Guidance on risk assessment of nanomaterials to be applied in the food and feed chain: human and animal health.” The updated guidance, published on August 3, 2021, covers the application areas within EFSA’s remit, including novel foods, food contact materials, food and feed additives, and pesticides. The guidance takes into account relevant scientific studies on physico‐chemical properties, exposure assessment and hazard characterization of nanomaterials, and areas of applicability. Together with the accompanying “Guidance on Technical requirements for regulated food and feed product applications to establish the presence of small particles including nanoparticles,” the updated guidance elaborates on physico‐chemical characterization, key parameters that should be measured, methods and techniques that can be used for characterization of nanomaterials, and their determination in complex matrices. The guidance also details aspects relating to exposure assessment and hazard identification and characterization. It discusses nanospecific considerations relating to in vitro/in vivo toxicological studies and outlines a tiered framework for toxicological testing. Furthermore, the guidance describes in vitro degradation, toxicokinetics, genotoxicity, and local and systemic toxicity, as well as general issues related to the testing of nanomaterials. According to the guidance, depending on the initial tier results, additional studies may be needed to investigate reproductive and developmental toxicity, chronic toxicity and carcinogenicity, immunotoxicity and allergenicity, neurotoxicity, effects on gut microbiome, and endocrine activity. The possible use of read‐across to fill data gaps, as well as the potential use of integrated testing strategies and the knowledge of modes or mechanisms of action, are also discussed. The guidance proposes approaches to risk characterization and uncertainty analysis.