Archives

October 18, 2012

ECHA Will Hold Webinar on REACH Registration Dossiers for Nanomaterials and Creates Nanomaterials Working Group

On October 30, 2012, the European Chemicals Agency (ECHA) will hold a webinar entitled “How to ensure the safe use of nanomaterials under REACH Part I: Characterisation of nanoforms of substances in registration dossiers.” According to ECHA, the webinar will provide information to registrants on the type of information to be included in a Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) registration dossier for a substance with nanoform(s). In addition, on...
October 11, 2012

Potassium Titanium Oxide SNUR Bans Manufacture of Particle Size Less Than 100 nm

On October 5, 2012, the U.S. Environmental Protection Agency (EPA) promulgated a final significant new use rule (SNUR) for potassium titanium oxide, which was previously the subject of a consent order under Section 5(e) of the Toxic Substances Control Act (TSCA). EPA states that, based on test data on the premanufacture notice (PMN) substance and structure activity relationship analysis of test data on analogous respirable, poorly soluble particulates (subcategory titanium dioxide), EPA...
October 10, 2012

EPA Announces RCC Nanotechnology Webinar and Requests Nominations for Case Studies

The Canada-U.S. Regulatory Cooperation Council (RCC) will hold a webinar on November 28, 2012, on its RCC Nanotechnology Work Plan. Canada and the U.S. created the RCC to align better their regulatory approaches in a number of areas, including nanotechnology. According to the U.S. Environmental Protection Agency (EPA), the purpose of the RCC’s nanotechnology initiative is to increase, where possible, regulatory transparency and coordination between the U.S. and...
October 3, 2012

EC Adopts Communication on Second Regulatory Review on Nanomaterials

On October 3, 2012, the European Commission (EC) announced its adoption of a Communication on the Second Regulatory Review on Nanomaterials, which assesses the adequacy and implementation of European Union (EU) legislation for nanomaterials, indicates follow-up actions, and responds to issues raised by the European Parliament (EP), EU Council, and the European Economic and Social Committee. The Communication concludes that “nanomaterials are similar to normal chemicals/substances in...
September 11, 2012

NRC Report on Science for Environmental Protection Examines Nanotechnology

On September 5, 2012, the National Research Council (NRC) released a pre-publication version of a report entitled Science for Environmental Protection:  The Road Ahead. The U.S. Environmental Protection Agency (EPA) asked NRC to assess EPA’s overall capabilities “to develop, obtain, and use the best available scientific and technologic information and tools to meet persistent, emerging, and future mission challenges and opportunities.” The report discusses nanotechnology as an example...
August 15, 2012

EU-OSHA Posts Literature Review on Risk Perception and Communication on Nanomaterials in the Workplace

On June 20, 2012, European Agency for Safety and Health at Work (EU-OSHA) posted a new literature review entitled Risk perception and risk communication with regard to nanomaterials in the workplace, which found “serious gaps in our awareness of the potential risks involved in handling nanomaterials at work, and serious shortcomings in the way that those risks are communicated to workplaces.” The review intends to: Summarize the general principles and theories of risk perception...
August 3, 2012

EPA Publishes Final Nanomaterial Case Study For Nanoscale Silver in Disinfectant Spray

On August 1, 2012, the U.S. Environmental Protection Agency (EPA) posted a final report entitled Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray, which EPA states “is intended to be used as part of a process to identify what is known and, more importantly, what is not yet known that could be of value in assessing the broad implications of certain nanomaterials.” According to EPA, “[t]he complex properties of various nanomaterials make evaluating them in the...
July 17, 2012

EPA Extends Due Date for Comments on Nanosilver Registration Review

According to a July 10, 2012, memorandum added to the registration review docket for nanosilver, the Federal Register notice announcing the opening of the docket erroneously listed the comment period end date as August 19, 2012. The U.S. Environmental Protection Agency (EPA) memorandum states that the comment period has been extended to September 10, 2012, “to allow for a full 60-day comment period [that] is standard for registration review docket openings.”
July 6, 2012

EPA Opens Registration Review Docket for Nanosilver

On July 6, 2012, the U.S. Environmental Protection Agency (EPA) announced the establishment of a registration review docket for nanosilver. EPA states that registration review is its “periodic review of pesticide registrations to ensure that each pesticide continues to satisfy the statutory standard for registration, that is, the pesticide can perform its intended function without unreasonable adverse effects on human health or the environment.” Registration review dockets...
July 2, 2012

EPA Nanomaterial Case Study Compares Multiwalled Carbon Nanotube and Decabromodiphenyl Ether Flame-Retardant Coatings Applied to Upholstery Textiles

The U.S. Environmental Protection Agency (EPA) announced on July 2, 2012, the availability of an external review draft document entitled Nanomaterial Case Study: A Comparison of Multiwalled Carbon Nanotube and Decabromodiphenyl Ether Flame-Retardant Coatings Applied to Upholstery Textiles (EPA/600/R-12/043A). EPA states that the draft document “does not draw conclusions regarding potential environmental risks or hazards of multiwalled carbon nanotubes (MWCNT); rather, it aims to identify...
June 23, 2012

Recent Developments in NRDC’s Case Concerning EPA’s Conditional Registration of Nanosilver

On April 16, 2012, the Natural Resources Defense Council (NRDC) filed its brief in its lawsuit against the U.S. Environmental Protection Agency (EPA) concerning EPA’s conditional registration for HeiQ AGS-20, an end-use product containing nanosilver. NRDC filed suit on January 26, 2012, in the U.S. Court of Appeals for the Ninth Circuit (California) against EPA, seeking to limit public exposure to the nanosilver’s use in clothing, baby blankets, and other textiles and prevent EPA...
June 12, 2012

ECHA Will Create Working Group on Nanomaterials

The European Chemicals Agency (ECHA) recently held a two-day workshop concerning its first experiences with nanomaterials under the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) program, with an emphasis on the evaluation process. ECHA, Member State Competent Authorities (MSCA), accredited stakeholders, and the European Commission (EC) discussed how nanomaterials in general have been characterized in registration dossiers. Currently, according to ECHA, the...
June 8, 2012

ECHA Updates Additional Guidance for Nanomaterials

On May 25, 2012, the European Chemicals Agency (ECHA) published three new appendices, updating Chapters R.8, R.10, and R.14 of the Guidance on Information Requirements and Chemical Safety Assessment.  ECHA updated the guidance based on the outcome of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Implementation Projects on Nanomaterials (RIP-oN) 3, which concerned aspects such as occupational exposure estimation and dose-response characterization for human...
May 15, 2012

EPA Releases Roadmap on Technology Innovation for Environmental and Economic Progress

On May 14, 2012, the U.S. Environmental Protection Agency (EPA) and the Department of Commerce announced efforts to launch an environmental technology initiative intended to help create American jobs in the growing environmental industry. EPA released a document entitled Technology Innovation for Environmental and Economic Progress: An EPA Roadmap, which states that EPA “will undertake policy, regulatory, financial, and voluntary actions, grounded in science, that will promote...
May 2, 2012

ECHA Announces Updated Guidance for Registering Nanomaterials

On April 30, 2012, the European Chemicals Agency (ECHA) announced the availability of three appendices, updating Chapters R.7a, R.7b, and R.7c of the Guidance on Information Requirements and Chemical Safety Assessment (IR & CSA). ECHA prepared a draft revision of the Guidance, based on the outcome of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Implementation Projects on Nanomaterials (RIP-oN) 2 final report. ECHA updated the Guidance via a fast-track...
April 18, 2012

ECHA Forwards Draft Guidance Concerning Nanomaterials to CARACAL

The European Chemicals Agency (ECHA) sent three new draft appendices to Chapters R.8, R.10, and R.14 of the guidance on information requirements and chemical safety assessment concerning recommendations for nanomaterials to the Competent Authorities for Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) and Classification, Labeling, and Packaging (CLP) (CARACAL). The draft appendices are based on the results of the REACH Implementation Project on Nanomaterials...
April 17, 2012

EU OSHA Announces French Report on Feasibility of Epidemiological Surveillance System for Workers Exposed to Engineered Nanomaterials

The European Agency for Safety and Health at Work (EU OSHA) posted an item on April 16, 2012, concerning a French report on the feasibility of an epidemiological surveillance system for workers exposed to engineered nanomaterials. EU OSHA notes that the French Health and Occupational Ministries asked the French Institute for Public Health Surveillance (InVS), supported by a multidisciplinary working group convened by the Institute for Public Health Research, to assess the feasibility of an...
April 4, 2012

EPA Promulgates SNUR for Infused Carbon Nanostructures

On April 4, 2012, the U.S. Environmental Protection Agency (EPA) promulgated, through a direct final rule, significant new use rules (SNUR) for 17 chemical substances that were the subject of premanufacture notices (PMN). This includes a SNUR for “infused carbon nanostructures (generic).” According to EPA, the PMN states that the generic (non-confidential) use of the substance is as an additive to provide conductive properties to reinforcements used in composites. EPA states that, based...
March 1, 2012

CoRAP Notes Nano Concerns for Two Substances

On February 29, 2012, the European Chemicals Agency (ECHA) announced the first Community Rolling Action Plan (CoRAP), which includes 90 substances that Member States will evaluate under the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) substance evaluation process. For each substance, ECHA notes the initial grounds for concern. For two substances, silicon dioxide and silver, the initial grounds for concern are “Substance...
February 22, 2012

ECHA Announces Plans to Update Guidance for Registration of Nanoform Substances

On February 22, 2012, the European Chemicals Agency (ECHA) issued a press release announcing that it is currently preparing an update of its Guidance on Information Requirements and Chemical Safety Assessment (IR & CSA) based on the European Commission’s Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Implementation Project on Nanomaterials (RIP-oN). Because the next registration deadline of May 31, 2013, is approaching quickly, ECHA “will facilitate...
February 9, 2012

EPA Posts Summary of 2011 Nanomaterial Case Studies Workshop

On February 9, 2012, the U.S. Environmental Protection Agency (EPA) posted a summary report on its January 2011 workshop on nanoscale silver. The workshop was the second in a series conducted by the National Center for Environmental Assessment (NCEA) to further the development of a research strategy for completing comprehensive environmental assessments of nanomaterials.  The basis of the workshop was the report Nanomaterial Case Study:  Nanoscale Silver...
January 30, 2012

EPA Extends Comment Period for Proposed SNURs

The U.S. Environmental Protection Agency (EPA) has announced that, in response to public comments, it will provide the public more time to comment on the December 28, 2011, proposed significant new use rules (SNUR) for 17 chemical substances that were the subject of premanufacture notices (PMN). Of particular interest, seven of the PMN substances’ reported chemical names include the term “carbon nanotube” (CNT) or “CNT.” EPA states “the comment period is being...
January 26, 2012

NRDC Files Suit to Block EPA’s Conditional Registration of Nanosilver

On January 26, 2012, the Natural Resources Defense Council (NRDC) filed a lawsuit in the U.S. Court of Appeals for the Ninth Circuit against the U.S. Environmental Protection Agency (EPA) concerning its conditional registration of a pesticide product containing nanosilver as a new active ingredient for use as a preservative for textiles.  NRDC states that it seeks to limit public exposure to the nanosilver’s use in clothing, baby blankets, and other textiles. On December 1, 2011, EPA...
January 25, 2012

NRC Publishes A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials

On January 25, 2012, the National Research Council (NRC) posted the pre-publication version of its report entitled A Research Strategy for Environmental, Health, and Safety Aspects of Engineered Nanomaterials. The U.S. Environmental Protection Agency (EPA) asked NRC to perform an independent study to develop and monitor the implementation of an integrated research strategy to address the environmental, health, and safety (EHS) aspects of engineered nanomaterials (ENM). NRC...
January 3, 2012

EPA OIG Concludes EPA Needs to Manage Nanomaterials More Effectively

On December 30, 2011, the U.S. Environmental Protection Agency (EPA) Office of Inspector General (OIG) released a report entitled EPA Needs to Manage Nanomaterial Risks More Effectively. According to OIG, the purpose of its review was to determine how effectively EPA is managing the human health and environmental risks of nanomaterials. OIG states that it found “that EPA does not currently have sufficient information or processes to effectively manage the human health and...
December 28, 2011

EPA Publishes Proposed SNURs for CNTs

The U.S. Environmental Protection Agency (EPA) published on December 28, 2011, proposed significant new use rules (SNUR) for 17 chemical substances that were the subject of premanufacture notices (PMN). Of particular interest, seven of the PMN substances’ reported chemical names include the term “carbon nanotube” (CNT) or “CNT.”  EPA states that because of a lack of established nomenclature for CNTs, the Toxic Substances Control Act (TSCA) Inventory names for CNTs are...
December 1, 2011

EPA Conditionally Registers Pesticide Product Containing Nanosilver As a New Active Ingredient

The U.S. Environmental Protection Agency (EPA) announced on December 1, 2011, that it is conditionally registering a pesticide product containing nanosilver as a new active ingredient. HeiQ AGS-20 is a silver-based antimicrobial pesticide product approved for use as a preservative for textiles.  The final registration is not yet in the docket.  We believe, but cannot confirm, the final registration is largely similar to the draft proposed registration issued last year. As...
November 9, 2011

EPA Seeks Information Concerning Discharges of Nanosilver from Industrial Manufacturing

The U.S. Environmental Protection Agency (EPA) published in an October 26, 2011, Federal Register notice its final 2010 Effluent Guidelines Program Plan, which includes a request for comment and information for its 2011 annual reviews. EPA requests information on a number of topics, including discharges of nanosilver from industrial manufacturing. EPA cites nanosilver’s use as an active pesticide ingredient, an antimicrobial in fabric; a preservative in textile products,...
November 4, 2011

ECHA Begins Consultation on Testing Proposal for Multi-Wall Carbon Nanotubes

On November 3, 2011, the European Chemicals Agency (ECHA) began a consultation on a testing proposal for multi-wall carbon nanotubes, synthetic graphite in tubular shape. Under the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) program, manufacturers and importers must obtain information on toxic effects of substances.  REACH requires that new testing of a substance involving vertebrate animals be carried out only as a last resort, however. ECHA states that, to...
November 2, 2011

EC Publishes Final RIPoN Reports

The European Commission (EC) began in 2009 a Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Implementation Project on Nanomaterials (RIPoN), which it intended to provide advice on key aspects of the implementation of REACH with regard to nanomaterials. The EC recently posted final reports concerning nanomaterials and information requirements (RIPoN 2) and chemical safety assessment (RIPoN 3). The EC states that, based on the scientific and...
October 24, 2011

EPA Posts Guidance to Facilitate Decisions for Sustainable Nanotechnology

The U.S. Environmental Protection Agency (EPA) posted a September 2011 guidance document entitled Guidance to Facilitate Decisions for Sustainable Nanotechnology, which was prepared by the National Risk Management Research Laboratory of the Office of Research and Development. EPA states that it developed the guidance to assist in assessing the sustainability of nanoproducts, and it is intended “to lay the groundwork for developing a decision-support framework through continual updates as...
September 28, 2011

REACH Conference Participants Discuss Nanomaterials

During the September 23, 2011, Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) conference organized by the European Chemicals Agency (ECHA) and European Commission (EC), Astrid Schomaker, Directorate-General (DG) Environment, stated that the EC has been working on a definition of nanomaterials, and that it “should be coming after the summer.” The EC previously stated in a letter to the Dutch Environment Ministry that it would publish a definition by the end of...
September 23, 2011

Meeting of Nano Interests Held in Washington, D.C.

On September 22, 2011, during a meeting of nano interests in Washington, D.C., the following people spoke: Jeffrey Weiss, Senior Director, Technical Barriers to Trade, Office of the United States Trade Representative, “U.S. Trade Policy and Nanotechnology”; Richard A. Canady, Ph.D., Director, Center for Human Health Risk Assessment Research Foundation, International Life Sciences Institute (ILSI), “NanoRelease and NanoCharacter Projects”; and Maria J. Doa, Ph.D., Acting Director of...
September 21, 2011

SNWG Releases Statement Concerning Nanosilver

The Silver Nanotechnology Working Group (SNWG) recently prepared a statement concerning nanosilver and its long history of safe and regulated use. SNWG notes the similarities between nanosilver and other antimicrobial silver materials available in the marketplace.  SNWG states that it “has interacted with the [U.S. Environmental Protection Agency (EPA)] in challenged exchanges on how best to regulate nanopesticides leading to a clear, reasonable, and responsible path for...
August 30, 2011

Denmark Publishes Literature Review for Seven Nanomaterials

Earlier this month the Danish Environmental Protection Agency (DEPA) published a document entitled Survey on Basic Knowledge about Exposure and Potential Environmental and Health Risks for Selected Nanomaterials, which is intended to provide an overview of the existing knowledge about seven of the most common nanomaterials, their environmental and health properties, the use of those nanomaterials, and the possibility of exposure of humans and the environment.  DEPA selected fullerenes, iron,...
August 4, 2011

NANO Act Promotes Development and Responsible Stewardship of Nanotechnology

Representative Mike Honda (D-CA) re-introduced on August 1, 2011, the Nanotechnology Advancement and New Opportunities Act (NANO Act), which seeks to promote the development and responsible stewardship of nanotechnology in the U.S. According to Rep. Honda, the legislation is designed to maintain the U.S.’s leadership role in nanotechnology research by promoting the development and commercialization of the results. At the same time, the NANO Act addresses concerns raised about the potential...
August 2, 2011

IATP Criticizes Development of Nanotechnology Products Without Regulatory Oversight

The Institute for Agriculture and Trade Policy (IATP) issued a June 29, 2011, report entitled Racing Ahead: U.S. Agri-Nanotechnology in the Absence of Regulation, which claims that at least 1,300 products with engineered nanotechnology materials (ENM) have been commercialized, “despite myriad uncertainties about the public health and environmental effects of ENMs.” According to the report, several steps are needed for an operative and mandatory regulatory structure for nanotechnology...
July 26, 2011

Comment Deadline Approaches for EPA’s Policy on Nanoscale Materials in Pesticide Products

Comments on the U.S. Environmental Protection Agency’s (EPA) proposed policy on nanoscale materials in pesticide products are due August 17, 2011. EPA offers two approaches for obtaining the information EPA believes it needs concerning nanoscale materials in pesticide products. Under the first approach, EPA would use Section 6(a)(2) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to obtain information regarding what nanoscale material is present in a registered pesticide...
July 19, 2011

EPA Regulatory Agenda Includes Notices Concerning Nanoscale Materials

The U.S. Environmental Protection Agency’s (EPA) July 7, 2011, Regulatory Agenda includes several notices concerning nanoscale materials: Test Rule for Certain Nanoscale Materials — EPA states that it is developing a test rule under Section 4(a) of the Toxic Substances Control Act (TSCA) to require manufacturers (defined by statute to include importers) and processors of the multiwall carbon nanotube described in Premanufacture Notice (PMN) P-08-199, certain clays (e.g., kaolin...
June 17, 2011

EPA Proposes Policy on Nanoscale Materials in Pesticide Products

The U.S. Enviromental Protection Agency (EPA) published in the June 17, 2011, Federal Register a notice describing several possible approaches for obtaining certain additional information on the composition of pesticide products. EPA focuses particularly on information about what nanoscale materials are present in registered pesticide products, and defines “nanoscale material” as “an active or inert ingredient and any component parts thereof intentionally produced to have at least one...
June 12, 2011

EPA Extends Comment Period on Nanoscale Materials in Pesticide Products

The U.S. Environmental Protection Agency (EPA) is expected to publish a Federal Register notice on July 13, 2011, extending the comment period concerning possible approaches for obtaining information about what nanoscale materials are present in registered pesticide products until August 17, 2011. EPA states that it received requests from CropLife America, the Biocides Panel of the American Chemistry Council, the Chemical Producers & Distributors Association, and the International Center...
June 10, 2011

EPA Proposes Policy on Nanoscale Materials in Pesticide Products

The U.S. Environmental Protection Agency (EPA) released on June 9, 2011, a pre-publication copy of a forthcoming Federal Register notice describing several possible approaches for obtaining certain additional information on the composition of pesticide products. EPA focuses particularly on information about what nanoscale materials are present in registered pesticide products, and defines “nanoscale material” as “an active or inert ingredient and any component parts thereof...
May 17, 2011

ECHA Preparing Nano Inventory from REACH and CLP Submissions

The European Chemicals Agency (ECHA) is compiling an inventory of nanomaterials included in the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) registration dossiers and Classification, Labeling, and Packaging (CLP) notifications for the European Commission (EC), and intends to deliver the inventory by the end of June 2011. The EC requested the inventory in response to the 2009 European Parliament communication on nanomaterials. An ECHA spokesperson stated that...
May 9, 2011

EPA Issues Final SNUR for Certain Multi-Walled Carbon Nanotubes

On May 6, 2011, the U.S. Environmental Protection Agency (EPA) promulgated a final significant new use rule (SNUR) under Section 5(a)(2) of the Toxic Substances Control Act (TSCA) for the chemical substance identified generically as multi-walled carbon nanotubes (MWCNT), which was the subject of premanufacture notice (PMN) P-08-199. Under the final SNUR, persons intending to manufacture, import, or process MWCNT for a use that is designated as a significant new use by the final rule must...
April 27, 2011

UK FSA Publishes Report of Consumers’ Views on Nano in Food and Food Packaging

On April 21, 2011, the United Kingdom’s (UK) Food Standards Agency (FSA) published a report of consumers’ views on the use of nanotechnology in food and food packaging. FSA convened a focus group in late 2010 and early 2011, and asked participants about their views on nanotechnology. According to FSA, the main findings are that: Participants’ reactions to nanotechnology and food reflected a variety of concerns. These included whether this was a necessary development,...
April 12, 2011

NanoSafety Consortium Submits Proposed Testing Agreement to EPA

On April 6, 2011, several members of the NanoSafety Consortium submitted to the U.S. Environmental Protection Agency (EPA) a proposed testing agreement under Section 4 of the Toxic Substances Control Act (TSCA). Under the proposed testing agreement, the substances to be tested may include multi-walled carbon nanotubes, double-walled carbon nanotubes, single-walled carbon nanotubes, and graphene nanoplatelets. Participants would conduct 90-day inhalation toxicity studies in rats, and submit...
March 23, 2011

Sweden Will Focus on Nanomaterials in National Action Plan

According to a March 10, 2011, press release, the risks connected with nanomaterials are one of the areas on which the Swedish Chemicals Agency (KemI) will focus in its national action plan, which will apply from 2011-2014. The press release states that the objective is for Sweden “to become one of the leading member states in the [European Union (EU)] in proposing new bans and restrictions.” Sweden expects the action plan to “lead to intensified cooperation and...
February 8, 2011

EPA Announces Nanotechnology Research Awards

On February 17, 2011, the U.S. Environmental Protection Agency (EPA) announced that it awarded $5.5 million to three consortia to support innovative research on nanotechnology. EPA states that, in collaboration with the United Kingdom’s (UK) Natural Environment Research Council, it is leading this scientific research effort to understand better the potential risks to people’s health and the environment. The grants EPA awarded are intended to help researchers determine whether certain...
January 26, 2011

EU-OSHA Announces Control Banding Tool for Nanomaterials

On January 25, 2011, the European Agency for Safety and Health at Work (EU-OSHA) announced that French Agency for Environmental and Occupational Health Safety (ANSES) experts have developed a control banding tool specific to nanomaterials that can potentially be used in any work environment in which nanomaterials are manufactured or used. With control banding, new products are classified into “bands,” which are defined after comparison with the hazard level of known...
January 18, 2011

Environmental Science & Technology Article Reviews History of Nanosilver and Policy Implications

On January 10, 2011, Environmental Science & Technology posted a peer-reviewed pre-publication article entitled “120 Years of Nanosilver History:  Implications for Policy Makers,” which shows that nanosilver in the form of colloidal silver has been used for more than 100 years and, according to the authors, has been registered as a biocidal material in the U.S. since 1954.  The article states that 53 percent of the U.S. Environmental Protection Agency (EPA)-registered biocidal silver...