Bergeson & Campbell, P.C. serves small, medium, and large pesticide product registrants and other stakeholders in the agricultural and biocidal sectors, in virtually every aspect of pesticide law, policy, science, and regulation.
Monsanto Agrees to Plead Guilty to Illegal Use of Methyl Parathion and to Pay $10.2 Million in Penalties and Restitution, Thereby Avoiding Felony Convictions for Related Hazardous Waste Violations
On November 21, 2019, the U.S. Department of Justice announced a settlement with Monsanto Company (Monsanto) in which Monsanto agreed to plead guilty to a misdemeanor count of illegally using the pesticide Penncap-M, a methyl parathion product that was cancelled by the U.S. Environmental Protection Agency (EPA) on July 27, 2010. This settlement of several criminal counts by Monsanto followed an investigation by the EPA Criminal Investigation Division. Under the existing stocks provision in the EPA cancellation order, continued use of Penncap-M became unlawful after December 31, 2013. In the settlement documents, Monsanto admits that its employees knowingly violated this order by using Penncap-M on July 15, 2014, to treat corn seed research crops at Monsanto’s Valley Farm research facility in Maui, Hawaii. Monsanto also admits that Monsanto employees directed other employees to re-enter the treated site seven days after the July 15, 2014, application, although the re-entry period established for this pesticide prior to its cancellation was 31 days. Monsanto further admits that it stored stocks of Penncap-M after December 31, 2013, when unused stocks of this product became an acute hazardous waste under the Resource Conservation and Recovery Act (RCRA), at several locations in Hawaii without obtaining the required permits.
As part of the settlement, Monsanto agreed to pay a total of $10.2 million in fines and penalties, which includes a maximum fine of $200,000 for illegal use of a cancelled pesticide, $6 million in fines for the hazardous waste violations, and $4 million in community service payments to Hawaii governmental entities for various environmental remediation programs. Monsanto also agreed to be sentenced to two years of probation. If Monsanto adheres to all of its obligations under this settlement, at the end of the two-year period of probation, the criminal felony counts for the RCRA hazardous waste violations will be dismissed with prejudice.
Although the agreement reached with Monsanto will allow Monsanto to escape any felony convictions, it is clear from the stiff penalties imposed (which include the maximum fine permissible for the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) violation) that EPA considers the violations at issue to be very serious. Pesticide research facilities often handle dangerous pesticides, and EPA typically affords such research facilities wide latitude to use unregistered active ingredients in small-scale research projects, but Monsanto has admitted that its personnel deliberately violated a FIFRA cancellation order, and did not comply with the restrictions on re-entry that were in place before the product in question was cancelled. Monsanto also has admitted that it stored stocks of a cancelled pesticide at several sites after they became acute hazardous waste without obtaining the required permits. The substantial penalties imposed may not seem surprising to some given those admissions.
The U.S. Environmental Protection Agency (EPA) recently settled two cases involving allegations of non-compliance with the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Although the Consent Agreement and Final Orders (CAFO) and Stop Sale, Use or Removal Orders (SSURO) issued in these cases are not yet available online, the penalty amounts at issue -- $200,000 and $1,489,000 -- reflect increased enforcement in targeted areas and EPA’s willingness to seek and obtain heroic penalties.
On November 18, 2019, EPA Region 9 announced that Decon7 Systems LLC (Decon7) would pay a $200,000 civil penalty in a settlement related to FIFRA violations. Specifically, EPA found that Decon 7:
On October 31, 2019, EPA Region 3 announced that it reached an agreement with AFCO C&S, LLC (AFCO), a chemical company located in Chambersburg, Pennsylvania, to resolve alleged FIFRA violations. AFCO agreed to pay a $1,489,000 penalty to settle the alleged violations that involved the use of 12 products to clean and sanitize food and beverage processing facilities. EPA alleges that AFCO sold and distributed ten unregistered pesticide products, a misbranded product, and a product that made claims beyond those permitted by its FIFRA registration.
The settlement also addresses violations of a SSURO that EPA issued to AFCO on July 13, 2018. AFCO engaged in sales and distributions that violated this order. AFCO has since discontinued sales of all of the involved products, except for one registered product.
On October 15, 2019, EPA posted a total of 11 documents to the registration review docket for paraquat dichloride (EPA-HQ-OPP-2011-0855). Of primary interest in the registration review process under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) are the draft human health and ecological risk assessments. Additional supporting documents posted to the docket include dietary, residential, and occupational exposure assessments; a review of analytical chemistry and residue data; a label use summary; a screening level usage analysis, results of a drinking water jar test; open literature and epidemiology literature reviews; and an incident report summary.
Paraquat is currently registered in the United States for use as an herbicide on over 100 crops in agricultural and commercial settings. All paraquat products are restricted use products and may be applied only by certified pesticide applicators. EPA has previously imposed additional restrictions and conditions to ensure the safe use of paraquat consistent with label directions. These actions include a safety awareness campaign, changes to labels and product packaging, and specialized training for certified applicators using paraquat. Evaluation of the effectiveness of these steps will be conducted in the registration review process.
Potential risks of concern to workers applying paraquat or entering treated fields are identified in the draft human health risk assessment, as are potential risks to bystanders from spray drift. Prior submissions to EPA suggest a link between proper use of paraquat and Parkinson’s Disease, but EPA’s review of relevant data does not support a causal relationship. This conclusion is not without controversy, as evidenced by an October 15, 2019, press release from the Center for Biological Diversity that calls out EPA’s failure to recognize a link between paraquat exposures and Parkinson’s Disease. The ecological risk assessment identifies potential risks to mammals, birds, adult honey bees, terrestrial plants, and algae. EPA is seeking comments on these and other issues raised in the draft risk assessments for paraquat. Comments will be accepted on these documents until December 16, 2019.
On October 31, 2019, as required by the 2018 Farm Bill, the U.S. Department of Agriculture’s (USDA) Agricultural Marketing Service published its interim rule, “Establishment of a Domestic Hemp Production Program” (Interim Rule). The Interim Rule proposal specifies rules and regulations governing hemp production in the U.S., including:
The Interim Rule does not alter the federal definition distinguishing hemp from marijuana, a distinction hinging on the levels of THC in the plant. Plants containing 0.3 percent or less THC on a dry weight basis are considered hemp, while plants exceeding this level of THC are marijuana. The Interim Rule introduces the term “acceptable hemp THC level” to account for a degree of uncertainty in testing results and explains how to interpret lab results with a measurement of uncertainty. This is a critical clarification given that THC levels dictate whether a grower is engaged in the legal production of hemp or is growing marijuana -- prohibited federally and in the majority of states.
The USDA is not proposing a single uniform testing method and will accept numerous testing methods and protocols employed by states. The Interim Rule does not include a federal seed certification program. The Interim Rule makes clear that interstate transport of hemp is permissible regardless of whether the states the shipment passes through allow hemp production.
The publication of the Interim Rule initiates USDA’s implementation of the hemp program, which includes reviewing state/tribal plans and issuing licenses. USDA will accept public comments on the Interim Rule for 60 days through December 30, 2019. Within two years of publication, USDA will publish a final rule. Also relevant for hemp producers are forthcoming proposals from the U.S. Food and Drug Administration and the U.S. Environmental Protection Agency (EPA) addressing the sale of cannabidiol (CBD) and pesticide approvals for application to hemp plants, respectively.
For some, federal policies facilitating hemp production not only is a long-awaited policy goal, but a kind of “gateway drug” (pun intended) for renewing the debate about approval for pesticide products to be used on the legal production of marijuana crops.
To date, the federal government position is that since marijuana production is not allowed under federal law, attempts by states to permit pesticides for state use are forbidden. Some states have argued that since their state law allows the production of marijuana crops, pesticide products should be subject to registration under Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 18 emergency use or FIFRA Section 24(c) special local needs.
Separate from any debate about marijuana production, residues of pesticides on hemp products intended for human consumption, such as CBD products, will force EPA to consider how such products should be reviewed. Those policies, in time, will be relevant to any eventual evaluation of similar exposure and risk assessment questions regarding approval of pesticide products to be used in marijuana production.
EPA Proposes Rule to Update the Worker Protection Standard Pesticide Application Exclusion Zone Requirements
On October 24, 2019, the U.S. Environmental Protection Agency (EPA) announced that it is proposing narrow updates to the Worker Protection Standard’s (WPS) provision on the Application Exclusion Zone (AEZ) requirements. By narrowing updates to the WPS, EPA states that it will “improve the long-term success of the agency’s Application Exclusion Zone requirements” and “would improve enforceability for state regulators and reduce regulatory burdens for farmers.” EPA believes narrowing updates to the WPS will also continue to protect the health of farm workers and other individuals near agricultural establishments who could be exposed to agricultural pesticide applications. The proposed updates are consistent with the 2019 Pesticide Registration Improvement Act (PRIA).
EPA Administrator Andrew Wheeler states that EPA’s proposal “would enhance the agency’s Application Exclusion Zone provisions by making them more effective and easier to implement.” Wheeler states that “our proposal will make targeted updates, maintaining safety requirements to protect the health of those in farm country, while providing greater flexibility for farmers.”
EPA will hold a 90-day public comment period and seeks input on select updates that were publicly suggested to EPA by both state pesticide agencies responsible for enforcing the provision and agricultural stakeholders since the AEZ requirement was adopted in 2015. The proposed updates are also consistent with the U.S. Department of Agriculture’s comments during a May 2017 meeting of EPA’s Pesticide Program Dialogue Committee.
Specifically, EPA is proposing to:
Publication of the proposed rule in the Federal Register will begin a 90-day comment period. Comments are due on or before January 30, 2020.
When EPA included the AEZ concept in its 2015 WPS updates, of chief concern for pesticide applicators, farmers, and state departments of agriculture were the compliance and enforcement practicalities of aspects of the AEZ requirements. For example, in scenarios where the AEZ extends to nearby roads and highways, it is difficult for pesticide applicators to be aware of every vehicle that may pass by that could enter the AEZ during applications. It is unclear if the revised AEZ requirements adequately address these practical realities. Agricultural stakeholders and pesticide applicators may wish to submit comments on the proposed revisions.
Additional information on the WPS is available on EPA's website.
On October 17, 2019, the U.S. Environmental Protection Agency (EPA) released the Spanish Translation Guide for Pesticide Labeling resource for use by all, including pesticide registrants that choose to display parts of their pesticide product label in Spanish. The purpose of the guide is to be a resource for the translation of the health and safety sections on pesticide labeling from English to Spanish. EPA states that the “guide is written in a universal form of Spanish to reach as many Spanish speakers as possible.”
While translating pesticide labels is not a requirement, EPA generally allows pesticide registrants to translate their product labels into any language so long as there is an EPA-accepted English version of the label and the translation is true and accurate. The guide is not intended to substitute for or eliminate the pesticide labels in English. An English version of all required labeling text is needed for all pesticide products in accordance with 40 C.F.R. Section 156.10(a)(3).
The guide provides translations for standard language typically used in the health and safety sections of pesticide product labels such as the:
EPA states that it “developed the Spanish translation guide in response to feedback from stakeholders who believe that having bilingual pesticide labeling is critical to the well-being of pesticide handlers, applicators, and farmworkers, many of whom do not speak English as a first language.”
The English statement appears in the left-hand column and the corresponding Spanish translation is available in the right-hand column of the guide. EPA states that the “guide will help registrants maintain accurate, consistent translations on product labels and ease their burden when adding Spanish translations.”
On September 30, 2019, the U.S. Environmental Protection Agency (EPA) released an updated Aquatic Life Benchmarks Table for registered pesticides. The update includes four newly registered pesticides and their degradants as well as new values for more than 30 previously registered pesticides. The benchmarks inform state and local regulators in their interpretation of water quality monitoring data. Waterbodies where benchmarks are exceeded may be prioritized for further investigation. EPA derived the latest updates from toxicity values from the most recent ecological risk assessments for the registered pesticides as part of the regular registration review. EPA aims to update the table on an annual basis. The full table and links to source documents for each of the benchmarks are accessible on EPA’s website here.
EFSA Opens Consultation Period on Two Pilot Assessments on the Risks Caused by Multiple Pesticide Residues in Foods
On September 17, 2019, the European Food Safety Authority (EFSA) opened a consultation period on two pilot assessments of the risks posed to humans by residues of multiple pesticides in food. EFSA is seeking comments from interested parties on the assessments. The first assessment considers the chronic effects of multiple pesticides on the thyroid system. The second looks at acute effects on the nervous system.
EFSA produced the assessments in collaboration with the National Institute for Public Health and the Environment for the Netherlands (RIVM) using monitoring data from 2014, 2015, and 2016. In approving pesticides for use in the European Union (EU), EFSA establishes a maximum level of pesticide residue (MRL) allowed in food or animal feed. The MRL considers the cumulative effects of pesticides. Pesticides may only be placed on the EU market if they have no harmful effects on humans, including cumulative effects. In the two pilot assessments, EFSA classified pesticides into “cumulative assessment groups” (CAG) based upon whether they produce similar toxic effects in a specific organ or system. EFSA states that “[t]he overall draft conclusion for both assessments is that consumer risk from dietary cumulative exposure is below the threshold that triggers regulatory action for all the population groups covered.”
In 2020, EFSA will prepare the assessments in final, which will serve to “inform risk managers in the European Commission and Member States who regulate the safe use of pesticides in the EU.”
EFSA will present the assessments at a special stakeholder event in Brussels, Belgium, on October 22, 2019. The meeting is intended to allow stakeholders with expertise and interest in the area to discuss the technical issues relating to the draft assessments. Registration for the meeting closes on October 11, 2019.
All comments must be submitted by November 15, 2019. Comments on the “Cumulative dietary risk characterisation of pesticides that have chronic effects on the thyroid” may be submitted at https://ec.europa.eu/eusurvey/runner/PC_CRA_Thyroid_Sept-2019. Comments on the “Cumulative dietary risk characterisation of pesticides that have acute effects on the nervous system” may be submitted at https://ec.europa.eu/eusurvey/runner/PC_CRA_Nerv_Syst_Sept-2019.
The two draft assessments are available on EFSA’s website.
EPA Seeks Comment on its Draft Antimicrobial Performance Evaluation Program (APEP) Risk-Based Strategy for Products in the Marketplace with Public Health Claims
On October 2, 2019, the U.S. Environmental Protection Agency (EPA) published a notice in the Federal Register announcing the availability of, and soliciting public comment on, the draft document entitled “Antimicrobial Performance Evaluation Program (APEP) A (Draft) Risk Based Strategy to Ensure the Effectiveness of Hospital-Level Disinfectants” (draft Strategy). EPA states that “The draft Strategy provides a framework to ensure that registered hospital-level disinfectants and tuberculocide products continue to meet Agency efficacy standards once they are in the marketplace.”
The draft Strategy was developed in response to EPA’s Office of Inspector General’s (OIG) report “EPA Needs a Risk-Based Strategy to Assure Continued Effectiveness of Hospital-Level Disinfectants,” which recommends EPA’s Office of Pesticide Programs (OPP) to develop a risk-based strategy to assure the effectiveness of public health pesticides used in hospital settings once products are in the marketplace. EPA developed the draft Strategy based on OIG’s recommendations.
EPA states that the draft Strategy uses a risk-based approach “to inform the Agency on the prioritization and selection of hospital-level disinfectants and associated label claims for testing,” and states that its order of priority is as follows:
Additional refinement factors may also be considered such as:
EPA states that it will be considering two options individually or in combination for obtaining samples for testing: (1) EPA purchase of products in the marketplace; and (2) product samples provided by the registrant. Several options for allocating efficacy and chemistry testing resources may be utilized individually or in combination; these options include: (1) Office of Pesticide Programs Microbiology Laboratory and the Analytical Chemistry Laboratory; (2) interagency agreements and contracts; (3) third-party verification testing; and (4) registrant testing; and/or Data Call-Ins.
In the Federal Register notice, EPA lists six focus questions on which it is specifically requesting public comment:
EPA states that the draft Strategy may be of interest to health care/hospital professionals and all entities who have EPA registered antimicrobial products that are available in the marketplace, particularly those with products that make hospital disinfectant claims (e.g., claims against Staphylococcus aureus and Pseudomonas aeruginosa) and other claims for notable public health pests (e.g., Clostridium difficile, methicillin resistant Staphylococcus aureus, Mycobacterium spp.).
All comments on the draft Strategy document must be received by EPA on or before December 2, 2019. EPA expects to publish the APEP final strategy in 2020 and schedule implementation to begin in 2022.
On October 1, 2019, the U.S. Environmental Protection Agency (EPA) issued a Federal Register notice announcing the that fees under the Pesticide Registration Improvement Extension Act of 2018 (PRIA 4) were increased by five percent for pesticide applications received on or after October 1, 2019. The five percent increase is on fee amounts established by Public Law 116-8, which became effective on March 8, 2019. The revised fees will remain in effect until September 30, 2021.
The fee schedule provided in PRIA 4 identifies the registration service fees and decision times organized according to the organizational units of the Office of Pesticide Programs (OPP) within EPA. EPA presents the schedules as 19 tables, organized by OPP Division and by type of application or pesticide subject to the fee, and lists the registration service fee for actions received in fiscal years 2020 and 2021. Applicants must submit fee payments at the time of application. EPA will reject any application that does not contain evidence that the PRIA 4 fee has been paid.
On September 24, 2019, the U.S. Environmental Protection Agency (EPA) announced the availability of the premises treatment final test guideline, under Series 810, Product Performance Test Guidelines. The guideline, 810.3500 Premise Treatment, provides recommendations on how to conduct efficacy testing against invertebrate pests in premises, such as cockroaches, ticks, mosquitoes, flies and wasps in connection with registration of pesticide products for use against public health pests. This guideline does not, however, apply to efficacy testing for treatment of livestock or pets, wide-area mosquito control, structural protection from termites, or bed bug products.
EPA states that “The final guideline clarifies the original guideline published in 1998 based on public comments and recommendations from the Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (FIFRA SAP).”
Revisions to 810.3500 include
Documents pertaining to the revision of the product performance guidelines, including public comment submissions, and the agency’s response to comments are available at www.regulations.gov in Docket Number EPA-HQ-OPP-2017-0693. More information on test guidelines is available on our blog.
EPA Seeks Comment on its Risk Assessment Methodology for Evaluating Potential Synergistic Effects of Pesticides on Non-Target Organisms
On September 9, 2019, the U.S. Environmental Protection Agency (EPA) Office of Pesticide Programs (OPP) published a notice in the Federal Register announcing the availability of, and an opportunity for comment on, a document describing an “interim process” that OPP’s Environmental Fate and Ecological Effects Division is currently using to evaluate potential synergistic effects of mixtures of pesticide active ingredients on non-target organisms. As part of a lawsuit challenging the 2012 decision by EPA to register Enlist Duo Herbicide (a combination of 2,4-D and glyphosate), OPP scientists learned that patent applications for some registered pesticide products included claims that particular combinations of active ingredients provide “synergistic” control of target species. Although EPA was not at that time considering potential synergies in assessing the risk for ecological effects on non-target organisms, based on the patent application claims regarding synergy for Enlist Duo, EPA decided to request that the reviewing court vacate its registration decision and remand the application for Enlist Duo for further study of these effects and any measures that might be needed to mitigate the risk to non-target organisms. This decision sparked much controversy, and many in industry were concerned that patent application claims were not being correctly interpreted by EPA for the category of pesticide products at issue.
The new document released by EPA for review and comments is entitled: “Process for Receiving and Evaluating Data Supporting Assertions of Greater Than Additive (GTA) Effects in Mixtures of Pesticide Active Ingredients and Associated Guidance for Registrants.” EPA states that it “has generally been applying this interim process since 2016.” The process described in the document has five steps: (1) registration applicants must search for any granted patents that include synergy (GTA) claims for combinations of pesticides; (2) applicants must review the patent claims and supporting data for relevance to ecological risk assessment; (3) applicants must report to EPA all effects testing data from the relevant patents; (4) applicants must do a statistical analysis (using a method prescribed by EPA) to determine whether any observations of GTA effects are statistically significant; and (5) EPA will review all submitted information to decide whether it should be utilized in ecological risk assessment.
In the Federal Register notice, OPP lists five specific areas pertaining to the interim risk assessment process described in the document on which it is requesting comment:
When the National Research Council (NRC) evaluated the importance of toxicological interactions between pesticide active ingredients in 2013, the NRC concluded that such interactions are rare, but that EPA should nonetheless consider such interactions when the best available scientific evidence supports such an evaluation. In the current Federal Register notice, EPA makes it clear that it is uncertain concerning the utility for risk assessment of the information used by manufacturers to support synergistic effects claims in pesticide patents. According to EPA, 24 applicants for new registrations have submitted patent data to date, but only three of these submissions contained information that indicated a need for further testing and no submission ultimately led to any adjustment of the ecological risk assessment. At this juncture, EPA will continue collecting patent data that may be pertinent to GTA effects, but when it has sufficient experience upon to base a general policy it may either continue or improve this process or discontinue it after explaining why.
When EPA requested that the reviewing court vacate and remand the registration EPA had granted for Enlist Duo, the parties seeking judicial review located data in the patent applications that EPA had not previously seen or reviewed and that EPA believed could possibly be pertinent to potential adverse effects on non-target plants. EPA concluded that it should revisit the decision based on the additional data. Although EPA decided to request vacatur and remand, the applicant Dow AgroSciences had arguably followed all of the procedures then in place, because FIFRA Section 3(c)(5) allows EPA to waive data requirements pertaining to efficacy, and EPA typically registers pesticide product that are not intended to protect public health without any independent evaluation of efficacy data. Nevertheless, in general EPA may choose to evaluate pesticidal efficacy data; such circumstances in the past often involved cases where EPA was required to consider whether pesticide benefits are sufficient to outweigh identified risks. In the Enlist case, EPA determined that it should do so where potential synergy in pesticidal efficacy is pertinent to evaluating ecological effects on non-target species.
What EPA must decide now is how often efficacy data that has been deemed adequate by the Patent and Trademark Office to support a patent for a new pesticide mixture will have any material significance in the context of ecological risk assessment. Before EPA makes a determination whether or not patent data has sufficient pertinence to continue requiring routine collection and evaluation of such data, EPA has decided it is prudent to afford all stakeholders an opportunity to comment on whether EPA has been asking the right questions.
All comments on the draft document must be submitted no later than October 24, 2019.
On September 4, 2019, the U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs’ Environmental Fate and Effects Division (EFED) announced that the next Environmental Modeling Public Meeting (EMPM) will be held on October 16, 2019. The EMPM is a semi-annual public forum for EPA, pesticide registrants, and other stakeholders to discuss current issues related to modeling pesticide fate, transport, and exposure for risk assessments in a regulatory context.
In a press release to the public, EPA indicates that the topics covered at the October meeting will include sources of usage data (relating to the actual application of pesticides, in terms of the quantity applied or units treated); spatial applications of usage data; model parameterization; extrapolation of usage data to fill in gaps; temporal variability of usage; and updates on ongoing topics. Presentations concerning the incorporation of pesticide usage data into environmental exposure and ecological risk assessments will also be included.
Registration is required. Requests to participate in the meeting must be received on or before September 23, 2019, as noted in the Federal Register notice.
On August 28, 2019, the U.S. Environmental Protection Agency (EPA) released the Frequently Asked Questions (FAQ) web resource for the Series 810 – Product Performance Test Guidelines: Antimicrobial Efficacy Test Guidelines. As of August 28, 2019, efficacy testing should be in compliance with the following Product Performance Test Guidelines published by EPA in February 2018:
The guidelines provide recommendations for the design and execution of laboratory studies to evaluate the effectiveness of antimicrobial pesticides against public health microbial pests. 83 Fed. Reg. 8666. EPA states that these FAQs “provide prompt and transparent guidance to all applicants regarding commonly asked questions concerning the 810 guidelines updated in February 2018.”
With the exception of confirmatory testing (as described under OCSPP guideline 810.2000, Section (B)(7)), all studies initiated on or after August 28, 2019, should be in compliance with the 2018 revised guidelines for testing. The study initiation date is defined under 40 CFR Part 160.3 as the date the protocol is signed by the study director. Studies that were initiated prior to the implementation date but submitted to EPA for review after the implementation date may use either the previous 2012 version of the guidelines or the 2018 revised guidelines, as appropriate. EPA states that it “intends to address confirmatory testing through a separate guidance, which will be made available for public comment prior to finalization.”
The FAQs include general testing questions and questions related to each specific guideline. The appendices to the FAQs include examples of label use-directions for dilutable products, repeat testing guidance with example scenarios, and sample virucidal calculations.
There has been some concern in the regulated community regarding the need for clarification on the guidelines before they became effective. EPA’s new FAQs are intended to provide these clarifications, but the timing of their issuance may be of concern to some. Also of interest is whether additional FAQs will be issued in the future.
On August 26, 2019, the National Institute of Environmental Health Sciences (NIEHS) announced that the results of an NIEHS-funded study show that graphene could provide alternatives to chemicals in insect repellant and protective clothing. The study, “Mosquito Bite Prevention through Graphene Barrier Layers,” was published in the Proceedings of the National Academy of Sciences. According to the abstract, the researchers hypothesized that graphene films may provide mosquito bite protection for light, fiber-based fabrics. The researchers investigated the fundamental interactions between graphene-based films and the mosquito species Aedes aegypti through a combination of live mosquito experiments, needle penetration force measurements, and mathematical modeling of mechanical puncture phenomena. The abstract states that “the results show that graphene or graphene oxide nanosheet films in the dry state are highly effective at suppressing mosquito biting behavior on live human skin. Surprisingly, behavioral assays indicate that the primary mechanism is not mechanical puncture resistance, but rather interference with host chemosensing.” The researchers propose that the interference is “a molecular barrier effect that prevents Aedes from detecting skin-associated molecular attractants trapped beneath the graphene films and thus prevents the initiation of biting behavior.” According to the abstract, placing water or human sweat on the external film surface circumvents the molecular barrier effect. In this scenario, the abstract states, “pristine graphene films continue to protect through puncture resistance -- a mechanical barrier effect -- while graphene oxide films absorb the water and convert to mechanically soft hydrogels that become nonprotective.”