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.

By Lynn L. Bergeson and Carla N. Hutton

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.”


 

By Lisa M. Campbell, Lara A. Hall, and Margaret R. Graham

On May 8, 2016, the U.S. Environmental Protection Agency (EPA) announced its invitation for public input regarding the “Strategic Roadmap:  New Approaches to Evaluate the Safety of Chemicals and Medical Products” (Roadmap), the development of which was coordinated by the National Toxicology Program’s (NTP) Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM).  ICCVAM states that the vision of the Roadmap is to “establish new approaches for evaluating the safety of chemicals and medical products in the United States that will increase confidence in alternative methods and improve their relevance to human health outcomes while maximizing efficiency and maintaining a commitment to replace, reduce, and refine animal use.”  ICCVAM’s Roadmap effort was introduced in March 2016.  A detailed presentation on the development of the Roadmap is available here.

ICCVAM, a permanent committee of the National Institute of Environmental Health Sciences (NIEHS) under the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), is composed of representatives from 16 U.S. federal regulatory and research agencies that require, use, generate, or disseminate toxicological and safety testing information. As a participating member of ICCVAM, EPA states that its role is to “encourage the development and use of alternatives to animal test methods, ensure that new methods are valid, review test method recommendations, and as appropriate, adopt these alternatives in our own regulatory programs.” 

Further information on the Roadmap is available on the NTP website.  Comments can be submitted by e-mail to .(JavaScript must be enabled to view this email address) by August 31, 2017.

There are also three upcoming public meetings that will provide additional opportunities to comment on topics relevant to this effort:

  1. ICCVAM Public Forum:  May 23, 2017, National Institutes of Health (NIH), Bethesda, Maryland;
  2. NTP Board of Scientific Counselors meeting: June 29, 2017, NIEHS, Research Triangle Park, North Carolina; and
  3. Scientific Advisory Committee on Alternative Toxicological Methods meeting: September 18-19, 2017, NIH, Bethesda, Maryland.

As ICCVAM’s commitment to replace, reduce, and refine animal use continues to draw public comment and gain support, there is an increasing need to demonstrate the utility and harmonization of predictive approaches in toxicology testing with the conventional safety evaluation of chemicals and medical products.  Bergeson & Campbell, P.C. (B&C®) continues to monitor the development, validation, and implementation of alternative in vitro and in silico test methods, high throughput screening assays, and computational models as they are integrated into global regulatory frameworks.