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National Institute for Occupational Safety and Health (NIOSH)

NIOSH Docket Office

Centers for Disease Control and Prevention

Department of Health and Human Services

February 18, 2020

Request for Information on Toxicological and Physicochemical Data of Engineered Nanomaterials To Evaluate in Developing Categorical Occupational Exposure Limits (OELs)[1]

CDC–2019–0111; NIOSH–332

Submitted electronically to https://www.regulations.gov

The Institute for Agriculture and Trade Policy (IATP)[2] appreciates this opportunity to respond to the Request for Information (Request). The major concern of this short letter is how to obtain information from the Environmental Protection Agency (EPA) registrations of nanotechnology enabled pesticide products and related documents that would assist NIOSH in developing OELs for farmworkers and greenhouse workers exposed to Engineered Nanoscale Materials (ENMs) and covered by the EPA’s “Revised Worker Protection Standard for Agricultural Pesticides,” which entered into force in 2019. 

EPA reviews the proprietary data and methodologies of the Agricultural Handler Exposure Task Force (AHETF), a consortium of 28 agricultural chemical companies.[3] EPA has accepted monographs for 11 AHETF pesticide handling scenarios, and these monographs are available on request. NIOSH should request and evaluate these monographs and their underlying data and methodologies to determine whether the methodologies and data collection design are useful for developing categorical OELs for farm workers and greenhouse workers mixing and applying pesticides products with ENMs.  

Additionally, NIOSH should evaluate whether the EPA’s FIFRA Scientific Advisory Panel paper on New Approach Methodologies for Refining Inhalation Risk Assessment for a known respiratory irritant in a registered pesticide product[4] can be applied effectively to determining inhalation OEL for pesticide products incorporating ENMs, particularly if those products come in a powder form that the applier must mix prior to application.

As far as IATP knows, EPA first registered an agricultural pesticide product incorporating ENMs — Dupont’s™ Kocide 3000® — in May 2015.[5] Kocide 3000® is registered for application on a broad range of horticulture plants and organic grains, both in open field and greenhouse conditions. Per the Kocide 3000® label, “use the product only in accordance with its labeling and with the Worker Protection Standard, 40 CFR part 170.” This instruction includes use of Personal Protection Equipment (PPE), with the use of additional equipment for application and exposure in greenhouse environments. The Kocide 3000® label described neither how administrative controls, e.g., the 48-hour Restricted Entry Interval, nor engineering controls, e.g., regarding mixing and application techniques, differ from those for a conventional pesticide. In our view, neither EPA, the Food and Drug Administration nor the U.S. Department of Agriculture should register pesticides with ENMs prior to consulting with NIOSH about any recommended engineering and administrative controls and PPE that has developed for occupational exposure to nanoscale chemicals.

The first peer reviewed study of Kocide 3000® was published three years after its EPA registration.[6] The article begins, “The environmental fate and potential impacts of nanopesticides on agroecosystems under realistic agricultural conditions are poorly understood. As a result, the benefits and risks of these novel formulations compared to the conventional products are currently unclear. Here, we examined the effects of repeated realistic exposures of the Cu (OH)2 nanopesticide, Kocide 3000®, on simulated agricultural pastureland in an outdoor mesocosm experiment over 1 year.” IATP is not aware of any comparable study of the occupational health impacts of repeated exposure to nanoscale copper hydroxide. IATP urges NIOSH to use life cycle assessment modeling to develop OELs for all ENMs in pesticide products.[7]

An internet-based review in 2018 of scientific literature on nanopesticides stated that the studies reviewed focused “mainly on advantages of nanopesticides in term of reduction of active ingredient to be used in association with less use of chemical agents to disperse it. Very few are data on comparative toxicity on cells line between nano and traditional formulations, showing mainly a lower toxicity for the first one. No animal or human data are available in literature in our best knowledge that compares toxicity between nano and traditional formulation.”[8] IATP has so far been unable to locate data and studies search published since 2018 that would assist NIOSH in developing categorical OELs for farm workers and greenhouse workers repeated exposed to nanoscale pesticide formulations. IATP hopes that NIOSH, through EPA, can obtain proprietary AHETF data and data collection design to assist NIOSH in developing OELs for repeated inhalation and dermal exposures in realistic agriculture field and greenhouse conditions.

For those pesticide active ingredient modes of action on plants that are well understood, such as that of copper hydroxide, IATP expects regrettably that EPA likely will register their nanoscale formulations without consulting NIOSH about recommended controls to be described in the product labeling and use instructions. If that is the case, challenges for NIOSH to determine categorial OELs for nanomaterials in pesticide products would include:

• Whether repeated exposures of farmworkers and greenhouse workers to the enhanced bio-availability and bio-durability of the nanoscale pesticide formulations require NIOSH to develop categorical OELs for inhalation and dermal exposure for active and adjuvant ingredients in the formulations;
• Whether new categorical OELs indicate that NIOSH work with EPA to develop PPE that would reduce farmworker and greenhouse worker exposure to nanoscale pesticide products. NIOSH has historically regarded PPE as the least preferable occupational health and safety control.[9] However, at least in open field applications, engineering and administrative controls to reduce farm worker exposure may be impracticable or ineffective. Kocide 3000®’s label is about 19 pages. How many workers are likely to carry those instructions or a shorter material safety data sheet into the field?
• Whether NIOSH’s cooperative agreement with EPA can be updated to include cooperation specifically on pesticide products with ENMs, preferably cooperative work prior to registration of those products.

IATP hopes that these brief remarks assist NIOSH in developing OELs for pesticide products incorporating ENMs. Thank you for your consideration of this information.

Respectfully,

Steve Suppan, Ph.D.

Senior Policy Analyst

[1] https://www.govinfo.gov/content/pkg/FR-2019-12-17/pdf/2019-27169.pdf

[2] The Institute for Agriculture and Technology is a 501 (c) (3) organization headquartered in Minneapolis, Minnesota with offices in Washington, D.C. and Berlin, Germany. IATP has submitted comments on nanotechnology and nanomaterials to the National Nanotechnology Coordinating Committee, the White House Office of Science and Technology, the Food and Drug Administration and the Environmental Protection Agency. This is our first communication with NIOSH.

[3] https://exposuretf.com/Home/AHETF/tabid/59/Default.aspx

[4] “Evaluation of a Proposed Approach to Refine Inhalation Risk Assessment for Point of Contact Toxicity: A Case Study Using a New Approach Methodology (NAM)” FIFRA Scientific Advisory Panel, Environmental Protection Agency Office of Chemical Safety and Pollution Prevention, August 30, 2018. https://www.regulations.gov/document?D=EPA-HQ-OPP-2018-0517-0002

[5] https://www3.epa.gov/pesticides/chem_search/ppls/091411-00002-20150507.pdf

[6] Marie Simenon et al, Plant and Microbial Reponses to Repeat CU(OH)₂ Exposures in the Agro-Ecosystem,” Frontiers in Microbiology, July 31, 2018. https://www.frontiersin.org/articles/10.3389/fmicb.2018.01769/full

[7] E.g. G. Kijko et al, Impact of Occupational Exposure to Chemicals in Life Cycle Assessment: A Novel Characterization Method Based on Measured Concentrations and Labour Hours,” Environ. Sci. Technol. 2015, 49, 14, 8741-8750. https://pubs.acs.org/doi/abs/10.1021/acs.est.5b00078

[8] F. Larese Filon, “Nanopesticides entering the market: new risks from ancient chemicals? The role of the skin route,” Occupational and Environmental Medicine, Vol. 75:2., 2018. Abstract. https://oem.bmj.com/content/75/Suppl_2/A470.3

[9] https://www.cdc.gov/niosh/topics/hierarchy/default.html