Portrait Larry Sheets

Knowing the Risks

When Larry Sheets chose his senior research project in high school, he began his lifelong focus on toxicology. Today, Dr. Sheets enjoys collaborating with scientists in academia and the agricultural industry to reach a common goal: ensuring the safety of crop protection products.

A wonderful aspect about toxicology and science is that it allows people to come together and talk about scientific facts in a non-confrontational way. We all work toward a common goal.

I was interested in toxicology before I understood that the field existed. My career in science basically started in high school. When I was a seventeen-year-old high school senior, I came up with the idea and designed a research project to look at the effects of birth control pills on the reproductive system of mice. An ambitious project, to say the least, but I learned a lot. Later, for my PhD thesis, I entered the highly-specialized area of neurotoxicology, which involves the examination of a chemical’s effects on the nervous system.

In toxicology, we focus on two questions. We ask if a chemical causes harm at any exposure level and what the exposure might be in real life. We must consider all kinds of exposure: the residue on food from crop protection products, the chemicals that might cling to our shoes or clothing after they’ve been used in the yard, and the exposure from contact with the floor after applications of pest control products. Because exposure can’t be exactly predicted, we establish a very wide margin of safety for the use of our products. It’s a basic principle of toxicology: it is the dose that matters most. That’s also true for crop protection products.

Larry Sheets

Specializing in Safety

One of my specialties has been developmental neurotoxicity, which focuses on the effects of chemicals on the developing brain. Brain cells in a fetus are growing and moving into position, and forming new connections. We have to make sure that the exposure to chemicals doesn’t disrupt these processes.

To work in this field, collaboration is required. A wonderful aspect of toxicology and science in general is that it allows people to come together and talk about scientific facts in a non-confrontational way. For a recent comprehensive review article about the developmental neurotoxicity of neonicotinoid insecticides, we gathered data from numerous sources in industry and academia. We scientists gladly pool our resources to ensure the safety of crop protection products.

Making life easier for farmers is important. It means a lot to me that I’m contributing to this cause by reliably evaluating crop protection products for safety.

Supporting Farming, Enjoying Nature

I’m a big believer in advancing modern agriculture. I grew up on a dairy farm with 300 head of cattle. At the time, it was a state-of-the-art operation with the latest milking equipment. I had to do chores every morning before going to school, and we never took any vacations. These early experiences made me understand that it’s important to make life easier for farmers. It means a lot to me that I’m contributing to this cause by reliably evaluating crop protection products for their safety.

In my free time, I still like to be close to the land. We live in a suburban community near Research Triangle Park. I enjoy barbecuing, which is basically cooking outside. I take care of our garden, including a pond, palm trees and banana plants. And because our property backs up to a protected watershed, we have an amazing abundance of wildlife I like to watch foxes, raccoons, ducks, woodpeckers and owls. Unlike cows, these animals don’t need constant care. They are there for pure enjoyment.

CV Larry Sheets


Born in Nevada, Missouri, USA


Bachelor of Science, Biology/Chemistry, Missouri State University


Master of Science, Cellular and Molecular Biology, Missouri State University


Ph.D. in Toxicology (honors), The University of Kansas Medical Center

1984 – 1987

Postdoctoral Fellow, US Environmental Protection Agency

1988 – 2001

Toxicology Specialist with promotions to Principal Research Scientist, Bayer CropScience, Stilwell, Kansas, USA

2001 – 2005

Research Fellow, Neurotoxicology, Bayer CropScience, Stilwell, Kansas, USA

2005 – 2007

Director, Neurotoxicology and Rodent Studies, Bayer CropScience, Stilwell, Kansas, USA

2007 – 2009

Head, Experimental Toxicology Laboratory, Bayer CropScience, Stilwell, Kansas, USA


Diplomate, American Board of Toxicology

2009 – 2019

Research Fellow, Regulatory Toxicology/Human Safety, Bayer CropScience; Research Triangle Park, North Carolina, USA

2019 – current

Research Fellow, Regulatory Toxicology/Human Safety, Bayer Crop Science; Chesterfield, Missouri , USA

Selected Publications

Recommendations for harmonization of data collection and analysis of developmental neurotoxicity endpoints in regulatory guideline studies.
Proceedings of workshops presented at Society of Toxicology and joint Teratology Society and Neurobehavioral Teratology Society meetings.
Neurotoxicol Teratol. 2017
Li A, LP Sheets, K Raffaele, V Moser, W Bowers.
Read on PubMed

A critical review of neonicotinoid insecticides for developmental neurotoxicity
Critical Reviews in Toxicology, Volume 46, 2016 - Issue 2
Larry P Sheets, Abby A. Li, Daniel J. Minnema, Richard H. Collier, Moire R. Creek, Richard C. Peffer

In Vitro to In Vivo Extrapolation (IVIVE) for human health risk assessment
Toxicology Letters S07-4
R. Conolly, T. McMullin, R.N. Hines, L.P. Sheets, S.M. Cohen

Developmental Neurotoxicity Study of Dietary Bisphenol A in Sprague-Dawley Rats
Toxicological Sciences (2010) 115 (1): 167-182.
Donald G. Stump, Melissa J. Beck, Ann Radovsky, Robert H. Garman, Lester L. Freshwater, Larry P. Sheets, M. Sue Marty, John M. Waechter, Jr, Stephen S. Dimond, John P. Van Miller, Ronald N. Shiotsuka, Dieter Beyer, Anne H. Chappelle, Steven G. Hentges

Neurobehavioral Assessment: A Survey of Use and Value in Safety Assessment Studies
Toxicological Sciences (2003) 76 (2): 250-261.
Lawrence D. Middaugh, Diana Dow-Edwards, Abby A. Li, J. David Sandler, Jennifer Seed, Larry P. Sheets, Dana L. Shuey, William Slikker, Jr., Walter P. Weisenburger, L. David Wise, Murray R. Selwyn


1995: Bayer Research Award: "The Merging of Mechanistic and Descriptive Investigations with the Standard Guideline Toxicology Studies for the Registration of a New Bayer Pesticide, FOE 5043 (AXIOM)"; Bayer CropScience
2003: Global Recognition Award: “Defense of Tebuconazole: Perinatal exposure to tebuconazole does NOT induce neuropathology in rats”; Bayer CropScience
2010: Outstanding Presentation: “Feasibility of the F1-Extended One-Generation Reproduction Study”; Society of Toxicology, Risk Assessment Specialty Section