What is Nootkatone? A Primer on the New Tool to Defend against Mosquitoes and Ticks

September 03, 2020|4:20 p.m.| ASTHO Staff

Every state and U.S. territory are at risk of vector-borne diseases. This year, dengue cases are on the rise in Puerto Rico. Florida has also reported locally transmitted cases of dengue this year. We are already seeing record numbers of cases in the Americas and the Caribbean, with 2019 seeing the highest number of cases on record in the Americas. Numbers of tickborne diseases continue to climb this summer, with Lyme disease continuing to be the most reported vector-borne disease in the U.S.

Those who want to limit their exposure to synthetic chemicals and pesticides may be hesitant to use repellents—along with those with sensitive skin and allergies. In order to address vector-borne disease threats, we need tools that people accept and are willing to use to protect themselves from bites. Because mosquitoes are increasingly resistant to insecticides, there is a demand for publicly supported insecticide options.

The Environmental Protection Agency (EPA) recently announced approval of the CDC-discovered and CDC-developed compound nootkatone for manufacturing use into insecticides and repellents. The hope is that nootkatone can help address these two needs in vector-borne disease prevention and control.

“Nootkatone represents a new tool to defend against mosquitoes and ticks and risks they pose to the public. Furthermore, because it occurs naturally in grapefruit peel and Alaskan Yellow Cedar trees, people may be more eager to use it,” said Ben Beard, PhD, Deputy Director of CDC’s Division of Vector-Borne Diseases.

Getting this approved by the EPA was a collaborative effort between CDC, Evolva (CDC’s licensed partner), and the Biomedical Advanced Research and Development Authority within the US Department of Health and Human Services. These groups played critical roles in discovery, applied research, and EPA registration of this compound. Now that it has been approved, it paves the way for manufacturers to develop nootkatone-based products for consumers to buy.

But what exactly nootkatone, and how is it used? Find some answers to FAQs about nootkatone below.

What is nootkatone made of, and what does it do?
Nootkatone is a compound found in minute quantities in Alaska yellow cedar trees and grapefruit skin. It can repel and kill ticks and insects, including mosquitoes.

Where do I recognize this scent from?

  • It has the characteristic smell and taste of grapefruit.
  • It has been widely used in the fragrance industry to make perfumes and colognes since it lasts on skin and clothing for several hours. It is also used in citrus-smelling shampoos, conditioners, and lotions.
  • Widely used in the food industry to flavor foods.
  • It takes several tons of grapefruit to produce just 1 kg (2.2 lbs.) of nootkatone. Evolva’s process allows nootkatone to be made in large amounts in a highly reproducible, contaminant-free, sustainable, and affordable manner.
  • Once rare and expensive, nootkatone is now being produced at a low cost.

What does it mean that nootkatone is an "active ingredient"?
Active ingredients are what make end-use products effective. For example, DEET is an active ingredient that is used in many brand name insect repellents.

How will nootkatone be used?
As an insect repellent applied to skin in low-volume and ultra-low volume sprays for public health use. It will not be used for agricultural use.

What makes nootkatone unique?

  • Nootkatone appears to kill biting pests in a different way from other insecticides, including pyrethroids, organophosphates, carbamates, and cyclodienes registered by the EPA.
  • Insecticides made with nootkatone can help in the fight against mosquitoes that have become resistant to current ones.

Courtney Youngbar is a senior analyst of environmental health at ASTHO
Kathy Dolan is the director of environmental health at ASTHO