Methyl nonyl ketone
2-Undecanone
2-Undecanone (methyl nonyl ketone) is a biochemical repellent active derived from wild tomato plants (Lycopersicon hirsutum), where it serves as a natural defense against insects. It also occurs naturally in bananas, cloves, ginger, and guava. Registered by the EPA as a biochemical pesticide, it was the first new repellent active ingredient approved in over 25 years and is used in DEET-free formulas against mosquitoes and ticks.
The evidence
- Efficacy of the new repellent BioUD against three species of Ixodid ticks2009LabWell-supported evidence
Laboratory choice-test bioassays of BioUD (7.75% 2-undecanone) versus DEET for repellency against the ticks Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis.
- Novel arthropod repellent, BioUD (2-undecanone), is an efficacious alternative to DEET2008LabWell-supported evidence
Arm-in-cage and field trials comparing 7.75% 2-undecanone (BioUD) against 7-30% DEET for mosquitoes (Aedes aegypti, Aedes albopictus) and ticks.
Regulatory notes
EPA-registered biochemical pesticide active ingredient (CAS 112-12-9). Originally listed via the EPA Substance Registry Services (SRS) export; classified as botanical based on its plant-derived origin (wild tomato). Not on the minimum-risk 25(b) exemption list — products using it require EPA registration.