"Repellent" - what is it, definition of the term
«Repellent» is a formulation—chemical, botanical, or physical—intended to discourage attachment or feeding by ectoparasites such as ticks, bugs, lice, and fleas; it releases volatile compounds that disrupt the insects’ sensory receptors, creating an environment they avoid and thereby lowering the risk of bites and infestations.
Detailed information
Insect deterrents designed for ticks, various bugs, lice and fleas function by interfering with the sensory pathways that trigger host‑seeking behavior. Chemical agents mask human odor, create repulsive odors, or irritate the arthropod’s nervous system, preventing attachment and feeding.
Key active substances include:
- DEET (N‑N‑diethyl‑m‑toluamide) – broad‑spectrum efficacy, prolonged duration, widely tested on ticks and biting insects.
- Picaridin (5‑[2‑hydroxyethyl]‑1‑methylpiperidine‑1‑carboxamide) – comparable protection to DEET, lower skin irritation risk.
- IR3535 (Ethyl butylacetylaminopropionate) – effective against mosquitoes and certain ticks, suitable for sensitive skin.
- Permethrin – applied to clothing, creates a contact‑kill zone for lice, fleas and ticks; not intended for direct skin contact.
- Essential‑oil blends (e.g., citronella, lemon eucalyptus, geraniol) – limited duration, useful for short‑term outdoor activities.
Application formats encompass sprays, lotions, wipes, and treated fabrics. Sprays and lotions are applied directly to exposed skin, typically at a concentration of 20‑30 % DEET or 20 % picaridin for optimal protection. Treated garments receive a 0.5 % permethrin coating, providing up to 70 wash cycles of efficacy. Wipes enable targeted treatment of equipment or pet fur, delivering micro‑dose concentrations of essential‑oil extracts.
Safety parameters require adherence to concentration limits established by regulatory agencies. DEET concentrations above 50 % increase the risk of dermatological irritation without proportionate gain in protection time. Permethrin must be applied in well‑ventilated areas; inhalation of aerosolized particles can cause respiratory discomfort. Pediatric use of any formulation should follow age‑specific guidelines, avoiding application to the face and hands of infants under two months.
Effectiveness assessments rely on controlled field trials measuring attachment rates after exposure. Studies show that a 30 % DEET preparation reduces tick attachment by 95 % over six hours, while a 20 % picaridin formulation achieves 90 % reduction against common biting bugs. Resistance monitoring indicates emerging tolerance in certain flea populations to permethrin, prompting incorporation of synergists such as piperonyl‑butoxide in newer formulations. « Integrated pest‑management strategies combine chemical deterrents with environmental controls to sustain long‑term efficacy ».