"Aerosol" - what is it, definition of the term
«Aerosol» denotes a colloidal system in which fine solid particles or liquid droplets are uniformly dispersed in a gaseous medium; particle diameters typically range from a few nanometers to several micrometers, allowing the mixture to remain suspended without rapid settling. Such dispersions may be generated intentionally (e.g., spray cans, medical inhalers) or occur naturally (e.g., volcanic ash, sea‑salt spray). Stability depends on particle size, density contrast, and ambient temperature, which influence gravitational settling and Brownian motion. Applications span atmospheric science, pharmaceuticals, and industrial processes.
Detailed information
Spray particles consist of liquid droplets or solid particles dispersed in a gaseous medium. Their size typically ranges from 0.1 µm to 100 µm, influencing residence time, deposition pattern, and penetration into micro‑environments where ectoparasites such as ticks, insects, lice and fleas may hide.
Particle size distribution determines aerodynamic behavior. Smaller droplets remain suspended longer, enabling diffusion into crevices and fabric fibers, while larger droplets settle quickly, delivering a concentrated dose on exposed surfaces.
Formulation components include active ingredients, solvents, propellants and surfactants. Active agents target nervous or metabolic pathways of the pests; solvents dissolve the agents and adjust viscosity; propellants generate the pressure needed for ejection; surfactants improve spreadability and adherence to substrates.
Key physical properties:
- Density: governs settling velocity and buoyancy.
- Vapor pressure: affects evaporation rate and droplet shrinkage.
- Surface tension: influences droplet formation during atomization.
Application methods vary according to target habitat:
- Direct spray onto host animals for rapid knock‑down of lice and fleas.
- Fogging in enclosed spaces to reach hidden tick refuges.
- Impregnation of fabrics and bedding to provide long‑term protection against insects.
Safety considerations focus on inhalation exposure, skin irritation and environmental persistence. Regulatory limits define permissible concentrations of propellants and active agents, while protective equipment such as respirators and gloves mitigates occupational risk.
Efficacy assessment relies on bioassays measuring mortality rates of the targeted ectoparasites after exposure to defined concentrations of the spray. Data inform optimal dosing regimens that balance rapid pest elimination with minimal adverse effects on non‑target organisms.
Maintenance of effectiveness requires periodic re‑application, especially in high‑traffic areas where particle loss through ventilation or abrasion is significant. Monitoring of resistance development among pest populations guides selection of alternative active ingredients to sustain control performance.