Automated spray can aerosol exposure system developed for inhalation studies involving products containing titanium dioxide nanoparticles.
McKinney-W; Jackson-M; Frazer-D
Toxicologist 2012 Mar; 126(Suppl 1):276
Inhalation exposure systems are necessary tools for determining the dose response relationships of inhaled toxicants under a variety of exposure conditions. An inhalation exposure system was designed and assembled that could house up to 12 rats and deliver respirable aerosols that were representative of those formed while using a pressurized spray can to their breathing space. A custom generator and support software were developed which could automatically keep the spray can's contents mixed and could precisely time the on / off cycle of the spray to achieve desired exposure levels. The inhalation exposure system also utilized a combination of air flow controllers, particle monitors, data acquisition devices, and custom software with automatic feedback control to achieve constant and repeatable exposure chamber temperature, relative humidity, pressure, and aerosol mass concentration. The automatic control algorithm was capable of delivering median aerosol concentrations to within + / - 0.2 mg/m3 of a user selected target value, ranging from 0.5 to 4 mg/m3, for inhalation exposures lasting 2 to 4 hours. The system was capable of reaching 95% of the target value in less than 8 minutes during the start up phase of an inhalation exposure. Particle distribution and morphology of the spray aerosol delivered to the exposure chamber were measured to verify that a fully dispersed and respirable aerosol was being delivered to the animals' breathing space. This exposure system provides a highly automated tool for exposing small laboratory animals to precise concentrations of aerosols produced by spray can products.
Nanotechnology; Health-hazards; Inhalants; Inhalation-studies; Exposure-methods; Exposure-assessment; Dose-response; Exposure-chambers; Laboratory-animals; Laboratory-equipment; Laboratory-testing; Aerosol-generators; Aerosols; Breathing-zone; Spraying-equipment; Sprays; Exposure-levels; Air-flow; Air-monitoring; Computer-models; Computer-software; Monitoring-systems; Control-systems; Controlled-environment; Mathematical-models; Particle-aerodynamics
The Toxicologist. Society of Toxicology 51st Annual Meeting and ToxExpo, March 11-15, 2012, San Francisco, California