Effects of a light coat, long hair, baseball cap, welder's helmet and light face shield on exposure to an anthropometrical manikin 'working' at an enclosing hood in a wind tunnel

Freon-134a concentrations were measured on an anthropometrically correct, clothed, heated, breathing manikin holding a contaminant source in its hands at waist height while standing at a small enclosing hood's face. The manikin and the enclosing hood were placed so that the enclosing hood was perpendicular to the flow of air through the wind tunnel. The samples were taken at the mouth (Cmouth), the nose (Cnose), outside the wind tunnel ambient left & right (Cambient), downstream of the wind tunnel (Cdownstream), and from the exhaust duct (C duct). All locations were sampled at the same time for approximately 20 minutes by drawing sampled air at 0.15 lpm into5 liter SKC Tedlar RTM sampling bags. Samples were analyzed by a Gasmet(TM) (Helsinki, Finland) Model DX4015 fourier transform infrared (FT-IR) gas analyzer to determine concentrations.;The research was done to investigate the effects of interventions on "exposures" to the anthropometrical manikin (i.e., Cmouth and Cnose). Test conditions included every combination of the two hood face velocities: Vface= 100 and 220 ft/min, two cross-draft velocities: Vcross= 14 and 63 ft/min, and six intervention conditions: Normal (no intervention), Light Coat, Basketball Cap, Long Hair, Light Face Shield, and Welder's Helmet.;The results showed that Vface, Vcross and different interventions had statistically significant effects (p< 0.01) on the concentrations at Cmouth. Light Coat, Basketball Cap, and most other interventions failed to consistently reduce exposures and often exacerbated them. However, the Light Face Shield and Welder's Helmet reduced exposures to nearly zero for all levels of Vface and Vcross. The lowest concentrations for each intervention were found when Vface= 220 fpm and Vcross= 14 fpm.