Students reported higher levels of irritation as compared to their instructors. At 3 sites, the instructors’irritation levels were inversely related to the level of FA detected (high FA exposure = low subject irritation score) (Table 3). Instructor irritation levels at 3 sites diminished as time progressed, while the instructors from sites D and E reported no irritation (0) throughout the study. This was an interesting find, as the instructor at site D had the highest mean personal exposure to FA (1.85±3.09 ppm), while the instructor at site E, who also reported no irritation, was exposed on average at a much lower FA level (0.38±0.21 ppm).