As stated in USEPA’s PR Notice 2007-3, when the Agency determines that the AHETF data offer more accurate estimates of handler exposure than other available data (including PHED), it will rely on the AHETF data to conduct its risk assessments.
To date, the EPA has determined that AHETF data for the following five use scenarios represent the best available data and are using these data in their risk assessments.
Open pour mixing/loading liquids
Open pour mixing/loading dry flowables
Open cab groundboom applications of liquids
Open cab airblast applications
Closed cab airblast applications
Closed cockpit aerial applications