Matt Call presented a seminar on Toxic Dust Exposure Monitoring to the Snake River Chapter of the ASSE in Boise, Idaho on February 21, 2012. Mr Call reported that the intent of ACGIH is is to replace “total particulate” TLVs with inhalable, thoracic or respirable particulate mass TLVs. He concluded that we may be underestimating exposures to aerosols and that there are more accurate sampling methods for measuring particulate matter in air than total dust. Examples of more modern approaches would be to use the IOM, or the “Button” size selective dust sampling devices.