In this case, use a larger bag and fill half-way to allow for expansion. Tedlar bags can be reused a few times if they are evacuated, flushed with clean air or nitrogen, and the background has been verified to be within acceptable levels. Contact SKC for a list of AIHA accredited laboratories that accept samples on a fee basis. Total dust sampling, in the traditional usage, refers to all dust particles that can be effectively collected using a filter cassette. Respirable dust refers to those dust particles small enough in size to get through the protective mechanisms of the nose upper airways and reach the gas exchange region of the lung.
Respriable dust is collected using a cyclone.
Some chemicals have total dust standards and some have both, depending on their potential health effects. Thoracic dust particles are those materials that are hazardous when deposited within the lung airways and the gas-exchange region. The action level is typically one-half the permissible exposure level. When exposures reach or exceed the action level, additional requirements apply, including medical surveillance, air monitoring, etc. Simply put, it is the concentration at which you must take some action.