In an effort to effectively evaluate the workplace for synthetic (organic) fibers, an air sampling protocol is being developed. The purpose of this discussion is to review the challenges of airborne sampling (total dust and respirable fibers) for synthetic organic fibers and to propose an airborne sampling method. Among the challenges to evaluate synthetic respirable fibers; 1) they are more prone to electrostatic charge than inorganic fibers and hence more difficult to get even distribution across a filter, 2) they are difficult to generate in consistent concentrations for method validation, 3) filter overloading can be a problem, 4) there are several counting techniques which can be utilized, 5) they are less dense than inorganic fibers, and 6) the root cause of potential health effects resulting from exposure has not been identified. There is no regulatory or guideline exposure limit (except as a nuisance dust - not other classified) for synthetic organic fibers. To address these challenges, a laboratory was commissioned to consistently generate known concentrations of respirable fibers of p-aramid and cellulose, using three collection and three counting techniques. Based on their preliminary results for fiber counting, the method selected for sampling respirable fibers is a modified NIOSH 7400 and is currently being field validated. To evaluate the workplace in which synthetic organic fibers are manufactured or processed, respirable fiber and total dust samples are being collected. The sampling is to include job task and full shift exposures. Statistical packages will be used to determine if the results are statistically valid and to determine exposure characterizations for each higher potential operation.