Fig. 1

Percent correctly identified by each probe type (soldering iron at high heat 350 ^oC, soldering iron at low heat 150 ^oC or flame-heated needle) for each fiber type according to expected response, with materials expecting to pass the hot needle test in A) synthetics and cellulose acetate in cigarette filters and fail in B) semi-synthetic and natural fibers. The “treated” cigarette filter fibers were digested in 1 M KOH for 72 h. Total % correct equally weights participant scores (i.e. does not account for differences in numbers of fibers tested across individuals)