Acute effects of exposure to vapours of standard and dearomatized white spirits in humans. 1. Dose-finding study.

A move from 'standard' white spirit (stdWS, 15-20% aromatics) to low-aromatic or dearomatized white spirit (deWS) has been seen, as the latter are considered to carry a smaller risk of health effects. However, data on health risks of deWS on humans are sparse. The aim of this dose-finding study was to identify thresholds of irritation and central nervous system (CNS) effects of the two types of white spirit, as a basis for more detailed studies. Four female and four male healthy volunteers rated symptoms related to irritation, smell and CNS effects on a 0-100 mm visual analogue scale while exposed to increasing levels of deWS or stdWS in eight 10 min steps from 0.5 to 600 mg m(-3). Combined ratings of questions related to irritation revealed statistically significant increases compared with pre-exposure ratings at 50 mg m(-3) and higher exposures. The ratings increased in a dose-dependent fashion, the medians reaching 'somewhat' for stdWS and 'hardly at all' for deWS. Higher ratings of irritation were found during exposure to stdWS compared with deWS, reaching significance only at 500 mg m(-3). The combined ratings of CNS effects reached 'hardly at all', and were significantly increased only for stdWS at 500 and 600 mg m(-3).