Sensory irritation caused by two organic solvents-short-time single application and repeated occlusive test in stingers and non-stingers.

Neurosensory irritation is a subjective phenomenon induced by a number of chemicals. Objectives. To investigate the sensory irritation induced by two organic solvents - n-octane and cumene - between two groups of volunteers, stingers and non-stingers, identified as such according to the results of a lactic acid stinging test (LAST). The immediate effects of the solvents were directly compared in a single simultaneous application test. The reaction intensities over time were studied in a repetitive irritation test over 4 days. The volunteers graded the reaction intensities by the use of a labelled magnitude scale. Cumene induced significantly stronger sensory irritation than octane in both the single and the repeated applications. Both substances induced less subjective irritation the more times the volunteers were exposed. The decline with time for cumene was statistically significant for the non-stingers but not for the stingers. However, no significant differences regarding the reaction intensities were detected in the direct comparisons of stingers and non-stingers. CONCLUSIONS. Further studies with larger sample sizes are needed to investigate a potential connection between the responsiveness to the sensory irritation caused by lipophilic irritants and lactic acid.