AN ANALYSIS OF NASAL IRRITATION THRESHOLDS USING A NEW SOLVATION EQUATION

In the present paper we have developed a quantitative structure-activi ty relationship (QSAR) equation for nasal pungency caused by nonreacti ve volatile organic compounds (VOCs), Our QSAR was developed upon prev iously published nasal pungency thresholds in anosmics, i.e,, patients lacking a sense of smell and thus responding only to sensory irritati on evoked by trigeminal nerve stimulation. The reported solvation equa tion, which fits the data with considerable precision, describes senso ry potency in terms of interaction via electron pairs, dipolarity/pola rizability, hydrogen bond acidity and basicity, and hydrophobicity, It correspondingly suggests relevant physicochemical properties of the b iophase where the sensory response is brought about. The equation impl ies that in the range of molecular size where nonreactive VOCs can pro duce any pungency, transport from the air to the biophase strictly det ermines potency. In this respect, the potency of nasal pungency shares characteristics with the ability of VOCs to cause narcosis and anesth esia. (C) 1996 Society of Toxicology