A new method using a health index (HI) to screen low level toxic organic substances in consumer products

To ensure selection of appropriate materials for industrial use in terms of toxicity, a procedure to estimate a health index (HI) that can be used for prioritizing less hazardous components of consumer products is described. The HI is based on the occupational exposure limits (OELs) of organic substances that compose the products. To calculate the HI of a product, it is often necessary to predict OEL values for the substances for which an OEL value has not yet been promulgated. We developed a method to estimate the OEL values from median lethal dose (LD50) data of rodent. A good correlation between known OEL values and the LD50 data was obtained by a multivariate regression analysis by introducing organic compensation coefficients, which were caluculated as 10 to the Bth power where B is the regression coefficient of dummy variables denoting the characteristics of the organic compounds such as functional groups, molecular structures, and so on. We believe that the use of the present method should be limited to predicting unknown OEL values for the HI and used for material prioritization. It should not be extended to determinations of regulatory OELs.