Databases compited by IQF The International QSAR Foundation has a special effort to compile high quality databases from the literature for use in QSAR modelling. Most organizations are aware of very large or even immense databases, the prospects for even larger databases from high throughput technology grow every year. Compiling another high quality database does not sound like a unique or particularly useful activity. However, if useful at all in modelling, a very small fraction of these data huge databases are useful in understanding why a chemical behaved the way in did in a particular test. They are recorded phenomena that reflect little about the exposure variables that influence the phenomenon. The lack of mechanistic QSAR models for most hazard assessment endpoints is testimony to the non-systematic nature of large databases. In cases where tests measuring thermodynamic variation are mixed with those that measure kinetic variation, the scant useful information is lost unless the experimenter was careful to record such information and the data compilations accurately reflect that record. All data and models are distributed to our partners and on the Internet. Priorities include data for inhalation toxicity, sensory irritation, glutathione reactivity, and butylamine reactivity. Information about databases donated to IQF ot developed in collaboration with IQF partners will be available soon.