Is toxicity is a chemical property?

Answer 1

Toxicity is quantitative because it can be measured, after a fashion.

The usual measure of toxicity is the LD50 (or some minor variation on it). This is the amount of the substance (usually specified as a fraction of body weight) required to kill half of a group of experimental animals (usually rats or mice). It's also customary to specify the method of exposure: injection, ingestion, rubbing it on them, or what.

So a given compound might have an LD50 of 1.2 mg/kg in mice (intravenous). This means that giving a 20g mouse an injection containing 24 micrograms of the material in question has a 50/50 chance of killing it. This may carry over (roughly) to other species, or it may not, and injecting 0.084 grams into a 70 kg person could be anywhere from almost completely safe to almost certainly lethal, depending on how efficient the human metabolism is compared to mouse metabolism in dealing with that particular chemical. However, at least it's a start.

Answer 2

Yes