Toxicity (noun)

1. The state or quality of being toxic, especially of being poisonous to living things.
2. The degree to which something is toxic or harmful.

Origin:

Late 16th century, from french toxicite or from latin toxicum, from greek toxikon 'poison for arrows,' from toxon 'bow, poison', from tochein 'to hit'.

Examples:

1. The toxicity of this chemical is high, therefore we should handle it with care.
2. The levels of toxicity in this lake are a cause for concern.
3. The toxicity of this waste will have to be reduced before it can be disposed of safely.
4. The toxicity of this plant has not yet been determined.
5. The toxicity of this food has been disputed among experts.