The extreme toxicity of cantharidin makes any use as an aphrodisiac highly dangerous.

Many species are characterised by the extreme toxicity of the sap.

Due to their extreme toxicity, keeping these species is strictly recommendable to very experienced and/or professionally trained people.

There has long been concern about the extreme toxicity of the bright red berries and their seeds on yew bushes.

Despite the extreme toxicity of the tropanes, they are useful drugs when administered in extremely small dosages.

Potassium cyanide or other cyanide compounds are also used, but only by experts due to its extreme toxicity.

At the time, dioxin was hailed as "the most toxic chemical synthesized by man," based on its extreme toxicity in guinea pigs.

You can see how its extreme toxicity makes it inappropriate for commercial use.

Mercury is a heavy metal with extreme toxicity, the ability to biomagnify, and long range atmospheric transport of its gaseous form.