The police inserted an undercover officer called Amanda as the receptionist and secretly replaced the fertilizer with a benign substance.

This metric requires further definition of a benign substance.

They worry that a seemingly benign substance could mutate into a harmful one and spread out of control.

Design materials to breakdown into benign substances by bacterial or other environmentally sound ways.

An additional dozen reports describe how more benign substances were used to mimic the spread of the poisons in other tests.

We who treat young victims of drug abuse realize that marijuana is not a benign substance.

It essentially uses the bacteria found in the soil to break down the trichloroethylene found on the site into benign substances.

Even carbon dioxide, which is itself a rather benign and relatively nontoxic substance, is a deadly danger.

The study noted that seemingly benign substances had turned out to have ugly side effects.

Some tests used benign substances meant to simulate the spread of the toxins.