Nonreactive (adjective)

1. Not tending to react or respond.
2. Not chemically reactive.

Origin:

From non- + reactive, formed in the mid 19th century.

Examples:

1. The patient was administered a nonreactive substance as part of a medical trial.
2. The nonreactive gas was used to fill the balloons.
3. The child had a nonreactive personality, and was unresponsive to any kind of stimuli.
4. The nonreactive material was used to insulate the wires from heat.
5. The nonreactive coating on the metal prevented it from corroding.