What is another word for unreactive?

Here are some words that can be used as synonyms for "unreactive," depending on the specific context:

General:

* Passive

* Inert

* Sluggish

* Indifferent

* Apathetic

* Unresponsive

* Insensitive

* Phlegmatic

* Stoic

Chemical:

* Stable

* Inactive

* Non-reactive

* Unresponsive

Emotional:

* Detached

* Aloof

* Cold

* Unfeeling

* Impassive

Please provide more context about the situation or the thing you are describing as "unreactive" so I can give you a more specific and accurate synonym.