Which chemical substance should never be mixed with ammonia?

Bleach should never be mixed with ammonia because the combination produces toxic chloramine gases. These gases can cause respiratory issues, throat irritation, and other serious health risks when inhaled. The chemical reaction between ammonia and bleach generates a highly hazardous environment, as these gases can lead to suffocation in poorly ventilated areas.

In contrast, vinegar, soap, and alcohol do not create the same dangerous gases when mixed with ammonia, even though mixing any cleaning agents should generally be approached cautiously to avoid unintended reactions.