What type of water may never be used to mix chemicals?

Chlorinated water is not suitable for mixing chemicals due to the potential for chemical reactions that can occur when chlorine is present. The chlorine can react with various compounds, leading to the formation of hazardous byproducts, which can compromise the integrity of the chemical mixture and pose safety risks. Additionally, the presence of chlorine in the water can affect the effectiveness of certain chemicals, especially in applications that require high purity or specific chemical compositions.

In contrast, raw water, product water, and brackish water may have their own limitations based on purity and contamination levels but do not inherently pose the same risk of adverse chemical reactions that chlorinated water does. Thus, using chlorinated water for mixing chemicals is not advisable due to these concerns surrounding chemical interactions and safety.