Carbonated mixers (like in a rum and soda) can affect intoxication by:

Carbonation, such as the bubbles in soda or sparkling mixers, may speed the absorption of alcohol into the bloodstream in some people, potentially causing a faster rise in BAC compared to a non-carbonated drink with the same alcohol content. While individual effects vary, this is one more reason a server cannot assume a given number of drinks affects everyone the same way. The key practical takeaway is to monitor each customer's actual signs of impairment, recognizing that factors like carbonation, drink strength, and food all influence how quickly alcohol takes effect.