Alcohol concentration refers to the number of grams of alcohol per how many liters of breath?

Alcohol concentration is specifically defined in terms of the quantity of alcohol present in a given volume of breath. The standard measurement used in law enforcement and breath alcohol testing is based on the ratio of grams of alcohol per 210 liters of breath. This measurement is critical because it provides a standardized way to assess a person's blood alcohol concentration (BAC) from breath samples.

The choice of 210 liters is derived from studies correlating breath and blood alcohol levels, which show that, on average, 210 liters of breath contain approximately the same amount of alcohol as 1 milliliter of blood. This standardization allows for consistent and reliable assessments that are crucial in legal and medical contexts. Other options do not align with this established standard for breath testing.