Final answer:
BAC is measured as grams of alcohol per 100 milliliters of blood, and BrAC as grams of alcohol per 210 liters of breath. The legal BAC limit for driving in the US is 0.08%. Factors such as gender and metabolism affect how alcohol is processed and the individual effects on the body.
Step-by-step explanation:
BAC is expressed in terms of grams of alcohol in every 100 milliliters of blood, and BrAC is expressed as grams of alcohol per 210 liters of breath. In the United States, a blood alcohol concentration (BAC) of 0.08% is commonly considered the legal limit for driving under the influence.
Blood alcohol content can be influenced by several factors including age, sex, body weight, and metabolism. The Breathalyzer device is used to assess the ethanol concentration in a person's breath and is an indicator of their blood alcohol level.
Alcohol is metabolized by the liver at a certain rate, with an average male metabolizing at 4.4 x 10^-2 mol L^-1 h^-1. This rate can differ between individuals, and it is noted that women metabolize alcohol more slowly than men. The effects of alcohol on the body can vary widely depending on the individual's BAC.
For example, a BAC of 0.20% typically indicates acute intoxication, while 0.30% can lead to unconsciousness, and 0.50% is potentially fatal.