What Does BAC Stand For?

You’ve probably heard the term Blood Alcohol Content (BAC) without thinking too much about it. Most people don’t need to know more than the general concept to keep themselves out of trouble.

But if you work in a bar or a restaurant that serves alcohol, you have a responsibility to be familiar with the concept of BAC. As an alcohol seller or server, understanding BAC levels can save lives and help you avoid legal trouble.

In this blog, we’ll define BAC and discuss how it affects your customers to help you maintain a responsible and safe drinking environment.

What Is BAC?

BAC, or blood alcohol concentration, is the percentage of alcohol in a person’s blood, also known as alcohol by volume. It’s calculated in grams of alcohol per 100 milliliters of blood.

Blood alcohol content is useful for both legal and medical purposes. From a medical standpoint, being able to determine the amount of alcohol circulating in someone’s blood can help doctors diagnose and treat alcohol poisoning. From a legal standpoint, an objective assessment of someone’s alcohol intoxication levels provides a fair way to enforce laws and policies about alcohol consumption.

What Is the Legal BAC Limit?

It depends on your age.

In 2004, all 50 states agreed to enforce a maximum BAC for drivers of 0.08 based on 30 years of scientific evidence.

This may be changing. In 2018, Utah lowered its legal maximum to 0.05. This resulted in a significant decrease in fatal crashes. Combined with the recommendations of the National Highway Traffic Safety Board Administration (NHTSA) and the National Transportation Safety Board (NTSB), we may eventually see 0.05 as a new national limit in the future.

But those numbers apply to legal drinkers. Since 1998, all 50 states have also had separate BAC limits that apply to people under the age of 21. These laws are often referred to as “zero tolerance,” but only 15 jurisdictions actually set the legal driving limit for those under 21 at 0.00. California and New Jersey put the youth driving BAC at 0.01, while the remaining states set it at 0.02.

How Can You Determine Someone's BAC?

The only foolproof way of determining someone’s BAC is actual BAC measurement. It can be determined by testing blood, urine, saliva, or breath.

Breath tests, measured by “breathalyzers” or breath alcohol concentration (BrAC) devices, are the most popular option due to their convenience on the go.

There are other methods for approximating BAC, like charts that alcohol servers can use to estimate patrons’ intoxication levels. However, due to the complex web of factors that influence BAC levels, these methods can only be used as educated guesses.

Factors That Affect BAC

Your BAC goes up when alcohol is absorbed into the bloodstream in the stomach and small intestine, and it’s reduced through elimination. Some is excreted unchanged by the kidneys, but most is metabolized by the liver. Absorption may change from hour to hour, while elimination happens at a relatively constant rate that varies by individual. Both are influenced by multiple factors, some of which you can see and some of which you can’t.

Alcohol servers need to understand the factors that affect BAC so they can make informed decisions about responsible alcohol service. 

Let’s start by debunking what does NOT affect blood alcohol concentration:

• Having a “high tolerance”
• Consumption of caffeine and other stimulants (including energy drinks as mixers)
• Taking a shower or splashing water on your face
• Popping a breath mint
• Eating food or drinking water after the alcohol is in your bloodstream

All of these things might mask the symptoms of alcohol consumption – you might feel more alert or smell less like you’ve been drinking. You may even “feel more sober.” However, none of this will change your BAC measurement, and your judgment and coordination will remain impaired.

Factors that impact BAC include:

• Amount Consumed. This must take into account both the number of drinks and drink strength. We’ll go over the concept of “standard drinks” below.
• Time. This includes both consumption rate and time since the last drink. Drinking more slowly gives your body time to eliminate what it’s absorbed. Time since your last drink is the only real way to “sober up.”
• Body Size. Due to the relative volume of blood into which the alcohol can be distributed, larger individuals will have a lower BAC from similar consumption.
• Body Composition. Someone with a higher percentage of body fat experiences a more rapid increase in BAC. Someone with a higher volume of water in their body will have a lower BAC for the same amount of alcohol consumed.
• Metabolic Rate. Individuals vary in how quickly their bodies can metabolize alcohol. A higher metabolism means a lower BAC.
• Hormone Levels. Higher testosterone gives you higher levels of an enzyme that breaks down alcohol. Additionally, testosterone impacts body composition (in terms of water and fat) in ways that lead to lower BAC.
• Food Eaten Before/During. When you drink alcohol while food is present in the stomach, it slows the rate of alcohol absorption.
• Drug Interactions. Some prescription and non-prescription drugs will slow alcohol metabolism, leading to a higher BAC.

Differences between men and women in body size, composition, and hormones mean that women often have a higher BAC than men with equal consumption.

You can find BAC calculator apps that can be useful in getting a ballpark for your own blood alcohol content.

What Is a Standard Drink?

Since different types of alcohol have different strengths, the concept of a “standard drink” helps you level the playing field so you can gauge your alcohol consumption.

In the U.S., a standard drink contains 14 grams (0.6 fl oz) of pure alcohol. That means:

• 12 ounces of beer at 5% ABV
• 8 ounces of malt liquor at 7% ABV
• 5 ounces of wine at 12% ABV
• 1.5 ounces of distilled spirits at 40% ABV (also known as 80-proof)

The difficult thing about converting to standard drinks is that individual drinks may have a higher or lower ABV, and the “standard” serving doesn’t always match up with real-world pours.

The Importance of Responsible Alcohol Service

More than half of all states allow bartenders to be held liable for drunk driving and other drinking-related damages. Alcohol servers have a responsibility to watch out for patrons who have already had enough and refuse to overserve. They also have a responsibility to prevent any underage sales.

That’s why bartenders and waitstaff need responsible beverage service training. A good training program ensures they know how to:

• Recognize an intoxicated individual
• Track the number of standard drinks served to patrons
• Understand their legal responsibilities
• Identify underage guests and potential third-party sales to minors
• Strategies for refusing service

Best Practices for Responsible Service

The responsibility for responsible alcohol service doesn’t end with staff – businesses are also responsible and potentially liable.

It’s important to have consistent strategies in place for protecting your business from overserved patrons. Best practices include:

• Establishing a clear protocol for when and how to refuse service to patrons.
• Enforcing consistent alcohol serving sizes to prevent unintentional overconsumption.
• Training all staff members in recognizing the signs of intoxication and the principles of responsible service.
• Creating effective communication systems so that staff are all on the same page regarding a customer’s level of intoxication.
• Implementing safe closing procedures, including last calls, evaluating guests’ sobriety before they leave, and offering alternatives like taxi services when called for. 

Keep Staff Compliant with TIPS Training Passports

Our TIPS courses explore many of the concepts we’ve talked about here but with a focus on skill-building and practical applications. By the time your staff completes TIPS training, they won’t just have theoretical knowledge – they’ll know how to provide responsible alcohol service.

TIPS Passports make it easy to keep employees up to date on quality training that complies with the requirements of local jurisdictions and insurance companies. In addition to bulk pricing, you’ll get access to manager tools for tracking progress, a learning management system with flexible integrations, and dedicated support for onboarding, setup, and management.

Enroll today!