Utah now officially has the nation’s lowest drunken driving limit.

Sunday at 12:01 a.m., a new law took hold lowering the state’s blood alcohol content (BAC) standard — used to determine when drivers are considered legally drunk — from 0.08 to 0.05 percent.

While the law was passed by the Utah Legislature — and signed by Gov. Gary Herbert — in 2017, its effective date was delayed until Dec. 30, 2018. It’s no coincidence that it’s the day before New Year’s Eve, when many people celebrate with too much liquor and alcohol-related injuries and fatalities increase.

“It’s been a long time coming,” said Rep. Norm Thurston, R-Provo, who sponsored the original legislation. “It’s good to have it take effect so we can have the public safety benefit.”

(Rick Egan | The Salt Lake Tribune) Rep. Norm Thurston talks about Utah's strict new DUI law, which lowers the blood alcohol limit from 0.08 to 0.05, effective Dec. 30. Wednesday, Dec. 26, 2018.

Despite enduring angry telephone calls, emails and negative advertisements, Thurston believes the current law sends the wrong message — that it’s OK to drink and drive as long as drivers are not buzzed. “Impairment begins with the first drink,” he said, "and if you are drinking, don’t drive.”

A member of The Church of Jesus Christ of Latter-day Saints, Thurston has previously insisted that Utah’s predominant faith, a major force in the state’s alcohol policies, did not get involved in the new law because he presented it as a public safety issue.

Even before the move, Utah regularly ranked among states with the fewest DUI fatalities in the nation. Thurston believes the new law will push those numbers even lower. “We are hoping to see small but easily measurable changes moving forward.”

Whether you love or loathe the new law, here are nine things you should know about it:

1. Officers are maintaining the status quo • Officials with the Utah Highway Patrol and other police agencies say the new law won’t change how they enforce DUI laws. They will continue to focus on impairment — signs that someone is not driving safely — rather than blood alcohol levels. In addition, UHP troopers and other officers have spent the past few months getting retrained in field sobriety tests to ensure what they do meets standards.

2. Alcohol limits are personal • Several factors affect BAC, including the number of drinks, age, gender, body weight and the amount of time that has passed since the first drink. One drink, according to the Centers for Disease Control and Prevention, is equal to 1.5 ounces of liquor, 12 ounces of beer or 5 ounces of wine. However, the National Transportation Safety Board, which supports a 0.05 limit and would like to see it implemented nationally, has said numerous studies show impairment starts after one alcoholic drink, and people are noticeably impaired at 0.04 — the BAC limit for commercial truck drivers.

3. Know your rights • In Utah, drivers who are pulled over by police “are not legally obligated" to take a Breathalyzer or a field sobriety test, said Salt Lake City attorney Jason Schatz, who specializes in DUI cases. That changes, however, once a person is arrested. Under Utah’s “implied consent” law, if a driver is arrested by an officer who believes the person has been driving under the influence, the motorist must consent to taking a chemical test to determine blood alcohol content. ”If you are arrested and don’t agree to the tests,” Schatz said, “the penalty can be more severe, 18 to 36 months in most cases.”

4. DUI arrests may not go up • Schatz is not convinced that the law will increase arrests or decrease DUI fatalities, given that the majority of alcohol-related fatalities happen at 0.15 percent BAC or higher. “Responsible drinkers are going to be careful and monitor their consumption. Those are the people that are not going to drive after drinking,” he said. “For the chronic drunk drivers, the repeat offenders, I don’t see that this change in the law will make them do anything different. They are still going to do what they do.”

(Rick Egan | The Salt Lake Tribune) Rep. Norm Thurston talks about the Utah's strict new DUI law, which lowers the blood alcohol limit from 0.08 to 0.05, effective Dec. 30. Wednesday, Dec. 26, 2018.

5. Data will be tracked • The Utah Department of Public Safety will be collecting numbers for alcohol-related injuries and deaths, said Thurston, who is the director of the state Office of Health Care Statistics and a self-described numbers and research guy. “It will take three to five years,” he said, “to observe the full effect of the law.”

6. Other states may join Utah • Thurston, who doesn’t drink alcohol but has said he doesn’t oppose others imbibing, has had conversations with officials in “close to a dozen states” about lowering the BAC limit. Bills have been proposed — but not passed — in Hawaii and Washington, and there is talk in California and New York, as well. “A lot of people are watching,” he said. The NTSB has estimated that a nationwide 0.05 limit could save at least 1,500 lives a year.

7. It’s part of Utah history • In 1983, Utah was the first state to lower its BAC level from 0.10 percent to 0.08, said Thurston, who believes it’s fitting that Utah lead the way again. “It took more than 20 years for all the states to get on board,” he said, noting that he expects the same to happen with 0.05. “States will come on board at their own pace.”

8. There’s a new drinking-responsibly campaign • While they initially opposed the law, restaurants, bars and tourism officials have shifted gears. They have joined forces with law enforcement on a new Enjoy Utah Responsibly awareness campaign that includes billboards, radio ads, social media posts and banners in restaurants. The campaign encourages Utahns to eat and drink, but use public transportation or ride-sharing to get home. There’s even a link on the website for $5 off a Lyft ride.

9. More liquor changes • While Thurston said he does not plan to propose another BAC reduction for Utah, he is working on two other liquor-related issues. Restaurants and bars have asked him to review the state’s dramshop laws, to better determine who is liable when a drunken driver causes injury or death. He also is working with the Utah Sheriffs’ Association to remove a statute that allows law enforcement officers to carry a weapon while intoxicated.

By the way, Thurston wasn’t scheduled to be in Utah when the 0.05 law took effect. He and his wife were to be on a cruise ship in the Caribbean celebrating their anniversary. That’s miles away from the questions and controversies, he said. “I’m happy to move on to other, less-controversial things.”