Why is the Blood Alcohol Concentration Limit Set at .08%

by the DUI attorneys at Ariano & Reppucci, PLLC

In Arizona, you can be charged for Driving Under the Influence (DUI) or Driving While Intoxicated (DWI) if you have a blood alcohol concentration (BAC) of 0.08% and you are in actual physical control of a vehicle. Certain agencies have recommended that the BAC be changed, but for the most part most states have agreed on one thing: a BAC of 0.08% for those who are 21 and older when in actual physical control of a vehicle can spell trouble.

Who sets the BAC limit?

Each state has its own specific laws and BAC levels to go with its DUI laws. Arizona has a “per se” BAC limit of 0.08% and a mandatory jail sentence.1 This means that having a BAC of 0.08% is illegal in and of itself when you are in actual physical control of a vehicle. The BAC limit for a driver of a commercial vehicle is more strict, as you can be arrested if your BAC is at 0.04%.2 If your BAC is up to a 0.15% then you will be charged with an aggravated DUI.3 Things get even more strict if you are underage and driving under the influence. Arizona has a zero tolerance law for underage DUIs, so the BAC level is a 0.0%.4

Why is the BAC limit 0.08% for those 21 and older?

Your BAC is determined by the weight of alcohol in a certain volume of blood.5 In 1998, President Clinton promoted a national BAC limit because of the amount of alcohol related deaths and injuries on the road.6 According to an article last year, over 70% of drunk driving fatalities occur because of drivers with BACs of 0.15% or more.7 The National Highway Traffic Safety Administration (NHTSA) was in charge of implementing the President’s directive and had sponsored several studies on the effectiveness of the per se laws which set BAC levels at 0.08%.8 Many organizations such as the US Surgeon General and the American Association of Neurological Surgeons also supported this movement.9 The recommendation was met with a lot of criticism, of course, especially from the restaurant business and the American Beverage Institute.

Will the BAC limits ever change?

It is possible, but it looks like if they did the laws could get more strict. Currently, all fifty (50) states in the United States set their BAC limits at 0.08%.10 Yet, last year the National Transportation Safety Bureau (NTSB) recommended lowering the BAC level to 0.05%.11 Some states such as New York already have laws that charge you with driving while ability impaired (DWAI) when you drive while intoxicated with a BAC between 0.05% and 0.07%, which counts as a traffic infraction instead of a crime.12 Arizona does not have a DWAI law, but it does have aggravated DUI laws just like many other states do.

The reason the NTSB wants a more strict BAC level is because of the annual statistics that show 10,000 people die in alcohol related traffic crashes while 170,000 are injured.13 Yet, the NTSB does not have any lawmaking power and can only recommend what it thinks is best.14 Some studies have shown that important cognitive functions that you use in driving such as hand-eye coordination degrade in many individuals with BACs at around 0.04% or higher.15 Despite NTSB’s recommendation, BAC level requirements still remain at 0.08%. Each state sets its own level of punishment and charges for any levels above and below that amount. If the BAC levels did change in Arizona, they would probably become more strict for commercial drivers as well and the zero tolerance law for underage drivers would most likely remain.

[1] Arizona DUI Laws, dui.findlaw.com, http://dui.findlaw.com/dui-laws-resources/arizona-dui-laws.html (last visited Dec. 22, 2014).

2 Arizona Drunk Driving Laws, drunkdrivinglaws.org, http://www.drunkdrivinglaws.org/arizonadrunkdrivinglaws.html (last visited Dec. 22, 2014).

3 Arizona DUI Laws, supra note 1.

4 Id.

5 How Is Blood Alcohol Concentration Determined?, emsaonline.com, http://www.emsaonline.com/mediacenter/articles/00000480.html (last visited Dec. 22, 2014).

6 Introduction, nhtsa.gov, http://www.nhtsa.gov/people/injury/research/pub/alcohol-laws/08History/1_introduction.htm (last visited Dec. 22, 2014).

7 Statements on NTSB Recommendation to Lower the BAC to .05, ablusa.org, http://ablusa.org/2013/05/statements-on-ntsb-recommendation-to-lower-the-bac-to-05/ (last visited Dec. 22, 2014).

8 Introduction, supra note 6.

9 Id.

10 John Giles, NTSB Recommends lowering blood alcohol level that constitutes drunken driving, usnews.nbcnews.com (May 14, 2013 5:01 PM), http://usnews.nbcnews.com/_news/2013/05/14/18250824-ntsb-recommends-lowering-blood-alcohol-level-that-constitutes-drunken-driving.

11 Id.

12 Mark Siesel, NTSB Recommends Reducing Intoxication Limit to 0.05%, newyorkdwilawyerblog.com (May 15, 2013), http://www.newyorkdwilawyerblog.com/2013/05/ntsb_recommends_reducing_intox.html.

13 Id.

14 Id.

15 Blood Alcohol Concentration (BAC), hsrc.unc.edu, http://www.hsrc.unc.edu/safety_info/alcohol/blood_alcohol_concentration.cfm (last visited Dec. 22, 2014).