Breathalyzer vs Blood Test in DUI Cases

Breathalyzers and blood tests are intended to measure the level of alcohol in a driver’s blood when he or she pulled over or arrested for drunk driving. The issue, whether the driver's blood alcohol content is above or below the legal limit, is central to most DUI cases. The legal limit in the U.S. is .08 percent; however, lower limits may apply to underage drivers and other special circumstances.

What is Blood Alcohol Content?

Blood alcohol content is determined by measuring the weight of alcohol in a particular amount of blood, which is relayed as a percentage. The legal limits are standard across the country have been set based on analysis of the amount of alcohol in the blood that impairs driving. However, some states also have additional penalties for drivers found with a BAC below .08.

To discuss the implications of blood alcohol content, and Breathalyzer tests and blood tests, you may want to contact a DUI attorney. For a free case evaluation with a local DUI attorney, fill out our free form below:

The Breathalyzer Test

The breathalyzer is a common tool used to determine a person's BAC (blood alcohol content). These tests creates an estimate of the amount of alcohol in the blood based on measuring a driver's breath.

A breath test is presumptive evidence in most states, meaning that there isn’t the burden of proof on the state. The defendant has to disprove such presumptive evidence. In most instances, when a breath test measures blood alcohol content as being above .08 percent, the court treats this as presumptive evidence that the driver in question is under the influence of drugs or alcohol.

In many states you are allowed to refuse a breath test, although refusing a test may bring about additional charges and penalties. In some states, if you refuse a breath test you may given a court-ordered blood test.

The Blood Test

A blood test is generally the most reliable way to measure the amount of alcohol in the blood. While it is unlikely, problems with direct testing of the blood might arise if the blood is not preserved correctly, if samples sit around for a long time or if errors occur in the lab testing process.

The laws on blood testing vary by state. In some states, to obtain a blood a judge must first sign off, but in others it is more permissible. There have been cases where a judge and nurse are on hand at a DUI roadblock which allows for blood tests to be taken on the spot of any suspected drunk drivers.

Should You Refuse a Breathalyzer or Blood Test?

There isn’t a set answer to this question. The various factors in your situation can have an impact on the consequences of the decisions that you make. Also, the laws vary from state to state when it comes to the penalties for refusing a blood alcohol content test.

If you do refuse a blood alcohol test, it is likely that your driver’s license will be suspended automatically for some period of time. Again, these penalties vary. In some states, for example, refusing to take a breath test or a Breathalyzer test can lead to an automatic several days in jail.

If you refused a breath test, were forced to take one or were otherwise charged with a DUI, speak with a DUI defense attorney about your rights. Get a free case evaluation with an attorney near you when you complete the free form on this page.

Laws may have changed since our last update. The information on this page is for general, informational purposes only and is not legal advice. Any legal advice will depend on your particular situation.

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