Being stopped for suspicion of driving under the influence (DUI) is a stressful situation. If law enforcement asks you to submit to a chemical test—either a blood or breath test—you may wonder which option is better. This decision can have legal and practical consequences, so it’s important to understand your rights and the implications of each test.
The Purpose of DUI Chemical Tests
Blood and breath tests are used to measure your blood alcohol concentration (BAC). In California, a BAC of 0.05% or higher is considered evidence of intoxication. Blood tests can also determine the type and amount of drugs in the system as well as alcohol levels. While both tests serve the same purpose, the methods and results can vary.
Breath Tests: The Basics
Breath tests, commonly administered using devices like a Breathalyzer, it gives your BAC based on the alcohol content in your breath at the time of the test. There are two types of breath tests, the field breath test with a portable PAS (preliminary alcohol screening) device and the official breath test with a larger machine, usually at the station or jail, that prints out the result at the time of test. These tests are widely used because they are:
- Quick: Results are available immediately.
- Non-invasive: The test involves blowing into a device, making it less intrusive than a blood draw.
- Convenient: Law enforcement can administer breath tests on-site, such as during a traffic stop or at a DUI checkpoint.
- No Drug Detection: Breath tests cannot detect drugs other than alcohol.
However, breath tests have limitations:
- Accuracy Issues: Generally are accurate – but factors like calibration errors, machine assumptions, certain medical conditions, or operator error can affect results.
- The Breath sample is not available for re-testing
Blood Tests: The Basics
Blood tests measure the exact amount of alcohol or drugs in your bloodstream at the time of the test. These tests are typically administered at by a law enforcement phlebotomist at the jail or dispatched to a hospital if injured. Advantages of blood tests include:
- Higher Accuracy: Blood tests provide a precise measurement of BAC.
- Blood tests delay testing, allowing for some burn off of alcohol.
- Blood is available for retesting while breath is not.
On the downside, blood tests are:
- Invasive: The process involves drawing blood with a needle, which some people may find uncomfortable.
- Time-Consuming: Testing usually delays the test because the phlebotomist may not be readily available. Blood Results are not immediate and require lab analysis which can take a several weeks after arrest.
- Drug Detection: Unlike breath tests, blood tests can detect the presence and amount of drugs, including prescription medications and illegal substances, in your system that may also impair your ability to drive.
LEGAL CONSIDERATIONS
In California, refusing a the official Breath or Blood test after being lawfully arrested for DUI can result in additional penalties. You do not have a right to talk with an attorney before deciding which test to take. The field PAS breath test is not mandatory unless you are under 21 years of age or are on DUI/Wet Reckless probation. These refusal penalties include:
- License suspension for a Refusal is not eligible for restriction and is much longer than the suspension for a failed test.
- Additionally, there can be mandatory additional custody for a Refusal.
If given the choice between a blood or breath test, your decision may depend on the specifics of your situation. For example:
- If You’ve just finished your last drink: Depending on the time of your last drink, a breath test might be preferable before that last drink is fully in your system, since it’s less invasive and provides immediate results. Your alcohol level usually rises 30-45 minutes after the last drink, then burns off overtime to a lower level. Things like empty of full stomach can delay absorption time.
- If You Haven’t Been Drinking But Have Taken Medication or other drugs: If drugs are suspected, then a blood test only may be offered. A breath test won’t detect drugs, so it may be a safer option to avoid complications if you are offered the choice and allowed to take a breath test instead of a blood test, especially if you have taken drugs that may also affect your ability to drive.
- Refusal to take a test, Law enforcement can get a warrant and forcibly draw your blood – so you loose two ways – additional penalties and suspension for a Refusal and they get your blood anyway.
What to Do if Stopped for DUI and offered a Field Breath Test or PAS:
- Stay Calm: Be polite.
- Field Breath PAS tests are optional for a first offense if 21 or older, but mandatory if under 21 or on DUI/WET Reckless probation.
- Field PAS Breath Tests can be fairly accurate but are not the official Blood Alcohol result because the equipment designed and used to show presence of alcohol and is not calibrated by the crime lab. The official larger breath machines which have a printed result or the blood test is required to avoid refusal consequences. These are usually both given at the station or jail after arrest. If for some reason the breath is unavailable then you must take the blood to avoid a refusal.
CONTACT A DUI ATTORNEY ASAP TO UNDERSTAND COURT AND DMV ISSUES
Choosing between a blood or breath test during a DUI stop is a personal decision influenced by your unique circumstances. Understanding the pros and cons of each option can help you make an informed choice. You do not have a right to talk with an attorney before deciding. If you’re facing DUI charges, consulting an experienced DUI attorney after your arrest is important to understand the Court proceedings, possible defenses and the administrative DMV suspension that requires contacting DMV within 10 days of your arrest to delay and challenge.
