Chemical Testing

Chemical Testing

Michigan Lawyers Handling DUI Charges

Under Michigan law, anybody arrested for a DUI in the state has given implied consent to have a breath or blood test. You may feel disheartened about the outcome of your chemical test. However, you should be aware that the police and the laboratory must follow specific procedures in order for a chemical test to be used as evidence at a DUI trial. It may be possible to fight DUI charges by challenging the chemical testing results. If you are concerned about chemical testing in connection with your DUI charge, you should consult the Michigan DUI lawyers at Michigan Defense Law.

Chemical Testing

Chemical tests are used to determine your blood alcohol concentration if the police suspect that you were operating your car under the influence or operating while visibly impaired. It is illegal to drive or operate a motor vehicle in Michigan with a blood alcohol concentration of more than .08%. For minors, the level is .02%. Different chemical tests may be used to determine blood alcohol concentration. Each of these requires the proper administration and calibration of equipment.

During the roadside investigation, you may be asked to take a preliminary breath test. The purpose of the test is to gather evidence that may substantiate probable cause to arrest you. If you refuse to submit to the preliminary breath test, you can be fined. However, refusal of the preliminary breath test, called a PBT, does not result in loss of your driver’s license.

If you have been lawfully arrested for drunk driving, you will be asked to take the chemical test to which you have given implied consent. Chemical testing may be conducted through a breath, blood, or urine sample. It may be used in both a criminal charge and an administrative hearing. If you do not submit to the chemical test, a report of implied consent refusal will be submitted to the Michigan Secretary of State’s office. You have 14 days to challenge the report. If you do not respond within that timeframe, you can have six points added to your driving record, and your license may be suspended for one year.

You may be asked to take a breath test at the police station. The test results will be more accurate than the test results taken on the portable device, but the results might not be reliable, and your criminal attorney may be able to challenge them. The results of the datamaster test given at the police station are only admissible against you if the Court is satisfied that the results are reliable. If you refuse the breath test at the police station, the police generally obtain a search warrant, which would require you to undergo a blood test.

Blood testing is considered the most accurate method of determining blood alcohol concentration. It occurs through a chromatograph. Your blood will be drawn and then mixed with chemicals. The separation of blood and alcohol makes it possible to figure out your BAC. There are various critical junctures during the process of blood testing, during which the results may be compromised. If your attorney believes that the results were compromised in your case, they can argue that the blood test results should be suppressed.

Rarely, you may be asked to take a urine test. Often, urine tests are administered because the police suspect that a driver is under the influence of drugs. However, these tests can also be used to test for drunk driving. Ethyl glucuronide testing is used to determine drug and alcohol consumption after the point at which the other two types of tests would be ineffective. This type of testing may be able to detect a biomarker for as long as 72 hours after initial consumption. Urine tests are not always accurate and sometimes produce false BAC results. It is extremely unlikely to be used in a Michigan drunk driving case but it is authorized under the drunk driving statute. Alcohol can take up to two hours to appear in your urine; your urine test might not show an accurate level of alcohol at the time that you were stopped by the police. Additionally, other prescription drugs could affect your BAC.


We may be able to get improperly obtained chemical testing results suppressed. For example, we may be able to argue that there was no probable cause to arrest you and that your Fourth Amendment rights were violated. In that case, the judge may rule that your chemical testing results should not be presented to the jury. For another example, we may be able to argue that your chemical testing results were improperly interpreted. In addition, there are administrative rules that the police are required to follow when obtaining a breath test or a blood draw. Failure to follow those rules can also result in suppression of the results or valuable arguments that can lend leverage to your negotiations or help your chances at trial.

Consult a Tenacious Michigan Attorney

If you are concerned about chemical testing results, you should consult our seasoned attorneys. Michigan Defense Law represents people in Oakland, Wayne, Macomb, Livingston and Washtenaw Counties. Call us at (248) 451-2200 or complete our online form.

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