Philadelphia DUI/DAI Defense Lawyer Providing Information About Blood Alcohol Tests

If you have been pulled over under suspicion of drunk driving, you will likely be asked to submit to a breath test and potentially to blood or urine tests if you are brought to the police station. While these tests can provide accurate measurements regarding level of intoxication, blood alcohol tests can be highly unreliable in certain circumstances.

The DUI defense attorneys at MyPhillyLawyer scrutinize the testing procedures and BAC results in drunk driving defense cases in order to best serve our clients’ interests. For aggressive representation, contact our Philadelphia law firm.

Problems With BAC Tests

Alcohol absorption: DUI offenses are related to blood alcohol content levels at the time a person is driving, not when the test is taken much later. However, because alcohol is absorbed into the system or metabolized over time, police frequently make the assumption that some of the alcohol in your system was already “burned off” and therefore, your BAC levels at the time you were driving were higher. As a result, higher BAC levels are tied to your charge. However, there are many factors that cause an individual to absorb alcohol at different speeds from the amount of water contributing to their body weight to the amount of fat in the foods eaten recently. In certain instances, the alcohol levels in the blood have not yet dropped at the time of the reading, yet police still assume BAC levels were higher.

Breath tests: Breathalyzer and intoxilyzer machines calculate BAC levels when the individual blows into the machine. If the machine is not calibrated properly, if the individual does not blow properly into the machine, or if there are other errors within the machine, an inaccurate reading may result. In many cases, there are functional errors within the system, however, the machine fails to warn of such errors. Routine maintenance or simple diagnostic tests can and should be performed to avoid false results.

Urine tests: As with any other test, BAC results derived from urine tests can be inaccurate. Urine chemical test results are based on an assumption that the individual being tested is average. On average, the ratio of alcohol in the urine to alcohol in the blood is 1.3 parts of alcohol in the urine to 1 part alcohol in the blood. But if the individual is not average, an inaccurate reading would result.

Blood tests: Blood tests are not used as much as breath tests or urine tests because blood tests are more costly and time consuming. Additionally, due to the technicalities with regards to how the blood is drawn and tested, the test can result in BAC levels that are arguably 15 to 20 percent higher than actual BAC levels.

When challenging BAC results, our DUI defense attorneys work with forensic experts to analyze the testing procedures, testing equipment, and other factors which may have contributed to a false reading. In certain cases, our thoroughness reveals testing procedures that do not comply with Pennsylvania laws or testing device protocol. As a result, the BAC results may be completely withheld from evidence and could result in a reduction of charges or even a dismissed case.

Don’t Refuse to Take the Test

Any person with a driver’s license who drives a vehicle in Pennsylvania has impliedly given their consent to take some form of chemical test (breath, blood, or urine) if suspected of alcohol impairment while operating a vehicle. Refusal will result in an automatic one-year license suspension and mandatory three days in jail. Additionally, the individual will face DUI/DAI charges as if they had tested with the highest BAC levels. Therefore, if convicted, they will face the harshest levels of punishments.

Philly DUI Defense Lawyer

Contact MyPhillyLawyer at 215-227-2727

For more information about blood alcohol tests or about DUI defense, contact the drunk driving defense lawyers at, in Pennsylvania.

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