A breathalyzer is an equipment or a device designed to test the alcohol concentration in a person’s breath and by extension in their system. When a person is arrested on a DUI suspicion, the officer may request them to submit to field sobriety tests to determine how impaired they are. One of the field sobriety tests a person would be subjected to is the preliminary alcohol screening (PAS). This is a breathalyzer test administered to determine one’s BAC level. Upon arrest, a suspect is expected to submit to a breathalyzer test at the station automatically. The results from a breathalyzer test are one of the crucial pieces of evidence a prosecutor will present in court during your DUI trial. Fortunately, there are various defenses against breathalyzer results.

The device is subject to regular malfunctions if not well calibrated. A lawyer can challenge the BAC results to the point that they can be dismissed as evidence against you in a DUI trial. If you are charged with a DUI offense as a result of breathalyzer results, you need to speak with a DUI attorney urgently. At The DUI Defense Attorney in Van Nuys California, we have extensive experience in defending our clients against DUI charges.

Breathalyzers and Alcohol Testing

The per se DUI laws make a presumption that a motorist is intoxicated if their BAC results are over the legal limits set by the law. Typically, for regular motorists, a motorist found driving with a BAC of 0.08% or higher will be presumed intoxicated and DUI charges will be brought against them. This is similar to a commercial driver whose BAC levels should not be at 0.04% or more. An underage driver will be prosecuted for intoxicated driving if their BAC levels read 0.01% or more.

In getting BAC levels, a motorist will be asked to submit to either a blood or breathalyzer test. California being an implied consent state, means that a motorist must automatically submit to the test, and if not, there will be consequences to their refusal. Although blood chemical tests give more accurate BAC results, the Supreme Court ruled against an automatic submission to the test. For officers to get a motorist's blood sample to test for intoxication, they must get a court order first. Blood tests are more common where a driver is suspected to be intoxicated by drugs or medications and not alcohol.

In carrying out a breathalyzer analysis, a suspect is asked to blow into a handheld device that detects the alcohol in one’s breath and calculates the BAC level. The results from the test offer one of the most substantial pieces of evidence during a DUI trial. However, these results are not without fault.

Regularly, the results from the breathalyzer test are accepted in court, but a DUI lawyer has various avenues to challenge their validity. For the results to stand in court, the police must show the breathalyzer device used in the testing is capable of producing valid and reliable results.

Title 17 Regulations on Breathalyzer Tests

There are regulations on how chemical tests to determine the alcohol content in one’s blood must be done. When the officer fails to follow these regulations, the defense lawyer can challenge the results and sometimes succeeds in getting them thrown out as evidence.

According to Title 17 regulations, breathalyzer machines must be maintained and calibrated regularly. The records on how the device is maintained and calibrated must be kept. Although these records are not part of the discovery packet following a DUI case, a defense attorney can request for them informally or formally.

Whether it is the PAS field device or the device at the office, the records for their maintenance and calibration must be kept. If the defense attorney can point out the irregularities in the servicing of the device, he or she can use this to challenge the validity of the results produced.

For breath tests to be accepted as valid, the various regulations under Title 17 must be followed. These requirements are:

  • The sample to be used of breath must be deep lung air or alveolar air
  • The suspect in intoxicated driving must be kept in continuous observation for not less than fifteen minutes before carrying out the breathalyzer test
  • During the fifteen minutes observation time, the officer should ensure the arrestee does not smoke, eat, vomit, eat or regurgitate
  • The device is used for breath testing is regularly calibrated at least at intervals of ten days. But if it reaches 150 uses regardless of it being less than ten days, it must be calibrated.

These regulations under Title 17 are necessary to ensure accurate and valid DUI tests are carried out. When these precautions are ignored, substantial problems can result. One of these would be the mouth alcohol that can contaminate the sample of breath given, and one ends up with elevated BAC results.

Aside from the above Title 17 regulations, other violations can result in invalid or questionable results. These violations are with regard to the maintenance and calibration of the device. Even with regular calibration, the operator must ensure the calibration is done correctly. The person that is charged with administering the breath test must also be well trained in the use of the equipment. If the device is not used as it is supposed to, the results will not be accurate.

Administering a Breathalyzer Test

As earlier discussed, when a person is stopped on intoxicated driving suspicion, the field officer will ask them to submit to various field sobriety tests. One of them may be the preliminary alcohol screening test (PAS). This test is conducted with the use of a handheld gadget that tests the level of alcohol in the driver’s breath. Once the officer feels there is enough evidence to call for further testing, the suspect is arrested and taken to the station. Before testing, the officer must inform the arrestee that:

  • No breath samples are saved for further testing. However, should they feel that the breathalyzer tests are inaccurate, they can opt for urine or blood tests. Samples of both the blood and urine can be kept for further analysis if one finds it necessary.
  • At least two breath tests must be carried out immediately following each other. The results from each test must not be too varied but within 0.02% from each other. If the difference between these two samples is significant, more breath samples will be required.
  • The set standards in taking the tests must be observed, and the arrestee told them. If these regulations were not adhered to, a defense attorney could challenge the process in court. The DMV is then burdened with showing the validity of the tests irrespective of the violations.
  • If the results from the breathalyzer machine show a high variance between the tests, the results are insufficient to indicate the driver had a BAC above the legal limit. In this case, the DMV may not suspend the driver’s license.
  • When the breathalyzer device is faulty, the prosecutor can try to use the results from the preliminary alcohol screening. Unfortunately, most officers in the field do not follow the fifteen-minute observation rule. Instead, once they are convinced the motorist was driving intoxicated, they bring them to the station for further testing. The defense attorney in fighting for their client will then show the fifteen-minute rule was not observed, and so the results are not valid as well.

The Ignition Interlock Device

When a person has been sentenced to probation following a DUI trial, one of the conditions is for them to install an ignition interlock device in their vehicle. This is also a mandatory requirement if one wishes to continue driving when their license is on suspension. Without an IID installed in your car, you cannot qualify to have a restricted driver’s license.

An ignition interlock device is a breathalyzer device installed in a person’s car to ensure they don’t drive intoxicated by alcohol. When a driver gets into the car, they will be required to breathe into the machine once they start the vehicle. If the device detects alcohol in the breath, the car will begin flashing lights, and the results are recorded. If your results are without any detectable alcohol, the driver can proceed to drive the car, but the device will keep asking for regular breath samples.

When these breathalyzer devices are not well maintained and calibrated, they will also register the wrong results. These results are relevant because one of the conditions for a person on probation is not to drive with any traceable alcohol amount in their blood or system. If the probation officer on reading the records notices the person has been operating with alcohol in their system, it can be a basis for revocation of the probation.

The law requires an ignition interlock device to be appropriately maintained and calibrated at all times. Regular calibration ensures the readings from the device are accurate.

The process of calibrating a breathalyzer is delicate. It requires a trained technician in an ideal environment to do it. Concentrations with alcohol are taken through the sensor unit to determine the value for testing. This is necessary to ensure the accuracy of the unit at any level of intoxication.

The breathalyzer is also run through a detailed diagnostic test. This is to ensure the mechanical functionality of the device is working correctly, the air is flowing well, and the accuracy level is high. Once the tests are completed, an assessment known as blind point to point is carried out to verify the device’s accuracy.

When a breathalyzer passes the extensive evaluation, it is given back to the owner with a report of its service. The report serves to show that the device is working optimally.

Benefits of Regular Calibration of Breathalyzers

The following are the benefits of routine breathalyzers’ calibration.

  • When the police department keeps their breathalyzer machines in good condition and is regularly calibrated, the readings from a suspect’s breath cannot be successfully challenged in court
  • The time taken to administer the results becomes shorter because there will be no significant variance between the two breath samples given
  • If you have an ignition interlock device installed in your car, it will not give wrong results or record false readings
  • The recorded BAC readings will be admissible in court
  • The breathalyzer device will last longer and always give valid results

Analyzing the Accuracy of Breathalyzers

To establish if a driver is operating a vehicle intoxicated by alcohol, police officers use different breath testing devices, also known as breathalyzers. The results from these breathalyzers are relied upon as crucial evidence by prosecutors in a DUI case. If the prosecutor has no other reliable evidence aside from the breathalyzer results, a challenge on the results by the defense can destroy their case.

Although these breathalyzer readings are highly depended on by prosecutors, they are not always accurate. When one consumes alcohol, it automatically enters their bloodstream. The blood that comes into the lungs releases alcohol vapor. The vapor leaves the body through breath, known as breath alcohol. This breath is filled with microscopic molecules of alcohol that are detected through the breathalyzer.

Unfortunately, the method of determining the alcohol concentration in a person through breath faces many errors. Many factors are the reason for these errors. These factors include:

  • The expected or approximated error margin of the device
  • The physical differences among motorists referred to as the partition ratio
  • Interference from the radio frequency
  • Improper and irregular calibration of the breathalyzer
  • Residual alcohol found in the motorist's mouth
  • An external element that interferes with the breath sample

The error level of a breathalyzer may depend on the type. Breathalyzers come in two kids: the preliminary alcohol screening device (PAS) and the Evidential Breath Test Device (EBT). Typically, police stations are equipped with EBT devices and are more accurate. The PAS devices are part of the field sobriety tests and are not as accurate as of the EBT. These devices are also more portable, making them easier to operate on the roadside.

Another breathalyzer device is an ignition interlock device (IID) that is installed in a driver’s car to prevent them from drunk driving. This is a device recommended by the DMV or the court. If a person wants to keep enjoying their driving privileges, they are required to install the gadget. The gadget, as earlier explained, works by taking the breath of the driver to measure it for alcohol. Just like the other breathalyzer devices, this, too, requires periodic maintenance and calibration to ensure accuracy.

The Error Margin in Breathalyzers

One of the most important reasons to keep breathalyzers well maintained and calibrated is to reduce the margin of error. Even when well maintained, breathalyzers have a margin of error. Some breathalyzers register a 0.01% error margin. This means that should your results register 0.08% of alcohol in your blood; the actual quantity could be anything between 0.07% and 0.09%. This margin of error is what many DUI lawyers use to argue the accuracy of the results.

Partition Ratio

Partition ratio is another reason why breathalyzers require regular calibration. The BAC levels are not directly achieved through breathalyzers. Breathalyzers compute the level of alcohol using a specific formula. The measurement of the breath alcohol is multiplied with a formula known as the partition ratio. The currently used partition ratio is 2,100.

Unfortunately, different individuals have varied partition ratios. Various factors affect the ratios of each person. These include:

  • The sex of the person – The partition ratio for men and women is different. However, only one average figure is used to arrive at the BAC levels.
  • Bodyweight – Heavy individuals can consume higher amounts of alcohol compared to small-bodied individuals.
  • Breathing patterns – How a person breathes can affect the kind of breath sample they will release to the breathalyzer
  • Body temperature – The BAC results can also be affected by the temperature of the individual

People do not have similar partition levels; neither are they consistent in an individual all their life. This variability is compensated by a preset typically lower ratio than it is in the majority of people. This means that most people benefit from the test because this ratio leads to an underestimate of the BAC levels. However, some individuals still have lower ratios. This will result in breathalyzers elevating their BAC results.

Radio Frequency Interference

Even with the regular calibration of breathalyzers, interference from radiofrequency can also result in invalid BAC results. Police radios release a lot of electromagnetic waves that lead to the malfunctioning of breathalyzers. Some breathalyzers are fitted with detectors for RFI. When the detectors sense interference from the radio frequencies, they automatically cancel any test in progress. Because of this, breathalyzers will require regular calibration and maintenance to ensure accurate results.

Mouth Alcohol

Breathalyzers are designed to measure alcohol from the lungs. Unfortunately, sometimes the mouth can have alcohol residue or that from the stomach can travel to the breathalyzer sample changer. When this happens, the results from the breathalyzer will be elevated.

The police are advised to observe the suspect for fifteen minutes continuously to avoid mouth alcohol from showing high BAC results. This is necessary to ensure that the suspect does not eat, drink, or regurgitate because these actions can bring alcohol residue in the mouth.

Find a Los Angeles DUI Lawyer Near Me

A conviction for a DUI offense will result in various penalties. Sometimes, a person can be wrongly convicted due to their elevated blood alcohol concentration. A BAC recording is one of the most significant pieces of evidence in a DUI case. However, BAC results from breathalyzers are not always accurate. One of the main reasons for their invalidity is the improper working of the device.

If the evidence a prosecutor has against you is the BAC results, a skilled DUI lawyer can challenge the results. This can be done in various ways, with one of them being checking the maintenance and calibration records of a breathalyzer. The DUI Defense Attorney in Van Nuys California can help you fight DUI charges against you. Call us at 818-253-1913, and let us fight these allegations on your behalf.