How Accurate is the Breathalyzer Test in SC?

How accurate is the breathalyzer test? Will it prove your innocence if you’ve been wrongfully arrested for DUI in SC?

Headed home late one night, you see blue lights in your rearview mirror. The officer approaches your car, asks for your ID and registration, then asks, “How much have you had to drink tonight?”

Whether you’ve had nothing to drink, one drink, or two drinks, that question is foreshadowing of what’s to come… the officer clearly suspects that you are DUI. Next, he asks you to step out of the car. Then, he asks you to perform field sobriety tests – you know you aren’t drunk, and the roadside “tests” should prove that.

Except now you’re wearing handcuffs in the back seat of a patrol car, on the way to the county jail as your car is being towed away. Surely the breath test will prove that you are not drunk, and the officer will release you, right?

Below, I’ll look at why the breathalyzer may not be as accurate as you think, and why, if you’ve been arrested for DUI, the breathalyzer results probably will not matter – regardless of the breathalyzer result, the officer is probably not going to release you…

How Accurate is the Breathalyzer Test?

Police, prosecutors, victim’s advocates, and breathalyzer manufacturers want the world to believe that breathalyzer tests are always accurate. It’s amazing and simple – you put the breath into this little black box, and it gives you the exact content of alcohol in a person’s blood (blood alcohol content, or BAC).

Breathalyzer manufacturers will fight to prevent defense attorneys and defense experts from getting the source code that shows how the machines work, claiming it is a “trade secret.” When testifying, police officers will claim that the machine is always accurate, but, when you question them further, they will usually admit they have no idea how the machine works.

Whether a breathalyzer test is accurate depends on many different factors including:

  • How you blow into the machine;
  • Whether the machine is properly calibrated;
  • Whether the simulator solution used in the machine is the right temperature and has not expired;
  • What you ate or drank (besides alcohol) before taking the test;
  • Whether there are any foreign objects in your mouth;
  • Whether you belch before blowing into the machine;
  • Whether there is radio interference that prevents an accurate reading;
  • Whether the officer knows how to operate the machine; and
  • Whether the officer tampers with the machine’s results.

How Does the Breathalyzer Test Work?

Although you blow into the machine, the result it gives is not your “breath alcohol content.” It gives a number that is supposed to be your blood alcohol content… how does that work?

Breathalyzer Calibration

First, the machine calibrates itself. It breaks open a small vial that contains what is called a “simulator solution.”

The simulator solution is supposed to be exactly .08 alcohol content – the machine tests it, and, if the result is .08, the machine tells itself it is calibrated, and everything is working fine.

And it should, if:

  • The simulator solution is .08 alcohol content;
  • The solution is the right temperature; and
  • The solution’s expiration date has not expired.

Your DUI defense attorney can access the records for the machine that you were tested on and download a report that contains data on the machine and the machine’s operators, including the simulator solution’s temperature and expiration date at the time of your breath test.

Conversion from Breath Content to Blood Content

When you blow into the machine, it is designed to test the air from the deepest part of your lungs, in the alveolar sacks where your breath transfers oxygen to your blood.

It comes up with a number – the “breath alcohol content.” But, that’s not the final result – it must now be converted to a number for the “blood alcohol content.” The machine does this by multiplying the breath alcohol content by 2100, which is the result it then gives for your blood alcohol content.

Why 2100?

The 1/2100 ration that the breathalyzer machine uses is arbitrary, and it is not accurate for most people. The actual conversion ratio for most people can vary from around 1/1800 to 1/2500, and it can even be different at different times for the same person depending on:

  • The person’s size and weight;
  • What they’ve had to eat or drink (apart from alcohol);
  • Whether they are male or female; and
  • Their metabolism.

Which means that the breathalyzer is not accurate for most people most of the time…

What Happens if You “Pass” the Breathalyzer?

You’ve been wrongfully accused of DUI, handcuffed, and taken to the county jail in the backseat of a police car. You are taken straight to the “Datamaster room,” where the officer asks you if you are going to blow into the machine.

Of course, you are! You need to prove your innocence and now is your chance, right?

Of course, the breathalyzer result may not be what you expected – if it says you are drunk, now the government has solid evidence to use against you in court.

On the other hand, if you take the test and blow a 0.00, will the officer release you?

It’s doubtful. In every case I have seen where my client blew a 0.00, the officer booked the person, left them in jail with a DUI charge, and wrote in their report that the person was intoxicated on drugs.

That leaves it up to you to immediately get a drug test to prove that you were not intoxicated on anything (you are guilty until proven innocent), or you can fight the DUI charges and hope that your DUI defense attorney can get them dismissed before your trial…

DUI Convictions Worldwide Based on Flawed Breathalyzer Results

Across the United States and in other countries around the world, governments have gotten DUI convictions based on breathalyzer results that have been proven to be wrong.

Although it is difficult (but not impossible) to prove when the machine has made a mistake, the courts cannot ignore wrongful convictions when it is proven that a police officer is tampering with the machine or the results to get convictions.

For example:

New Jersey Breathalyzer Results Flawed

More than 20,000 DUI convictions in New Jersey may be reopened and dismissed or retried after a state police sergeant was convicted of tampering with the results by falsifying the calibration records on machines in five different counties.

What about the officers who are not caught, charged with a crime, and convicted of tampering with the machines? Do we really believe that this was the only officer who is tampering with DUI breathalyzer results?

Massachusetts Breathalyzer Results Flawed

Thousands of DUI cases were affected in Massachusetts last year when investigators discovered that a state crime lab was withholding evidence from DUI defense lawyers including information that the machines were not properly calibrating…

Australia Breathalyzer Results Flawed

Police in Victoria, Australia reportedly faked more than 250,000 roadside breath tests in order to meet quotas. Good thing they fixed that, right?

Well, no. The Transport Accident Commission found that the officers “may have falsified the tests to meet targets,” but also announced that:

  • There was no fraud or criminal activity by the officers;
  • The 250,000 faked breath tests did not affect any prosecutions;
  • No officers reported the misconduct; and
  • No individual officers have been “spoken to” about the incident.

Washington Breathalyzer Results Flawed

In Washington State, experts who analyzed the Alcotest 9510’s source code found that the test gave inaccurate results that were too high – the experts were then immediately served with a cease and desist order by the manufacturer who claimed that they were violating a protective order and revealing trade secrets.

Defense experts in Massachusetts and New Jersey also found that the machines were flawed, and the results were not accurate. The courts, however, ruled that the machines were A-OK and allowed the states to continue using them…

DUI Defense Lawyer in Charleston, SC

How accurate is the breathalyzer test in Charleston, SC?

If you’ve been charged with driving under the influence (DUI) in Charleston, SC, get an experienced DUI defense attorney on your side immediately who knows how to get the evidence in your case, analyze the evidence, and fight to get your case dismissed or win it at trial.

Call DUI defense attorney Grant B. Smaldone now at (843) 808-2100 or schedule a consultation through our website to talk to a Charleston, SC DUI defense lawyer today.