Field Sobriety, Breathalyzers & Blood Tests

Are You Required to Take a Breath, Blood or Field Sobriety Test in Washington?

A DUI stop can be one of the most stressful and uncertain moments of your life. The decisions you make in those first few minutes can have lasting consequences for your license, your record, and even your freedom. Should you take a field breath test or submit to a field sobriety exam? What about a breathalyzer or blood test after your arrest?

In Washington state, the laws around these tests can be confusing, and a simple misstep could complicate your situation. That’s why understanding your rights is so important – and why having experienced legal representation on your side can make all the difference.

Can You Legally Refuse Field Sobriety Tests in Washington?

Yes, you can legally refuse to perform field sobriety tests and roadside breathalyzer tests in Washington – and in many cases, that may be the wisest choice. Field sobriety tests are not required by law, and there is no automatic legal penalty for declining to participate in them.

Unlike chemical tests after your arrest, such as a breathalyzer at the police station, field sobriety and roadside breathalyzer tests are considered voluntary. This means that law enforcement officers cannot force you to perform them. Your driver’s license also cannot be suspended just for saying no to a field sobriety or roadside breathalyzer test.

That said, even if you refuse a field sobriety test, you can still face consequences. Police officers are trained to build DUI cases using a variety of observations. If you decline a field test, they can still arrest you based on what they’ve seen, smelled, or heard – like slurred speech, bloodshot eyes, an open container of alcohol, or the odor of alcohol or cannabis. And while you won’t be punished simply for refusing, prosecutors can still try to use your refusal as circumstantial evidence of impairment, arguing that you declined the field tests because you thought you might fail.

What many people don’t realize is that field sobriety tests are often administered under stressful and less-than-ideal conditions – on the side of a busy road, at night, in poor weather. You may be tired, scared, or physically unable to perform the tests correctly, even if you’re sober. Saying “no” to these tests can limit the amount of subjective evidence collected against you and better preserve your legal options moving forward.

You may think that if you “pass” a field sobriety test, the law enforcement officer will let you go and you won’t face any more charges, but this is very rare. And even if you’ve had nothing to drink or smoke, you could still “fail” these imprecise roadside tests – and that failure can be used as evidence against you later in court.

If you’re unsure how to respond, it’s within your rights to respectfully decline taking a field sobriety test and state that you would like to speak with a lawyer before answering any further questions or performing any tests. This is not you being difficult – it’s you thinking ahead and taking steps to protect yourself in a high-stakes situation.

Common Field Sobriety Tests Used in Washington DUI Stops

When conducting field sobriety tests (FSTs), law enforcement officers may ask you to perform the following types of tests. You have the right to refuse these tests:

1. Roadside Preliminary Breath Test (PBT) – This is a handheld breathalyzer that may be used at the scene of your traffic stop to estimate your blood alcohol content (BAC). This test is voluntary, and the results are not admissible in court to prove that you were impaired. However, officers may use the test to establish probable cause to arrest you. You are within your rights to decline these roadside preliminary breath tests.
2. Horizontal Gaze Nystagmus (HGN) Test – You may be asked to follow a small object (usually a pen or flashlight) with your eyes. The officer will watch for involuntary jerking of your eyes, which may be more pronounced when a person is impaired.
3. Walk-and-Turn Test – You must take 9 heel-to-toe steps in a straight line, turn on one foot, and return in the same manner. The officer will look for balance, coordination, ability to follow instructions, and signs of swaying or stepping off the line.
4. One-Leg Stand Test – You may be instructed to raise one leg approximately 6 inches off the ground and hold it for 30 seconds while counting out loud. Officers will observe for signs of imbalance, hopping, or putting your foot down.
5. Finger-to-Nose Test – With your eyes closed and head tilted back, you may be asked to touch the tip of your nose with your index finger, alternating hands. This test checks for coordination and spatial awareness, but may be difficult even when sober.
6. Rhomberg Balance Test – You may be asked to stand still with your feet together, eyes closed, and head tilted back for an estimated 30 seconds. The officer will watch you for swaying, extra body movements, or an inability to judge the time.
7. Counting or Alphabet Test – Officers may ask you to count backwards from a certain number or recite a portion of the alphabet. While not part of the standardized tests, these are occasionally used to assess concentration and cognitive function.
8. Modified Walk-andTurn or Stand-and-Balance Variants – In some cases, law enforcement officers may use alternative or modified versions of the core tests listed above if a driver has physical limitations or other challenges.

Only the first three tests—the HGN, Walk-and-Turn, and One-Leg Stand—are considered Standardized Field Sobriety Tests (SFSTs) by the National Highway Traffic Safety Administration (NHTSA). These tests are meant to follow specific procedures to be considered reliable, but even then, their accuracy can vary widely based on how they’re carried out and analyzed. Real-world conditions are rarely ideal, and if an officer deviates even slightly from the protocol, the accuracy of these field sobriety tests drops significantly.

How Reliable Are Field Sobriety Tests?

Even though law enforcement officers across Washington state widely use field sobriety tests, their reliability is far from guaranteed. While these tests are intended to help officers assess whether a driver may be impaired, their accuracy depends heavily on how they’re administered and maintained, and the results can be influenced by a wide range of external factors that may have nothing to do with alcohol or drugs.

In practice, field sobriety tests often involve a subjective interpretation by the officer who’s conducting your traffic stop. What one officer sees as a “clue” or sign of impairment, another might ignore or misinterpret. This creates opportunities for bias – especially if the officer already suspects that you’re under the influence even before you begin.

Many things can cause a completely sober person to “fail” a field sobriety test, including:

• Medical conditions such as vertigo, arthritis, or inner ear disorders
• Medications that may cause shaking, sweating, dilated pupils, or other symptoms
• Uneven surfaces, poor lighting, traffic distractions, or bad weather
• Neurological issues or current or past injuries
• Fatigue or anxiety during the time of your traffic stop
• Footwear, such as high heels, sandals, or boots
• Your age, weight, flexibility, or physical fitness

These variables can compromise your balance, coordination, and motor function – which are exactly what field tests rely on. But law enforcement officers are not trained medical professionals and may not properly account for these factors.

Because of their many weaknesses, field sobriety tests are frequently challenged in court. A strong legal defense can call into question whether the tests were conducted properly, whether the environment was safe and controlled, or whether physical or psychological factors might have impacted your performance. As a result, it’s not uncommon for judges and juries to view these tests as only part of the picture – and not definitive proof of impairment. This is why it’s important to have a defense attorney who understands the science behind these tests and knows how to effectively challenge their validity.

What Is Washington’s Implied Consent Law?

Washington’s implied consent law states that by choosing to drive on public roads, you automatically consent to chemical testing (breath or blood) after you’ve been lawfully arrested for a DUI. This law is designed to encourage cooperation with DUI investigations by attaching penalties if you refuse these tests after your arrest. Here’s how it works:

• If you’re lawfully arrested for DUI, the officer is required to inform you of your rights and tell you the consequences of refusing a test after your arrest.
• After your arrest, you may be asked to take a breath test. If a breath test isn’t available, or if drugs are suspected instead of alcohol, you may be asked to take a blood test.
• You have the right to refuse testing even after your arrest, but this triggers immediate administrative penalties – even before your DUI case is resolved.

The implied consent law does not apply to roadside field sobriety tests or preliminary breath tests (PBTs). This rule applies only after a lawful arrest, and only to official breath or blood tests intended to be used as evidence in court. It’s a powerful law with serious consequences – and one of the reasons DUI cases can become complicated without good legal guidance.

What Happens If You Decline a Breathalyzer After Arrest?

Once you’ve been lawfully arrested for a suspected DUI in Washington, you will typically be asked to take a breath test at the police station or jail, commonly referred to as the Evidentiary Breath Test (EBT). This is not the same as the roadside preliminary breath test (PBT), which is voluntary. The evidentiary breath test falls under Washington’s implied consent law, which means that refusing carries significant consequences.

If you decline the post-arrest breathalyzer test, the Washington Department of Licensing (DOL) will automatically begin administrative penalties against you, which include:

• A 1-year driver’s license suspension for a first refusal or a 2-year driver’s license suspension for a second or subsequent refusal within 7 years.These penalties apply even if you are never convicted of a DUI in criminal court.  
• Using your refusal as evidence in your DUI case that you were guilty.
• Mandatory installation of an ignition interlock device (IID) for at least one year.

Click here to see the full Washington DUI sentencing grid.

It’s also important to understand that refusing the breath test does not guarantee you won’t be tested. In serious cases — such as those involving injuries, repeat offenses, or when the officer has the time and resources — law enforcement may obtain a search warrant to collect a blood sample anyway.

The decision to refuse testing after your arrest should never be taken lightly. It can significantly complicate your case, both at the DOL hearing and in court. In reality, the only time it might make strategic sense to refuse is when law enforcement does not intend to pursue a search warrant for a blood test — a judgment call that’s hard to make in the moment. That’s why speaking with a lawyer as soon as possible – ideally, immediately after your arrest and before deciding whether or not to take the test – can help you make an informed, strategic choice.

Are Blood Tests Mandatory, and Can You Say No?

After an arrest, you may be asked to take a blood test if:

• A breath test is not feasible (because of injury, unconsciousness, or refusal),
• Drugs, rather than alcohol, are suspected to be the cause of impairment, or
• The law enforcement officer obtains a search warrant for a blood draw.

You have the right to say no to a blood test. However, just like refusing a breathalyzer test after an arrest, there are serious consequences to refusing a blood test.

If you refuse a blood test after arrest, and the officer does not have a warrant, your refusal will be treated the same as refusing a breath test. You will face license suspension, a potential increase in criminal penalties if you get convicted, and your refusal can be used as evidence against you in court. And in many cases, officers will respond by seeking a warrant for a blood draw, especially if your case involves suspected drug impairment, an accident, or injuries.

If law enforcement gets a warrant, then your refusal no longer protects you from testing. Resisting a court-ordered blood draw could result in additional charges and penalties.

In other words, while you can refuse a blood test initially, the protection offered by that refusal is limited, and it won’t necessarily prevent the state from getting a sample through lawful means. Understanding your rights – and the likely next steps – is key to protecting yourself legally.

Can You Be Convicted of DUI Without Chemical Test Results?

Yes – you can be convicted of a DUI in Washington even if you refused a breath or blood test. While chemical test results are often a central piece of evidence in DUI cases, they are not required for the state to prove its case against you. Washington law allows prosecutors to rely on other types of evidence to show that you were driving under the influence, such as:

• Officer observations like slurred speech, bloodshot eyes, unsteady gait, open containers, or the smell of alcohol or marijuana on you or in your vehicle
• Driving behavior such as swerving, speeding, or failing to stop properly
• Performance on field sobriety tests (if you agree to take them)
• Statements that you made during or after the traffic stop
• Video footage from the patrol car or body camera
• Refusal to submit to testing, which can be used as evidence of guilt

Your behavior, your words, and the officer’s description of your physical and mental condition can all be used to argue that you were impaired. Refusing a test might limit the state’s evidence in one way, but prosecutors can then use your refusal as evidence. Ultimately, your refusal does not prevent you from being charged or convicted.

This is why having a strong legal defense is so important, especially in cases where chemical testing was not performed. A skilled attorney can challenge the reliability of subjective evidence and highlight alternative explanations for the officer’s observations. In sum, while you do have the right to refuse chemical testing after an arrest, doing so often makes your legal path more difficult, not less. It’s critical to make these decisions with a clear understanding of the law and, ideally, the support of an experienced attorney who knows how to protect your best interests. At Garguile Law, we’re here to help you navigate the legal realities of chemical testing. Contact us now to get started on a strategic defense.