Cannabis DUI Laws in Washington

Washington (WA)Per Se THC Limit

This state sets a specific THC blood concentration limit. Drivers at or above this level are legally considered impaired.

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DUI Law Details

THC Limit

5 ng/mL blood

legal threshold

Testing Method

Blood, field sobriety, DRE evaluation

authorized methods

Implied Consent

Yes

required for licensed drivers

First Offense Penalty

1 day to 364 days in jail, fines $940-$5,000, 90-day license suspension

Test Refusal Penalty

1-year license revocation

Overview

Washington was one of the first states to establish a per se THC limit alongside recreational cannabis legalization in 2012 (Initiative 502). The limit is 5 nanograms of active THC per milliliter of blood. Unlike Colorado's permissible inference, Washington's limit creates a per se standard.

Washington uses blood testing as the primary method for measuring THC levels, supplemented by field sobriety tests and DRE evaluations. The state has extensive experience with cannabis DUI enforcement and has been a model for other states considering similar laws.

Key Facts

•Per se limit: 5 ng/mL active THC in blood
•Established alongside legalization in 2012 (I-502)
•Per se standard — not just a permissible inference
•First offense carries 1 day to 364 days in jail
•1-year license revocation for test refusal
•Fines range from $940-$5,000 for first offense

Frequently Asked Questions

What is Washington's THC driving limit?+

Washington has a per se limit of 5 ng/mL of active THC in whole blood. This is a strict legal limit, not a permissible inference like Colorado's.

How is Washington's THC limit different from Colorado's?+

Both states have a 5 ng/mL limit, but Washington's is a per se standard (automatic legal threshold), while Colorado's creates a 'permissible inference' that can be rebutted with evidence.

What are the penalties for a first cannabis DUI in Washington?+

A first offense carries 1 day to 364 days in jail, fines of $940-$5,000, and a 90-day license suspension.

How long does THC stay above 5 ng/mL after use?+

This varies significantly by individual. Occasional users may drop below 5 ng/mL within a few hours, while regular users may remain above the limit for much longer. There is no reliable rule of thumb.

Related State DUI Laws

Explore cannabis DUI laws in other states with similar regulations or neighboring jurisdictions.

Colorado

Per Se THC Limit

Oregon

Effect-Based Standard

Montana

Per Se THC Limit

California

Effect-Based Standard

Continue Exploring

Washington Cannabis Market

Disclaimer: The information on this page is provided for educational and informational purposes only and does not constitute legal advice. Cannabis remains illegal under US federal law. Washington DUI laws and regulations are subject to change and may vary by local jurisdiction. THC limits, penalties, and testing methods described here are based on publicly available information and may not reflect the most current regulations. Always verify current laws with official Washington state resources and consult with a qualified attorney for legal guidance. Cannabismarketcap does not guarantee the accuracy or completeness of any information presented.