Washington voters approve Initiative 502 to legalize and tax adult-use cannabis

On Election Day, November 6, 2012, Washington voters approved Initiative 502 (I-502) by a margin of 55.70% Yes (1,724,209 votes) to 44.30% No (1,371,235 votes). Passing alongside Colorado’s Amendment 64 on the same night, Initiative 502 made Washington one of the first two U.S. states to legalize recreational cannabis for adults aged 21 and older.

How Washington’s law worked—and how it differed from Colorado’s

While Colorado allowed existing medical dispensaries to apply first for recreational licenses and legalized personal home growing, Washington’s Initiative 502 created a separate three-tier licensing system overseen by the Washington State Liquor Control Board (renamed the Liquor and Cannabis Board):

• Possession limits: Adults 21+ could possess up to 1 ounce of usable cannabis flower, 16 ounces of solid cannabis-infused edibles, or 72 ounces of liquid cannabis products.
• No recreational home grow: Unlike Colorado, I-502 did not legalize home cultivation for non-medical consumers; only registered medical cannabis patients remained permitted to grow plants at home.
• Driving standard: I-502 established a per se THC blood limit of 5 nanograms per milliliter of blood for driving under the influence.

When legal possession and retail sales began

• December 6, 2012: Adult possession of up to 1 ounce became legal statewide thirty days after the election.
• July 8, 2014: Washington’s first licensed retail cannabis stores opened for business.
• Massachusetts on the same night: Also on November 6, 2012, Massachusetts voters approved Question 3 with 63.3% Yes, legalizing medical marijuana in the Commonwealth.