So . . . it is now legal to recreationally use marijuana in the State of Nevada. How has the legalization of marijuana in Nevada impacted Nevada’s drugged-driving laws? More specifically, how has the legalization of marijuana in Nevada impacted Nevada’s marijuana-DUI laws? You should be disappointed to learn that it has not . . . or, at best, not really. I will explain why you should be disappointed in a moment. First, a brief history on Nevada’s marijuana and marijuana-DUI laws may be useful.

Prior to January 1, 2017, it was illegal in Nevada to possess or use marijuana. In fact, most people then and now were/are shocked to learn that it was a felony to use marijuana prior to January 1, 2017. Prior to the legalization of the recreational use of marijuana, Nevada’s marijuana-DUI law provided as follows:


[i]t is unlawful for any person to drive or be in actual physical control of a vehicle on a highway or on premises to which the public has access with an amount of a prohibited substance in his or her blood . . . that is equal to or greater than . . . [2 ng/ml of “marijuana” in the blood or 5 ng/ml of “marijuana metabolite” in the blood.] (There were also per se levels for urine (marijuana and marijuana metabolite)).


What you might not know is that the foregoing levels have been and are routinely attacked as having no correlation to impairment. In fact, in a study performed by the Washington State Patrol Forensic Laboratory Services Bureau, which was sponsored by the National Highway Traffic Safety Administration (“NHTSA”), the authors concluded that based upon patterns of use and dosage, “[i]t is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects.” Accordingly, the authors opined that “[i]t is inadvisable to try and predict effects based on blood THC concentrations alone . . .” Significantly, the authors also opined that it is “impossible to predict specific effects based on THC-COOH concentrations.”

The main isomer and principal psychoactive constituent of marijuana is Delta-9 tetrahydrocannabinol (THC). This is the component that gets you high. This is the “marijuana” that has a current per se blood level of 2 ng/ml. Your body then metabolizes THC down to its active metabolite of Hydroxy-THC (11-OH-THC). Research has shown that levels of Hydroxy-THC in the blood can also correlate to impairment. However, your body next metabolizes the Hydroxy-THC down to a secondary inactive metabolite commonly referred to as Carboxy-THC (THC-COOH). While Carboxy-THC is also a metabolite of THC, there is absolutely no empirical evidence tending to correlate levels of Carboxy-THC with impairment. In fact, quite the opposite; research establishes that Carboxy-THC remains in the blood for up to thirty days depending on the individual’s frequency of use and dosage, a month after the high from THC has passed. Research shows that Carboxy-THC remains in habitual user’s blood for weeks and in occasional user’s blood for several days. Still, Nevada’s marijuana-DUI law provided that an individual will be considered per se under the influence of marijuana if their blood contained 15 ng/ml or more of “marijuana metabolite.”


Your next questions should be Why do Nevada’s DUI laws criminalize conduct that is not DUI? Why has this law not been challenged and overturned? Actually, the foregoing levels of marijuana have been constitutionally challenged as having no correlation to actual impairment. See Williams v. State, 118 Nev. 536, 50 P.3d 1116 (2002). In Williams, the Nevada Supreme Court upheld Nevada’s per se marijuana-DUI laws. However, the Nevada Supreme Court did not uphold the laws because they determined the per se levels correlated to impairment, but rather, because at the time using marijuana was illegal and therefore “banning driving by persons with any measurable amount of illicit drugs was constitutional because ‘the legislature was reasonable in determining that there is no level of illicit drug use which can be acceptably combined with driving a vehicle; the established potential for lethal consequences is too great.’” In fact, citing to Williams, the Nevada Supreme Court recently recognized that Nevada’s marijuana-DUI law did not require impairment. See Sheriff, Clark County v. Burcham, 124 Nev. 1247, 1253, 198 P.3d 326, 330 (2008) at fn 13 (“explaining that NRS 484.3795(l)(f), which applies to a person who has a prohibited level of a controlled substance in his or her blood, does not require impairment . . .” (citing Williams, 118 Nev. at 548–49, 50 P.3d at 1124).


In other words, because using marijuana was illegal, setting per se levels for DUI-impairment, even where there was no correlation between the levels and actual impairment, would survive constitutional muster based alone upon the government’s interest in maintaining safe highways.


Flash forward to January 1, 2017.


The recreational use of marijuana has been legalized in Nevada. The relevant statute, in pertinent part, provides:


“it is lawful, in this State, and must not be used as the basis for prosecution or penalty by this State or a political subdivision of this State, and must not, in this State, be a basis for seizure or forfeiture of assets for persons 21 years of age or older to . . . [p]ossess, use, consume, purchase, obtain, process, or transport marijuana paraphernalia, one ounce or less of marijuana other than concentrated marijuana, or one-eighth of an ounce or less of concentrated marijuana . . .”


Now . . . a reasonable person would presume that the legalization of marijuana would necessarily require an amendment to Nevada’s marijuana-DUI laws. It would make no sense to continue to criminalize unimpaired driving based upon threshold levels of a substance that can be lawfully consumed. Right?

In fact, all of the other seven States that have legalized the recreational use of marijuana have marijuana-DUI laws that either prohibit driving while impaired by marijuana (versus driving while having some magical blood level of THC that has no correlation to impairment) or have higher per se levels:

Alaska: no per se law; must prove impairment;

California: no per se law; must prove impairment;

Colorado: 5 ng/ml or higher of marijuana only gives permissible inference of impairment & no per se law for metabolite;

Maine: no per se law; must prove impairment;

Massachusetts: no per se law; must prove impairment;

Oregon: no per se law; must prove impairment; and

Washington: 5 ng/ml or higher & no per se law for metabolite).


On July 1, 2017, the Nevada legislature did amend Nevada’s marijuana-DUI laws. However, rather than amending the law to make it more rational (i.e., amend it to punish drivers that are actually impaired by marijuana), the amendments did not increase the previous per se levels at all. Specifically, the legislature amended the marijuana-DUI laws to remove urine as a potential matrix for analysis and to clarify the definition of “marijuana metabolite.” Thankfully, the legislature did amend the definition of “marijuana metabolite” to mean Hydroxy-THC, not Carboxy-THC. The new marijuana-DUI law provides as follows:

It is unlawful for any person to drive or be in actual physical control of a vehicle on a highway or on premises to which the public has access with an amount of any of the following prohibited substances in his or her blood that is equal to or greater than:


Prohibited substance                                                                   Blood Nanograms per milliliter Blood Nanograms per milliliter


(a) Marijuana (delta-9-tetrahydrocannabinol)                                   2 2
(b) Marijuana metabolite (11-OH-tetrahydrocannabinol)                   5 5



At the beginning of this blog I stated that you should be disappointed in the current marijuana-DUI laws. The reason you should be disappointed is simple; given the substantial variables that impact marijuana-consumption and impairment, there is simply no correlation between an individual’s THC levels and impairment. It is NOT like alcohol and DUI (which is another argument entirely). As I advised you earlier, even a study sponsored by NHTSA came to this conclusion. Why should this study matter to you? NHTSA is the federally funded organization that is responsible for the standardization of DUI field sobriety tests. They are the organization that sets policy and protocol for the certification of law enforcement officers as “DREs” (drug recognition experts or evaluators in marijuana-impaired cases). They are the organization that sets the curriculum for DUI recognition, investigation and arrest for law enforcement officers. In other words, they are on MADD’s side, not the ACLUs. Obviously, the purpose of this blog is not to advocate DUI or even relaxed DUI laws. The tragedies of DUI in this country are legion. I am a Las Vegas native and have an 11-year-old son. The last thing I would advocate for Nevadans is a law that permits impaired drivers to endanger Nevada motorists.


However . . . there is a flip-side to that coin; driving under the influence laws are supposed to prohibit and punish driving under the influence, not driving with a random level of a legally consumable substance (or metabolite of a legally consumable substance) in your system. We do not charge a woman with murder for rejecting a man at a night club three hours before the man decides to commit suicide, regardless of the woman’s alleged BAC at the time of the rejection. Imagine if your son or daughter was involved in a car accident an hour after he/she “took a drag” from a joint. They would potentially be facing mandatory years in prison if someone died or was even substantially harmed predicated only upon some random level of substance in their blood.


If you are losing interest in this article because “neither you nor you loved ones ‘smoke pot,’” consider the following study.    In 2015, the Journal of Analytical Toxicology published an article concerning an experiment on the effects of second-hand smoke of marijuana. The scientists who conducted the experiment concluded:


that environmental exposure to cannabis smoke should be avoided by nonsmokers and potentially has implications for those who undergo drug testing and those engaged in safety-sensitive activities (e.g., driving). Extreme exposure of nonsmokers could lead to positive drug tests and drug-induced behavioral changes not unlike those produced by active cannabis smoking. In fact, the scientists concluded that ‘[p]ositive tests for THC in . . . blood were obtained for nonsmokers up to 3 h[ours] following exposure.’


The results of the foregoing study revealed that 16 out of the 18 non-smoking participants that were exposed to second-hand marijuana smoke tested positive for THC from 15 minutes to 3 hours after being exposed. Even more alarming, 4 of the 18 non-smoking participants tested positive for THC above Nevada’s current per se levels for THC (2 ng/ml or above); one of which tested positive at 5.6 ng/ml just 15 minutes after exposure. Although the authors of the study characterized the second-hand exposure as “extreme,” the study reveals that non-smokers were simply seated next to smokers for hour-long sessions. Testing positive for THC after just 15 minutes of “exposure” from being seated next to someone sounds more like a Tuesday-night poker game than “extreme exposure.”


So . . . you may now legally consume marijuana in Nevada. Congrats. I would like to be able to simply caution you to “imbibe responsibly” just like every alcohol company does in their advertisements. The problem with the foregoing warning, with marijuana, is that it is insufficient. Although you can drink responsibly to avoid criminal prosecution for alcohol-DUIs, you can interact with your fellow citizens responsibly to avoid criminal prosecution for crimes against the person, there is really no way for you to consume marijuana responsibly (or play poker next to a friend that is smoking) unless you also forfeit the ability/right to drive. Until Nevada’s marijuana-DUI laws are amended to punish driving while impaired by marijuana, the circumstances will not change.

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The Legalization of Marijuana and Nevada’s Marijuana-DUI Law
This article helps explain how Marijuana consumption and DUI laws can affect you.