Legalization of Marijuana in Colorado: Employer Guidelines for Workers’ Compensation Claims


Legalization of Marijuana in Colorado:

Employer Guidelines for Workers’ Compensation Claims

N. Elizabeth Quick, Esq.


On November 6, 2012, Colorado became the first State to legalize marijuana with the passage of Amendment 64. Under Amendment 64, persons over the age of twenty-one will be allowed to legally possess up to one ounce of marijuana[1]. However, the Amendment contains a provision for employers, subsection six (6). This provision states, “Nothing in this section is intended to require an employer to permit or accommodate the use, consumption, possession, transfer, display, transportation, sale or growing of marijuana in the workplace or to affect the ability of employers to have policies restricting the use of marijuana by employees.”

Despite Colorado legislation, possession and growing of marijuana remains illegal under federal law, and is classified as a Schedule I Controlled Substance under the Federal Controlled Substances Act. Given the conflict between State and Federal Law, how do employers proceed? State laws which conflict with, or are contrary to, federal laws are invalid[2]. We anticipate substantial litigation regarding the constitutionality of Amendment 64, and the Department of Justice has pledged to challenge Amendment 64 in federal court. Given that Federal Law ultimately controls, we recommend all employers update, or implement, a “no tolerance” policy for drugs and alcohol.

While marijuana may be legal in Colorado, employers may still use consumption of marijuana as a basis for a safety rule violation or termination for cause in a workers’ compensation claim. The hallucinogenic agent in marijuana is THC, and can be detected at a level of 5ng/mL[3].  THC is stored in the body’s fat, making it possible to detect for up to 13 days[4]. However, only 20% of THC is detectible in a urine screen[5], as the THC has already passed through the body.  If an employer is randomly testing employees for drug use, we recommend urine screens as the standard protocol. The THC present in the drug screen will be sufficient to show use and support a termination for cause defense.

However, THC is also detectible in the blood, and blood tests will show the current levels of THC in the employee’s bloodstream; the level of THC intoxication (see footnote 5). While a toxicologist may testify regarding THC levels expected in a “recreational user” versus the THC levels present in a blood sample, there is currently no State recognized level of marijuana intoxication. Despite this oversight in regulation, we recommend employers require employees to submit to a blood test if an accident or safety rule violation has occurred. The practice of employer-required blood tests has repeatedly been upheld by the Courts[6].

To prove a safety rule violation, the employer and insurer must show the injury was caused by the employee’s marijuana use[7]. The blood sample will allow the toxicologist to testify regarding how the level of THC in the employee’s blood would have affected job performance at the time of the injury. Common signs of marijuana impairment include: distorted perceptions; impaired coordination; difficulty with thinking and problem solving; and problems with learning and memory[8].

In summary, despite the passage of Amendment 64, employers may continue to hold their employees accountable for marijuana use on the job through the safety rule violation and termination for cause provisions of the Workers’ Compensation Act. Please do not hesitate to contact our office so that we may provide additional guidance on this issue on a case by case basis.





[2] Gibbons v. Cipollone v. Liggett Group, Inc., 505 U.S. 504 (1992).

[3] Am J Addict. 2009; 18(3): 185–193.

[4] Drew, M., et al, “The Metabolism of Marijuana.” Achieve Solutions 1999., National Institute on Drug Abuse “Marijuana: Facts for Teens.” Revised March 2008., National Institutes of Health “Workshop on the Medical Utility of Marijuana.” February 1997., National Highway Traffic Safety Administration “Cannabis / Marijuana” Accessed November 2008., NORML “The ABCs of Marijuana and Drug Testing.” Apr 01, 2004.

[5] Huestis, M. A. (2005). “Pharmacokinetics and Metabolism of the Plant Cannabinoids, Δ9-Tetrahydrocannibinol, Cannabidiol and Cannabinol”.Cannabinoids. Handbook of Experimental Pharmacology 168 (168): 657–90.

[6] American Federation of Government Employees, Local 2391 v. Martin, 969 F.2d 788 (9th Cir.1992), and National Treasury Employees Union v. Yeutter, 918 F.2d 968 (D.C.Cir.1990). Skinner v. Railway Labor Executives’ Ass’n, 489 U.S. 602, 109 S.Ct. 1402, 103 L.Ed.2d 639 (1989), National Treasury Employees Union v. Von Raab, 489 U.S. 656, 109 S.Ct. 1384, 103 L.Ed.2d 685 (1989), O’Connor v. Ortega, 480 U.S. 709, 107 S.Ct. 1492, 94 L.Ed.2d 714 (1987).

[7] C.R.S. § 8-42-112 (1)(a)(b)