Last year, Minnesota legalized the recreational use of cannabis for adults over the age of twenty-one. In a prior eLaw article, I wrote about the tension between the Lawful Consumable Products Act’s (“LCPA”) prohibition on adverse employment action arising from an employee’s off-duty, off-premises use of cannabis and the sensitivity of available cannabis tests without a reliable way to differentiate between positive results arising from off-duty, off-premises use and current intoxication or recent use.[1] Existing laboratory tests of urine or blood for cannabis can detect cannabis used within three days for a one-time user and within more than thirty days for chronic heavy users.[2] As a result, employers testing for cannabis, even within the restrictions placed on such testing last year, could find themselves with LCPA liability for taking adverse employment action based on a urine or blood test. But a recent change in Minnesota law authorizing oral fluid testing, while not solving the problem, may make it easier for employers to navigate between the LCPA and the Drug and Alcohol Testing in the Workplace Act, as amended.
In the 2024 legislative session, the Minnesota legislature modified Minnesota Statutes sections 181.950, .951, and .953 to authorize employers to use “oral fluid test[s]” in their drug and alcohol testing programs, as long as the tests are not more sensitive than licensed, accredited, or certified laboratory tests.[3] The bill was aimed at eliminating the need to travel off-site and allow newly hired employees to start work immediately.[4] The bill’s sponsor cited concerns that off-site drug and alcohol testing causes potential employees to abandon job offers because they will not go to the testing facility to complete the test and causes delays in employee start dates.[5] While it seems that the authorization of oral fluid testing was not aimed at providing employers with a testing option that allows the detection of more recent cannabis use with the potential elimination of more temporally remote use, that is one of the effects of the change in the law. The sensitivity of oral fluid screening tests for cannabis in oral fluid screening tests drops rapidly post-consumption as compared to laboratory tests—even laboratory tests which also use oral fluid.[6] Studies conducted on oral fluid screening tests have shown varying levels of sensitivity over time, with some tests returning negative results every time beyond the two-hour post-consumption mark, and others returning negative results about half the time by the twenty-hour post-consumption mark.[7] In any event, oral fluid screening tests generally are examining a much shorter timeframe than traditional blood or urine laboratory tests.[8]
If an employer chooses to implement oral fluid testing, the employee must be informed of the test result at the time of the oral fluid test.[9] If the result is positive or inconclusive, the employee may request a laboratory test within 48 hours.[10] Tests still must be administered according to the employer’s drug and alcohol testing program, and tests for cannabis must be limited to those employees for whom cannabis remains defined as a “drug.”
By choosing the right oral fluid test, employers may mitigate some of the risk arising from the tension between the LCPA and the high sensitivity of laboratory cannabis tests. Selecting a test which only detects more recent use makes it less likely that an employee will test positive for off-duty, off-premises use. However, this is far from foolproof, and will not prevent all potential liability. In addition, the link between detected THC levels and intoxication is still unreliable.[11] Furthermore, choosing an oral fluid test with too low sensitivity may put other employees, customers, and the workplace more generally at risk, if it ultimately allows intoxicated employees to continue working, thus exposing the employer to an entirely different set of liability. As a result, prudent employers should rely on more than only a positive drug test when taking adverse employment action based on suspected marijuana intoxication. Observing and documenting other signs of intoxication, such as appearance, smell, and behavior is important and will help stave off defenses based on off-duty, off-premises use.
Changes in cannabis testing will continue to come, and employers will continue to need to adapt. Challenges with detecting recent cannabis use and actual impairment are not unique to the employment world, with impaired driving enforcement being the most obvious non-employment example. As technology improves, it may become easier to navigate the LCPA as it relates to cannabis, like it is for alcohol. Until then, risk mitigation strategies such as implementing oral fluid testing with a sensitivity that balances the risk of detecting off-duty use and the need to prevent an intoxicated workforce and relying on other indicators of intoxication and drug use when taking adverse employment action may be the best course of action.
[1] See Adam N. Froehlich, Drug Testing Employees in the Age of Legal Recreational Cannabis, eLaw: Employment & Human Resources, Fall 2023, https://www.gislason.com/employment-human-resources-spring-2023-2/.
[2] Karen E. Moeler, et al., Clinical Interpretation of Urine Drug Tests: What Clinicians Need to Know About Urine Drug Screens, Mayo Clinic Proceedings, Mar. 18, 2017, at 774, 778–781.
[3] 2024 Minn. Laws. Ch. 110, Art. 7, §§ 4–8.
[4] Brian Basham, Lawmakers Want to Add Oral Test Option as Preemployment Alternative to Drug Screening, Session Daily, Feb. 15, 2024, 4:48 PM, https://www.house.mn.gov/SessionDaily/Story/18064.
[5] Id.
[6] Erica Wennberg, et al., Roadside Screening Tests for Cannabis Use: A Systematic Review, 9 Heliyon e14630,14 (2023).
[7] Id. at 13.
[8] Compare id. at 13 with Moler, et al., supra, at 774, 778–781.
[9] 2024 Minn. Laws. Ch. 110, Art. 7, § 8.
[10] Id.
[11] See Field Sobriety Tests and THC Levels Unreliable Indicators of Marijuana Intoxication, Nat’l Inst. of Justice, April 5, 2021, https://nij.ojp.gov/topics/articles/field-sobriety-tests-and-thc-levels-unreliable-indicators-marijuana-intoxication; Inmaculada Fierro, Juan Carlos Gonzalez-Luque, & F. Javier Alvarez, The Relationship Between Observed Signs of Impairment and THC Concentration in Oral Fluid, 144 Drug and Alcohol Dependence 231 (2014).
