Colorado Drug Testing Laws for Employers

Nothing Prescribed

There is no Colorado testing statute and no agency designating safety-sensitive occupations. Pre-employment, random and post-accident testing are all available, and nothing dictates how the program is built. What Colorado has instead are three consequence statutes a multi-state employer has to build around — two that pay you back, and one that creates exposure.

Two Statutes, Two Sets of Preconditions

This is the Colorado problem in one table's worth of detail.

Workers' compensation, C.R.S. 8-42-112.5. Nonmedical benefits are reduced fifty percent where the injury results from the presence during working hours of controlled substances not medically prescribed, or a blood alcohol level at or above 0.10 percent (or a lower applicable federal level), as evidenced by a forensic drug or alcohol test conducted by a medical facility or laboratory licensed or certified to conduct such tests. Three conditions sit inside that one sentence, and each is a place a program can quietly fail.

The same subsection adds a collection obligation employers often miss: a duplicate sample from any test must be preserved and made available to the worker for a second test at the worker's expense. Where the test is positive, it is presumed the employee was intoxicated and that the injury was due to the intoxication — a presumption rebuttable only by clear and convincing evidence. Nonmedical benefits means everything other than medical, surgical, nursing and hospital services and supplies, so medical treatment itself is not reduced.

Unemployment, C.R.S. 8-73-108(5)(e)(IX.5). Disqualification requires a previously established written policy, a licensed or certified facility, and uses 0.04 percent.

So the alcohol thresholds differ by more than double, and only one of the two requires a written policy. The practical answer is straightforward and worth stating plainly: build to the stricter of the two and you qualify for both. That means a written policy established in advance, a forensic test at a licensed or certified facility, a preserved duplicate sample, and the lower alcohol threshold.

A separate fallback sits in C.R.S. 8-42-112(1)(b), which reduces compensation fifty percent where injury results from the employee's willful failure to obey any reasonable rule adopted by the employer for the employee's safety.

The Lawful Activities Statute Is the Live Exposure

C.R.S. 24-34-402.5(1) makes it a discriminatory or unfair employment practice to terminate an employee for engaging in any lawful activity off the employer's premises during nonworking hours — unless the restriction relates to a bona fide occupational requirement or is reasonably and rationally related to the employment activities and responsibilities of a particular employee or a particular group of employees, rather than to all employees, or is necessary to avoid a conflict of interest or its appearance.

Two features matter for a large program:

• The exception is written around particular employees or groups, not blanket company-wide rules. An employer relying on it should be able to explain why the tested population in particular needs the restriction. A uniform all-employee policy is exactly the shape the exception is drafted against.
• Fee shifting always applies at your size. The sole remedy is a civil action for damages, and a prevailing plaintiff recovers court costs and a reasonable attorney fee. That fee provision is inapplicable only to employees of businesses with fifteen or fewer employees during twenty or more calendar work weeks — which does not describe an employer of several hundred or several thousand. Modest claims are therefore worth filing against you.

Whether a positive random test that reflects only off-duty consumption triggers this statute is a question Colorado appellate courts have addressed rather than the legislature. It is not resolved on the face of the statute, and we are not going to resolve it here — but it is the single most useful question to put to your employment counsel about Colorado.

Cannabis: No Protection Statute, One Open Question

Colorado has no cannabis employment protection statute. C.R.S. 44-10-104(5)(a) provides that nothing in the Colorado Marijuana Code requires an employer to permit or accommodate use, consumption, possession, transfer, display, transportation, sale or cultivation of regulated marijuana in the workplace, or affects the ability of employers to have policies restricting employee use. Subsection (b) preserves the right of anyone occupying, owning or controlling property to prohibit or regulate marijuana there.

On the medical side, C.R.S. 25-1.5-106 creates the medical marijuana program — registry cards, debilitating conditions, physician standards, a medical review board, the program cash fund — and the word employer does not appear in it.

That leaves the lawful activities statute as the only theory available to a Colorado employee, and it protects lawful activity rather than cannabis specifically. Whether cannabis use qualifies given its federal status is a case-law question, and the answer should be confirmed with counsel before relying on it in either direction.

Applicants

Nothing restricts pre-employment testing, there is no cannabis-specific applicant protection of the kind California has, no statute bars asking applicants about prior drug or cannabis use, and no statute conditions applicant testing on a conditional offer. Note the drafting point above: the lawful activities statute reads on its face as an employee protection rather than an applicant protection, though whether it nonetheless reaches hiring decisions is an interpretive question rather than one the statute answers.

A Note on Currency

The citations here are to the 2024 edition of the Colorado Revised Statutes published by the Office of Legislative Legal Services, which was the most recent edition posted at the time of review. Colorado's constitutional cannabis provisions are published only through a subscription portal that could not be read directly, so the cannabis entries here are grounded in verified statutory text and reference the constitutional sections only as the statutes themselves do. Both points are worth knowing if you are checking a 2025 or 2026 session change.

Where This Lands

Colorado's employment base spans aerospace and defense, healthcare, construction, transportation and warehousing, oil and gas extraction, tourism and outdoor recreation, and a substantial cannabis cultivation and retail sector. For employers with genuinely safety-sensitive populations the lawful activities exception is defensible with documentation; for office-weighted employers running uniform company-wide testing, it is the provision most likely to produce a claim.