Delta-8 THC, the 2018 Farm Act, and the Growing Challenges of Drug Testing and Impairment
How the 2018 Farm Act Changed Cannabis Legality
The passage of the Agriculture Improvement Act of 2018, commonly known as the Farm Act, fundamentally changed the legal landscape for cannabis-related substances in the United States. While the legislation was intended to clarify the legality of hemp and promote agricultural innovation, it has also introduced significant complexity for employers, policymakers, cannabis users, and others who rely on drug testing and impairment determinations.
What is Delta-8 THC and The Problems for Drug Testing
One of the issues at the center of this challenge is delta-8 THC, a psychoactive cannabinoid derived from hemp. The Farm Act legalized hemp by defining it as cannabis containing no more than 0.3 percent delta-9 THC on a dry-weight basis. This narrow definition, focused solely on delta-9 THC, unintentionally opened the door for other intoxicating cannabinoids that can be synthesized from hemp-derived CBD. Delta-8 THC is the most prominent example.
From a drug testing perspective, this distinction matters. Standard workplace drug tests are designed to detect THC metabolites, not to differentiate between delta-9 THC from marijuana and delta-8 THC derived from hemp. As a result, an individual may test positive for THC despite believing they were using a federally legal product. This creates confusion, dispute, and mistrust, particularly when the individual does not perceive their conduct as illegal or unsafe.
Impairment vs. Presence: The Core Scientific Gap
The impairment issue further complicates matters. Delta-8 THC produces psychoactive effects that are similar to, though often described as milder than, delta-9 THC. Research suggests delta-8 can still impair reaction time, judgment, and cognitive performance, all functions that are critical in safety-sensitive roles and impact worker productivity and driver performance. Yet there is no widely accepted impairment threshold for THC including delta-8, nor have newer technologies that measure impairment at the roadside or in the workplace been widely adopted to provide a more comprehensive case when determining recent use of impairing THC as its use soars.
Employers and regulators are thus caught between competing realities. On one hand, a substance may be lawful under federal hemp definitions and sold openly in gas stations, vape shops, and online marketplaces. On the other hand, the same substance can trigger a positive drug test and potentially compromise workplace safety, roadside safety and worker productivity. The disconnect between legality, detection, and impairment is becoming increasingly difficult to reconcile.
State Delta-8 THC Laws and the Compliance Patchwork
State laws add another layer of complexity. Some states have moved to restrict or ban delta-8 THC, while others remain silent or explicitly allow its sale. This patchwork approach makes it challenging for multi-state employers, law enforcement, and professionals to apply consistent standards or policies. What is legal in one jurisdiction may be prohibited in another, yet drug testing results look the same across state lines.
As the cannabis marketplace continues to evolve, the limitations of traditional drug testing models are becoming more apparent. The Farm Act did not eliminate risk; it shifted it into a gray area where science, law, and workplace policy often lag behind consumer access and innovation. Addressing this gap will require clearer regulatory guidance, improved testing methodologies, and a more nuanced understanding and objective measure of impairment versus presence.
Until then, use of delta-8 THC will remain a source of confusion and conflict, raising important questions about fairness, safety, and accountability in a rapidly changing legal and scientific environment.
Frequently Asked Questions About Delta-8 THC and Drug Testing
Can delta-8 THC cause a positive drug test?
Yes. Delta-8 THC is metabolized similarly to delta-9 THC, and standard drug tests cannot tell the difference. Using delta-8 can result in a positive THC test.
Does delta-8 THC cause impairment?
Yes. Delta-8 THC is psychoactive and can impair judgment, reaction time, and cognitive function, particularly in safety-sensitive activities.
How should employers handle delta-8 use?
Employers should treat delta-8 like other THC products, clearly communicate testing risks, and focus policies on safety and impairment rather than legality.
About The Author
Nina M. French is a nationally recognized expert in workplace drug and alcohol testing, impairment, safety, and regulatory compliance. With 30+ years of experience, she provides litigation support and expert witness testimony, translating complex issues, policies, and testing practices into clear, defensible guidance for courts.
About Capwell Consulting Group
Capwell Consulting Group is a nationally recognized litigation support and risk mitigation consulting firm specializing in highly regulated industries. Our firm provides industry-leading guidance, research, reporting, and expert witness testimony for legal proceedings involving employment screening & negligent hiring, FCRA litigation, drug & alcohol testing, and medical device quality and regulatory compliance matters. With over three decades of industry experience, Capwell Consulting Group is a trusted advisor to employers, attorneys, and consumers around the globe.
The information published within is provided for educational purposes only. The information is not intended to or constitute legal advice; instead, all information, content, and materials are published for general informational purposes only and not considered the views of a particular expert or consultant of Capwell Consulting Group, LLC. © 2026 http://www.capwellconsulting.com