THCA, Delta-8, and Drug Testing
A plain-language guide for HR teams running background and drug testing programs
If a candidate has told you, “It was legal THCA,” or “I only used Delta-8, you can buy it at the gas station,” you are not alone. These conversations are happening in HR offices across Texas right now. And if you are not sure what to say back, that is a reasonable position to be in. The rules changed recently, and nobody sent HR a memo.
This article explains what is going on, what it means for your drug testing program, and what you can do about it. No technical background required.
This is general information for employers and HR professionals, not legal advice. For guidance specific to your company, talk to your legal counsel.
First: What are these products, in plain terms?
There are a few terms you will hear from candidates. Here is what they actually mean:
Delta-9 THC
This is the compound in cannabis that gets people high. It is what your drug test is designed to detect. It is federally illegal and illegal in Texas.
THCA
THCA is found in raw, unheated cannabis plants. On its own, it is not psychoactive, meaning it does not produce a high. But the moment it is smoked, vaped, or cooked, it converts into Delta-9 THC. Once that happens, the body processes it identically to any other THC source. Your drug test cannot tell the difference.
Delta-8 THC
Delta-8 is a different form of THC, typically made from hemp. It does produce psychoactive effects. It has been sold legally in many states, including Texas, but its legal status has been shifting. Delta-8 vape products are now banned in Texas. Its broader legal status is still being contested in courts.
What this means for you
When a candidate says “it was legal,” they may be right about the product they bought, or they may not be. Either way, your drug test result does not change. The test detects THC metabolites regardless of which product produced them.
What the Texas Rule Change Does and Doesn't Change
Starting March 31, 2026, Texas changed how it calculates the legal THC limit for hemp products. Under the new rule, THCA now counts toward the total THC calculation.
What that means in practice: most THCA flower and smokable products sold in Texas retail stores now exceed the legal limit. Those products are effectively off the shelves.
The change is a legal classification decision made by Texas regulators. It is not a new type of drug test. It is not a new substance. Your lab is running the same tests it always has.
What this means for you
You will likely see more candidates referencing THCA products, particularly those they bought before March 31 or sourced outside Texas. The product's legal status does not change how your policy applies. A positive is a positive.
“The law changed. The science did not. What we spend a lot of time on right now is helping HR teams have confident, consistent conversations when candidates push back on results.— Chandra Kill, President & CEO, KRESS Employment Screening
If you are weighing the benefits of pre-employment drug testing for the first time, the fundamentals have not shifted.
What does your drug test actually detect?
Most workplace drug tests detect a metabolite called THC-COOH. A metabolite is what your body produces after processing a substance. THC-COOH looks exactly the same whether it came from THCA, Delta-8, or Delta-9 products.
Here is how the testing process works:
- Step 1, Initial screen: A urine sample is tested using an immunoassay. If the result is above the cutoff threshold (typically 50 ng/mL), it is flagged as a presumptive positive.
- Step 2, Confirmatory test: A second, more precise test (usually GC-MS or LC-MS/MS) confirms the result. The confirmatory cutoff is 15 ng/mL. This step reduces false positives significantly.
- What the test cannot do: Identify which specific product caused the result. There is no standard employment drug test that can distinguish between THCA, Delta-8, and Delta-9 as the source.
A line you can use when candidates push back
“Our screening detects THC metabolites. The test cannot identify which product produced the result. Our policy applies to the result, not the product story.”
How long does THC stay in someone’s system?
Detection time depends on the type of test, how often the person uses it, and individual factors like metabolism and body composition. These are general ranges, not guarantees.
Test Type | Detection Window | Notes |
Urine | 1 to 30 days | Most common for employment. Frequent users may detect longer. |
Saliva | Up to 72 hours | 24 hrs for occasional users; up to 72 hrs for frequent users. |
Hair | Up to 90 days | Longer window; used when historical use matters. |
Blood | Hours to days | Short window; mainly used to detect very recent use. |
What can you do?
The good news: you probably do not need to overhaul your program. You need to tighten a few things so you are not caught off guard in a candidate conversation or a dispute.
1. Check your policy language
Your policy should say your program tests for THC metabolites, not “marijuana” or “cannabis.” It should also state that the test cannot identify the source product. Two short sentences. That is it.
- Add: “This program tests for THC metabolites. Results do not identify the product source.”
- Add: List the testing categories that apply: pre-employment, post-accident, random, reasonable suspicion, or whichever categories your program includes.
2. Brief your hiring managers
Hiring managers are usually the first ones to hear a candidate’s product story. They need one clear instruction: the product story does not change the result, and they do not have the authority to promise a retest or an exception. That decision belongs to HR and your policy.
If a hiring manager promises a candidate they can “work around it,” that inconsistency is where disputes start. One clear message to your managers now prevents a much harder conversation later.
3. Prepare two short candidate messages
You do not need a legal brief. You need two clear, calm sentences for two moments:
- Before the test: “Our screening includes a test for THC metabolites. This test cannot determine the source product. If you have questions, contact us before your test date.”
- After a positive result: “Your screening results have been received. [Next step]. If you have questions, please reach out to [contact name and method].”
4. Follow your process every time
This is the most important one. Consistency is what protects you and the candidate from being treated differently from anyone else. If your policy says a positive result triggers a specific process, follow that process. Every time. No exceptions for compelling stories.
Who handles what?
KRESS documents the result and routes it correctly. HR holds the policy line. If a result needs to go to a Medical Review Officer (MRO) for evaluation, that happens through the proper channel, not through an HR conversation about whether a product was or was not legal.
Quick answers to the questions you’re probably hearing
Can we tell if the THC came from THCA vs. Delta-9? | No. Standard employment drug tests detect THC metabolites. They cannot identify which product produced those metabolites. |
A candidate wants a retest. Do we have to do that? | A retest does not change what the original result detected. Follow your policy. If your policy does not address retests, that is worth clarifying with your legal counsel. |
What if the candidate says the product was legal in Texas? | The legal status of the product does not change the test result or the way your policy applies. Apply the policy consistently. |
Does the March 31 Texas rule change affect how we test? | No. The lab process is identical. The rule change affects which products are legally sold in Texas retail, not how THC is detected in a drug test. |
What does an MRO do in this situation? | A Medical Review Officer evaluates medical explanations for a positive result. They do not evaluate product legality. Route MRO-eligible results to the MRO, and keep HR out of that evaluation. |
What to do if you want a second set of eyes
If your policy language has not been reviewed recently, or if your team is fielding more of these candidate conversations than you are comfortable with, that is worth a conversation.
Talk to a KRESS screening specialist. We will review your current drug testing policy, flag what needs updating, and explain exactly which steps we handle from there. We are a real team based in Houston, and we answer the phone when you call.