Workplace Drug Testing: Choosing Between 4-Panel and 5-Panel (with THC)

TL;DR: If your priority is maximizing detection of commonly abused substances, including marijuana, choosing a 5-panel drug test may be best for your organization. If your organization (or state law or local policy) limits testing for THC, a 4-panel test (which can be configured to omit THC) may be appropriate. 

Read on for a practical comparison, detection-window context, HR and legal considerations (including DOT rules), and real-world guidance to implement testing confidently with the help of drug screening coordinators.

What “4-Panel” And “5-Panel” Actually Test

• 5-panel drug test — commonly screens for: THC (marijuana), cocaine, opiates, amphetamines/methamphetamine, and phencyclidine (PCP). This is the most common baseline for general workplace screening.
• 4-panel drug test — typically covers the same five categories, except it omits THC, or, less commonly, omits another category depending on employer needs. Employers choose a 4-panel when they specifically want to avoid screening for marijuana.

Quick Comparison (At A Glance)

Feature	4-Panel (no THC)	5-Panel (with THC)
Substances typically screened	Cocaine, Opiates, Amphetamines, PCP	Cocaine, Opiates, Amphetamines, PCP, THC (marijuana)
Best for	Employers in states with legalized marijuana who don’t want to test for THC	Employers who want marijuana included (safety-sensitive roles, federal contractors)
Detection window (urine, typical)*	1–7 days for most; varies by drug	THC: 1–30+ days (single to chronic use). See Legal & HR section. (NCBI)
Typical sample	Urine (instant cups like STATCUP available)	Urine (instant cups or lab confirmation)
Use case	Some white-collar roles, non-DOT employers avoid THC	Construction, manufacturing, transportation (non-DOT employers), safety-sensitive roles
Pros	Lower employee friction where medical/recreational cannabis is legal	Stronger deterrent and broader safety protection
Cons	May miss marijuana impairment; less comprehensive	May detect lawful off-duty cannabis use—HR policy complexity

* Detection windows are approximate and influenced by frequency of use, metabolism, and laboratory cutoffs. See citations. (NCBI)

Real-World Example Scenario

A mid-sized facilities company with 120 field technicians in multiple states switches from a 4-panel (no THC) to a 5-panel after a series of near-miss incidents. Practical steps they could take:

1. Work with a third-party administrator to implement random testing.
2. Train supervisors on signs of impairment and proper incident documentation.
3. Route positives through a Medical Review Officer (MRO) to confirm legitimate prescriptions.
4. Offer confidential assistance for employees who tested positive and were eligible for support.

After updating the handbook and offering an education + return-to-work program, the company records a measurable drop in safety incidents over 12 months and improves insurance negotiations with their carrier. 

If you need help operationalizing something like this, a dedicated drug testing coordinator can assist with program setup, MRO coordination, and kit fulfillment.

Legal & HR Considerations (must-read)

1. DOT & safety-sensitive roles: If you employ safety-sensitive personnel covered by DOT rules, follow 49 CFR Part 40 and the specific DOT agency regulations (FMCSA, FAA, FTA, PHMSA, etc.). DOT has strict procedures for specimen collection, testing, and consequences. Non-compliance can shut down operations or trigger fines.
2. State marijuana laws vary: Many states have legalized medical and/or recreational marijuana, and some have protections for employees who are medical cannabis patients. Employers must balance safety and legal risk, especially for off-duty, lawful use. The National Conference of State Legislatures (NCSL) provides a regularly updated overview of state cannabis policies that is essential for multi-state employers.
3. Medical Review Officer (MRO): Always route positives through an MRO to confirm prescription explanations or legitimate medical use. This step reduces wrongful terminations and legal exposure.
4. Policy clarity: Your drug & alcohol policy should state which panels you use (4 vs 5), when tests will be administered (pre-employment, random, post-accident), disciplinary steps, and reasonable accommodation procedures. Keep documentation and train managers.
5. Privacy & ADA considerations: A positive result may implicate privacy and disability law (Americans with Disabilities Act) if the cause is a prescribed medication. Consult counsel for complex cases.

How to Choose 

• Are any employees covered by DOT? → If yes, follow DOT panel requirements and Part 40 procedures.
• Is workplace safety critical (e.g., heavy machinery, driving)? → Prefer 5-panel (with THC) to detect marijuana.
• Do you operate in states with medical/recreational cannabis? → Consult state law (NCSL) and tailor policy. 
• Budget and test cadence: instant cups (on-site) like STATCUP are cost-effective for screening; positives can be sent to certified labs for confirmation.  Consider 5 panel drug test or 4 panel drug test product options. 

Practical Implementation Tips

• Use integrated cups with adulterant checks (pH, SG, oxidants) to reduce tampering.
• Random testing requires a fair, statistically defensible selection method.  Document it.
• For post-accident testing: document the incident, secure the scene, and follow your policy. DOT employers have additional notice/time rules under Part 40. 
• Maintain a relationship with a reliable lab and an MRO — speed of confirmations matters for business continuity.

What DrugTesting.com Brings

• Two decades of program experience coordinating MROs, labs, and on-site screening.
• Nationwide kit distribution + program design (pre-employment, random, post-accident).
• Product examples: STATCUP instant cups with adulterant detection — ideal for fast screening and lab transport.

Takeaways

1. For maximum safety coverage, choose a 5-panel drug test (includes THC).
2. If state law, company culture, or sensitivity to lawful off-duty cannabis matters, consider a 4-panel while documenting rationale.
3. Always pair screening with a clear drug & alcohol policy, MRO confirmation, and legal guidance for multi-state operations (see DOT resources and NCSL). 

Comparison Chart 

Question	Choose 4-Panel	Choose 5-Panel
Need to detect marijuana?	No	Yes
DOT safety-sensitive employee?	Not applicable (federal rules apply)	Not applicable (DOT has its own spec)
Multi-state with legalized cannabis?	Consider reducing disputes	Use if safety requires detection
Best for	Roles where THC testing is undesirable	Construction, transport, safety-sensitive

Conclusion

More than a compliance decision, selecting between a 4-panel and a 5-panel drug test is a matter of protecting your employees, safeguarding productivity, and reducing costly incidents. 

Whether your priority is staying compliant with DOT standards, respecting state marijuana laws, or simply improving workplace safety, having a clear policy backed by testing from reliable drug screening coordinators is essential.

Ready to take the next step?

• Talk to a drug testing coordinator to design a compliant program tailored to your industry.
• Order kits online today: choose the 5 panel drug test for comprehensive screening or the 4 panel drug test if THC testing is not required.
• Ensure your policy, testing schedule, and HR procedures are documented and communicated to every employee.

With more than 20 years of experience, DrugTesting.com has helped businesses nationwide create safer, more productive workplaces. Get started today and make workplace safety a competitive advantage.