Key Takeaways:
- Specimen Validity Testing (SVT) ensures urine drug test samples are accurate by detecting tampering, adulteration, and substitution.
- SVT detects adulteration, substitution (synthetic urine), and dilution (excessive water intake) to manipulate drug test results.
- SVT is required by agencies like the DOT and HHS to ensure fair, accurate, and compliant drug testing in the workplace.
When it comes to workplace drug testing, accuracy and integrity are non-negotiable. Employers rely on test results not just to make informed hiring decisions, but also to meet strict DOT and industry compliance requirements. Any attempt to tamper with a specimen threatens safety, compliance, and fairness.
That’s where Specimen Validity Testing (SVT) comes in. As a quality control step in urine drug testing, SVT helps laboratories confirm that a specimen is authentic, untampered with, and reliable. At WorkforceQA, we provide advanced drug and alcohol testing services, including SVT, to safeguard workplace safety and compliance.
In this article, we’ll explain what SVT means, how it works, what it detects, and why it’s a critical tool for employers.
What Is Specimen Validity Testing (SVT)?
Specimen Validity Testing (SVT) is the laboratory process of determining firming whether a urine specimen is consistent with normal human urine. It is a built-in quality control measure designed to detect specimen tampering, adulteration, substitution, dilution, or substances that interfere with the analysis..
SVT is often conducted on drug testing in a variety of settings, including:
- General Workplace drug testing programs
- DOT-regulated testing for commercial drivers and other safety-sensitive employees
- Legal and court-ordered drug testing
- Clinical monitoring and pain management testing
Why SVT Matters for Employers and Safety
1. Preventing Drug Test Cheating
Common tampering methods include adulteration, dilution, and substitution. Without SVT, these attempts might go undetected, resulting in unsafe hires, compliance violations, and increased liability risks.
2. Ensuring Accurate and Fair Results
SVT doesn’t just protect employers; it also protects employees. By detecting tampering, SVT prevents false accusations and ensures a level playing field for all participants.
3. Meeting Regulatory Requirements
The DOT, Nuclear Regulatory Commission (NRC), Department of Health and Human Services (HHS) and other regulatory agencies require SVT as part of federally mandated drug testing programs. WorkforceQA follows all federal standards and best practices to ensure compliance.
How Specimen Validity Testing Works
All urine specimens are initially tested to measure creatinine, specific gravity, pH, and nitrites or other oxidants.
Creatinine Levels
- Normal range: ≥20 mg/dL
- If creatinine is <20 mg/dL, the specific gravity is measured.
Specific Gravity
- Normal range: ~1.003–1.020
- If the specific gravity <1.003 and the creatinine is <20, but >5 mg, the specimen is considered dilute.
- If the specific gravity is <1.001 and the creatinine is <2 mg, the specimen is considered substituted. It is not consistent with a physiologically occurring human urine specimen If the specific gravity and creatinine measurements are abnormal, but do not meet the definitions above, the specimen is invalid for further testing
pH Level
- Normal physiological range: 4.5–9
- Results of pH <4 or >11 indicate adulteration of the specimen with acids or bases (alkaloids) .
- Questionable pH measurements (4.0—4.5 or >9 but <11) are considered invalid for testing and generally another specimen must be collected.
Oxidants & Nitrites
- Detects nitrites and oxidizing agents such as bleach, hydrogen peroxide, or chromates.
- Nitrites above 500 mcg/mL are indicative of tampering and specimen adulteration. Nitrites 200-500mcg/mL are reported as invalid and may be due to physiological properties of the urine or dietary practices.
Other Adulterants
Certain commercial products marketed to “beat drug tests” contain various substances or chemicals, which may be indicated by the SVT and can then undergo additional analysis for a specific adulterant or interfering substance flagged by SVT.
Common Methods of Tampering That SVT Detects
Specimen adulteration and substitution generally happen at the collection site. Most urine specimens obtained for drug testing purposes are not directly observed or witnessed while the employee is urinating.
Adulteration
The employee adds something to his/her urine specimen that will interfere with the laboratory testing, mask drugs in the urine, or destroy drug metabolites present in the urine.
Substitution
Substitution is when the employee replaces his or her own urine with a synthetic urine product, a liquid resembling urine in color or consistency, animal urine, or even with someone else’s urine. The substitute specimen is surreptitiously brought into the collection site and put into the collection container in the privacy of the toilet room. There are sophisticated devices designed to pass these substitute specimens off as the employee’s own freshly voided urine specimen. These devices heat the substitute specimen to internal body temperature, and enable them to look like human urine.
Dilution
A dilute urine in which both the creatinine and specific gravity are below the normal range for the general population may be the result of an intentional attempt to manipulate the urine drug test. Adding water to a specimen during the collection or consuming excessive fluids immediately prior to the specimen collection may lower the amount of drug/metabolite in the urine below the cut-off values used to report a specimen as positive. Thus, a negative dilute urine may be a “false negative” result. Federal drug testing rules allow for a negative dilute test to be re-collected with instructions to the employee to limit excessive water intake in the hours preceding the test.
What Happens If a Specimen Fails SVT?
If a specimen fails SVT, it may be reported by the laboratory as “invalid,” adulterated or substituted. A MRO (Medical Review Officer) reviews the results and interviews the employee to discuss the laboratory findings. The MRO may also consult with the laboratory toxicologist for additional information about the specimen.
For invalid results, the MRO will ultimately cancel the test and order the re-collection of another specimen, often using direct observation collection procedures to deter tampering during the collection.
For adulterated or substituted results, the MRO, after interviewing the employee, reports the test as a refusal to test.
Advanced Trends in SVT
As tampering methods evolve, SVT technology advances too. Current trends include:
- Use of biomarkers (like urinary tract glycoproteins) to detect synthetic urine.
- Expanded detection for new adulterants found in commercial “detox” products.
- Enhanced lab technology to stay ahead of modern tampering attempts.
At WorkforceQA, we continually update our methods to address emerging threats and maintain the integrity of our testing.
Partnering with WorkforceQA for Reliable Drug Testing
Specimen Validity Testing is a tool to ensure drug test results are accurate, reliable, and fair . By detecting urine specimen dilution, adulteration, or substitution, SVT safeguards workplace safety, ensures regulatory compliance, and maintains fairness for all participants.
WorkforceQA combines advanced drug and alcohol testing services with deep compliance expertise, supporting organizations in regulated industries and beyond. WFQA includes SVT in drug testing laboratory services, and along with extensive quality controls in our DOT physicals and background check services, we strive to ensure that every drug test, DOT physical exam, and background check is accurate and meets compliance and regulatory standards.
👉 Learn more about WFQA’s Drug and Alcohol Testing Services.
