Toxicology Expert’s Testimony on Hair Follicle Testing Admitted
Posted on October 2, 2025 by Expert Witness Profiler
Plaintiff Darius Danzy filed this suit against CSX Transportation Inc. in this action under Title VII of the Civil Rights Act of 1964, as amended (“Title VII”) alleging “unlawful employment practices on the basis of race.”
Plaintiff’s claims arise out of a pre-employment drug-screening that Defendant administered to Plaintiff through third party drug testing companies, Psychemedics Corporation (“Psychemedics”) and Omega Laboratories, Inc. (“Omega”).
According to the Plaintiff, Defendant discriminated against him because of his race as a “Black-African American” by subjecting him to narcotic testing that disparately impacts the “class of Black African Americans” due to the allegedly unreliable and inaccurate method of hair follicle testing used by Defendant through Psychemedics in its pre-employment drug screening.
The Defendant retained Dr. R.H. Barry Sample to review the testing performed by Psychemedics of Plaintiff’s underarm hair specimen.
Plaintiff sought to exclude the testimony of Sample and the hair test results provided by Psychemedics pursuant to Rules 702 and 104(a) of the Federal
Rules of Evidence.
Toxicology Expert Witness
Dr. R.H. Barry Sample is a forensic toxicologist with a Ph.D. in the field of Pharmacology from Indiana University and has worked in the field of forensic toxicology for over thirty-five years.
For over twenty years Sample worked as the Director of Science and Technology for Quest Diagnostics, “one of the largest forensic workforce (workplace) drug testing laboratory providers in the United States.” Sample served two separate four-year terms as a member of the Substance Abuse and Mental Health Services Administration (“SAMHSA”) Drug Testing Advisory Board (“DTAB”) and advised on the SAMHSA drug testing activities and laboratory certification program.
Sample continues to serve as a commissioner and laboratory inspector for the College of American Pathologists (“CAP”) in its Forensic Drug Testing (“FDT”) accreditation program (“CAP-FDT”). Sample has been licensed or certified by various states as a laboratory director in the area of forensic workforce drug testing.
Discussion by the Court
Sample opined that Psychemedics’ test results are accurate and scientifically reliable and that Omega’s test results confirmed the accuracy of Psychemedics’ test results.
Plaintiff primarily brought a relevance-based argument that hair follicle testing itself is legally improper as this methodology is not included in the regulations of SAMHSA.
A. Relevance
According to the Plaintiff, SAMHSA in its 2020 Proposed Hair Guidelines explicitly excludes Benzoylecgonine (“BZE”) as a reliable confirmatory marker due to its low concentrations in hair and the absence of validated thresholds.
Plaintiff contended that “Congress explicitly assigned SAMHSA the exclusive
role to regulate drug testing in Federally regulated industries through the Omnibus Transportation Employee Testing Act.”
Sample served two (2), four-year terms as a Member of the SAMHSA Drug Testing Advisory Board which advises the Assistant Secretary of SAMHSA, on the review of the direction, scope, balance, and emphasis of the SAMHSA drug testing activities and the drug testing laboratory certification program.
The Court found that his experience provided him with unique insights into the scope and requirements of SAMHSA drug testing. Sample acknowledges that “only urine drug testing is possible under DOT rules” and that the hair sample test that Defendant undertook “is not covered by the requirements of the DOT, Federal Railroad Administration (‘FRA’), or [SAMHSA].”
Sample noted that “neither the DOT nor SAMHSA (which the DOT relies on for technical guidelines) have published final requirements for hair testing.”
The Omnibus Transportation Employee Testing Act of 1991 directed the Secretary of Transportation to develop regulations for the testing of employees for drugs and alcohol in four sectors of the transportation industry, including railroads.
Notably while the statute requires that “laboratories and testing procedures for controlled substances, incorporate the Department of Health and Human Services scientific and technical guidelines,” they do not prohibit a private employer in the railroad industry from conducting additional drug testing procedures beyond those prescribed by the DOT.
In sum, the Court held that Sample’s opinions are outside the common experience of lay persons and, therefore, explains the unique process of hair follicle testing for drug usage.
B. Reliability
Plaintiff’s primary objections to Sample’s report focus on its reliability. Specifically, Plaintiff contended that there is a lack of reliable, scientific evidence surrounding the use of BZE as a biomarker in hair testing.
However, Sample provided a thorough summary of the documents he reviewed in support of his report, as well as the work he undertook in forming his opinions.
Sample noted that both of the laboratories that tested Plaintiff’s hair follicle “are accredited under the CAP-FDT Accreditation Program for hair testing as well under the New York State Department of Health – Clinical Laboratory Evaluation Program for hair testing” and that they both hold “ISO/IEC 17025 accreditation.”
Plaintiff’s critique did not make detailed arguments finding fault with specific elements of Sample’s methodology or approach. Rather, Plaintiff appeared to argue that because other sources, including the federal government, have allegedly come to different conclusions, Sample ’s methodologies must be flawed. The Court, however, held that Plaintiff’s objections relate to the weight to be given to Sample’s opinions, not their admissibility.
The Court found that the Defendant has demonstrated by a preponderance of the evidence that Sample and his report satisfied the standard for expert
scientific testimony.
Held
The Court denied the Plaintiff’s motion to exclude the testimony of Dr. R.H. Barry Sample.
Key Takeaway:
The Court’s reliability analysis focuses on the “‘principles and methodology’ employed by the expert, not on the conclusions reached.”
In addition to his own experience, Sample explained that his opinion is based on “peer-reviewed scientific literature regarding forensic workforce drug
testing.” Sample also cited peer-reviewed sources in support of his
conclusions.
Case Details:
| Case Caption: | Danzy V. CSX Transportation, Inc. |
| Docket Number: | 5:23cv621 |
| Court Name: | United States District Court, North Carolina Eastern |
| Order Date: | September 19, 2025 |
