1 

2024 Medical Review Officer (MRO) Case Studies – Urine 

These case studies provide examples to supplement the Department of Health and 

Human Services (HHS) MRO Guidance Manual, February 1, 2024.

The manual and case studies apply to federal agency drug testing programs that come 

under Executive Order 12564 dated September 15, 1986, section 503 of Public Law 100-

71, 5 U.S.C. section 7301 note dated July 11, 1987, and the HHS Mandatory Guidelines for 

Federal Workplace Drug Testing Programs using Urine (88 FR 70768) dated October 12, 

2023 (effective February 1, 2024). 

The manual and case studies do not apply to specimens submitted for testing under 

Department of Transportation (DOT) Procedures for Transportation Workplace Drug and 

Alcohol Testing Programs (49 CFR Part 40).

The MRO Case Studies will be updated as needed to reflect new information. The current 

version is available on the Drug Testing page under Medical Review Officer (MRO) 

Resources on the Substance Abuse and Mental Health Services Administration 

(SAMHSA) website:

https://www.samhsa.gov/workplace
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Table of Contents for Urine Case Studies

Case #1 Laboratory Reported Result: Positive for Marijuana Metabolite (Δ9-

Tetrahydrocannabinol-9-Carboxylic Acid [Δ9-THCA])–30 ng/mL......................4

Positive Drug (Marijuana).........................................................................................................4

Case #2 Laboratory Reported Result: Positive for Morphine–5,200 ng/mL .........................5

Case #3 Laboratory Reported Result: Positive for Codeine–4,800 ng/mL ...........................6

Case #4 Laboratory Reported Result: Positive for Codeine–17,340 ng/mL and

Morphine–6,350 ng/mL ...........................................................................................7

Case #5 Laboratory Reported Result: Positive for Methamphetamine–950 ng/mL............8

Case #6 Laboratory Reported Result: Positive for Cocaine Metabolite 

(Benzoylecgonine [BZE])–1,200 ng/mL ................................................................9

Case #7 Laboratory Reported Result: Positive for Morphine–4,150 ng/mL ......................10

Case #8 Laboratory Reported Result: Positive for Methamphetamine–1,250 ng/mL 

with 255 ng/mL Amphetamine.............................................................................11

Case #9 Laboratory Reported Result: Positive for Methamphetamine–942 ng/mL 

with 250 ng/mL Amphetamine.............................................................................13

Case #10 Laboratory Reported Result: Adulterated; Nitrite = 850 mcg/mL ......................15

Case #11 Laboratory Reported Result: Invalid Result; Oxidant Activity ≥50 

mcg/mL Chromium (VI) equivalents ...................................................................16

Case #12 Laboratory Reported Result: Adulterated–Nitrite = 1800 mcg/mL and 

Invalid Result–Bottle A and Bottle B–Different Physical Appearance ............17

Case #13 Laboratory Reported Result: Positive for Morphine–5,000 ng/mL and 

Adulterated–Chromium(VI) = 90 mcg/mL...........................................................18

Case #14 Laboratory Reported Result: Positive for Marijuana Metabolite (Δ9-

THCA)–60 ng/mL and Cocaine Metabolite (BZE)–120 ng/mL...........................19

Case #15 Laboratory Reported Result: Substituted–Creatinine = 1.5 mg/dL and 

Specific Gravity = 1.0005 .....................................................................................20

Case #16 Laboratory Reported Result: Negative and Dilute–Creatinine = 6.2 

mg/dL and Specific Gravity = 1.002 ....................................................................21

Case #17 Laboratory Reported Result: Substituted–Creatinine = 1.0 mg/dL and 

Specific Gravity = 1.0005 and Invalid Result–Abnormal pH = 4.0....................22

Case #18 Laboratory Reported Result: Rejected for Testing–Fatal Flaw: Bottle A 

label/seal broken ..................................................................................................23
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Case #19 Laboratory Reported Result: Invalid (two times, different reasons) – 

Negative on the second observed collection ....................................................24

Case #20 Split Laboratory Reported Result: Failed to Reconfirm for Marijuana 

Metabolite–Reason: Invalid Result–Oxidant Activity ≥200 mcg/mL 

Nitrite Equivalents................................................................................................26

Case #21 Split Laboratory Reported Result: Failed to Reconfirm Cocaine 

Metabolite (BZE)–BZE not detected....................................................................28

Case #22 Split Laboratory Reported Result: Failed to Reconfirm [Chromium (VI)] ..........29

Case #23 Laboratory Reported Result: Positive for Marijuana Metabolite (Δ9-

THCA)–420 ng/mL (Medical Marijuana) ..............................................................30

Case #24 Laboratory Reported Result: Positive for 6-Acetylmorphine (6-AM)–17 

ng/mL (Morphine Not Reported Positive)...........................................................31

Case #25 Laboratory Reported Result: Invalid (Two Times, Different Reasons); 

Acceptable Explanation for Abnormal pH (Transit Time/Temperature)..........32

Case #26 Laboratory Reported Result: Invalid Two Times, Same Reason; 

Negative Result Required–Medical Evaluation..................................................34

Case #27 Laboratory Reported Result: Positive for Cocaine Metabolite (BZE)–

10,564 ng/mL, Collector Errors—MRO Responsibilities...................................36

Case #28 Laboratory Reported Result: Positive for Codeine–15,340 ng/mL, 

Morphine–4,350 ng/mL, and Oxycodone–2,320 ng/mL .....................................37

Case #29 Laboratory Reported Result: Positive for Morphine–4,350 ng/mL, 

Additional Drug; Verified Negative Drug–Possible Safety Concerns..............38

Case #30 Laboratory Reported Result: Positive for Hydromorphone–600 ng/mL 

and Codeine–3,350 ng/mL ...................................................................................40

Case #31 Laboratory Reported Result: Positive for Oxycodone–2,510 ng/mL.................42

Case #32 Laboratory Reported Result: Positive for Codeine–15,340 ng/mL and 

Morphine–2,350 ng/mL.........................................................................................43
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Case #1 Laboratory Reported Result: Positive for Marijuana Metabolite (Δ9-

Tetrahydrocannabinol-9-Carboxylic Acid [Δ9-THCA])–30 ng/mL

Positive Drug (Marijuana)

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal Drug Testing Custody and Control Form (CCF) (Copy 1). The information on the

electronic report matched the information on the Federal CCF. The collector used the term 

“express carrier” in Step 4 of the Federal CCF rather than stating the specific name of the

delivery service. Otherwise, the Federal CCF was properly completed by the collector and the 

laboratory.

Discussion: A collector is required to provide the specific name of the delivery service on the

Federal CCF; however, it is considered an insignificant discrepancy when the correct name is 

not provided. No action is needed to correct the discrepancy.

Before a final determination can be made, the Medical Review Officer (MRO) must discuss the

positive test result with the donor. During the donor interview, the donor claims he tested positive 

because of passive inhalation. He states that he was at a party on Saturday night at which 

several individuals were smoking marijuana, but he did not smoke marijuana himself. The

Federal CCF documents that the donor’s specimen was collected two days after the claimed

passive exposure occurred.

Conclusion: Clinical studies have shown that it is highly unlikely that a non-smoking individual 

could inhale sufficient smoke by passive inhalation to result in a sufficient drug concentration in 

urine for detection at the cutoff concentrations used in the federal agency program. The

circumstances described by the donor do not explain the presence of the marijuana metabolite

in the donor’s urine. The MRO may not accept a claim that a laboratory positive result is due to 

passive inhalation or ingestion of edible products containing tetrahydrocannabinol (THC). 

MRO Reported Result: Positive for Marijuana Metabolite. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs

(February 1, 2024), Sections 4.1.3.3.q, 5.2.1.5.b.ii, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs using Urine, 88 FR 70768 

(dated October 12, 2023) effective February 1, 2024, Section 13.5.d.1. 
5 

Case #2 Laboratory Reported Result: Positive for Morphine–5,200 ng/mL 

Verified Positive Drug (Morphine)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor does not recall using any 

prescription medications that may have contained codeine or morphine. The donor does not

recall having eaten any poppy seeds around the time of the urine collection. In other words, the 

donor does not have an explanation for the positive result.

The MRO does not find any clinical evidence of abuse of opiates.

Conclusion: The donor does not have a valid morphine prescription to substantiate the positive 

morphine result. The urine confirmatory cutoff for morphine (i.e., 4,000 ng/mL) is above 

concentrations seen in urine after consumption of poppy seed food products. When the

concentration of morphine is greater than or equal to 4,000 ng/mL, the MRO is required to report 

the test result as Positive. 

MRO Reported Result: Positive. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.4.1, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 
6 

Case #3 Laboratory Reported Result: Positive for Codeine–4,800 ng/mL 

Verified Positive Drugs (Codeine)

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor denies using any medication that 

may have contained codeine. 

The MRO does not find any clinical evidence of abuse of opiates.

Conclusion: The donor does not have a valid codeine prescription to substantiate the positive 

codeine result. Although the quantitative test results indicate that a medication containing 

codeine was most likely taken by the donor, the MRO is required to report a Positive result when

there is no clinical evidence of use and the concentration of codeine is greater than or equal to 

2,000.

MRO Reported Result: Positive. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.4.1, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 
7 

Case #4 Laboratory Reported Result: Positive for Codeine–17,340 ng/mL and Morphine–

6,350 ng/mL 

Verified Negative Drugs (Codeine, Morphine); Possible Safety Concerns

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that he was taking a 

prescription medication containing codeine (i.e., Tylenol with codeine) at the time of the drug 

test and the interview. The donor submits a copy of his medical record to prove that the

medication was properly prescribed to treat back pain.

Conclusion: The donor provided a valid prescription to substantiate the positive codeine and 

morphine results. Therefore, the MRO is not required to determine if there is any clinical 

evidence of abuse.

MRO Reported Result: Negative. 

Note: This case introduces the question of what the MRO should do in the case of safety 

concerns related to the presence of a drug reported as Positive by the laboratory but that is 

reported as Negative by the MRO. 

The MRO Guidance Manual states that within the HHS program, the MRO is not required to 

discuss safety aspects of the donor’s job function. An MRO’s decision to contact an employer 

regarding safety issues related to a donor’s valid prescription (i.e., legal drug use) is subject to 

the MRO’s independent and voluntary choice and any obligations the MRO may have with the 

donor’s employing agency. Therefore, before discussing aspects of job safety with an agency, 

the MRO should review the terms of their service agreement with the agency and any agency 

policies or rules that govern issues related to safety and/or seek private legal counsel. HHS and 

SAMHSA take no position regarding whether an MRO’s independent decision to disclose safety 

related information (or other drug testing information, such as numerical values) in the context of 

a donor’s legal drug use is legal or appropriate in any given circumstance because this issue is 

outside the scope of the Mandatory Guidelines. Please refer to the MRO Guidance Manual, 

Chapter 6, Section 6.3, Occupational and Public Safety, regarding handling safety issues 

involving valid prescriptions.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.5.3, 5.4.1, 6.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.2 
8 

Case #5 Laboratory Reported Result: Positive for Methamphetamine–950 ng/mL

Positive Drug (Methamphetamine)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor denies taking any prescription 

medications but states that he had used some over-the-counter (OTC) decongestants and a 

Vicks® VapoInhaler® at the time of the drug test.

The MRO sends a written request to the laboratory to obtain the quantitative amphetamine

result. The laboratory reports an amphetamine concentration of 145 ng/mL.

Note: Because methamphetamine metabolizes to amphetamine, the presence of amphetamine

is consistent with methamphetamine use. 

The MRO requests that the laboratory perform a chiral analysis to determine which enantiomers 

of methamphetamine are in the specimen. Because l-methamphetamine is a legitimate

component of some OTC nasal decongestant products, the MRO wants to be certain that the

reported methamphetamine is not attributable to using a decongestant inhaler. The laboratory 

reports that approximately 90 percent of the methamphetamine is the d-enantiomer. Some 

decongestant inhalers contain l-methamphetamine (listed in the ingredients as 

levmetamfetamine); however, d-methamphetamine cannot be ascribed to the use of an OTC 

product. 

Conclusion: The donor does not have a valid prescription or other authorization to use 

methamphetamine and does not provide a legitimate medical explanation for the positive drug 

test result.

MRO Reported Result: Positive for Methamphetamine

Note: Early in 2016, l-methamphetamine was removed from the Vicks® VapoInhaler®, and a 

reformulated inhaler was reintroduced to the market. However, a number of decongestant 

inhalers on the OTC market contain l-methamphetamine. This ingredient may also be identified 

as levmetamfetamine, l-desoxyephedrine, or levmethamphetamine. Examples of current 

levmetamfetamine products include but are not limited to Amoray® Vaporizing Inhaler (in which 

it is not listed as an active ingredient), NeilMed Sinu Inhaler®, and Equate® Vapor Inhaler. In 

addition, Vicks® VapoInhalers® containing l-methamphetamine may remain in some medicine 

cabinets.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.1.1, Appendix F-Table 6

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3
9 

Case #6 Laboratory Reported Result: Positive for Cocaine Metabolite (Benzoylecgonine 

[BZE])–1,200 ng/mL 

Positive Drug (Cocaine Metabolite)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor denies using cocaine but claims that 

cocaine was used as a topical anesthetic prior to a laryngoscopic procedure. The donor submits 

a copy of the medical record that documented the use of cocaine for the procedure, and the

MRO verifies that use with the physician who performed the procedure. The medical record 

supports the use of cocaine hydrochloride; however, this drug was used 10 days before the

urine specimen was collected.

Conclusion: Because the documented use of cocaine occurred 10 days before the drug test, 

the positive result cannot be attributed to this medical use of cocaine. Generally, the detection

window for the cocaine metabolite in urine is two to three days after use when using the cutoff 

concentrations required for testing federally regulated specimens.

MRO Reported Result: Positive for Cocaine Metabolite. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.3.1, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3
10

Case #7 Laboratory Reported Result: Positive for Morphine–4,150 ng/mL

Verified Positive Drug (Morphine)

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that he was taking Ultram® 

(tramadol) at the time that he submitted his urine specimen. The donor also states that he 

routinely eats poppy seed bagels.

Conclusion: The morphine concentration is inconsistent with eating poppy seeds. The urine 

confirmatory cutoff for morphine (i.e., 4,000 ng/mL) is above concentrations seen in urine after 

consumption of poppy seed food products. During the interview, the MRO is satisfied that there 

is no clinical evidence of opiate abuse. Additionally, Ultram® cannot cause a urine specimen to

test positive for morphine because tramadol does not metabolize to morphine.

MRO Reported Result: Positive. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.5.3, 5.4.1, 6.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 
11

Case #8 Laboratory Reported Result: Positive for Methamphetamine–1,250 ng/mL with 

255 ng/mL Amphetamine

Verified Negative Drugs (Methamphetamine, Amphetamine); Possible Safety Concerns

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory. The

MRO had a blanket request on file at the laboratory to receive quantitative amphetamine results

for all specimens reported positive for methamphetamine.

Discussion: Note: Because the methamphetamine concentration is significantly higher than the

amphetamine concentration, the amphetamine appears to be present as a metabolite of 

methamphetamine.

During the interview with the donor, the MRO asks the donor to list the drugs he was taking at 

the time of the drug test, and the donor states that he was using a decongestant inhaler for sinus 

congestion and Valium® (diazepam) for anxiety.

Note: The donor volunteered this information because he thought the Valium® may have caused

the positive drug test. 

To determine whether the methamphetamine came from decongestant inhaler use, the MRO 

requests that the laboratory perform a chiral analysis to determine which enantiomers of 

methamphetamine are in the specimen. The results show that over 95 percent of the

methamphetamine and amphetamine present in the urine were the l-enantiomers.

Conclusion: The chiral analysis supports the use of an OTC decongestant inhaler as the reason

for the positive drug test result. 

MRO Reported Result: Negative.

Note: This case introduces the question of what the MRO should do in the case of safety 

concerns related to the presence of a drug reported as Positive by the laboratory but that is 

reported as Negative by the MRO.

The MRO Guidance Manual states that within the HHS program, the MRO is not required to 

discuss safety aspects of the donor’s job function. An MRO’s decision to contact an employer 

regarding safety issues related to a donor’s valid prescription (i.e., legal drug use) is subject to 

the MRO’s independent and voluntary choice and any obligations the MRO may have with the 

donor’s employing agency. Therefore, before discussing aspects of job safety with an agency, 

the MRO should review the terms of their service agreement with the agency and any agency 

policies or rules that govern issues related to safety and/or seek private legal counsel. HHS and 

SAMHSA take no position regarding whether an MRO’s independent decision to disclose safety 

related information (or other drug testing information, such as numerical values) in the context of 

a donor’s legal drug use is legal or appropriate in any given circumstance because this issue is 

outside the scope of the Mandatory Guidelines. Please refer to the MRO Guidance Manual, 
12

Chapter 6, Section 6.3, Occupational and Public Safety, regarding handling safety issues 

involving valid prescriptions.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.5.3, 5.1.1, 6.3, Appendix F-Table 4, 6

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 
13

Case #9 Laboratory Reported Result: Positive for Methamphetamine–942 ng/mL with 250 

ng/mL Amphetamine

Positive Drug (Methamphetamine, Amphetamine) 

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory. The

MRO had a blanket request on file at the laboratory to receive quantitative amphetamine results

for all specimens reported positive for methamphetamine.

Discussion: During the interview with the donor, the donor states that he had taken Adipex-P® 

(phentermine) for weight control, had taken a free sample given to him by his physician (but 

could not remember the name of the sample), frequently uses a decongestant inhaler for a stuffy

nose, and uses several nutritional supplements from a health food store. 

The MRO contacts the donor’s physician, who indicates that she had given the donor free

samples of Tenuate® (diethylpropion HCl) to take before taking Adipex-P®.

The MRO contacts the laboratory and is told that neither diethylpropion nor phentermine 

metabolize to methamphetamine or amphetamine; however, the decongestant inhaler does 

contain l-methamphetamine. (Table 6 of the MRO manual lists other drugs that may be 

metabolized to amphetamine or methamphetamine.)

To determine whether the decongestant inhaler caused the positive result, the MRO requests that

the laboratory conduct a chiral analysis to determine which enantiomers of methamphetamine

are in the specimen. The laboratory reports the following results: 37 percent dmethamphetamine and 63 percent l-methamphetamine.

Conclusion: Neither Tenuate® nor Adipex-P® was responsible for the presence of 

methamphetamine or amphetamine in this urine specimen. Neither of these products contain 

methamphetamine or amphetamine, and neither of these products is metabolized to

methamphetamine or amphetamine. In addition, nutritional supplements do not explain the drug

test results. If the decongestant inhaler were the only source of methamphetamine in this urine, 

the percentage of l-methamphetamine would have been greater than 80 percent. Thus, the

donor ingested another source of methamphetamine containing the d-isomer.

MRO Reported Result: Positive for Amphetamine and Methamphetamine. 

Note: An MRO may request enantiomeric testing with a blanket request (i.e., a request for 

enantiomeric testing of all methamphetamine-positive specimens or all specimens with a 

positive amphetamine initial test) or on an individual specimen basis. MRO requests are not 

needed if the laboratory reflexes ALL regulated specimens to enantiomeric testing based on 

positive initial or confirmatory test results.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.1.1, Appendix F-Table 4, 6
14

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3
15

Case #10 Laboratory Reported Result: Adulterated; Nitrite = 850 mcg/mL

Refusal to Test (Adulterated: Nitrite)

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor claims to have been eating cured

meats for dinner. 

Conclusion: Based on the information available, eating foods containing nitrite or nitrates could 

not cause the nitrite concentration in a urine specimen to be at or above the 500-mcg/mL cutoff 

concentration for nitrite adulteration. The donor did not have a legitimate explanation for the

presence of nitrite.

MRO Reported Result: Refusal to Test [Adulterated–Nitrite]. 

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.e.2
16

Case #11 Laboratory Reported Result: Invalid Result; Oxidant Activity ≥50 mcg/mL 

Chromium (VI) equivalents

Test Cancelled (Invalid: Oxidant Activity)

Laboratory Report: The laboratory sent an electronic report and an image of the completed 

Federal CCF (Copy 1) to the MRO. The information on the electronic report matched the

information on the Federal CCF. The Federal CCF was properly completed by the collector and 

the laboratory. Before reporting an Invalid result to the MRO based on oxidant activity, the 

laboratory must attempt to contact the MRO to decide whether additional testing at a different

laboratory would facilitate obtaining a definitive result. In this case, the laboratory and MRO 

discussed the result and agreed that additional testing was not necessary.

Discussion: During the interview with the donor, the donor claims to have no idea how an

oxidant could be in her urine specimen. When encountering this situation, the MRO may 

evaluate all comments, medications, and medical conditions that might be verified and account 

for any oxidative activity in the specimen.

Conclusion: The donor did not provide a legitimate medical explanation.

MRO Reported Result: Test Cancelled [Invalid Result–Oxidant Activity]. The MRO directs the

agency to immediately collect another specimen using a direct observed collection procedure.

Note: The references allow the reporting of an Invalid result if the oxidant is verified using a 

general oxidant colorimetric test (with a value equal to or greater than the 50-mcg/mL chromium

(VI) equivalent cutoff). Most laboratories use the nitrite equivalent results when the nitrite 

concentration is equal to or greater than 200 mcg/mL; however, the reporting of chromium (VI) 

equivalents is allowed.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.4, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.f 
17

Case #12 Laboratory Reported Result: Adulterated–Nitrite = 1800 mcg/mL and Invalid 

Result–Bottle A and Bottle B–Different Physical Appearance

Refusal to Test (Adulterated: Nitrite)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: The MRO discusses the results with the donor, and the donor denies tampering

with the urine specimen.

Conclusion: Although the MRO is required to contact the donor and give the donor an 

opportunity to explain the Adulterated result, the criteria established by the Mandatory 

Guidelines to report a specimen as Adulterated preclude any legitimate medical explanation for

the presence of an adulterant. For this urine specimen, the Invalid result provides additional 

information that may be useful if the donor requests that the split (Bottle B) specimen be tested

by a second certified laboratory. The fact that Bottle A and Bottle B have different physical 

appearances may suggest that the nitrite would not be reconfirmed in the split (Bottle B) 

specimen. 

Generally, the MRO reports all Positive, Adulterated, Substituted, and Invalid results to the

federal agency. However, in this case, the MRO reports only the Adulterated result to the

agency. Reporting both Refusal to Test (Adulterated) and Test Cancelled (Invalid Result) for the 

same urine specimen is confusing. The reason for the Invalid result (Bottle A and Bottle B–

Different Physical Appearance) will most likely affect only the testing of the split (Bottle B) 

specimen if the donor requests that the split (Bottle B) specimen be tested for nitrite, as reported 

in the primary (Bottle A) specimen. The MRO should only report the Invalid result if the split 

specimen was tested and reported by the laboratory as failed to reconfirm.

MRO Reported Result: Refusal to Test [Adulterated–Nitrite].

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.2, 4.3, 5.6.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.e.2
18

Case #13 Laboratory Reported Result: Positive for Morphine–5,000 ng/mL and 

Adulterated–Chromium(VI) = 90 mcg/mL

Positive Drug (Morphine); Refusal to Test (Adulterated: Chromium VI)

Laboratory Report: The laboratory sent an electronic report and faxed a copy of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory. The 

laboratory had the capability to confirm chromium (VI). 

Discussion: During the interview with the donor, the donor states that he does not know why 

his specimen was positive for morphine or why it was reported as Adulterated. 

The MRO does not find any clinical evidence of abuse of opiates.

Conclusion: The donor does not have a valid morphine prescription to substantiate the 

positive morphine result. The urine confirmatory cutoff for morphine (i.e., 4,000 ng/mL) is 

above concentrations seen in urine after consumption of poppy seed food products. For the

Adulterated result, no legitimate medical explanation is provided for the presence of a highly 

toxic oxidant in the urine specimen.

MRO Reported Result: Positive and Refusal to Test [Adulterated–Chromium (VI)]. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.4.1, 5.6.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 and 13.5.e.2
19

Case #14 Laboratory Reported Result: Positive for Marijuana Metabolite (Δ9-THCA)–60 

ng/mL and Cocaine Metabolite (BZE)–120 ng/mL

Positive Drugs (Cocaine Metabolite, Marijuana)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor claims that he tested positive for

marijuana because he was at a party and had eaten brownies that contained marijuana and that 

he tested positive for cocaine because a dentist had used lidocaine prior to a dental procedure. 

The Federal CCF documented that the donor’s specimen was collected three days after he

claimed to have eaten the brownies and one day after the dental procedure.

Conclusion: Donors have claimed unknowingly ingesting marijuana in brownies to explain 

positive test results for many years. Given the current concentrations of THC found in edibles, it 

is possible that after ingesting brownies, a donor’s urine drug test would be positive for the 

marijuana metabolite. With regard to the cocaine metabolite, lidocaine does not contain cocaine

and does not metabolize to the cocaine metabolite. The MRO may not accept a claim that a 

laboratory positive result is the result of passive inhalation or ingestion of edible products 

containing THC.

MRO Reported Result: Positive for Marijuana Metabolite and Cocaine Metabolite. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.3, 5.2, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3. 
20

Case #15 Laboratory Reported Result: Substituted–Creatinine = 1.5 mg/dL and Specific 

Gravity = 1.0005

Refusal to Test (Substituted)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor claims to have been performing

strenuous activity and drinking large amounts of fluid for several days prior to the collection 

procedure because it was hot outside.

The HHS criteria for identifying substituted specimens are based on the physiological ranges of 

creatinine concentrations and specific gravity values of normal human urine. When a reason is 

given for a Substituted result, the MRO must decide if the donor is providing a legitimate medical 

explanation. When a medical explanation is provided, the MRO should request that the agency

have the donor provide another urine specimen using a direct observed collection procedure. 

The MRO should not report the final result to the agency until the laboratory reports the test 

result for the second specimen. The criteria for Substituted based on those established by HHS 

essentially eliminate the possibility that the thresholds will be exceeded by normal function of 

the human body.

In this case, the laboratory reports that the second specimen, collected under direct observation, 

has a creatinine concentration of 5.5 mg/dL and a specific gravity of 1.003. 

Conclusion: The creatinine and specific gravity results for the second specimen are not similar 

to those for the first specimen. The donor’s explanation that he drank large quantities of fluids 

prior to the first test is not a legitimate explanation for the Substituted result.

MRO Reported Result: Refusal to Test [Substituted]. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.2, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.e.2
21

Case #16 Laboratory Reported Result: Negative and Dilute–Creatinine = 6.2 mg/dL and 

Specific Gravity = 1.002

Negative and Dilute

Laboratory Report: The laboratory reported the specimen using a computer-generated 

electronic report.

Discussion: The MRO is not required to interview a donor whose urine specimen is reported as 

Negative for drugs and dilute.

Conclusion: A dilute result may indicate that a donor intentionally consumed large amounts of 

fluid or took diuretics in an attempt to reduce any drug concentrations to below the cutoffs used; 

however, this is not necessarily the case. A donor could provide a dilute specimen in other

situations (e.g., the donor was allowed too much fluid to drink to provide a specimen when

required at the collection site). 

MRO Reported Result: Negative and Dilute. The MRO directs the agency to immediately collect 

another specimen from the donor (i.e., notifying the donor to report to the collection site without 

delay). The second collection is not to be a direct observed collection.

Second Collection Laboratory Reported Result: Negative and Dilute–Creatinine = 8.0 mg/dL

and Specific Gravity = 1.002 

Discussion: If the recollected specimen provides a negative or negative/dilute result, the MRO 

should report a Negative result to the agency, with no further action required.

Conclusion: A second dilute finding may indicate that a donor can produce urine that meets the

program criteria for dilution under some conditions, including working in hot weather conditions 

and drinking large amounts of fluid, taking a diuretic, drinking caffeinated beverages, drinking

fluids immediately before providing the specimen, or drinking fluid to provide a specimen when

required at the collection site.

MRO Reported Result: Negative. 

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.1, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.b.1. 
22

Case #17 Laboratory Reported Result: Substituted–Creatinine = 1.0 mg/dL and Specific 

Gravity = 1.0005 and Invalid Result–Abnormal pH = 4.0

Refusal to Test (Substituted)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that he does not know why 

his urine specimen was reported as Substituted and Invalid. 

The MRO informs the donor that he has the right to request that the split (Bottle B) specimen be

tested in a second laboratory for the Substituted result but not for the Invalid result. 

Conclusion: The Substituted result is considered a Refusal to Test, but the Invalid result (by

itself) would normally lead to a cancelled test and immediate collection of a second specimen

using a direct observed collection procedure. The MRO should report only the Substituted result 

to the agency. When the laboratory reports an invalid result in conjunction with a positive, 

Adulterated, or Substituted result, do not report the verified invalid result to the Federal agency 

at this time. The MRO takes action for the verified invalid result(s) for the primary (A) specimen 

only when the MRO verifies the positive, adulterated, or substituted results as negative based 

upon a legitimate medical explanation. If the donor requests a split (Bottle B) retest at a second

certified laboratory, and the Substituted result is not reconfirmed, the MRO can then report the 

Invalid result to the federal agency. Whereas both a failure to reconfirm and an Invalid result will 

lead to a cancelled test and immediate recollection using direct observation, the MRO will have 

Invalid result information for the first specimen to review when he/she reviews the recollected 

specimen’s test results.

MRO Reported Result: Refusal to Test [Substituted]. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.2, 5.6.4, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.e.2
23

Case #18 Laboratory Reported Result: Rejected for Testing–Fatal Flaw: Bottle A 

label/seal broken

Test Cancelled (Fatal Flaw: Broken Seal)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: The Mandatory Guidelines designate some specific specimen and documentation

problems as either “fatal flaws” or “correctable flaws.” Laboratories generally identify fatal flaws 

during receipt and accessioning and do not test such specimens or stop testing if the flaw is 

identified after testing has been initiated. For errors that require the laboratory to reject the 

specimen if not corrected, the laboratory must accession and hold the specimen while taking 

action to resolve the problem (i.e., by obtaining a memorandum for the record [MFR], from the

collector). The laboratory must delay testing the specimen until the collector provides the

documentation to recover these correctable flaws. 

A broken seal on a primary (Bottle A) specimen is fatal unless the split (Bottle B) specimen can

be redesignated as the primary (Bottle A) specimen. Bottle B may be redesignated as Bottle A if 

the volume of urine in Bottle B is sufficient to conduct the required tests, and the bottle seal is 

intact. In that case, the laboratory will test Bottle B and report a result. When redesignation

occurs, the laboratory notes the redesignation on the CCF. If and when the specimen is reported

Positive, Adulterated, or Substituted, and the donor requests a retest of the split (Bottle B) 

specimen, the laboratory will inform the MRO that a split specimen is not available.

Conclusion: Because the laboratory rejected the specimen for testing, and there was no 

documentation of redesignation, the MRO knew that it was not possible to redesignate the

specimens (i.e., Bottle B as Bottle A). 

MRO Reported Result: Test Cancelled: Fatal Flaw: Bottle A seal broken. The MRO 

recommends that the agency collect another specimen from the donor. The recollected 

specimen must be the same type (i.e., urine).

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.1.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.h. 
24

Case #19 Laboratory Reported Result: Invalid (two times, different reasons) – Negative 

on the second observed collection

Negative

Laboratory Report: Invalid Result–Abnormal pH = 9.4.

The laboratory sent an electronic report and faxed the completed Federal CCF (Copy 1). The

information on the electronic report matched the information on the Federal CCF. The Federal 

CCF was properly completed by the collector and the laboratory.

Note: Laboratories are not required to contact the MRO prior to reporting when a specimen

meets the criteria for reporting as Invalid based on abnormal pH. 

Discussion: The CCF includes no collector or laboratory remarks indicating a problem with the

collection or the specimen. The CCF indicates that the collection was performed on a Monday in 

the winter and that the specimen was delivered to the laboratory early morning on the next day 

(Tuesday). Laboratory staff accessioned the specimen immediately upon delivery. The MRO 

concludes that the specimen was not exposed to high temperatures during transportation,

During the interview with the donor, the donor gives no explanation for the Invalid result. He 

denies having tampered with the specimen.

Conclusion: Transportation and temperature did not account for the pH in the Invalid range.

MRO Reported Result: Test Cancelled: Invalid Result–Abnormal pH. The MRO directs the

agency to immediately collect another specimen using a direct observed collection procedure.

Second (re-collected) Laboratory Report: Invalid Result—Creatinine <2 mg/dL and Specific 

Gravity Acceptable.

The laboratory sent an electronic report and an image of the completed Federal CCF (Copy 1) to

the MRO. The information on the electronic report matched the information on the Federal CCF. 

The Federal CCF was properly completed by the collector and the laboratory.

Note: Laboratories are not required to contact the MRO prior to reporting when a specimen

meets the criteria for reporting as Invalid based on creatinine and specific gravity.

Discussion: This is the second Invalid specimen and was collected under direct observation.

Conclusion: No legitimate explanation exists for the Invalid result. The MRO does NOT contact 

the donor.

MRO Reported Result: Test Cancelled: Invalid Result–Creatinine <2 mg/dL and Specific Gravity 

Acceptable. The MRO directs the agency to immediately collect another specimen using a direct

observed collection procedure.

Third (second observed) Laboratory Report: Negative
25

The laboratory sent an electronic report with all required information and the testing result. 

Discussion: This is the third specimen collected and the second under direct observation.

Conclusion: The specimen result is valid. The MRO reports the result. 

MRO Reported Result: Negative. 

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.4, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.f and 13.5.a
26

Case #20 Split Laboratory Reported Result: Failed to Reconfirm for Marijuana 

Metabolite–Reason: Invalid Result–Oxidant Activity ≥200 mcg/mL Nitrite Equivalents

Test Cancelled (Failed to Reconfirm)

Split Specimen Laboratory Report: Laboratory B faxed a copy of the completed Federal CCF 

(Copy 1) and its Split Specimen Report for the specimen. Laboratory B properly completed Step

5b on the Federal CCF. The Split Specimen Report contained additional explanatory information 

as required, including the results of specimen validity tests performed for the specimen, and was 

signed and dated by the certifying scientist.

Discussion: Laboratory B received the split (Bottle B) specimen from the primary laboratory 

with a copy of the MRO’s request to test the split specimen for the marijuana metabolite (THCA), 

the drug metabolite that was reported positive in the primary (Bottle A) specimen. When 

Laboratory B was unable to reconfirm the presence of THCA, the laboratory conducted

specimen validity tests to determine if there was a reason for not reconfirming the presence of

THCA. Laboratory B did not identify the presence of a specific adulterant in the split specimen; 

however, it did find oxidant activity (i.e., ≥ 200 mcg/mL nitrite-equivalents) in the split specimen. 

At this point, Laboratory B contacted the MRO to decide whether additional validity testing at a 

third laboratory might reveal a specific adulterant. Laboratory B stated that it does not perform 

the tests required to report a specimen as Adulterated but performs testing only to identify the 

possible presence of adulterants and then report a specimen as Invalid. 

After discussing the results with Laboratory B, the MRO decides to send the specimen to

Laboratory C for confirmatory testing for specific oxidizing adulterants. Laboratory C finds a 

nitrite level above the 200 mcg/mL cutoff for an Invalid result but below the 500 mcg/mL cutoff

for Adulteration and reports an Invalid result (nitrite = 350 mcg/mL) for the split (Bottle B) 

specimen.

Conclusion: Unlike drug analytes, because a low concentration of nitrite may be present in 

normal human urine, laboratories are required to use the same nitrite cutoffs (i.e., ≥ 200 mcg/mL 

for Invalid and ≥ 500 mcg/mL for Adulterated) for both primary (Bottle A) and split (Bottle B) 

specimens. Although nitrite was present in both the primary (Bottle A) specimen and the split 

(Bottle B) specimen, the marijuana metabolite in Bottle B may have been affected more by nitrite 

because more time had elapsed between collection and testing of this bottle than for Bottle A. 

As a result, the nitrite had additional time to act on the drug analyte. Therefore, the results for 

both the primary (Bottle A) and split (Bottle B) specimens are consistent.

MRO Reported Result: Failed to Reconfirm for Marijuana Metabolite, Invalid Result–Nitrite, and

Test Cancelled for both the primary and split specimens. The MRO directs the agency to

immediately collect another specimen using a direct observed collection procedure and reports 

the failed to reconfirm and cancelled test to the appropriate regulatory office.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.4, 5.6.4, Appendix D, , Appendix F-Table 4, 5
27

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 16.6.e
28

Case #21 Split Laboratory Reported Result: Failed to Reconfirm Cocaine Metabolite 

(BZE)–BZE not detected

Test Cancelled (Failed to Reconfirm)

Split Specimen Laboratory Report: Laboratory B faxed a copy of the completed Federal CCF 

(Copy 1) and its Split Specimen Report for the specimen. Laboratory B properly completed Step

5b on the Federal CCF. The Split Specimen Report contained additional explanatory information 

as required, including the results of specimen validity tests performed for the specimen, and was 

signed and dated by the certifying scientist.

Discussion: Laboratory B received the split (Bottle B) specimen from the primary laboratory 

with a copy of the MRO’s request to test the split specimen for BZE, the drug metabolite

reported positive in the primary (Bottle A) specimen. The copy of the Federal CCF (Copy 1) sent 

with the specimen documented Laboratory A’s reported concentration of 10,786-ng/mL BZE. 

When Laboratory B was unable to reconfirm the presence of BZE, the laboratory conducted

specimen validity tests to determine if there was a reason for not reconfirming the presence of

BZE. Laboratory B did not identify an adulterant, the specimen was not substituted, and there 

was no evidence to support reporting an Invalid result. 

If Laboratory B believes that BZE may be present in the split specimen but cannot obtain a valid 

result (e.g., because of an interferent affecting its assay), Laboratory B must contact the MRO to

decide whether testing at a third laboratory would be useful. In this case, Laboratory B did not 

contact the MRO to discuss this possibility because its confirmatory drug test indicated that BZE 

was not present in the split (Bottle B) specimen.

Conclusion: There is no apparent reason for the discrepancy in the results for the primary 

(Bottle A) and split (Bottle B) specimens.

MRO Reported Result: Failed to Reconfirm for Cocaine Metabolite and Test Cancelled for both

the primary and split specimens. The MRO reports the failed to reconfirm and cancelled test to

the appropriate regulatory office.

Note: The Mandatory Guidelines do not require the MRO to direct the agency to complete an 

additional collection. This case does not state that a Negative result is needed for a federal 

agency applicant/pre-employment, return-to-duty, or follow-up test; however, if the agency 

needs a Negative result for any of those purposes, the agency can request a second collection.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.4, Appendix F-Table 4, 5

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 14.6.d
29

Case #22 Split Laboratory Reported Result: Failed to Reconfirm [Chromium (VI)] 

Test Cancelled (Failed to Reconfirm)

Split Specimen Laboratory Report: Laboratory B sent an image of the completed Federal 

CCF (Copy 1) and its computer-generated electronic Split Specimen Report for the specimen. 

Laboratory B properly completed Step 5b on the Federal CCF. The Split Specimen Report 

contained additional explanatory information as required and included the electronic signature of 

the certifying scientist with the date that the signature was executed.

Discussion: Laboratory B received the split (Bottle B) specimen from the primary laboratory 

with a copy of the MRO’s request to test the split specimen for Chromium (VI), which was 

detected (Adulterated) in the primary (Bottle A) specimen. When Laboratory B tested the split 

specimen, it was unable to verify the presence of Chromium (VI). At this point, Laboratory B 

stopped testing the split (Bottle B) specimen and reported the failed to reconfirm result to the

MRO.

Conclusion: There is no apparent reason for the discrepancy in the results for the primary 

(Bottle A) and split (Bottle B) specimens.

MRO Reported Result: Failed to Reconfirm [Chromium (VI)] and Test Cancelled for both the

primary and split specimens. The MRO reports the failed to reconfirm and cancelled test to the

appropriate regulatory office.

Note: The Mandatory Guidelines do not require the MRO to direct the agency to complete an 

additional collection. This case does not state that a Negative result is needed for a federal 

agency applicant/pre-employment, return-to-duty, or follow-up test; however, if the agency 

needs a Negative result for any of those purposes, the agency can request a second collection. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections Appendix F-Table 4, 5

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 14.6.j
30

Case #23 Laboratory Reported Result: Positive for Marijuana Metabolite (Δ9-THCA)–420 

ng/mL (Medical Marijuana)

Positive Drug (Marijuana)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor admits marijuana use. However, the

donor produces a prescription for medical marijuana, which is legal in the donor’s state of 

residence. The donor claims that his physician prescribed marijuana to alleviate shoulder pain 

from a previous work injury and states that he only uses marijuana on weekends when he does 

not work.

Conclusion: The donor’s marijuana use is consistent with the positive drug test result, and no 

legitimate medical explanation exists for the drug test result.

MRO Reported Result: Positive for Marijuana Metabolite. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.2, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.2.iii
31

Case #24 Laboratory Reported Result: Positive for 6-Acetylmorphine (6-AM)–17 ng/mL 

(Morphine Not Reported Positive)

Positive Drug (6-AM)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: Note: Although morphine is generally present (i.e., at or above the program cutoff 

of 4000 ng/mL) in positive 6-AM specimens, morphine may not be present or may be present 

below the 4,000 ng/mL morphine cutoff in a positive 6-AM specimen for several reasons. For

example, the donor may have used heroin close to the time of collection; the donor may have a 

metabolic defect in the metabolism of 6-AM, resulting in prolonged excretion; the donor’s

morphine metabolic pathways may have been altered; or another substance may have 

interacted with 6-AM or morphine.

During the interview with the donor, the donor denies heroin use. 

Conclusion: When a laboratory reports a specimen as positive for the heroin metabolite (6-AM), 

it is proof of heroin use. There is no legitimate medical explanation for a positive 6-AM result.

MRO Reported Result: Positive for 6-AM. 

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.4, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3. 
32

Case #25 Laboratory Reported Result: Invalid (Two Times, Different Reasons); 

Acceptable Explanation for Abnormal pH (Transit Time/Temperature)

Test Cancelled and Remark (Invalid: Creatinine < 2 mg/dL & Specific Gravity acceptable)

Laboratory Report: Invalid Result–Creatinine <2 mg/dL and Specific Gravity Acceptable. 

The laboratory sent an electronic report and an image of the completed Federal CCF (Copy 1). 

The information on the electronic report matched the information on the Federal CCF. The

Federal CCF was properly completed by the collector and the laboratory.

Note: Laboratories are not required to contact the MRO prior to reporting when a specimen

meets criteria for reporting as Invalid based on creatinine and specific gravity results.

Discussion: During the interview with the donor, the donor provides no explanation for the 

Invalid result. She denied having tampered with the specimen. The CCF includes no collector or 

laboratory remarks indicating a problem with the collection or the specimen.

Conclusion: There is no apparent explanation for the Invalid result. The reason for the test was 

Random. 

MRO Reported Result: Test Cancelled and Remark: Invalid Result–Creatinine <2 mg/dL and

Specific Gravity Acceptable. The MRO directs the agency to immediately collect another

specimen using a direct observed collection procedure.

Second (Recollection) Laboratory Report: Invalid Result–Abnormal pH = 9.4. 

The laboratory sent an electronic report and an image of the completed Federal CCF (Copy 1). 

The information on the electronic report matched the information on the Federal CCF. The

Federal CCF was properly completed by the collector and the laboratory.

Note: Laboratories are not required to contact the MRO prior to reporting when a specimen

meets criteria for reporting as Invalid based on abnormal pH results.

Discussion: The CCF shows that the specimen collection was observed, and the female 

observer’s name is entered in the Remarks line in Step 2. The collection time and date were

9:30 AM on July 1 (Friday). The CCF shows that the specimen was received at the laboratory on 

July 5 (Tuesday). 

Note: The MRO does not contact the donor when the donor’s second specimen also meets the

criteria for reporting as Invalid. 
33

The MRO notes the extended time (four days) between specimen collection and receipt by the 

laboratory. She first contacts the collector to discuss time and temperature issues. The collector 

informs the MRO that he had placed the sealed specimen package in refrigerated storage until 

5:00 PM on Friday, awaiting pickup by a local courier. When the courier had not arrived by 5:00 

PM, the collector placed this and other sealed specimen packages in a locked outside container

for pickup. The collection site was closed on Monday because of the July 4 holiday. When staff 

arrived at the collection site on Tuesday morning, July 5, the specimens were still in the locked 

box. Outside temperatures over the preceding four days were in the high 90s. Collection site

staff returned the sealed specimen packages to refrigerated storage and called the laboratory. A

laboratory courier retrieved the specimens from the collection site at 10:45 AM. 

Conclusion: The second specimen’s exposure to high temperatures for an extended time may 

account for the high pH result in the Invalid range. The reason for the test was Random; thus, a 

Negative result is not required (as would be required for a federal agency applicant/preemployment, return-to-duty, or follow-up test). 

MRO Reported Result: Test Cancelled and Remark: Invalid Result (Abnormal pH). The MRO 

informs the agency that no recollection is required because there is an acceptable explanation

for the Invalid result.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.4, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.f. 
34

Case #26 Laboratory Reported Result: Invalid Two Times, Same Reason; Negative Result 

Required–Medical Evaluation

Negative

Laboratory Report: Invalid Result–Abnormal pH = 9.4. 

The laboratory sent an electronic report and faxed the completed Federal CCF (Copy 1). The

information on the electronic report matched the information on the Federal CCF. The Federal 

CCF was properly completed by the collector and the laboratory.

Note: Laboratories are not required to contact the MRO prior to reporting when a specimen

meets the criteria for reporting as Invalid based on abnormal pH. 

Discussion: The CCF includes no collector or laboratory remarks indicating a problem with the

collection or the specimen. The CCF shows that the collection occurred on August 6 (Friday) and 

that the specimen was received at the laboratory on August 11 (Wednesday). The MRO first 

contacts the collector to discuss time and temperature issues. The collector states that the

specimen was picked up by a commercial transporter on August 6. The MRO contacts the

laboratory. Laboratory staff cannot explain the delay but state that the specimen was 

accessioned immediately upon delivery. The MRO concludes that the specimen may have been

exposed to high temperatures during transportation, which could account for the abnormally high

pH.

During the interview with the donor, the donor provides no explanation for the Invalid result. He 

denies having tampered with the specimen.

Conclusion: The five-day transit time may account for the Invalid result. However, because this 

was a return-to-duty drug test, the federal agency requires a Negative result.

MRO Reported Result: Test Cancelled and Remark: Invalid Result (Abnormal pH). The MRO 

directs the agency to immediately collect another specimen using a direct observed collection

procedure.

Second (Recollection) Laboratory Report: Invalid Result–Abnormal pH = 9.2. 

The laboratory sent an electronic report and faxed the completed Federal CCF (Copy 1). The

information on the electronic report matched the information on the Federal CCF. The Federal 

CCF was properly completed by the collector and the laboratory.

Discussion: The CCF shows that the specimen collection was observed. The collection 

occurred on August 16 (Monday), and the specimen was received at the laboratory on August 20

(Thursday). 

Note: The MRO should not contact the donor when the donor’s second specimen also meets the 

criteria for reporting as Invalid. 

The MRO contacts the collector who states that the specimen was picked up by a commercial 

transporter on August 16. The MRO contacts laboratory staff who states that the specimen was 
35

accessioned immediately upon delivery. The MRO concludes that the specimen may have been

exposed to high temperatures during transportation, which could account for the abnormally high

pH. 

Conclusion: Although there is an explanation for the high pH, the federal agency requires a 

Negative result for a return-to-duty drug test. The MRO arranges for a medical evaluation of the

donor and finds no clinical evidence of drug abuse.

MRO Reported Result: Negative. With the report to the federal agency, the MRO provides 

written notations regarding the medical evaluation, an explanation of the reason for the medical

evaluation, and the reason for the determination made based on the medical evaluation.

References: 

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.6.4, Appendix F-Table 4, 5

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.4.f. 
36

Case #27 Laboratory Reported Result: Positive for Cocaine Metabolite (BZE)–10,564 

ng/mL, Collector Errors—MRO Responsibilities

Positive Drug (Cocaine metabolite); Collection Errors; MRO Responsibilities

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1) and an MFR from the collector. The collector had printed his name but 

had not signed the Federal CCF in Step 4. The information on the electronic report matched the

information on the Federal CCF. The Federal CCF was properly completed by the laboratory.

Discussion: The collector’s MFR addresses the signature omission and was sent to the

laboratory the day after specimen receipt. There are no other problems with the submitted

documents. 

MRO Reported Result: The MRO conducts the donor interview and reports the specimen as 

Positive for Cocaine Metabolite to the federal agency.

In reviewing his records, the MRO notes that the same collector had omitted his signature on the

CCF for another specimen collected one week earlier. The MRO should monitor the frequency

of documentation errors, notify the responsible party (e.g., collector, Instrumented Initial Testing 

Facility [IITF], laboratory) when an error occurs more than once a month, and direct them to take 

corrective action to prevent recurrence of the errors.

Additional MRO Actions: The MRO should send a letter notifying the collector employer or 

collector (if self-employed) of the errors and the need for corrective action. The MRO should 

also send a copy of the letter to the federal agency for follow-up.

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.1.3, 5.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 and 15.2.a
37

Case #28 Laboratory Reported Result: Positive for Codeine–15,340 ng/mL, Morphine–

4,350 ng/mL, and Oxycodone–2,320 ng/mL 

Positive Drug (Oxycodone); Verified Negative (Codeine, Morphine)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the 

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that he was taking a 

prescription medication—APAP #4—at the time of the drug test and the interview. The donor

submits a copy of his medical record to prove that the medication was properly prescribed to 

treat back pain. The donor is unable to provide additional medical information. 

Conclusion: Although the donor provides documentation to support the laboratory findings of 

codeine and morphine, the documentation provided does not support the finding of oxycodone.

MRO Reported Result: Positive for Oxycodone. 

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.5.2, 5.4.1, 5.4.2, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 and 13.5.d.2
38

Case #29 Laboratory Reported Result: Positive for Morphine–4,350 ng/mL, Additional 

Drug; Verified Negative Drug–Possible Safety Concerns

Verified Negative Drug (morphine); Possible Safety Concerns (Fentanyl)

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the 

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that, at the time of the drug 

test and the interview, he was using a fentanyl patch prescribed for pain control after recent back 

surgery. He also reports contracting a recent upper respiratory infection (URI) from his spouse. 

During his last URI, he remembered using a behind-the-pharmacy-counter cough preparation

containing codeine, which he obtained from the local pharmacy. The donor submits a copy of the 

pharmacy record showing that he had received a codeine cough preparation the same day as

the specimen collection. 

Conclusion: Fentanyl will not cause a positive test result under the Federal Drug-Free 

Workplace Program. Codeine preparations are available behind the pharmacy counter in some 

states, but their distribution must be recorded by the pharmacist. The MRO must ensure that the 

codeine cough preparation was dispensed prior to the time the specimen was collected. 

MRO Reported Result: Negative.

Note: This case introduces the question of what the MRO should do in the case of safety 

concerns related to drug information disclosed by the donor during the interview with the MRO 

(i.e., use of a prescription drug that is not tested under the federal program) or a drug reported 

as Positive by the laboratory that is reported as Negative by the MRO.

The MRO Guidance Manual states that within the HHS program, the MRO is not required to 

discuss safety aspects of the donor’s job function. An MRO’s decision to contact an employer 

regarding safety issues related to a donor’s valid prescription (i.e., legal drug use) is subject to 

the MRO’s independent and voluntary choice and any obligations the MRO may have with the 

donor’s employing agency. Therefore, before discussing aspects of job safety with an agency, 

the MRO should review the terms of their service agreement with the agency and any agency 

policies or rules that govern issues related to safety and/or seek private legal counsel. HHS and 

SAMHSA take no position regarding whether an MRO’s independent decision to disclose safety 

related information (or other drug testing information, such as numerical values) in the context of 

a donor’s legal drug use is legal or appropriate in any given circumstance because this issue is 

outside the scope of the Mandatory Guidelines. Please refer to the MRO Guidance Manual, 

Chapter 6, Section 6.3, Occupational and Public Safety, regarding handling safety issues 

involving valid prescriptions.

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.4.1, 6.3, Appendix F-Table 4
39

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.2 
40

Case #30 Laboratory Reported Result: Positive for Hydromorphone–600 ng/mL and 

Codeine–3,350 ng/mL

Verified Positive Drug (Codeine); Verified Negative (Hydromorphone); Possible Safety 

Concerns

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the 

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the MRO, the donor states that at the time of the drug test 

and the interview, he was taking Dilaudid (Hydromorphone), which was prescribed for pain 

control after a recent femur fracture. He provides a report from his personal physician and 

records from the pharmacy showing the drug was dispensed one week before the specimen

collection. He offers no records or comment regarding the codeine found. 

Conclusion: The donor does not have a valid codeine prescription to substantiate the positive 

codeine result. The urine confirmatory cutoff for codeine (i.e., 2,000 ng/mL) is above 

concentrations seen in urine after consumption of poppy seed food products. The Dilaudid 

(hydromorphone) prescription would justify the hydromorphone laboratory findings, but

hydromorphone does not metabolize to codeine.

MRO Reported Result: Positive. The donor has a valid prescription for hydromorphone and the

codeine concentration is greater than 2,000 ng/mL. 

Note: This case introduces the question of what the MRO should do in the case of safety 

concerns related to the presence of a drug reported as Positive by the laboratory but that is 

reported as Negative by the MRO.

The MRO Guidance Manual states that within the HHS program, the MRO is not required to 

discuss safety aspects of the donor’s job function. An MRO’s decision to contact an employer 

regarding safety issues related to a donor’s valid prescription (i.e., legal drug use) is subject to 

the MRO’s independent and voluntary choice and any obligations the MRO may have with the 

donor’s employing agency. Therefore, before discussing aspects of job safety with an agency, 

the MRO should review the terms of their service agreement with the agency and any agency 

policies or rules that govern issues related to safety and/or seek private legal counsel. HHS and 

SAMHSA take no position regarding whether an MRO’s independent decision to disclose safety 

related information (or other drug testing information, such as numerical values) in the context of 

a donor’s legal drug use is legal or appropriate in any given circumstance because this issue is 

outside the scope of the Mandatory Guidelines. Please refer to the MRO Guidance Manual, 

Chapter 6, Section 6.3, Occupational and Public Safety, regarding handling safety issues 

involving valid prescriptions.

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 5.4.1, 5.4.2, 6.3, Appendix F-Table 4
41

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.3 and 13.5.d.2
42

Case #31 Laboratory Reported Result: Positive for Oxycodone–2,510 ng/mL

Verified Negative Drug (Oxycodone); Possible Safety Concerns

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the 

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that she had been taking 

Percodan since she slipped and fell on her tail bone 14 months ago. The donor submits a copy 

of her medical record to prove that the medication was properly prescribed and a record from the 

pharmacy showing that the medication was dispensed prior to the specimen collection date.

Conclusion: The MRO made a determination regarding the validity of the prescription. In this 

case, the donor provided documentation consistent with the laboratory report of oxycodone. 

Note: This case introduces the question of what the MRO should do in the case of safety 

concerns related to the presence of a drug reported as Positive by the laboratory but that is 

reported as Negative by the MRO.

The MRO Guidance Manual states that within the HHS program, the MRO is not required to 

discuss safety aspects of the donor’s job function. An MRO’s decision to contact an employer 

regarding safety issues related to a donor’s valid prescription (i.e., legal drug use) is subject to 

the MRO’s independent and voluntary choice and any obligations the MRO may have with the 

donor’s employing agency. Therefore, before discussing aspects of job safety with an agency, 

the MRO should review the terms of their service agreement with the agency and any agency 

policies or rules that govern issues related to safety and/or seek private legal counsel. HHS and

SAMHSA take no position regarding whether an MRO’s independent decision to disclose safety 

related information (or other drug testing information, such as numerical values) in the context of 

a donor’s legal drug use is legal or appropriate in any given circumstance because this issue is 

outside the scope of the Mandatory Guidelines. Please refer to the MRO Guidance Manual, 

Chapter 6, Section 6.3, Occupational and Public Safety, regarding handling safety issues 

involving valid prescriptions.

MRO Reported Result: Negative.

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.5.3, 5.4.2, 6.3, Appendix F-Table 4

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.2
43

Case #32 Laboratory Reported Result: Positive for Codeine–15,340 ng/mL and Morphine–

2,350 ng/mL

Verified Negative Drugs (Codeine, Morphine); Possible Safety Concerns

Laboratory Report: The laboratory sent an electronic report and an image of the completed

Federal CCF (Copy 1). The information on the electronic report matched the information on the 

Federal CCF. The Federal CCF was properly completed by the collector and the laboratory.

Discussion: During the interview with the donor, the donor states that while shoveling snow to 

go to work, he immediately experienced severe back pain. He says the pain was similar to what 

he experienced when he had a disc rupture five years ago. Because he had some pain 

medication left over from a root canal 13 months ago, and the expiration date of the medication 

had not passed, he took it for his pain. The medication was originally prescribed to be taken on 

an as-needed basis. He reports that the label said APAP #4. He rested for the next three days, 

and because the pain medication was working, he did not seek medical attention. He subsequently 

felt better and went to work the day they were conducting drug testing. The donor submits a copy 

of the prescription bottle showing the dentist’s name and date, which was, in fact, 13 months 

prior to the drug test. The donor is unable to provide additional medical information. 

Conclusion: The donor has a valid prescription for the lawful possession of codeine and 

morphine that specifies no time limitations on the use of the drug (even if the expiration date on 

the dispensed prescription has expired). 

Note: This case introduces the question of what the MRO should do in the case of safety 

concerns related to the presence of a drug reported as Positive by the laboratory but that is 

reported as Negative by the MRO.

The MRO Guidance Manual states that within the HHS program, the MRO is not required to 

discuss safety aspects of the donor’s job function. An MRO’s decision to contact an employer 

regarding safety issues related to a donor’s valid prescription (i.e., legal drug use) is subject to 

the MRO’s independent and voluntary choice and any obligations the MRO may have with the 

donor’s employing agency. Therefore, before discussing aspects of job safety with an agency, 

the MRO should review the terms of their service agreement with the agency and any agency 

policies or rules that govern issues related to safety and/or seek private legal counsel. HHS and 

SAMHSA take no position regarding whether an MRO’s independent decision to disclose safety 

related information (or other drug testing information, such as numerical values) in the context of 

a donor’s legal drug use is legal or appropriate in any given circumstance because this issue is 

outside the scope of the Mandatory Guidelines. Please refer to the MRO Guidance Manual, 

Chapter 6, Section 6.3, Occupational and Public Safety, regarding handling safety issues 

involving valid prescriptions.

MRO Reported Result: Negative for morphine and codeine.

References:

HHS Medical Review Officer Guidance Manual for Federal Workplace Drug Testing Programs 

(February 1, 2024), Sections 4.5.3, 5.4.1, 6.3, Appendix F-Table 4
44

Mandatory Guidelines for Federal Workplace Drug Testing Programs, 88 FR 70768 (dated 

October 12, 2023) effective February 1, 2024, Section 13.5.d.2