CPC CPC Adulteration & Specimen Validity Testing 2 — Questions and Answers
Question 1: What specific gravity range indicates a substituted specimen under federal drug testing guidelines?
- Less than 1.001 or greater than 1.020 (Correct answer)
- Less than 1.003 or greater than 1.030
- Less than 1.010 or greater than 1.025
- Less than 1.005 or greater than 1.015
Correct answer: Less than 1.001 or greater than 1.020
Specific gravity outside 1.001–1.020, combined with creatinine below 2 mg/dL, meets the federal criteria for a substituted specimen.
Question 2: A donor's specimen is reported as 'dilute.' What does this finding indicate?
- The specimen has creatinine between 2–20 mg/dL and specific gravity between 1.001–1.003 (Correct answer)
- The specimen contains a foreign chemical that interferes with drug testing
- The specimen was left unrefrigerated and degraded before reaching the laboratory
- The specimen volume was insufficient for testing
Correct answer: The specimen has creatinine between 2–20 mg/dL and specific gravity between 1.001–1.003
A dilute specimen has low but not absent creatinine (2–20 mg/dL) and specific gravity (1.001–1.003), suggesting either natural over-hydration or intentional dilution.
Question 3: Under DOT regulations, what action is typically required when a pre-employment test result is reported as dilute negative?
- The employer may, but is not required to, conduct a recollection under direct observation (Correct answer)
- The employer must automatically order a second collection under direct observation
- The result is treated as a negative and no further action is needed
- The MRO must request a split specimen retest
Correct answer: The employer may, but is not required to, conduct a recollection under direct observation
For a dilute negative pre-employment result, the employer has the discretion to require a recollection under direct observation per their written policy, but it is not mandated.
Question 4: What laboratory finding would classify a specimen as 'invalid' under federal validity criteria?
- Presence of an unidentified interfering substance or results that are outside expected physiological ranges (Correct answer)
- A pH reading between 4.5 and 8.5 with no other abnormal indicators
- A specimen temperature that was within the acceptable range at collection
- A creatinine level between 20 and 300 mg/dL
Correct answer: Presence of an unidentified interfering substance or results that are outside expected physiological ranges
An invalid result occurs when the laboratory cannot complete testing due to an interfering substance or results that are inconsistent with normal human physiology.
Question 5: When a specimen is reported as 'invalid,' what is the MRO's required next step?
- Contact the donor to determine if there is a legitimate medical explanation, then order a recollection if no explanation is provided (Correct answer)
- Report the result as a refusal to test without contacting the donor
- Automatically cancel the test and require a new collection
- Forward the case directly to the employer for disciplinary action
Correct answer: Contact the donor to determine if there is a legitimate medical explanation, then order a recollection if no explanation is provided
The MRO must attempt to contact the donor for a medical explanation; if none is found, the MRO orders a recollection under direct observation.
Question 6: Which of the following is NOT a specimen validity test parameter measured by the laboratory?
- The donor's blood alcohol concentration (BAC) (Correct answer)
- Creatinine concentration
- Specific gravity
- Oxidant or oxidizing adulterant presence
Correct answer: The donor's blood alcohol concentration (BAC)
Blood alcohol concentration is measured by a separate breath or blood alcohol test; it is not part of urine specimen validity testing.
CPC CPC Adulteration & Specimen Validity Testing 2
What specific gravity range indicates a substituted specimen under federal drug testing guidelines?