MRO Drug Testing Procedures 3

Question 1

What initial testing method is required for DOT federal workplace urine drug screening?

Accepted Answer

Immunoassay

Answer

Immunoassay is the required initial screening method for all federally mandated urine drug tests.

Question 2

Which method must be used to confirm a positive immunoassay result in a federal workplace drug test?

Accepted Answer

GC-MS or LC-MS/MS

Answer

GC-MS or LC-MS/MS provides the definitive structural identification required for a confirmed positive result.

Question 3

What is the DOT initial immunoassay cutoff concentration for marijuana metabolite (THC-COOH) in urine?

Accepted Answer

50 ng/mL

Answer

The federally mandated initial screening cutoff for marijuana metabolites is 50 ng/mL.

Question 4

What is the GC-MS/LC-MS/MS confirmatory cutoff for THC-COOH in federal workplace urine testing?

Accepted Answer

15 ng/mL

Answer

The confirmatory cutoff for THC-COOH is 15 ng/mL, which is lower than the initial screen to ensure the screen's positive result is valid.

Question 5

Which five drug classes make up the standard DOT federal workplace urine drug testing panel?

Accepted Answer

Marijuana, cocaine, opiates, phencyclidine, and amphetamines

Answer

The DOT 5-panel tests for marijuana metabolites, cocaine metabolites, opiates, phencyclidine (PCP), and amphetamines.

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