TOXICOLOGY
Frequently Asked Questions
Our toxicology experts have resolved questions and concerns for thousands of customers. The information found on this webpage can help answer many common questions and assist you in managing a substance abuse testing program. The questions listed here are constantly updated, expanded, and refined to ensure that you have access to the very latest information.
Commonly Asked Questions
What is specimen adulteration?
Methods to adulterate urine samples for substance abuse testing generally fall into three categories:
- Urine substitution – substitution of one’s own urine sample with one which is clean or other products that have a similar appearance to urine.
- Urine dilution – ingestion of excessive amounts fluids or compounds such as diuretics for flushing out the system
- Urine adulteration – direct addition of adulterants or masking agents to urine specimen in order to interfere with the test
Can passive exposure cause a positive drug screen for THC?
This is highly unlikely. In general, routine passive exposure to marijuana smoke will not result in a positive screening result for cannabinoids in excess of a 50 ng/mL cutoff.
Why are screening and confirmation cutoff levels different?
Screening cutoffs are intentionally set higher to act as an initial filter, minimizing false positives from trace contamination or passive exposure while ensuring efficient processing of large sample volumes. In contrast, confirmation cutoffs are lower because confirmatory testing employs highly specific and sensitive analytical techniques such as GC-MS or LC-MS/MS.
This two-tier approach ensures that only samples with a reasonable likelihood of true drug use proceed to confirmation, while the lower threshold at the confirmatory stage provides accurate, legally defensible verification of positive results.
Onsite Device Questions
How do I use my rapid screening devices?
Our in-depth and interactive device training procedures will ensure you and your agency perform effective drug screens in a manner consistent with manufacturer recommendations. Once you've completed the device training, take a quiz to test your knowledge of a specific device. If you pass, you'll receive a Product Training Certificate*.
*PRODUCT TRAINING CERTIFICATE:
Our product training certification ensures that collection, device testing and result interpretation are performed in a manner consistent with manufacturer recommendations. RTL's product training certification is NOT an accredited proficiency certification for DOT or workplace specimen collection/testing. Contact DATIA, SAPAA or Office of Drug & Alcohol Policy & Compliance (DOT) for more information on specimen collection/testing certification.
Do the rapid test results hold up in court?
The on-site device provides only a preliminary analytical test result. A more specific analytical method, preferably liquid chromatography/tandem mass spectrometry (LC-MS/MS) or gas chromatography/mass spectrometry (GC-MS), must be used to obtain a confirmed analytical result. Any result, which is contested or used punitively, and especially, if taken to court, must be confirmed. To setup a laboratory confirmation account, contact your sales representative.
How do I know if the test device is negative?
If the test is negative, lines appear in the control region (C) and next to each particular drug name in the test region. The negative result indicates that the drug concentration is below the detectable cutoff level. Any visible line in the test region-regardless of how faint or dark-indicates a negative result. Variations in line intensity are normal and do not affect interpretation. If a line is present, even faintly, the test should be considered negative.
IMPORTANT PROCEDURE NOTE: Refer to the manufacturer's product insert for complete instructions, limitations, and warnings.
How do I know if the test device is positive?
If the test is presumptive positive, lines appear in the control region (C), and no line appears in the test region next to a particular drug name. This positive result indicates that the drug concentration is above the detectable cutoff level. All positive results are presumptive and should be confirmed by an alternate method (e.g. LC-MS/MS or GC-MS).
IMPORTANT PROCEDURE NOTE: Refer to the manufacturer's product insert for complete instructions, limitations, and warnings.
How do I know the test device is working properly?
A control line will be present if the test is working properly. If a control line does not appear, repeat the test with a new device. Insufficient specimen volume or incorrect procedural techniques are most likely the reasons for control line failure. Review the procedure and repeat the test using a new device. If further assistance is required, please contact your sales representative.
IMPORTANT PROCEDURE NOTE: Refer to the manufacturer's product insert for complete instructions, limitations, and warnings.
What is the shelf life of the on-site screening devices?
The on-site screening devices have a shelf life of up to 24 months from the date of manufacture. The expiration date is indicated on each individual foil pouch and can be used up until that date.
IMPORTANT PROCEDURE NOTE: Refer to the manufacturer's product insert for complete instructions, limitations, and warnings.
Do the screening devices need refrigeration?
No, as stated on the "Storage and Stability" section of the product insert, the test device should be stored at 2º to 30ºC (36-86ºF) and will be effective until the expiration date.
IMPORTANT PROCEDURE NOTE: Refer to the manufacturer's product insert for complete instructions, limitations, and warnings.
General Lab Testing Questions
What laboratory technology and equipment does Abbott utilize?
Our laboratories utilize a combination of gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme immunoassay.
How do I collect a specimen for laboratory confirmation?
Laboratory drug and alcohol test results are often used in legal proceedings. The manner in which specimens are collected and handled is very important. Specimens must be handled and controlled by collection site personnel throughout the collection process. Abbott provides suggested specimen collection and labeling guidelines via the Learning XChange training website. It is the responsibility of individual collection agencies to adopt their own policies and procedures according to their needs in compliance with individual state and federal regulations.
What does ng/mL mean?
Drug testing cutoff levels are usually expressed in the units of measure ng/mL (nanograms per milliliter). A quantitative positive GC-MS or LC-MS/MS result is commonly expressed in ng/mL.
Urine Lab Testing Questions
What are the urine screening cutoffs and methodologies?
Abbott screens urine specimens by enzyme immunoassay (EIA). An immunoassay is a test that uses antibodies to detect the presence of drugs and other substances in urine. The initial screening process does not measure the specific amount of drug present in urine samples. It provides either a positive or negative result, indicating the presence or absence of detectable drug metabolites above a specific cutoff level. Contact your sales representative for your agency's specific cutoff details.
What are the urine confirmation cutoffs and methodologies?
Confirmations are available by gas chromatography-flame ionization detection (GC-FID), gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on your agency's account settings, specimens may be confirmed by one or more of the aforementioned methods. GC-MS and LC-MS/MS provide identification of the molecule(s) based on characteristic fragmentation patterns at specific retention times. Contact your sales representative for your agency’s specific cutoff details.
What is the importance of checking the urine temperature strip on the collection cup?
Under normal situations fresh urine will display a temperature between 90 and 100 degrees Fahrenheit on the temperature strip, if read within 4 minutes of the collection. Should the temperature strip not register, the specimen should be immediately re-checked using a new cup (or strip) and the results recorded on the requisition. Specimens with a temperature out of range may indicate a substituted or adulterated sample.
What is the importance of checking urine creatinine levels?
Creatinine is a metabolic by-product of muscle metabolism, and normally appears in urine in relatively constant quantities over a 24-hour period with"normal" liquid intake. Therefore, urine creatinine can be used as an indicator of urine water content (dilution) or as a marker identifying a specimen as human urine. Greater than normal intake of water will increase the urine water content (lowering the creatinine level) consequently diluting any drug which may be present in urine. Conversely, a limited intake of water can lead to an abnormally concentrated urine specimen (as occurs with dehydration) resulting in elevated creatinine levels.
Oral Fluid Lab Testing Questions
What are the oral fluid screening cutoffs and methodologies?
Specimens collected with the oral fluid collection device are sent to Abbott for screening by enzyme immunoassay (EIA). Positive screens are confirmed by either gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), or by gas chromatography-flame ionization detection (GC-FlD). Contact your sales representative for your agency’s specific cutoff details.