Urine testing for EtG detects the actual ethanol in the body, which reflects current use within the past few hours (depending on how much is ingested). The presence of EtG/EtS in urine indicates that ethanol was ingested within the previous 3 to 4 days, or approximately 80 hours after ethanol has been ingested. Therefore, EtG/EtS is a more accurate indicator of the recent ingestion of ethanol than measuring for the presence of ethanol itself.
Nail Testing – Fingernails and Toenails
Nails provide a test sample that is simple to collect, very difficult to adulterate and easy to ship and store. Drugs are incorporated into the nail from the blood stream and remain locked in the nail as it grows. Drugs can be identified in nail clippings 1-2 weeks following ingestion and the window of detection may extend from 3 months up to 6 months after the last usage. Environmental exposure is immediately detectable. Fingernails grow approximately 3 millimeters (mm) to 5 mm per month, and toenails grow at a much slower rate of 1 mm per month. Drugs can be detected in toenail clippings up to 1 year after ingestion. The optimum amount of nail clippings needed is 100 mg. If trimming all 10 fingernails, each clipping must be at least 2 mm to 3 mm long.
Hair provides a test sample that is simple to collect, moderately difficult to adulterate and easy to ship and store. 100 mg or a 1.5-inch sample of approximately 200 strands, collected from the scalp, can, for most drugs, provide up to a 3 month drug history. When scalp hair is not available, an equal volume of body hair may be collected for testing. Most drugs appear in scalp hair 1-7 days after ingestion, and peak concentrations occur about two weeks after. Urine, on the other hand, for a drug like cocaine, only yields about 2-3 days of prior drug exposure history.
Measuring Ethyl Glucuronide (EtG) in Nail and Hair Samples
Nail and Hair EtG tests are the first and only tests to reliably report a donor’s alcohol exposure for the past 90 days. EtG is a minor product of alcohol metabolism and is therefore a direct alcohol biomarker. A USDTL (US Drug Testing Laboratory) study sponsored by NIAAA of 600 college students showed that EtG levels in nails and hair related extremely well to the number of drinks reported.
Previous alcohol tests in other matrices did not provide a large enough exposure history for many healthcare professionals monitoring risky alcohol drinking behavior.
Urine, for example, only provides a few days, at best, using EtG analysis. EtG in hair and nails has the best time-line, follow-back history of any alcohol assay, using LC-MS/MS, high-sensitivity methodology. Nail samples are the preferred specimen over hair samples since fingernails show no bias. Because cosmetic
treatments destroy the presence of some drugs and biomarkers in hair, many donors are not able to provide a valid sample. 5280 Drug Testing Company requires a sample volume of 100 milligrams for fingernails or hair. Turn around time is approximately 48 hours for initial screening, with up to 2 extra days for confirmation of presumptive positives.