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Ethyl Glucuronide (EtG) and Ethyl Sulfate (EtS) Concentrations Following Use of Ethanol Containing Mouthwash

Mouthwash and other oral hygiene.

Mouthwash and other oral hygiene. | Sourced by Freepik©


Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are minor nonoxidative direct biomarkers of ethanol ingestion. The 2-5 day detection window of EtG and EtS is superior to direct ethanol measurements, which is approximately 1 hour per standard drink. The sensitivity of EtG and EtS in urine for beverage ethanol consumption is greater than 90 percent and is therefore an extremely important assay for the early detection of relapse in alcohol abstention programs. Other indirect markers, such as CDT, GGT, MCV, EDAC, WBAA, and FAEE have sensitivities of less than 90 percent and are therefore useless as a key indicator of relapse.

The controversy outlined in the Substance Abuse Treatment Advisory raises the issue of the detection of EtG and EtS in urine as being too sensitive. To date, there is little if any published data on the correlation of unintentional ethanol exposure and the detection of EtG and EtS in urine.

One possible source of unintentional ethanol ingestion is the use of ethanol-containing mouthwashes and breath sprays. These products can contain between 8-26% ethanol by weight. A typical 32-fluid oz package of ethanol-containing mouthwash can contain up to 20 standard 12g drinks. Ethanol is easily absorbed in the oral cavity, and inevitably, some will trickle down the back of the throat.


The use of mouthwash was studied by using Target Brand Antiseptic Mouthrinse –Spring Mint (ethanol 21.6%) as described on the package directions, which indicates a 20 mL dose (3/4 capful) swished between the teeth for 30 seconds. After both subjects demonstrated negative EtG and EtS baseline results, this procedure was initiated and carried out once an hour for eight hours. Urine specimens were collected at 2 hours, 4 hours, 6 hours, 8 hours, and 16 hours (first void the next morning). The specimens were analyzed at USDTL for creatinine and ethanol on an Olympus AU640 using standard protocols. The limit of detection for urine ethanol was 3 mg/dL. EtG and EtS determinations were performed at USDTL using standard protocols on an API 2000 LCMSMS. The limit of detection for EtG and EtS was 38.7 ng/mL and 7.2 ng/mL, respectively.

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