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From: Robert Swotinsky, MD
Password: orange
Date: 24 Aug 2009
Time: 18:26:33 -0700
Remote Name: 98.229.131.90
I would guess the "specificity" referred to in the Warde Laboratory information sheet refers to specificity for ethanol ingestion as opposed to non-beverage exposure to alcohol, e.g., skin cleansers and mouthwash. There is as yet no consensus on a urine EtG cutoff level that offers adequate sensitivity and is specific for beverage alcohol. That cutoff may well be in the 1,000 - 2,000 ng/mL range. Your concern about urine EtG testing with a cutoff of 500 ng/mL is well founded because there is a good chance someone will be falsely accused of beverage alcohol ingestion when they actually were exposed through mouthwash or cough medicine or some other non-beverage source. Consider sharing with your client the SAMHSA advisory from 2006. Point out to the school that it may be contributing to low levels of EtG if it makes Purel and other alcohol-based skin cleansers available, particularly in these days of concern over spreading H1N1 virus. If you research some of the literature on this, I think you'll see why I'm suggesting a higher cutoff, e.g., at least 1000 ng/mL.