100 ng/ml - most commonly used to monitor individuals for professional or clinical reasons, such as impaired health professionals. Some criminal justice use.
250 ng/ml- currently the most commonly used level. This level has a high enough cut-off to avoid most incidental exposure.
500 ng/ml – This level of testing will detect about 90% of episodes of alcohol use as compared to 100 ng/ml testing. Commonly used in routine clinical and forensic applications as most "innocent positives" (that is, non-negative results due to inadvertent alcohol exposure) occur below the 500 ng/ml level.