The 0.02 Agreement Criteria in Breath Alcohol Needs to be Reconsidered
The 0.02 agreement criteria doesn't scale with concentration and shouldn't be used to charge a person with a test refusal.
Many states have duplicate agreement criteria for breath alcohol samples.
If the samples vary by too much from one another this could mean that one or both of the samples are contaminated with mouth alcohol.
Mouth alcohol ≠ refusal
In the state of Minnesota, both samples must be within 0.02 g/210L of each other. Another test must be performed if the samples fall outside of this range.
If, on the second test, the samples fall outside of the 0.02 g/210L criteria again, the officer will often charge with a refusal.
The justification for this is that MN law states:
“Two deficient breath tests, as defined by paragraph (d), constitute a refusal.” (MN Statute 169A.51.5)
In MN, refusals come with harsher penalties than if one had a valid breath test above 0.08 g/210 L.