Every grey-top blood vial contains two critical chemical powders: an anticoagulant to keep the blood from clotting, and a preservative called sodium fluoride. The preservative has a vital job: it stops microorganisms and bacteria from growing inside the tube.

Like any chemical product, these vials have a strict expiration date printed on the label. If the police use an expired vial to collect your sample, the sodium fluoride may be degraded and useless. Without an active preservative, a natural biological process called fermentation (or neo-genesis) takes place inside the sealed tube. Microorganisms consume the natural sugars in your blood and produce entirely new alcohol as a byproduct. By the time the lab tech tests the sample weeks later, the machine reads a combination of the alcohol that was in your system plus the new alcohol created by the bacteria, resulting in a falsely inflated BAC.

• Expired Tube Lot Numbers: We demand the manufacturing and expiration records for the exact batch of vials used during your blood draw.
• Improper Temperature Storage: If blood samples are left sitting in hot police vehicles or non-refrigerated lockers, fermentation speeds up drastically.
• A Lack of Chemical Mixing: Officers must invert the vial immediately after the draw to mix the chemicals with your blood. Failing to do so can allow the blood to spoil even in an unexpired tube.