Challenging the Breath Test in Chicago DUI Cases

1. Machine Calibration Problems

• Breath machines must be regularly calibrated (fine-tuned) to work correctly.

• Missed or improper calibration creates faulty readings.

• Illinois law requires strict compliance with testing rules under Illinois Administrative Code Title 20, Part 1286.
  Benefit: Calibration errors often lead to suppressed (thrown out) results.

2. Improper Officer Training

• Officers must follow step-by-step procedures when giving the test.

• If they skip steps—like the required observation period—the test can be challenged.
  Benefit: When procedures aren’t followed, the results lose credibility.

3. Mouth Alcohol Contamination

Substances inside the mouth can artificially raise BAC levels:

• Mouthwash

• Breath fresheners

• Recent burping or regurgitation

• Dental work (like braces or retainers)

Example:
Imagine someone takes a breath mint before driving. The machine may detect alcohol vapors from the mint—not from their bloodstream.

4. Medical Conditions Affecting the Test

Certain health issues can create false positives:

• Acid reflux or GERD

• Diabetes (ketones can mimic alcohol)

• Asthma inhalers
  Benefit: Medical records can be powerful evidence to challenge reliability.

5. Environmental Interference

Outside factors can also affect accuracy:

• Radio frequency interference

• Temperature issues

• Residual cleaning chemicals in the testing room
  Real-life analogy:
  Think of a bathroom scale on uneven flooring—it won’t give a true reading.