Are blood tests more accurate than breath tests?
Analysis of blood for alcohol concentration is considered much more accurate and reliable than the breath testing instruments. However, there are also potential problems with blood tests, such as fermentation of the sample (inadequate preservative in the test tube and/or lack of refrigeration), coagulation problems, lack of sterilization, and contamination by using an alcohol-based sterilization agent. There may also be problems with the chain of custody of the blood sample.
