Breath testing machines have always had various faults that created potential defenses to a DUI attorney. The newest generation of machines also have a multitude of potential errors and faults that may render a breath test inaccurate. According to Matthew Ruff, a DUI Attorney in Torrance California, One of the best ways to attack a breath test is to use a defense expert in the area of toxicology. Many experts have a vast amount of experience working within the states crime lab and often bring with them a substantial amount of credibility given the fact they once worked and testified on behalf of the prosecution. When it comes to breath testing each case needs to be examined carefully to scrutinize the breath samples for possible error as it relates to a person's true blood alcohol level. One of the most fruitful areas of attack in recent years is on the issue of interfering substances. When we say interfering substances, we mean the breath machine is picking up substances other than alcohol but reporting them as a BAC result. This is especially true for older breath machines and virtually all PAS devices sense the basic working of these machines rely on the use of a fuel cell that reacts to various substances and may display those substances as a blood alcohol level when in fact the true BAC or blood alcohol level may be much lower.
Some people in certain professions are more prone to interfering substances than others .for example occupational exposure to toluene for example will show up as alcohol on various machines as well substances containing acetone .when these substances are inhaled, for example ,during the course of a person's occupation ,this exposure can cause a false positive for alcohol and can increase the true blood alcohol levels by as much as point .05 %. Though this may not seem like a significant amount for persons subject to zero tolerance even a fraction of a percentage point can result in termination of employment or the loss of their drivers license. One example of a person who may be exposed to interfering chemicals could be someone who works in an industrial setting ,someone who paints for a living ,works in a auto body shop ,or is a janitor by trade .He or she may be exposed to certain compounds which can enter the bloodstream and cause in interfering substance error in the blood-alcohol test .
In one recent publicized case a painter was arrested for DUI and his blood-alcohol level was reported as being above the legal limit . it turns out is exposure to certain chemicals such as acetone and the like in its trade may have caused in artificially high BAC level and subjected him unfairly to criminal prosecution . an expert in the area of toxicology could be utilized to convey to the jury at trial how certain substances may falsely influence the breath machine . some scientific studies seem to infer that interference from a variety of chemicals may have a deleterious affect on certain breath testing machines used in DUI prosecutions .