Much has been said about the problems inherent with breathalyzer tests in Arizona. These include handheld machines used in the field, as well as stand alone machines used in police stations. Essentially, the calibration on them may not always be up to date, which would lead to inaccurate results.
The fallibility could be upwards of .04 percent. In close cases, this could mean the difference between a criminal conviction and innocence. It could also be the difference between a felony and a misdemeanor charge, and with it, the specter of serious jail time.
Even with the reliability issues with breathalyzer tests, more law enforcement agencies are starting to use saliva tests to determine if someone is under the influence of alcohol or illegal drugs. Essentially, the tests pick up the residue of such substances and ostensibly give police officers probable cause to arrest someone on suspicion of driving while impaired or under the influence of alcohol.
However, the saliva tests come with their own set of problems. It is rumored that the tests must be discarded directly after they are used; meaning that the very proof that led to probable cause is no longer available and cannot be used in court. This is likely a reason why a number of state legislatures (including Arizona) do not require police do use them in the course of a traffic stop.
Nevertheless, if you are stopped and required to submit to a saliva test, an experienced criminal defense defense attorney can advise you of your rights and options.
Source: WREG.com, Arkansas law now allows saliva tests at DUI stops, July 25. 2013