The Preliminary alcohol screening (PAS) device is a breathalyzer machine used by the police on the scene of a DUI arrest.  Keep in mind that its purpose is to be one of many field sobriety tests administered to determine whether the individual is under the influence of alcohol. It is not determinative of blood alcohol content, it is simply a factor for the police to take into consideration on deciding whether to arrest for driving under the influence.

Vehicle Code 23612(h) provides the authority:

(h) A preliminary alcohol screening test that indicates the presence or concentration of alcohol based on a breath sample in order to establish reasonable cause to believe the person was driving a vehicle in violation of Section 23140, 23152, or 23153 is a field sobriety test and may be used by an officer as a further investigative tool.

The PAS retains no breath sample and it is not equipped to detect mouth alcohol.   By law, the police are supposed to inform any individual that they are requesting to take a test the following admonitions:

(1) The officer is requesting the test be administered to assist in determining if the person is under the influence;

(2) Taking the test does not satisfy the person's duty to submit to an additional blood or breath test pursuant to the “implied consent”  laws of Vehicle Code 23612(a)(1); and

(3) You have the right to refuse the test. Veh. Code 23612(i)

1. The fact that you refused to take the PAS cannot be used against you later in court, since you have a legal right not to take the test.  (People  v. Jackson (2010. 1^st Dist.) 189 Cal.App. 4^th 1461)

If the individual does complete the PAS test, the evidence of the results is only admissible if the prosecution satisfies the following foundational requirements:

(1) Law enforcement complied with Title 17 of the California Code of Regulations, which states the terms for the maintenance of the PAS equipment and the proper training for those administering the test. (People v. Wilson (2003, Cal.App 1^st Dist) 114 Cal.App 4^th 953)

Or;

(2) Law Enforcement complied with the standards set out in People v. Adams (1976) 59 CA3d 559, which are:

1. The PAS device used was in proper working order;
2. The PAS was properly administered;
3. The officer administering the PAS was competent and qualified.

i. Not always an easy hurdle when the operator was the police officer.

Even when the prosecution is able to satisfy one of the above requirements for admission into evidence, they still have to show that the proper admonishments were given.  If they are unable to show that the proper admonishments were given, particularly the admonishment that you have a right to refuse the PAS, then your dui attorney should file a Motion to Exclude the PAS results from evidence and should be successful if the admonition (or the complete admonition) was not given.

References & Resources:

People v. Wilson (2003, Cal.App 1st Dist

People v. Adams (1976) 59 CA3d 559