Certification of the Intoxilyzer in Texas

The rules for breath testing are contained in the Texas Administrative Code under Title 37, Part 1, Chapter 19 of the breath alcohol testing regulations. The rule for the certification of the Intoxilyzer is found at Rule §19.2 Instrument Certification.

The provisions of Rule §19.2 were adopted to be effective March 26, 2006, under 31 TexReg 2189. The rules were first amended to be effective June 26, 2013, under 38 TexReg 3988. The rules were last amended to be effective January 12, 2015, under 40 TexReg 250.

Contact a criminal defense attorney to learn more about DWI breath testing in Fort Worth and Tarrant County, TX. Find out more about the administrative rules and ways to fight to have the court throw out the breath test reading at trial because of any compliance issues with these rules.

Call an experienced DWI attorney in Fort Worth at Law Offices of Richard C. McConathy to discuss your case. Call (817) 422-5350 today.


Rule §19.2 Instrument Certification

(a) The Office of the Scientific Director, Breath Alcohol Testing Program, Texas Department of Public Safety (hereinafter referred to as the scientific director) shall approve and certify all breath alcohol testing instruments to be used for evidential purposes.

(1) The scientific director will establish and maintain a list of approved instruments by manufacturer brand or model designation for use in the state.

(2) A manufacturer or designated representative desiring approval of an instrument not on the approved list may submit an instrument to the scientific director. Examination and evaluation of the instrument to determine if it meets the criteria for approval or certification as an evidential instrument will be done at the discretion of the scientific director. Costs associated with such a submission will be done at the expense of the submitting entity.

(b) In order to be approved each instrument must meet the criteria as detailed in this subsection:

(1) Expired breath specimens shall be analyzed.

(2) The instrument shall incorporate a reference system, the result of which must agree within plus or minus 0.01g/210L of the nominal value or such limits as set by the scientific director.

(3) The specificity of the procedure shall be adequate and appropriate for the analyses of breath specimens for the determination of alcohol concentration for law enforcement.

(4) Any other tests deemed necessary by the scientific director to correctly and adequately evaluate the instrument to give correct results in routine breath alcohol testing and be practical and reliable for law enforcement purposes.

(c) Upon proof of compliance with subsection (b) of this section the instrument will be placed on the list of approved instruments.

(1) Inclusion on the scientific director's list of approved instruments will verify that the instrument by manufacturer brand or model designation meets the criteria of subsection (b) of this section.

(2) The scientific director may, for cause, rescind approval of and remove an instrument by manufacturer brand or model designation from the approved list.

(d) The technical supervisor shall determine if a specific instrument by serial number is of the same manufacturer brand or model designation as is shown on the scientific director's approved list and meets the criteria for certification as stated in subsection (b)(2) of this section and when required, shall provide direct testimony or affidavit of this information.

(e) The scientific director, or a designated representative or technical supervisor, may, for cause, remove a specific instrument by serial number from evidential testing and withdraw certification thereof.

(f) Certified evidential instruments should not ordinarily be used for public information programs. Individuals with appropriate breath alcohol testing technical expertise, such as a certified technical supervisor, should disseminate this type of public information.


This article was last updated on Monday, April 3, 2017.

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