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Ignition Interlock

Lower Breath Volume Sample for Medical Exemption
DPS has determined the minimum breath sample volume for ignition interlock devices may be reduced to 1.2 liters for a device use with diminished lung capacity. Diminished capacity may be established through documentation from either a physician or the supervising court, advising of the necessity for the lower breath volume requirement. This documentation should be maintained in the manner required of calibration and maintenance records under Texas Administrative Code §19.25 (37 TAC 1, Ch. 19).

This policy is based on the Model Specifications adopted by the National Highway Traffic Safety Administration (NHTSA). DPS is currently revising its administrative rules and will incorporate this change therein. However, the policy is effective immediately and may be applied to current device users.

The Texas Transportation Code §521.2476 requires DPS establish minimum standards for vendors of Ignition Interlock Devices (IID) who conduct business in Texas and procedures to ensure compliance with those standards, including procedures for the inspection of a vendor’s facilities.

RSD staff certifies vendors to install, download, remove, repair, replace and make reports of all required data recorded by the device.

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