‘0.000’ Air Blank Test A Legal Prerequisite For Admissibility Of Breathalyzer Evidence: Kerala High Court
The petitioner was allegedly riding his scooter dangerously while under the influence of alcohol.
Justice V.G. Arun, Kerala High Court
The Kerala High Court has ruled that an Air Blank Test yielding a '0.000' reading is a legal prerequisite for the admissibility and validity of breathalyzer test results in cases involving allegations of drunk driving.
The petitioner had been charged under Section 185, Section 181 read with Section 3(1) of the Motor Vehicles Act, 1988 and Section 281 of the Bharatiya Nyaya Sanhita (BNS).
A Bench of Justice VG Arun held, “it is mandatory to conduct an Air Blank Test and ensure that the calibration is at 'zero' before taking breath sample using a breath alcohol testing device. This precisely is the reason why, the DGCA made it mandatory to run an Air Blank Test on the instrument and obtain the reading ‘0.000’ before each breathalyzer test.”
Advocate Faheem Ahsan S appeared for the petitioner, while Senior Public Prosecutor MC Ashi appeared for the Respondents.
According to the prosecution, the petitioner was riding his scooter dangerously while under the influence of alcohol, thereby endangering public safety.
However, petitioner argued that the breathalyzer test was improperly conducted it was administered after his arrest, rather than at the time he was stopped, which violates proper testing protocols. He was not subjected to a medical examination within two hours of his arrest, which is a requirement under Section 204 of the Motor Vehicles Act. Further, he highlighted a glaring discrepancy in the Air Blank Test reading: instead of displaying the expected 0.000 mg/100 ml, the device showed 412 mg/100 ml, thereby casting serious doubt on the subsequent breath test reading of 41 mg/100 ml.
While the State maintained that the final police report demonstrated the petitioner was driving in a manner that endangered human life, the Court found the breathalyzer result unreliable due to the faulty air blank test, which should have immediately rendered the device suspect.
Moreover, since no medical test was conducted within the legally mandated two-hour window, the Court found no conclusive evidence that the petitioner had consumed alcohol. As a result, the charge under Section 185 could not be sustained.
On the issue of driving without a valid licence, the Court observed that the petitioner did in fact hold a valid driving licence at the relevant time, thus invalidating the charge under Section 181 read with Section 3(1) of the Motor Vehicles Act.
However, the Court declined to quash the charge under Section 281 of the BNS, which deals with rash or dangerous driving. The Court held that whether the petitioner drove in a manner that endangered human life is a matter of fact that should be determined at trial.
The High Court quashed the final report and all further proceedings related to Sections 185 and 181 r/w 3(1) of the Motor Vehicles Act. The charge under Section 281 of the BNS was allowed to continue to trial.
The Court also took note of the lack of awareness among police officers regarding the mandatory ‘zero’ calibration in air blank tests. It directed the Senior Public Prosecutor to forward a copy of the judgment to the Director General of Police (DGP) so that necessary instructions could be issued to all law enforcement personnel regarding the proper use of breathalyzer devices.
Cause Title: Saran Kumar S v. State of Kerala & Anr., [2025:KER:48676]
