Evidential breath alcohol measurements in South Africa

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  • Evidential breath

    alcohol measurements

    in South Africa


    27 July 2016

    14th APMP workshop


    Mudalo Isabel Jozela

  • Statistics

    1755 Killed in Road Crashes in South Africa during 2015 Festive Season (1 December 2015 to 11 January 2016)

    (Released date 12 January 2016 by RTMC)

    Major contributor: Drunk and driving

    Over 6000 motorists were arrested for drunk and driving during 2015 Festive Season

    o Driving under the influence of alcohol is a criminal offenceo According to WHO South Africa consumes 10-12 litres of pure

    alcohol (2014), ranking them as the African country whoconsumes the most alcohol per capita

  • Applications

    Law Enforcement

    Construction sites

    Professional driving



  • History

    Evidential breath analysers (EBAs) were introduced in 1997

    NMISA has been responsible for calibration since 1997

    Around 400 instruments were calibrated per year

    Dry and wet calibration method

    NMISA was responsible for the dry gas calibration

  • Dry gas calibration1

    Certification of secondary reference gas standards

    Locally made secondary reference


  • Dry gas calibration2

    Secondary reference gas standards used for calibration

    Calibration range 0,2 mg/L to 0,8 mg/L

    Ten measurements of each reference gas

    Dedicated gas port

    Measuring principle -Infrared at wavelength of 9m

  • Drger models

    Drger Alcotest 7110 Evidential

    2015 onwards

    Drger Alcotest 9510 Evidential


  • Legislation

    o National Traffic Act 93 of 2006

    The breath alcohol limit :-

    0,24 mg/L for all drivers and 0,10 mg/L of breath for professional drivers

    o Legal Metrology act

    o SANS 1793 Requirements of EBA calibration

  • Evidential breath analyser (EBA)

    Measures the mass concentration of ethanol by analysing deep-lung air (exhaled air)

    EBAs shall be capable of expressing measurement results in terms of ethanol content in the exhaled breath

    Measurement unit as per SANS 1793 is mg/L

    The relationship between the blood alcohol content and the breath alcohol composition is governed by Henrys law

    "At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid


  • Case Study 2011- real caseHendriks Court case 2011

    Accused breath alcohol concentration- 0,95 mg/L measured using Drger Alcotest MKIII 7110

    Reliability of the instrument was in question

    Problems identified were;

    Reliability -accurate determination of the alcohol concentration in the breath

    Calibration of the instrument used

    Training of the traffic officers for the correct use of the instrument, documentation of charge dockets, maintenance of the instrument

    Tampering with the instrument after calibration

    Recommendation from the case;

    Temperature of the exhaled breath should be measured.

    Test subject should blow two times before the instrument provides a final result


    This led to the re-establishment of the technical working group for drug and alcohol testing for the revision of SANS 1793

    New evidential breath analyzer was produced by Drger and currently the only EBA allowed in South Africa


  • Role playersNational prosecuting authority (NPA)


    Ensures that perpetrators of crime are charged and held responsible

    National Metrology Institute of South Africa (NMISA)


    Underpins testing and calibration through measurement accuracy & traceability

    Calibration of EBA

    National Regulator for Compulsory specifications (NRCS)


    Administrates regulation to ensure compliance and protect human health and safety

    Granted approval and Drager 9510 EBA in South Africa

    South African bureau of Standards (SABS)


    Documentary standards for validated methods used in industry

    SANS 1793:2013

    Technical working group for drug and alcohol testing

    Department of transport

    Law enforcement

    Road safety

    Regulation of transport sector

  • Improvements (New vs Old)

    For accurate determination of breath alcohol

    Breath temperature compensation

    BAC- Breath alcohol concentration at 340C

    Heated mouth piece

    Next calibration date be added after calibration

    Improved sealing and packing after calibration-calibration void if seal is broken stickers

    Instruments sent straight to the department after calibration by NMISA

    The new SANS 1793 2013 addresses all the improvements mentioned

  • New EBA

    Introduced in 2015 in South Africa

    Wet calibration done using ethanol CRMs

    It has a Heated breath hose @340C

    Calibration/blowing done using breath hose andmouthpieces

    Using water bath and breath simulators

    Drger Alcotest 9510 new features

  • Calibration of the instrument

    Calibration process

    Three certified solutions of ethanol are used: 0,2 mg/l, 0.4 mg/l and 0.8 mg/l according to new SANS 2013 document

    Traceable to the NMISA organic laboratory

    Breath hose and mouth piece are connected to the water bath/breath simulator

    Breath hoseMouth Piece

    Water Bath/ breath simulator Simulators at kept at 34oC

  • Calibration certificate


    concentration of

    aqueous ethanol


    Temperature of

    the bath (C)

    Mass concentration of

    ethanol in air (mg/)

    Certificate number

    619,3 32 0,211 Batch 0250/15

    981,8 37 0,465 Batch 0251/15

    2069,0 34 0,804 Batch 0252/15

    Mass concentration of ethanol in air using the Dubowskis equation

    = 0.04145 103

    2 (0.06583)

    Where t is the temperature in degrees Celsius (C)

  • After calibration

    Instrument calibration label (F)

    Sealing the instrument- No tampering allowed (A-E)

    Calibration void if seals are broken




    D E


  • Role out of Drger Alcotest 9510

    Role out started in 2015

    Implementation phase, 1 August 2016 in Western Cape

    SAB Sponsoring the EBA to priority areas Contributing back to the country by promoting safety on

    the road and in the work place

  • Positive remarks

    Drager instruments are being introduced back to

    South Africa

    Breathalysers provide reliable measurements

    Quick and reliable results in a few minutes

    Blood tests will still be done

  • Conclusion

    Breathalysers offer reliable and quick results in a

    few minutes

    Traceable to the SI unit mass-

    Ethanol CRMs

    Law enforcement and safety of




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