Evidential breath alcohol measurements in South Africa

Evidential breath

alcohol measurements

in South Africa

TQM-5126-1

27 July 2016

14th APMP workshop

Mongolia

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

Manufacturing

Mining

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

NDIR PRGM

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 9µm

Dräger models

Dräger Alcotest® 7110 Evidential

2015 onwards

Dräger Alcotest® 9510 Evidential

2004-2013

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 Henry’s 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’’

TQM-5126-1

Case Study 2011- real caseHendriks’ Court case 2011

• Accused breath alcohol concentration- 0,95 mg/L measured using Dräger 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

Outcome

• 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 Dräger and currently the only EBA allowed in South Africa

TQM-5126-1

Role playersNational prosecuting authority (NPA)

• Prosecution

• Ensures that perpetrators of crime are charged and held responsible

National Metrology Institute of South Africa (NMISA)

• Metrology

• Underpins testing and calibration through measurement accuracy & traceability

• Calibration of EBA

National Regulator for Compulsory specifications (NRCS)

• Regulation

• 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)

• Standardization

• 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

Dräger 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

Mass

concentration of

aqueous ethanol

(mg/ℓ)

Temperature of

the bath (°C)

Mass concentration of

ethanol in air (mg/ℓ)

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 Dubowski’s equation

𝐶𝑎𝑖𝑟 = 0.04145 𝑥10−3𝐶𝐻2𝑂𝑥 𝑒𝑥𝑝 (0.06583𝑡)

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

A

B

C

D E

F

Role out of Dräger 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

personnel

THANK YOU