Evidential breath alcohol measurements in South Africa
Transcript of 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