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1 European standardisation of ofdour measurement: the state of play of CEN/TC264/WG2 Olfactometry and WG41 Instrumental Odour Monitoring by Ton van Harreveld ARPA workshop, Trieste, Italy, February 19, 2018 >>> Environmental odour management >>> Product and material testing >>> Calibration, Proficiency, Testing, Reference Material

2 Sensory Expertise delivered worldwide

3 What is CEN? European Standardization - A key instrument for the Single Market Standards are documents that set out specifications and other technical information with regard to various kinds of products, materials, services and processes. Standards provide a basis for mutual understanding among individuals, businesses, public authorities and other kinds of organizations. They facilitate communication, commerce, measurement and manufacturing. European Standards bring benefits to businesses and consumers in terms of reducing costs, enhancing performance and improving safety. They also help to ensure the compatibility of different components, products and services. European Standards can be used to enhance safety and performance, improve energy efficiency, and protect consumers, workers and the environment. They complement European and national policies, and make it easier for businesses and other actors to respect relevant legislation. European Standardization is a key instrument for consolidating the Single Market and facilitating cross-border trade within Europe and also with the rest of the world. It is a valuable tool for strengthening the competitiveness of European companies, thereby creating the conditions for economic growth.

4 Progress on the revision of EN13725: Air quality Determination of odour concentration by dynamic olfactometry Standardisation is a slow process..: 1991: CEN/TC264/WG2 work item approved by TC264 Air Quality on March 13, : EN13725 published, 12 meeting later : Revision initiated, WG2 reactivated 2018: Revision meeting 14 in February 2018/19 revised standard expected to become available Experts in the working group Nominated by CEN members > the national standardisation organisations On a volunteer basis (not funded by CEN) On personal title (not representing an entity) Mirror groups can be instated to maintain contact with profession Organised by a secretariat (NEN, Netherlands) and a convenor

5 Revised scope This European Standard specifies a method for the objective determination of the odour concentration of a gaseous sample using dynamic olfactometry with human assessors. The standard also specifies a method for the determination of the emission rate of odours from stationary sources, in particular: point sources (conveyed or ducted emissions through stacks or chimneys), conveyed area sources (e.g. biofilters), fugitive emissions. This standard can also be used to determine diffuse emissions (area or volume sources without conveyed outward flow) under specific conditions The primary application of this standard is to provide a common basis for evaluation of odour emissions in the member states of the European Union.

6 Scope includes The field of application of this European Standard includes: the measurement of the mass concentration at the detection threshold of pure odorous substances in g/m 3 or mol/m 3 the determination of the EROM value of odorous substances, in mol; the measurement of the odour concentration of mixtures of odorants in ou E /m 3 ; the measurement of the emission rate of odorous emissions from point sources and surface sources (with and without an outward flow), including pre-dilution during sampling; the sampling of odorants from emissions of high humidity and temperature (up to 200 C); the determination of effectiveness of end-of-pipe mitigation techniques used to reduce odour emissions

7 Scope does not include the measurement of odours potentially released by particles of odorous solids or droplets of odorous fluids suspended in emissions; the measuring strategy to be applied in case of variable emission rates; the measurement of the relationship between odour stimulus and assessor response above detection threshold; direct measurement of hedonic tone (or (un)pleasantness) or direct assessment of potential annoyance; field panel methods which are the subject of CEN standard EN16841 Ambient Air Determination of odour in ambient air by using field inspection, Part 1: Grid Method; direct olfactometry, including field olfactometry measurement of odour recognition thresholds; measurement of odour identification thresholds.

8 Main themes represented in small scale task groups Task group 1: Sample storage and materials for olfactometry Task group 2: Reference material for panel selection and panel management procedures Task group 3: Sampling of passive area sources (without flow) Task group 4: Sampling of active area sources (biofilters) Task group 5: Dynamic dilution during stack sampling Task group 6: Implications of EN air quality - measurement of stationary source emissions and other relevant sampling standards Task group 7: Calculation of uncertainty Task group 8: Compatibility of Yes/No and Forced Choice methods Task group 9: Health and safety issues

9 Sample storage and materials for olfactometry Findings: Recovery in olfactometer dilution system was researched using PTR/MS in Denmark Slow but complete recovery found for specific compounds Partial recovery found for H2S Modifications Stainless steel without silicate coating no longer suitable material

10 Reference material for panel selection and panel management procedures Findings n-butanol transferability to real world odours considered to be a tenuous claim Opening up the possibility to use more relevant reference odorants Opening up the possibility to used multi component reference mixtures Modifications Procedure defined for experimentally linking the EROM for a compound or defined odorant mixture to the reference EROM of n-butanol

11 Sampling of passive area sources (without flow) Findings Sampling was poorly developed in original EN13725 text Modifications Comprehensive sampling procedure was included, using VDI3880 as the starting point

12 Sampling of active area sources (without flow) Findings Sampling was poorly developed in original EN13725 text Modifications Comprehensive sampling procedure was included, using VDI3880 as the starting point Wind tunnel not standardised on design, but rather on performance in standard conditions. Mass transfer on a liquid surface of acetone diluted in water under standard conditions

13 Dynamic dilution during stack sampling Findings Sampling was poorly developed in original EN13725 text Modifications Comprehensive dilution procedure was included, using VDI3880 as the starting point Includes Static sampling Dynamic sampling

14 Implications of EN air quality - measurement of stationary source emissions and other relevant sampling standards Findings The EN13725 needed to be aligned with applicable standards for air sampling Modifications Many systemic changes, on level of wording, definitions and calculation

15 Calculation of uncertainty Findings The original standard focussed on QA&QC using n/butanol It was felt the focus should include real world samples Some sources of uncertainty were not addressed, in particular the uncertainty caused by using different panel member compositions There was a general push to improve performance and reduce uncertainty Modifications A new, detailed and comprehensive approach to uncertainty assessment was introduced The use of n/butanol remains a key element of QA/QC The use of alternative reference materials or multi compound reference mixtures was explicitly mad possible, by defining a method to determine EROM values linked to the reference EROM for n-butanol The uncertainty assessment now also includes the use of paired duplicate analysis with differently composed panels to obtain a more realistic assessment of within laboratory uncertainty Measures to improve uncertainty are still under consideration. The most important improvement could be reached by increasing minimum panel size from 4 to a higher number

16 Compatibility of Yes/No and Forced Choice methods Findings: There was some doubt on the compatibility of the two modes of presentation Modifications After an analysis of data provided by WG2 members no significant differences in the results from the two modes were found Both presentation modes remain in the standard

17 Health and safety issues Findings Health and safety risk assessment needed a more complete treatment in the standard. After all, the method involves exposure of human volunteers to air samples Modifications A more comprehensive Health and Safety clause was introduced, focussing on: H&S for panel members and assessors H&S for sampling technicians H&S for laboratory testing staff

18 Expectation on progress This week meeting 14 Aiming to finalise draft revised standard in 2018 Enquiry in 2018/2019 Translation, verification and publication in 2019

19 Progress of CEN/TC264/WG41 in drafting EN???: Air quality Instrumental odour measurement WG41 was established in 2015 Has attracted many experts, from academia, industry, consultants Focus is on Definitions: what is an e-nose? The approach is inclusive Criteria for developing and validating mathematical models linking instrument metrics to odour Validation of measurement results benchmarked to odour measurement In February 2018 we will have the 7 th meeting Standard expected to be completed in 2019? A parallel WG42 focusses on low cost air quality sensors

20 WG41 scope This European Standard specifies requirements for instrumental odour monitoring systems for the monitoring of odour in ambient air, indoor air and in emissions to ambient air. The primary application is to generate odour metrics that are relevant indicators for the presence and attributes of odour as would be perceived by human observers. A benefit of instrumental odour monitoring systems is that they can be used for continuous measurement. Odour monitoring systems are typically limited in their ability to mimic human olfaction and its very specific sensitivity to a large number of odorants. Human olfaction involves approx. 400 highly specific classes of olfactory receptor cells, from which the signals are aggregated in the brain to one odour perception [ref1]. Odour monitoring systems are typically less evolved and therefore currently only give indicative results. Odour sensors are often sensitive to both odour relevant molecules and also to odour irrelevant molecules. Odour sensors can also be subject to other interferences such as humidity and temperature. This can lead to both false positive and false negative sensor signals as far as odour relevance is concerned. The quality of the odour sensor signal, the mathematical treatment and the validation of correlation of the odour metric with human odour perception are therefore key topics in this European Standard.

21 WG41 scope includes: Instrumental odour monitoring in ambient air. Instrumental odour monitoring in indoor air. Instrumental odour monitoring in odorous gas emissions. Instrumental odour monitoring of the odour removal efficiency of end-of-pipe devices used to reduce odorous gas emissions. The method of correlating sensor signal based metrics to the presence and attributes of odour. The method of validating the sensor signal based metrics to the presence and attributes of odour.

22 .and the WG41 scope does not include The measurement of odour concentration in ou E /m 3 NOTE Odour concentration in ou E /m 3 is measured according to EN Monitoring of hedonic tone (or pleasantness or unpleasantness). Direct assessment of odour annoyance. The technical design of the odour sensors or the odour measurement system The monitoring of air quality for purposes of environmental health and safety.

23 Four Task Groups established TG1 Requirementsfor instrumental odour monitoring TG2 Validating the relationship odour metric and odour TG3 Terms and definitions TG4 Descriptions and review of scope relevant technologies

24 TG 1: Requirements for instrumental odour monitoring Instrument must be able to: detect the presence or absence of odour above a given threshold (i.e. instrument detection limit) identify and classify relevant odours at different concentrations quantify the odour (odour magnitude) and to give stable responses with varying atmospheric conditions (T, RH) What about relevant EN standards for monitoring? EN Stationary source emissions - Quality assurance of automated measuring systems EN Air quality. Certification of automated measuring systems. Performance criteria and test procedures for automated measuring systems for periodic measurements of emissions from stationary sources In ambient air Detection of odour (presence or absence): ou E /m 3 Identification/classification of odours: 1-100ou E /m 3 Quantification of odour magnitude: ou E /m 3 In emissions Classification/identification: not necessarily Quantification of odour magnitude: ou E /m 3 In indoor air Detection of odour (presence or absence): ou E /m 3 Identification/classification of present odours:1-100ou E /m 3 Quantification of odour magnitude: ou E /m 3

25 WG41 in action again in Trieste 20 & 21 February 2018, meeting 7

26 Thank you for your attention!