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How to Interpret Odor Nuisance Regulations


The most common approach to regulating odor impacts is through the interpretation of odor nuisance. The origins of odor nuisance regulations come from English Common Law which balances the rights of individuals. One has the right to swing their arm up to the point that a closed fist approaches another person’s nose. At that point, the other person’s right not to be assaulted prevails.

Odor nuisance does not prevent a person from creating or releasing odors, even offensive odors, from their property. However, that action is limited by the potential impact those odorous emissions have on their neighbors. The allowable threshold is not always clear. Like squirmy children in the back seat of a car, how close can you come to touching someone without being a threat?  “He’s touching me! No I’m not!” The allowable emission of odorous compounds without being a nuisance is also subject to interpretation.

Nuisance impacts are the most common reason that odors impacts are mitigated. While most states have prohibitions of nuisance impacts under common law, few states define what odor concentrations are associated with nuisance odor impacts and even fewer define what the frequency and duration of those impacts should be. In most cases, nuisance impacts must be verified by a regulatory authority to be considered valid.


Learn more about Odor By-Laws


Odor nuisance language can appear in an air quality statue as part of the definition of key words, such as “air pollution”, “air contaminant” or “nuisance”. It may also appear as a separate odor nuisance standard. An odor is a nuisance if it “unreasonably interfere with the proper enjoyment of the property of others” (Code of Maryland Regulations, Title 26 – Department of the Environment, Subtitle 11 – Air Quality .01 Definitions), “unreasonably interferes with the enjoyment of life or the use of property” (Connecticut DEM Regulations, Section 22a-174-23. Control of odors), and “unreasonably interfere with the enjoyment by the people of life or property” (Title 9 Virginia Air Code, 9VAC5-10-20. Terms defined).

To interpret odor nuisance standards, it is necessary to explicitly define what type of odor episode you are trying to mitigate and set frequency, intensity, duration values appropriate for that episode. There are common elements in the language of odor nuisance that allows us to interpret useful values. First, the affected person must not only detect an odor, the person must recognize the odor as being distinct from other background odors and be specific to a particular source. In a laboratory, a trained odor panelist can detect an odor is present in a sample when compared to carbon filtered air at 1 odor unit, even if the panelist cannot describe the odor. At about 2 to 3 odor units, a panelist can describe the character of an odor when mixed with carbon filtered air. For an untrained observer to detect an odor in the natural environment where there are competing odors, the odor concentrations need to be between 5 and 10 odor units.

The duration of the odor episode must be sufficiently long duration to interfere with the activities at the person’s property. The duration of the odor episode may be further extended by the requirement that a regulatory official confirm or verify that the odor is present. While a person can perceive an odor in a few seconds, it may take several minutes before the presence of the odor disrupts activities at a person’s property. It may take several minutes more before the affect person acts by filing an odor compliant. If a regulatory official is needed to confirm that an odor is present before a formal complaint can be filed, an odor may need to persist for a period of an hour or more.

To be a nuisance, an odor episode must be unreasonable. While a single odor episode may be unpleasant and disruptive, it may also have been accidental or unavoidable. Odor episodes that re-occur over a period of time become preventable and are an unreasonable imposition on the surrounding community. The relationship between frequency and duration and frequency and intensity are inversely related. Odor episodes with low odor concentrations and persist for short periods of time can be tolerated more frequently than high odor concentrations that persist for long periods of time.

odor nuisance plume

Example of a real time odor plume based on onsite continuous odor monitoring


Offensive odors provoke the strongest response. They may also be distinctive in their character relative to normal background odors, so that even a low odor concentration can result in a sharp response. However, even more pleasant odors if they have a high odor concentration and persist for an extended period of time with a high frequency of occurrence can be a nuisance.

When odor nuisances are interpreted in this manner, it is possible to apply standard measurement, monitoring and modeling methods to evaluate odor impacts and develop appropriate mitigation measures.



You want to know more onInternational Odor Regulations?Free review for downloadClick here


Odour Measurement Instruments and Odour Management Workshop - Compost Canada


After Nova Scotia, Edmonton, Vancouver and Toronto, the Compost Council of Canada concludes the Grand Canadian Tour of technical workshops - Compost Matters in Canada - in Winnipeg, Manitoba March 18th & 19th.

Compost Manitoba

Once more, Odotech is proud to partner to this great initiative an provide an technical session on odour management for organic waste facilities.

The workshop is hosted by Green Manitoba & Recycling Product News and numerous attentees are expected.

Green Manitoba Logo Recycling Product News 


Key matters for the industry will be covered:

  • Modernizing the Fertilizers Act and Regulations

  • Composting in Manitoba

  • Outreach to Residents and the IC&I Sector

  • Composting and Gardening Programs in the North

  • Compost Collection Program at the University of Winnipeg 

  • Updates from the Manitoba Composting Association Corporation

  • Compost Research on Potato Diseases and Production

  • Potency of Manure Compost: Knowing the Limit for Crop Production

  • IC&I Composting for Manitoba's Capital Region

  • Essentials of Odour Management at Organics Management Facilities, given by

    Jacinthe Bisson, Eng, Senior odour expert, Odotech inc.

Jacinthe is the leader of our Odor Science groupe. She ran numerous odour studies, odour observer committee and electronic nose projects.

Odotech is proud to be associated with the Compost Council of Canada to present the segment on the Essentials of Odour Management at Organics Management Facilities. We have prepared a special presentation for composting facilities, anaerobic digestion projects, landfills and others. Key topics will be address to provide attendees a complete tool box from the science of odour perception and odour metrology, odour management planning, odour impact assessment, continuous odour monitoring and odour control.

electronic nose composting plant 

Odotech has been in the business of odour management for 15 years and lead over 700 projects in all types of industries with teams of specialists in North America, Europe and Latin America. Odour studies, odour mitigation plans and prevention programs, Odour Monitoring System (e-nose) and real-time modeling tools (More than 100 systems installed, nearly half on organic waste sites). From 2009 to 2013 we worked with 70+ organic plants in Canada, USA, France, Chile, Norway, Brazil, Columbia, Belgium, Switzerland, Israel (Composting, Digestion, Landfills and integrated sites).


Harvest Power odor monitoring


Download the registration form


For additional information, please visit, email at or call 1-877-571-4769


Get the pre\u002Dtraining PPTEssentials of organics odour mangement

Measure Odor & H2S in Sewer Collection Systems in Real Time


The Water Environment Federation (WEF) Collection Systems Committee, in cooperation with the Chesapeake Water Environment Association and the National Association of Sewer Service Companies are holding the Collection Systems 2014 Conference this week in Baltimore, Maryland. This conference will draw professionals from around the region and across the country who share an interest in improving the combined and separate sanitary sewer collection systems. 


Odor and H2S emissions are major concerns for collection systems. What if operators could diagnose odor problems in minutes instead of hours or days?  How much could they save in chemicals, time, implementing new process and infrastructure corrosion?  Find out at the Collection Systems 2014 Conference this week!

OdoWatch is the only technology that measures odors the way humans experience them, in D/T or odor units.  Together with the real-time dispersion modeling created from actual on-site weather data and the emissions from odor sources, OdoWatch displays color-coded plumes of odor concentrations on and off site where they may be a nuisance.  No other technology provides such accurate, timely information on odors and H2S. Fnd information on OdoSulf, the newest H2S monitoring technology that can uses the OdoWatch platform to provide real-time plumes of hydrogen sulfide impact. Operators using OdoWatch for odor and H2S monitoring have saved hundreds of thousands of dollars in OPEX and CAPEX.

Contact Sharon Paterson, Kruger Product Manager for OdoWatch at to meet her at the conference.  See you at the event!


Get the WEFTEC abstractH2S Vs. Odor Units




Odour Monitoring Equipment Supplier‎


The OdoWatch Platform is a turnkey solution to provide all necessary equipment for real time odour monitoring. It includes the required odour and gas sensors and a weather station. It records and stores all monitoring data so you can review exactly what happened in the past.

Headwoirks odor monitoring

The e-noses are positioned near the odour sources of the site and measure the odour continuously. The odour data from the e-noses and the weather data from the weather tower are sent to the OdoWatch software, which models the atmospheric dispersion and displays the site’s odor plume calculated by AERMOD or CALPUFF. OdoWatch is calibrated to recognize and quantify (in odour units) the odours of each site.

Odotech's electronic nose has the capability to continuously monitor and record odour levels. It is composed of a matrix of 16 MOS sensors. OdoWatch also has the capability to continuously monitor and record H2S gas concentrations and integrate Multigas Detectors for real-time monitoring of up to four (4) different gases (H2S, NH3, SO2, VOC, etc.) concentrations.

Free White Paper How an eNose Does Work  

The OdoWatch Platform is installed all over the word from desert to northern areas (-20°C to +50°C). All units have weatherproof NEMA 4X enclosures.

In order to correctly monitor atmospheric dispersion, the OdoWatch platform is equipped with a Weather Station installed onsite for continuous weather condition monitoring and recording. Measured weather conditions are wind direction, wind speed, atmospheric pressure, rain, temperature, humidity and solar radiation. The Weather Station must be installed in an area free of weather turbulences caused by adjacent structures.

All devices installed on site transmit their data using eaither GPRS radios or radio wireless communications. Data is transmitted on a continuous and uninterrupted basis. Radio signals are 2.4 GHz frequency hopping spread spectrum (2.4 @ 2.4835GHz) in a master-slave configuration. No radio operating license is normally required .

OdoWatch can be accessed on the internet using a web browser. All odour, contaminant and weather data can be displayed in the OdoWatch interface. The OdoWatch Platform provides email notifications and Alerts points signaling when pre-set olfactory thresholds are exceeded.

odor monitoring Grit Removal 

Installation of the equipment of the OdoWatch platform is done by Odotech technicians. Training for operators and maintenance personnel is provided with corresponding documentation (O&M Manuals). Odotech provide all necessary training for maintenance people and operators.

All equipment installed onsite require either 120 Vac/ 60 Hz or 240 Vac/50Hz. Depending on the type of emission sources, it may be require to install heated lines and gas preparation units to prevent from humidity condensation.For the eNose, SulfNose and Multigas Detectors installation, it can be either on an existing structure or a custom pole. 


Odour Management session at Compost Matters in Atlantic Canada


Compost Matters in Atlantic Canada

FEBRUARY 11th & 12th 2014 - in AMHERST, Nova Scotia, the Compost Council of Canada initiates a grand Canadian tour of technical workshops.

Interesting topics will be covered:

Regulatory Updates: Modernizing the Fertilizers Act & Regulations

Technology and Processing Management:

  • Essentials of Odour Management at Organics Management Facilities

  • Ongoing Updates to the County of Colchester’s Composting System Incorporating Compostable Plastics in Municipal Organics Recycling Programs

Research: The Composting Process as a Means of Controlling Aleutian Disease in Mink

Compost Markets:

  • Lawn & Turf Soil Improvement Utilizing Dehydrated Compost Topdressings and Organic Fertilizers

  • CQA Analyses: How to Interpret and Make Best Use of the Analysis

  • The Compost Quality Alliance: Going Above and Beyond

  • Parameters of Quality 

Odotech is proud to be associated with the Compost Council of Canada to present the segment on the Essentials of Odour Management at Organics Management Facilities. We have prepared a special presentation for composting facilities, anaerobic digestion projects, landfills and others. Key topics will be address to provide attendees a complete tool box from the science of odour perception and odour metrology, odour management planning, odour impact assessment, continuous odour monitoring and odour control. 

how to gage compost odor


Download the registration form


For additional information, please visit, email at or call 1-877-571-4769


Get the pre\u002Dtraining PPTEssentials of organics odour mangement

Luigi Lo Basso, MBA joins Odotech as Vice President of Finance



photo llobasso

 February 5, 2014 - Montréal, Canada – Odotech Inc. (, a smart odor tracking and monitoring company, announced today that Mr. Luigi Lo Basso, MBA has been appointed to the role of Vice President of Finance of Odotech. As VP Finance, Mr. LoBasso will partner with the CEO and the executive team to shape Odotech's financial agenda for profitable growth.

He brings over 30 years’ experience with growing entrepreneurial and multinational public and private companies in Latin America, Asia, Europe, North America and the Middle East. His expertise includes developing business strategies; accounting, financial and administrative management; budget preparation and analysis; internal controls; policies and procedures; relationship management; and managing change.

I am proud to join Odotech - the world leader in real-time odor tracking management solutions.  OdoWatch - a dynamic odor monitoring and forecasting solution helps plant operators improve processes and reduce operating costs,” says Luigi LoBasso. “With offices in Montreal, France and Chile, this is an incredible opportunity for me to use my knowledge and experience to create a sound fiscal climate for the business internationally” he adds.


About Odotech Inc.

Odotech is an Cleantech company with a patented electronic nose system – OdoWatch - specializing in the measurement and monitoring of odors at waste water treatment plants, composting sites, landfills, rendering plants and industrial odor producing plants. The system alerts operators when odors begin to reach threshold values, enabling them to proactively respond before an odor problem occurs. As the population grows, moves close to odor emitting sites, the need for odor management is growing exponentially. Odotech services its international clients with sales and operations offices in Santiago Chile, Lyon France and Head Office and Manufacturing in Montreal Quebec.


- 30 –


CONTACT:       Marvin Garellek, International Sales Manager |

Odotech inc, 3333 Queen Mary Rd, Suite 301 Montreal, Quebec, H3V 1A2

(514) 340 5250 |


Perception & Measurement of Odors Compared To Noise


Odor perception involves several dimensions such as the detection threshold, the perceived intensity, the odor character (description of the odor or the odor image), the hedonic tone (appreciation) and the emotions they generate. With such complexity, one might think that odors are subjective and it is impossible to quantify them objectively.

To measure odors, best practices call for olfactometry and measuring odor concentration expressed in odor units per cubic meter of air (OU/m3). The perception/detection threshold of an odorous gas is defined as the gas concentration at which 50% of a human jury perceives or not, the odor in an olfactometry laboratory. This is unrelated to an odor quality determination. By definition, the perception threshold is equivalent to 1 OU/m3. The number of dilutions of the odorant mixture required to obtain 1 OU/m3 (detection threshold) indicates the concentration " OU/m3 ". For example, if 10 dilutions are required to reach the detection threshold, the odorant sample contained 10 OU/m3

odor concentration

Is it possible to draw an analogy between the perception of odors and noise?

Indeed. Both the public and professionals are familiar with the noise measurement expressed in decibels. Noise is also formed of frequencies (treble or bass). Series of sounds can create melodies that would trigger emotions.

Noise level: The number of decibels would be equivalent to the concentration of odors (odor level). In both cases there is an objective quantification method for the perception of our environment.

Noise composition: Sound frequencies would be equivalent to the chemical molecules that make up an odor. Like noise, an odor may be generated by a single odorous molecule (1 sound frequency) or a cocktail of molecules as is usually the case (multiple frequencies to noise). Like noise where some frequencies are undetectable, some olfactory molecules are imperceptible to humans, while dogs may react to certain sounds and odors hidden to us.

Melody: The different sounds amalgamated can compose a melody that may be familiar, as a fragrant chemical cocktail that could compose the odor of a flower bouquet 

Orchestre symphonique Montreal Odeur Melange fleur

The musical choices are personal to everyone. One can recognize a melody and appreciated it or not. Some will enjoy rock or techno music while others prefer classical music. Melodies, as well as odors, will appeal to our memories and provoke positive or negative emotions.

In noise measurement, it is irrelevant to assess the appreciation of the noise, as a melody can be enjoyable for some and unbearable for others. It is rather the assessment that a number of decibels is not exceeded. It is the same for measuring odor with  using odor concentration. People have their own olfactory preferences.

sonometre odeur decibel odeur 

To measure noise one will need to use a sonometer to quantify decebels and frequencies, while for odors, we use an olfactometer (odor concentration) and a gas analyzer, e.g. a chromatograph coupled to a spectrogram mass to know the chemical composition. An electronic nose can be used to quantify both the odor concentrations and identify odors images (melodies). 

Want to know more? Download our WhitePaper on Olfactometry versus Chemical Odor Characterization. Or our WhitePaper on the principles of how an electronic nose works.

White PaperMetrology of odors: Olfactometry vs. Chemical Analysis   White PaperHow Does Work an Electronic Nose

Did you Know that Our Sense of Smell is Affected by the Holiday Season?


During this end of year holiday time which signals the start of the new year, we are busy buying the best gifts and our senses are overwhelmed with: Christmas songs, decorations and visuals that all work to create that Christmas magic.

The scents associated with Christmas time immerse us. The aroma of traditional dishes like turkey and tourtières from different regions, a slice of Panetonne in the morning, the smell of the christmas tree and cinnamon candles throughout the house. The olfactive memory taps into our earliest childhood memories. All these odors awaken our emotions.

The Odotech team wishes you a very happy and festive holiday season. Peace, Health and Joy for 2014.


Odor Xmas resized 600

Congrats to the Odor team of Bristle-Affair Movember



Thank you thank thank you for your donations, support and participation.

The 2013 Bristle-Affair Movember Campaign has collected 2,443$ and it means the world to us. 

Odor Movember

Your donations will support world-class men’s health programs that combat prostate and testicular cancer and mental health challenges. The funds we received during our 2013 moustache growing season will be distributed between a multitude of men’s health programs & initiatives including:

-          Prostate Cancer Canada Foundation

-          the Canadian Prostate Cancer – Genome Network

-          ASAP Canada


-          Canadian Kids Help Phone

A big thank you to all our private donations as well as our 3x corporate sponsors! Without your generous support, this year’s success would not have been possible.

jwrl Geomatics Galerie Claude Lafitte  See odor 


Five member of Odotech proudly joined the Bristle Affair Movember team. Please vote on your favorite Mustache in the comment section!

Our team leader: Nicholas, Odor monitoring installation and maintenance manager


David, Odor monitoring software development manager


Marc, Odor monitoring manufacturing and quality control manager


Carlos, Odor dispersion modeling software development


Thierry, President & Chief Executif Officer, Senior Odor expert


Please vote for your favorite Mustache in the comment section

I Love Moustache


Thanks for caring. 


The Bristle Affair Movember team and all grand-fathers, fathers, sons, grand-sons, uncles, close friends & neighbours.



As an official global charity, Movember’s vision is to have an everlasting impact on the face of men’s health. During November each year, Movember is responsible for the sprouting of millions of moustaches around the world. Through the power of the moustache, vital funds and awareness are raised to combat prostate and testicular cancer and mental health challenges.

Movember encourages men to join the movement by growing a moustache for the 30-days of November. After REGISTERING on, these generous Mo Bros start the month clean-shaven, then grow and groom their Mo (slang for moustache), asking friends and family to donate to their efforts. With their new moustaches, these Mo Bros act as walking and talking billboards, bringing awareness to men’s health issues and prompting conversations wherever they go.
Movember’s not just for Mo Bros. Mo Sistas are an important part of Movember’s success. Once REGISTERED, Mo Sistas raise funds and encourage the men in their lives to get involved. Essentially, Mo Sistas do everything that Mo Bros do, without a Mo. Learn more about Mo SistasHERE.
At the end of the month, Mo Bros and Mo Sistas celebrate their Movember journey by throwing their own Movember EVENTS or attending one of the official GALA PARTÉS held around the world.

Movember supports world class MEN’S HEALTH PROGRAMS that combat prostate and testicular cancer and mental health challenges. These programs, directed by the Movember Foundation, are focused on awareness and education, living with and beyond cancer, staying mentally healthy, living with and beyond mental illness and research to achieve our vision of an everlasting impact on the face of men’s health.

Movember - a global movement
Since its humble beginnings in 2003 in Melbourne, Australia, when 30 Mo Bros first grew moustaches, Movember has grown to become a truly global movement inspiring more than 4 million Mo Bros and Mo Sistas to participate across 21 countries worldwide. Movember is also aware of Mo Bros and Mo Sistas supporting the campaign and men’s health causes from across the globe, from Moscow to Rio de Janeiro, and everywhere in between. Together these selfless Mo Bros and Mo Sistas have raised $447 million which are funding 577 projects aimed at achieving OUR VISIONof having an everlasting impact on the face men's health.

Significant steps have been taken toward achieving our vision, but there is still always more to be done. To see the impact Movember is making now please visit the PROJECT INDEX section which describes all the funded projects, review our ANNUAL REPORT or our FINANCIAL PERFORMANCE.


Odors Measurement – Olfactometry vs. Chemical Analysis


Characterization via chemical analysis and sensory or olfactometric characterization have advantages and drawbacks. Despite the known benefits of the conventional chemical analysis characterization (accuracy, reproducibility, etc.),

Sulfur odor detection

olfactometric measures are generally preferred due to the characteristics of the measured parameters:

  • Complex blend, in the environmental samples, of numerous odors with low concentrations,
  • Interaction between mixed odors, without a simple predictive model of the effects of the perceived odor,
  • Low odor perception thresholds comparatively with the detection limits of the analytical methods.

The main advantages of olfactometry derive from the direct correlation between the odor and the sensitivity of the detector being used, i.e. the human nose. Odors are quantified objectively in odor concentration (unit per cubic meter (O.U./m^3) or Dilution to Threshold (D/T)).

Odorant quantification

The effects of synergy and masking between different odorous compounds can be observed in samples. Numerous researchers have studied odorous mixtures and have created models to predict the effect that the mixtures’ composition has on the perceived odor (composition and concentration). In general, the use of these models is limited and applies only to the experimental conditions of the study. As well, the mixtures of compounds are mostly studied in the laboratory because of the complexity of mixed odors.

Studies have identified dominant odorous compounds in environmental samples. For waste water treatment procedures where H2S is the predominant odor show the values of r2 between the H2S and the odor concentrations to be as low as 7 to 69%. This means that other odorous compounds were responsible for 31 to 93% of the odor concentrations. Specifically removing H2S could have left up to 93% of the existing odor. H2S is certainly odorous but measuring only H2S is certainly not an accurate odor level assessment approach.

Chemical measurements are used to identify and quantify chemical compounds contributing to odor.

Laboratory chemical odor resized 600

It is complementary to odor unit assessment by olfactometer or continious odor monitorig (electronic nose). It should always be kept in mind that in chemical analysis, while being expensive, many odorous compounds will be missed and they do not provide odor characteristics that describe the human experience of odor because mixtures of gas have unpredictable different interactions in the nose.

You want to know more? Read our White paper on Metrology of odors – Olfactometry vs. chemical analysis

White PaperMetrology of odors: Olfactometry vs. Chemical Analysis


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