Repealed the odour regulation of Apulia, Italy

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 arcelormittal taranto  The region of Apulia in sourthern Italy published last year a new legislation on odour management, the Legge Regionale Puglia 32/2018. This legislation was a bit different from other odour legislations around the world cause it defined different odour impact criteria (OIC) according to the sensitivity of the people affected by the odour impact. Last week the Constitutional Court of Italy repealed this new legislation. Why?

 Taranto is a beautiful coastal city in the region of Apulia that happen to be also the location of Europe's largest steelworks. This factory, now part of ArcelorMittal, was key in Italian 2018 election campaign. At that time the Italian party Five star Movement promised to close the factory after years and years of odour complaints and other environmental issues.

 Now the Five Star Movement is in charge of the Italian government and of course they did not close the plant, but instead they handed it to the new owners. Probably the region of Apulia foresaw this situation and that is why they issued a new Regional Law on odour management (Legge Regionale Puglia 32/2018), repealing, by the way, the previous one (Legge Regionale Puglia 23/2015).

   This interesting and thorough regulation consists of 9 articles and a Technical Annex that is in fact, the most important part of the legislation. There are many aspects to consider in this legislation, some of them new, some of them not that new. An interesting approach in this legislation is a new set of Odour Impact Criteria (OIC) based on the sensitivity of the receptors, according to the following table.

Receptor Class Description of the class OIC
1 Residential areas with an edification index over 1,5 m³/m² 1 ouε/m³
2 Buildings with a collective continuous use (hospitals, schools, etc) 1 ouε/m³
3 Residential areas with an edification index below 1,5 m³/m² 2 ouε/m³
4 Buildings or areas with a collective commercial continuous use (markets, offices, monuments) 2 ouε/m³
5 Buildings or areas with a collective discontinuous use (fairs, stadiums, religious places, etc) 3 ouε/m³
6 Areas with a prevalent industrial, livestock or agricultural use 4 ouε/m³
7 Areas with buildings with not constant presence of human groups (farmlands, uninhabited areas) 5 ouε/m³
8 Touristic areas, even though they are close to another area with a natural value. 1 ouε/m³

  These odour levels should be at most 175 hours every year and are fixed no matter the offensiveness of the perceived odour.

   Now, this legislation was of application to a list of almost 100 industrial activities included in Directive 2010/75/EU, the so-called European Industrial Emission Directive (IED) in force, by the way, in 28 European countries. That is, this regulation of the region of Apulia included this steelworks in Taranto.

     However, in last week's sentence, the Constitutional Court has rewritten this regional legislation, stating that it cannot apply to activities under the IED. That is, it does not apply to this plant in Taranto. With this sentence, the Constitutional Court has left the region of Apulia, and thus the rest of Italian areas, a bit more unprotected and powerless to tackle odour impact in their territories. Why did the Constitutional Court do so?

   This question is difficult to answer, considering that the former Italian Government made a minor modification in the Italian regulation on the environment, adding article 272-bis, giving the regions of Italy the power to regulate an odour impact. So this sentence is difficult to understand, and it does not protect the citizens of Taranto nor the interests of this steel plant of Taranto.

   A pity.

   Italy has a few regional odour regulations; learn more about them here.

 

   If you find this article interesting, you might also be interested in these articles.

 

Carlos Nietzsche Diaz Jimenez's Avatar

Carlos Nietzsche Diaz Jimenez

Carlos is the editor-chief of olores.org and has been in the odour world since 2001. Since then, Carlos has attended over 90 conferences in odour management, both national and international and authored a few papers on the subject. He has also organized a few international meetings and courses. Carlos owns a small company named Ambiente et Odora (AEO). He spends his free time with his wife and his twins, Laura and Daniel, and of course, writing on olores.org.

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Odour regulations

Legislation on odours

 There is a wide range of legislative initiatives to deal with odour emission, however the approach taken by many countries differ in the scope or the field of control.

  In this section we would like to include all the initiatives taken by the countries to manage odour emission.

 

 

Content

Odours

What are Odours?

Odours are defined (1) as the resulting sensation of the reception on a stimulus by the olfactory sensory system. The way the human respond to an odour stimulus depends on its sensory properties, in particular, Odour Concentration, Intensity, Quality and Hedonic Tone. The combined effect of these properties is related to the degree of annoyance that an odour can cause.

Odour Concentration

The odour concentration is defined within the European Standard EN 13725 as the number of European odour units in a cubic metre of gas at standard conditions. Therefore, the odour concentration is measured in "European Odour Units" and its symbol is "uoE".

In short, the odour concentration has similar characteristics than decibels in the sense that they are both properties linked to the human senses. The odour concentration is calculated from the number of times that an odorous gas has to be diluted in order to reach the odour threshold of a group of people or panel specially trained and selected, but with a normal sense of smell. In fact, the geometric mean of the individual odour threshold of each person is calculated.

Wait a minute ¿what is the odour threshold?

The odour threshold of any odorant is the minimum concentration at which anybody with a normal sense of smell is able to detect it. It is also called the detection threshold and it has a couple of more technical definitions in the EN 13725, but we will not go there.

The process can be better explained with a simple example. Let's suppose that we have an odorous gas (that is, an odorant) and we dilute it with odourless air 10 million times. Probably, when we present this gas to be smelled by a member of a panel, she (or he) will not detect anything. If we dilute the odorant less and less, there will be a moment in which this person will be able to detect the diluted mix. This way, if the gas has been diluted 30 times with odourless gas in order to reach the detection threshold, it is estimated that the initial odour concentration of the gas was 30 uoE... for this person, of course.

Statistically that is a bit weak, so the same procedure is made for a group of minimum 4 people. In this case, the geometric mean of the individual odour thresholds is calculated and this way we get the odour concentration of an odorant. The important fact to take into account here is that it does not matter the people that participates in the measurement, it does not matter if they are male or female, young or not so young, if they are from China or from Belgium, the result will be repeatable and reproducible within an uncertainty range.

The measured values depend, of course, on the kind of sensory test, the selection of the panel, the criteria of detectability and other factors.

Odour Intensity

In fact, Odour concentration does not inform about how strong is an odour perceived. In contrast, odour intensity does bring information about the degree of annoyance of an odour, that is, odour intensity express the strength of the odour sensation.

Let us suppose using another example that we could measure a sample of odour collected from the vicinity of a restaurant. If we got a concentration of, let's say 10 uoE. ¿Does this mean that the annoyance perceived by the neighbours is 10 times higher than when there was no restaurant?

The answer is NO.

Unfortunately, the "Concentration" magnitude is not lineal and depends on many factors. An odour can remain undetected above a certain concentration, its composition may have alterations, its hedonic tone could change from an "annoying odour" at low concentration, to a "pleasant odour" at higher concentration (or the opposite), or it could be perceived with the same degree of annoyance with 2 uoE or with 15 uoE.

Odour intensity is the strength of the perceived odour sensation and in many cases It is related with the concentration of an odorous substance. The following equation could define the relation between Odour intensity (I) and concentration (C). “K” is a constant and “n” is the exponent.

Stevens law

Also

Stevens's law formula

This is known as Stevens' law or the power law. For odours, n ranges from about 0.2 to 0.8, depending on the odorant.

For an odorant with n equal to 0.2, a 10-fold reduction in concentration decreases the perceived intensity by a factor of only 1.6; whereas for an odorant with n equal to 0.8, a 10-fold reduction in concentration lowers the perceived intensity by a factor of 6.3.

The dependence can also be described as a theoretically derived logarithmic function according to Weber and Fechner (2):

Weber Fechner relation

where C0 is the threshold concentration; and kw is the Weber-Fechner coefficient or Weber ratio.

Which one of these 3 equations applies depends on the method used. To this date, no theory has been able to derive the psychophysical relationship from knowledge about the absolute odour threshold of various substances.

Odour intensity is determined in ambient air by means of odour inspections. There are a few standards on the calculation of odour intensity in ambient air such as the ASTM E544-18 or the much used VDI Guideline 3882 sheet 1.

The following table illustrates the different levels of intensity that can be registered in a field inspection according to the VDI 3882.1.

OdourIntensity stage
not perceptible 0
very faintly 1
faint 2
distinct 3
strong 4
very strong 5
extremely strong 6

Odour Quality

Odour quality or character is that property that identifies an odour and differentiates it from another odour of equal intensity. Basically this parameter provides information about what the substance smells like.

The odour character is described by a method known as multidimensional scaling or profiling. In this method, the odour is characterized by either the degree of its similarity to a set of reference odours or the degree to which it matches a scale of various descriptor terms. The result is an odour profile.

Odour Hedonic Tone

Hedonic tone is a property of an odour related to its pleasantness.

When the hedonic tone of an odour is evaluated in the neutral context of an olfactometric presentation, the panellist is exposed to a controlled stimulus in terms of intensity and duration. The degree of pleasantness or unpleasantness is determined by each panellist experience and emotional associations (3).

A distinction has to be made between the acceptability and the hedonic tone of an odour. When an odour is evaluated in the laboratory for its hedonic tone in the neutral context of an olfactometric presentation, the panellist is exposed to a controlled stimulus in terms of intensity and duration. The degree of pleasantness or unpleasantness is determined by each panellist's experience and emotional associations.

Other Properties

  Although Intensity, Concentration, Character and Hedonic tone are intrinsic properties of the odours, there are other important parameters related with this sensation that have a certain importance, sometimes a neat one. For example the persistence of an odour is related to the change in the odour intensity when diluting an odour. The frequency of an odour is the percentage in time that is possible to detect this odour in the atmosphere. For example the German norm VDI 3940 defines the odour frequency as the percentage of odour hours in a year, defining the percentage odour time as the ratio between the time fractions that an assessor is able to recognize an odour and the total measurement duration.