European olfactory unit

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Human nose

The European odor unit (GE E ; English European odor unit (ou E )) is the unit of measurement commonly used in Europe for quantifying odors. It is standardized in the EN 13725 standard. In relation to a volume, it is used to indicate odor concentrations.

Definition and background

By definition, an odor unit per cubic meter (1 GE / m³) represents the odor concentration at the odor threshold, which leads to an odor impression in 50% of the population. The difficulty with olfactometry , i.e. the measurement of odors, is to relate the stimulus triggered by a substance to the physiological effect in humans. The relation of the odor unit [UU / m³] to half of the population is based on the definition of the lethal dose, which is also based on an effect in 50% of a population. To establish reproducibility, the European Reference Odor Mass (EROM) is defined as the reference unit. One EROM corresponds to 123 µg n-butanol . Based on this, the European odor unit is understood to be the amount of odorous substances which, after evaporation in 1 m 3 of neutral air under normal conditions, produce the same physiological reaction in a group of test persons as 123 µg n-butanol when this is evaporated in 1 m 3 of neutral air under normal conditions . The odor unit was defined in a comparable way in VDI 3881 Part 1, which dates from 1986 and was replaced by DIN EN 13725 in 2003, but without specifying a reference substance : 1 GE / m 3 corresponded to the odor threshold .

Analogous to the recording of noise immissions, standard EN 13725 proposes specifying odor levels in decibels (dB od ), since a change in stimulus strength does not mean a similar change in the increase in effectiveness. The threshold concentration of 1 GE E / m 3 serves as a reference value.

use

Odor concentrations, i.e. odor units per reference volume, are used in several subordinate regulations, such as 30th BImSchV or TA Luft . Both sets of rules provide for a limit value or an emission limit of 500 GE / m 3 for waste treatment plants . Restrictions on odor emissions are also the subject of numerous approval notices.

Concentration data from measurements are commercially rounded to check compliance with permit requirements and shown with two significant digits. So z. B. Four-digit results rounded to whole hundreds and five-digit results rounded to whole thousands.

literature

  • DIN EN 13725: 2003-07 Air quality; Determination of the odor concentration with dynamic olfactometry; German version EN 13725: 2003. Beuth Verlag, Berlin.

Individual evidence

  1. ↑ a b DIN EN 13725: 2003-07 air quality; Determination of the odor concentration with dynamic olfactometry; German version EN 13725: 2003. Beuth Verlag, Berlin. P. 18.
  2. ↑ DIN EN 13725: 2003-07 air quality; Determination of the odor concentration with dynamic olfactometry; German version EN 13725: 2003. Beuth Verlag, Berlin. P. 7.
  3. ↑ VDI 3881 sheet 1: 1986-05 olfactometry; Odor threshold determination; Fundamentals (olfactometry; odor threshold determination; fundamentals). Beuth Verlag, Berlin. P. 8.
  4. ^ Gerhard Winneke, Ralf Both, Franz-Bernd Frechen, Markus Hangartner, Wolfgang Medrow, Monika Paduch, Karl-Heinz Plattig, PH Punter: Characterization of odor nuisance . Dust - Reinhaltung der Luft , Volume 55 (1995) 3, pp. 113-118.
  5. ↑ Monika Paduch: The odor level as a key parameter for differentiating between odor reduction and odor reduction . Hazardous substances - keeping the air clean , Volume 73 (2013) 10, pp. 429–434.
  6. ↑ VDI 3884 sheet 1: 2015-02 olfactometry; Determination of the odor concentration with dynamic olfactometry; Implementation instructions for the standard DIN EN 13725 (Olfactometry; Determination of odor concentration by dynamic olfactometry; Supplementary instructions for application of DIN EN 13725). Beuth Verlag, Berlin. P. 32.