Handbook of Solvents - George Wypych - ChemTech - Ventech!

18.1 Measurement and estimation of solvents emission and odor 1225
VOC concentration alone is not sufficient for determining the quality of coated surfaces
must also be evaluated.
18.1.6.5 Example of odor determination in industrial plants: Odor
measurement in an industrial varnishing plant
In a study parallel to the measurements of the VOC emission at the varnishing lines of a furniture
company, as described in Section 18.1.4.3.2, 1 st Example, odorant concentrations
were sampled in the exhaust air from the individual chimneys by means of olfactometry. 29
All conditions of measurement described in Section 18.1.4.3.2 also apply to the determination
of the odorant concentration.
The results are contained in Table 18.1.5 as odorant concentration in GE (odorant
units)/m 3 and in the mass flow in TGE/h (one thousand odorant units per hour). The evaluation
of the analytical determination of individual components resulted in the main components
being butyl acetate and ethyl acetate. Due to the very low odorant threshold of butyl
acetate (0.03 mg/m 3 ), as compared to other available substances, (ethyl acetate 22 mg/m 3 ),
butyl acetate may be assumed to be responsible for for the bulk of detectable odor.
An immediate comparison of samples taken at the same point in time resulted in the
following data:
concentration of butyl acetate: 8 mg/m 3
odorant concentration: 115 GE(odorant units)/m 3
Adopting the value quoted in the literature for the odorous threshold of butyl acetate at
0.03 mg/m 3 , which equals one odorant unit, the odorant concentration estimates a butyl acetate
concentration of about 4 mg/m 3 . This value is in the same range as the value established
for butyl acetate by gas chromatography. In these comparisons one has to consider that
odorant thresholds may deviate by one to two exponents to even ten, according to literature
sources. 51
Measurements taken in the housing area about 300 m away from the chimneys of the
varnishing plants could not establish any solvent-typical components in the gas analysis.
The maximum concentration value for TVOC was at 0.004 mg/m 3 .
Also the spreading calculation, which was carried out on the basis of the determined
solvent concentration, showed that there should be no significant odor annoyance in the vicinity
of the emission source. The results of the spreading calculation on the basis of measured
solvent concentrations are considerably more precise, since solvent concentrations
may be determined more exactly than odorant concentrations.
The spreading calculation was done using the software package “IMMPROG-P” by
AIRINFO AG, Switzerland, and carried out according to a method of the Odor Emission
Guideline of the German State of Northrhine-Westfalia/Geruchsimmissions-Richtlinie des
deutschen Bundeslandes Nordrhein-Westfalen. 34
REFERENCES
1 Council Directive 1999/13/EC of March 11, 1999 of the limitation of emissions of volatile organic
compounds due to the use of organic solvents in certain activities and installations.
2 ISO/DIS 4618-4: 1999-12-03, Paints and varnishes - Terms and definitions for coating materials - Part 4:
Terms relating to raw materials.
3 Technische Regeln für Gefahrstoffe TRGS 610 “Ersatzstoffe, Ersatzverfahren und
Verwendungsbeschränkungen für stark lösemittelhaltige Vorstriche und Bodenbelagsklebstoffe”; Absatz
2.7, 04.06.1992.
4 M. Scheithauer, I-Lack 66, 325 - 331 (1998).