Objective odor analysis of incidentally emitted compounds using the Langage des Nez® method: application to the industrial zone of Le Havre

Combined assessment of health hazard and odour impact of soils at a contaminated site: a case study on a defunct pharmaceuticals factory in China

Surveys and assessments of contaminated sites primarily focus on hazardous pollutants in the soil with less attention paid to odorants. This makes the management of contaminated sites difficult. In this study, hazardous and odorous pollutants in the soil were assessed for a large site that was previously used for production of pharmaceuticals to determine the degree and characteristics of soil contamination at pharmaceutical production sites, for undertaking rational remediation measures. The main hazardous pollutants at the study site were triethylamine, n-butyric acid, benzo(a)pyrene (BaP), N-nitrosodimethylamine (NDMA), dibenzo(a,h)anthracene (DBA), total petroleum hydrocarbons (C10-C40) (TPH), and 1,2-dichloroethane; TEA, BA, and isovaleric acid (IC) were the main odorants. As the type and distribution of hazardous and odorous pollutants differ, it is necessary to separately assess the impact of these pollutants at a contaminated site. Soils in the surface layer pose significant non-carcinogenic (HI = 68.30) and carcinogenic risks (RT = 3.56E-5), whereas those in the lower layer only pose non-carcinogenic risks (HI > 7.43). Odorants were found at considerable concentrations both in the surface and lower layers, with the maximum concentrations being 29,309.91 and 41.27, respectively. The findings of this study should improve our understanding of soil contamination at former pharmaceutical production sites and should inform the assessment of the risks posed by contaminated sites, with problems associated with odour, and possible remediation strategies.

Understanding of the residual odor of fatty esters used as emollient in cosmetic products

OBJECTIVE

Fatty esters are known for their versatility, but in addition to their performance as emollients, emulsifiers, solubilizers, or dispersing agents, they have to meet more and more criteria to be used in cosmetic products. Thus, their olfactory characteristics are expected to be as neutral as possible. However, despite a step of deodorization during the synthesis of fatty esters, a residual odor is currently still perceived at the end of the process.

METHODS

In this study, a specific analytical methodology combining sensory with chemical analyses was implemented to characterize the residual odor of two fatty esters and to determine its origin. Ethyl oleate and isononyl isononanoate were selected and underwent a sensory analysis to evaluate their odor intensity and odor profile. Volatile compounds released by these esters were assessed by GC-MS after Solid-Phase MicroExtraction (SPME) and amongst them, odor-active compounds were brought into light using Gas Chromatography coupled with Mass Spectrometry and Olfactometry (GC-MS-O) analyses.

RESULTS

On the isononyl isononanoate chromatogram, only peaks corresponding to the different isomeric ester forms were evidenced while around 70 volatile compounds were detected in the ethyl oleate headspace, including esters, aldehydes, hydrocarbons, and ketones. Isononyl alcohol used as raw material in the synthesis was proven to be responsible for isononyl isononanoate final odor. As for ethyl oleate, of the 23 odor-active compounds perceived, 14 have been identified; they are mainly esters and saturated as well as unsaturated aldehydes.

CONCLUSION

A novel measurement approach was presented to analyze trace odors of fatty esters and the results will be useful to control their deodorization by targeting appropriate strategies with the aim either to avoid the formation or remove the identified odorant compounds. This study may be further expanded by investigating the impact of deodorization on odor-active compounds for a complete understanding of their contribution to the fatty ester global odor.