Occupational Exposure Risk in Olfactometry: Contribution of Compounds with High Odour Thresholds

Combustion stack emissions are generally of limited odour relevance, as they typically show low odour
concentrations (Cod), but may contain compounds whose odour perception occurs at concentrations close to
or above occupational exposure reference values. During dynamic olfactometry, these samples may therefore
require low dilution factors, leading to increased exposure concentrations for panellists. This study assesses
potential occupational exposure concerns associated with combustion stack samples in dynamic olfactometry.
The approach was based on the chemical analysis of real emission samples to quantify combustion-related
compounds, the preliminary estimation of the Hazard Index (HI), the definition of a sample-specific minimum
dilution value (MDV) not to be exceeded during olfactometric analysis, and the comparison between measured
Cod and MDV. Based on the obtained results, it is possible to affirm that a non-negligible proportion of the
investigated samples showed critical or near-critical conditions with respect to MDV, indicating that this class of
matrices may present relevant operational constraints during dynamic olfactometry despite its limited odour
relevance. Therefore, particular attention needs to be paid to combustion stack samples to protect panellists’
health. A targeted procedure based on preliminary compound screening, risk estimation, and prior definition of
MDV is proposed to support safe testing conditions and effective protection of panellists’ health.