1. Scope

This practice presents a general strategy for using an analytic, odorant-prioritization based approach to environmental odor assessment. This strategy is based upon the premise that, while the composition of environmental odors detected by human receptors carries the potential for extreme complexity, simplification typically occurs with increasing downwind distance from the source. An odorant prioritization protocol (OPP) is a strategy which encourages initial identification of odor and focuses upon the minimum subset of odorous gases which are detectable at the odor frontal boundary. This integrated strategy uses Solid Phase Microextraction (i.e. SPME) air sampling and Multi-Dimensional Gas Chromatography- Mass Spectrometry-Olfactometry (i.e. MDGC-MS-O) chemical analysis followed by Synthetic Formulation based Odor-Matching for odorant assignment validation. The OPP approach to environmental odor assessment is not presented as a replacement or substitute for established, quantitative Dynamic Dilution Olfactometry methods (e.g. CEN/TC 264; ASTM E679 ; ASTM E-1432) which form the current regulatory and enforcement basis for odor air quality impacts. Rather, this OPP approach is a voluntary, qualitative and complementary assessment strategy for focused odor assessment and monitoring in support of odor mitigation strategy development. This standard represents a rapid, preliminary environmental odor survey effort which can focus the conventional sensory and instrument-based assessment efforts which follow; efforts typically reflecting far greater detail and complexity. This survey approach is equally applicable to both ambient, work place, and indoor air environments. The primary difference between the three being the sampling techniques and strategies which are required specific to each air source.

Keywords

Sensory

Rationale

Present methodologies to odor assessment and monitoring fall into the categories of sensory-only and instrument-only approaches. Each of these approaches, are commonly applied independently to a targeted odor source. This can generate massive amounts of data which are not directly linked: creating difficulty in addressing an environmental odor issue and in identifying the odorant(s) contributing to the perceived odor. Use of Multi-Dimensional Gas Chromatography- Mass Spectrometry-Olfactometry (MDGC-MS-O) which integrates a human sensory investigator into the integrated analytical system merges the sensory-only and instrument-only approaches providing a mechanism for directly linking data that will lead to correlating the chemical species causing an odor and assist in identifying the odor source. Once the species and source responsible for odor have been identified efficient mitigation of odor can occur.

The title and scope are in draft form and are under development within this ASTM Committee.