trimethyl amine 0.00021ppm - Methylene chloride 214ppm Table - link ppm volume
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||Gregory Leonardos , David Kendall & Nancy Barnard (1969) Odor Threshold Determinations of 53 Odorant Chemicals, Journal of the Air Pollution Control Association, 19:2, 91-95, DOI: 10.1080/00022470.1969.10466465 link p.94 table I
||Abstract:"In order to assist in assessing potential odor problems arising from chemical manufacturing operations, the odor thresholds of 53 commercially important odorant chemicals have been determined using a standardized and defined procedure… The odorants were presented to a trained odor panel in a static air system utilizing a low odor background air as the dilution medium. The odor threshold is defined as the first concentration at which all panel members can recognize the odor. The effect of chemical purity has been determined by measuring the odor threshold of materials representing different modes of manufacture or after purification by gas chromatographic procedures."
||P.93 right column bottom paragraph:"The odor threshold reported for each chemical is the concentration at which all panelists recognize the odor. All concentrations are calculated as parts per million by volume. The minimum threshold observed was with trimethyl amine at 0.00021 ppm (0.21 ppb). Methylene chloride was not described below a concentration of 214 ppm. The 53 compounds studied represent a range of six orders of magnitude in threshold concentrations (Table I). Odor descriptions (other than chemical name) used to describe the odor quality of the odorant chemical are included in Table I."