These practices are designed to outline two preferred procedures for referencing the odor intensities of any odorous material in the suprathreshold region on the ASTM Odor Intensity Referencing Scale. The method by which the reference odorant vapors are to be presented for evaluation by a panel of at least eight independent judgments is specified, but the manner by which the test sample is presented will depend on the nature of the sample, and is not defined herein. The methods, where a geometric progression scale with a ratio of 2 is recommended, are generally done by comparing the odor intensity of the sample to the odor intensities of a series of concentrations of the reference odorant 1-butanol (n-butanol). The two procedures differ in the method by which the diluted 1-butanol vapors are prepared. In Procedure A (dynamic scale method), a dynamic-dilution apparatus is used. This is equipped with a series of sniffing ports from which constant concentrations of 1-butanol emerge at constant volumetric flow rates in air. In Procedure B (static-scale method), a series of Erlenmeyer flasks containing known concentrations of 1-butanol in water is used.

1.1 This practice is designed to outline a means for referencing the odor intensities of a material in the suprathreshold region.

1.2 The general objective is to reference the odor intensity rather than other odor properties of a sample.

1.3 This practice is designed to reference the odor intensity on the ASTM Odor Intensity Referencing Scale of any odorous material. This is done by a comparison of the odor intensity of the sample to the odor intensities of a series of concentrations of a reference odorant, for example, 1-butanol (n-butanol).

1.4 The method by which the reference odorant vapors are to be presented for evaluation by the assessors is specified. The manner by which the test sample is presented will depend on the nature of the sample, and is not defined herein.

1.5 Test sample presentation should be consistent with good standard practice (1, 2)2 and should be explicitly documented in the test report.

1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See Annex A1 for specific safety data.

1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.