ASTM International

Standard Practice for Determination of Odor and Taste Thresholds By a Forced - Choice Ascending Concentration Series Method of Limits
 N E679

Annotation

This practice describes a rapid test for determining sensory thresholds of any substance in any medium.

It prescribes an overall design of sample preparation and a procedure for calculating the results.

The threshold may be characterized as being either (a) only detection (awareness) that a very small amount of added substance is present but not necessarily recognizable, or (b) recognition of the nature of the added substance.

The medium may be a gas, such as air, a liquid, such as water or some beverage, or a solid form of matter. The medium may be odorless or tasteless, or may exhibit a characteristic odor or taste per se.

This practice describes the use of a multiple forcedchoice sample presentation method in an ascending concentration series, similar to the method of limits.

Physical methods of sample presentation for threshold determination are not a part of this practice, and will depend on the physical state, size, shape, availability, and other properties of the samples.

It is recognized that the degree of training received by a panel with a particular substance may have a profound influence on the threshold obtained with that substance (1).2

Thresholds determined by using one physical method of presentation are not necessarily equivalent to values obtained by another method.

2 The boldface numbers in parentheses refer to the list of references at the end of this practice.