Concerning odors, even those generally considered agreeable, under certain
conditions can become unbearable, depending upon the variability of emission
and reception conditions. This particularity is known by the acronym “FIDOL,”
which stands for the following: (1) frequency: how often an individual is exposed
to odour; (2) intensity: the strength of the odor; (3) duration: the length of a
particular odor event; (4) offensiveness/character: the character relates to the
“hedonic tone” of the odor (meaning “smells like”), which may be pleasant, neutral,
or unpleasant; and (5) location: the type of land, use, and nature of human activities
in the neighborhood of an odor source.