Hair in Toxicology: an important bio-monitor is a scientific and practical book. Hair testing began slowly about 28 years ago, initiated perhaps by Baumgartner’s pioneering article. Sachs suggested an erratic growth thereafter, with a “gold rush” period between 1986 and 1992, typified by relatively uncritical use of hair testing, followed by a “hang over” period between 1992 and 1996 characterised by more critical reflection. It seems that a renewed “gold rush”—at least of published papers if not of conclusive results—began thereafter. Hair allegedly offers one crucial potential advantage when compared with—for example, blood or urine as a medium for divination—the long time window. Whereas blood and urine can only indicate use for a few days, hair offers the possibility of retrospective use examination for at least several months. A number of other advantages of using hair are sometimes cited (difficult to falsify, easy to store, lengthy shelf life, low body invasion, etc.). Hair …