ABSTRACT
Investigators characterizing solvent-release sites may overlook 1,4-dioxane because (1) they are not required to look for it and (2) they do not fi nd a compelling reason to sample for chemical compounds that are not among the known or regulated threats to drinking water and human health. Awareness of the widespread occurrence of 1,4-dioxane as a co-contaminant of methyl chloroform is still growing, but is not yet widespread; consequently, most site investigators do not direct the laboratory to analyze for 1,4-dioxane. A sensitive and reliable laboratory analytical method was not available until 1997, when the California Department of Health Services developed a method for low-level detection of 1,4-dioxane (Draper et al., 2000). Other solvent-stabilizer compounds may also be overlooked because (1) most investigations of solvent-release sites focus on analyzing for familiar chlorinated aliphatic hydrocarbon compounds and (2) the methods used are unsuitable for trace detection and quantifi cation of ethers, alcohols, and other highly soluble compounds that have been used as solvent stabilizers.
