This test method covers the determination of the xylene-insoluble matter in creosote and creosote-coal tar solution. Since this method is empirical, strict adherence to all details of the procedure is necessary for close agreement of results among laboratories. Test Method D38 covers the sampling of wood preservatives prior to testing. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.