The objective of this text has always been to allow an assessment of the degree of chemical exposure based on the analytical determination in human biological specimens of the quantitative presence of the most frequently encountered substances, or of a physiological parameter reflecting their presence. This eleventh edition has added an additional 275 substances for a total of nearly 1800 unique entries. We continue to provide this in a single volume by making efficient use of the available space on each printed page. The new entries are quite varied in their purpose; some examples include several antidotes (octreotide, sugammadex), antifungal agents (butenafine, sertaconazole, antiseptics (resorcinol, sanguinarine), artificial sweeteners (advantame, sucralose), dietary supplements (curcumin, higenamine, iodine, theanine), drugs of abuse (AH-7921, 25C-NBOMe, diphenidine), fungicides (chlorothalonil, iprodione), gases (carbon dioxide, methane), herbicides (bispyribac, nitisinone), hypnotics (suvorexant, tasimelteon), industrial chemicals (caprolactam, chloroprene), insecticides (chlorfenvinphos, prallethrin), mushroom poisons (ibotenic acid, muscimol), performance enhancers (ligandrol, meldonium, xenon) and rodenticides (coumatetryl, flocoumafen).