ABSTRACT
XRD — See x-ray diffraction. XRF — See x-ray fluorescence analyzer. xylem — Tissue that conducts water and minerals in vas-
cular plants. xylene (C6H4(CH3)2) — A colorless liquid with an aro-
matic odor and which has three isomeres (ortho-, meta-, para-); MW: 106.2; BP: 292, 269, 281°F, respectively; Sol: insoluble; Fl.P: 63, 84, 81°F, respectively; sp. gr. 0.88, 0.86, 0.86, respectively. They are present in coal and wood, tar, naphtha, etc. They are used in the manufacture of dyes and as raw materials for polyester fibers. They are hazardous to the eyes, skin, respiratory system, and digestive system. Symptoms of exposure include dizziness; excitement; incoherence; staggering gait; irritation of the eyes, nose, and/or throat; vomiting; abdominal pain; and nausea. OSHA exposure limit (TWA): 100 ppm [air].
