Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program. Community Right-To-Know List.

OSHA PEL: TWA 100 ppm; STEL 150 ppm
ACGIH TLV: TWA 100 ppm; STEL 150 ppm; BEI: methyl hippuric acids in urine at end of shift 1.5 g/g creatinine; Not Classifiable as a Human Carcinogen
DFG MAK: (all isomers) 100 ppm (440 mg/m³); BAT: 150 μg/dL in blood at end of shift
NIOSH REL: (Xylene) TWA 100 ppm; CL 200 ppm/10M
DOT Classification:  3; Label: Flammable Liquid

For occupational chemical analysis use NIOSH: Hydrocarbons, Aromatic, 1501.

A xylene is an aromatic hydrocarbon consisting of a benzene ring with two methyl substituents. The three isomeric xylenes each have a molecular formula of C₈H₁₀, though the more informative semi-structural formula C₆H₄(CH₃)₂ is also used commonly. With  the cas number 1330-20-7, it is also called Dimethylbenzene, Methyltoluene, Xylol (mixed isomers). A xylene is any of a group of very similar organic compounds. They are clear liquids with a sweet odor.

Physical properties about xylene are: (1)ACD/LogP: 3.271; (2)ACD/LogD (pH 5.5): 3.27; (3)ACD/LogD (pH 7.4): 3.27; (4)ACD/BCF (pH 5.5): 180.19; (5)ACD/BCF (pH 7.4): 180.19; (6)ACD/KOC (pH 5.5): 1433.03; (7)ACD/KOC (pH 7.4): 1433.03; (8)Index of Refraction: 1.5; (9)Molar Refractivity: 35.903 cm³; (10)Molar Volume: 121.984 cm³; (11)Polarizability: 14.233 10-24cm³; (12)Surface Tension: 28.7910003662109 dyne/cm; (13)Density: 0.87 g/cm³; (14)Flash Point: 25 °C; (15)Enthalpy of Vaporization: 35.66 kJ/mol; (16)Boiling Point: 140.567 °C at 760 mmHg; (17)Vapour Pressure: 7.61299991607666 mmHg at 25°C

Preparation of xylene: Xylenes are produced by dehydrocyclodimerization and by methylating of toluene and benzene. Via the Isomar process, the ratio of isomers can be shifted to favor p-xylene, which is most valued. This conversion is catalyzed by zeolites.

Uses of xylene: Like other solvents, Xylene (CAS NO.1330-20-7) is also used as an inhalant drug for its intoxicating properties. Xylene is often used as a solvent and in the printing, rubber, and leather industries. It is also used as a cleaning agent for steel and for silicon wafers and chips, a thinner for paint, a pesticide , and in paints and varnishes. In animal studies it is often swabbed on the ears of rabbits to facilitate blood flow and collection, although the area must subsequently be cleansed with alcohol to prevent inflammation. In biochemistry, xylene is also used for making slides of specimens hydrophobic in preparation for coverslip mounting.

You can still convert the following datas into molecular structure:
(1)Smilesc1(ccccc1)C.C*;

The toxicity data is as follows: