Xylenes

General Information

 * Xylene is an aromatic hydrocarbon, and is a colorless, sweet-smelling liquid or gas occurring naturally in petroleum, coal and wood tar.


 * Laboratory-grade xylene is composed of m-xylene (40–65%), p-xylene (20%), o-xylene (20%) and ethyl benzene (6-20%) and traces of toluene, trimethyl benzene, phenol, thiophene, pyridine and hydrogen sulfide.


 * The current Occupational Safety and Health Administration permissible exposure limit for xylene is 100 ppm as an 8-h time-weighted average (TWA) concentration.


 * Xylene in air can be smelled at concentrations as low as 0.08 to 3.7 ppm (parts of xylene per million parts of air) and can begin to be tasted in water at 0.53 to 1.8 ppm.

Hazards

 * Exposure to xylene can occur via inhalation, ingestion, eye or skin contact.
 * It is primarily metabolized in the liver by oxidation of a methyl group and conjugation with glycine to yield methyl hippuric acid, which is excreted in the urine. Smaller amounts are eliminated unchanged in the exhaled air. There is a low potential for accumulation.
 * Xylene causes health effects from both acute (<14 days) and also chronic (>365 days) exposure.
 * The type and severity of health effects depends on several factors, including the amount of chemical you are exposed to and the length of time you are exposed for.
 * The material safety data sheet (MSDS) rating assigned is for a moderate hazard, indicating safe handling precautions should include goggles, protective clothing, ventilation, and proper gloves, with storage of the material in a cool, dry, well-ventilated location since it is highly flammable.

Medical Research Uses
Xylenes are used in the laboratory to make baths with dry ice to cool reaction vessels, and as a solvent  to remove synthetic immersion oil from the microscope objective in light microscopy.undefined Its high solvency factor allows maximum displacement of alcohol and renders the tissue transparent, enhancing paraffin infiltration.

In medical research, xylenes are used in histological laboratories for tissue processing, staining and cover slipping.   In staining procedures, its excellent dewaxing and clearing capabilities contribute to brilliantly stained slides.

 Possible Substitutions


 * Paraclear  (Scientific Device Laboratory)
 * Clearify™  (American Master Tech)
 * Naturalene™ (American Master Tech)
 * MasterClear™ (American Master Tech)
 * Clear-Rite (Thermo Scientific)
 * Shandon Histosolve  (Thermo Scientific)

Other Uses
Xylene is used as a solvent in the printing, rubber, paint and leather industries. It is found in small amounts in airplane fuel, gasoline and cigarette smoke. Xylene is used in histological laboratories for tissue processing, staining and cover slipping and also in root canal procedures as a guttapercha solvent. Xylene is a cleaning agent, e.g., for steel, silicon wafers, and integrated circuits.















<p style="color:rgb(102,102,102);font-family:arial;line-height:normal;text-align:left;vertical-align:top;"><span style="font-family:arial,sans-serif;"> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2996004/

<p style="color:rgb(102,102,102);font-family:arial;line-height:normal;text-align:left;vertical-align:top;"><span style="font-family:arial,sans-serif;"> http://en.wikipedia.org/wiki/Xylenes