Commercially sold xylene is created by mixing the three major isomers of dimethylbenzene. The result is a clear, colorless, flammable liquid with a sweet odor. Xylene is most commonly produced from crude oil by the alkylation process, but the carbon chemical is also a by-product when raw coal is converted to coal gas or coal tar. Xylene is often used in the printing, painting and leather industries for cleaning printing plates, silkscreens and leather.
Most of the health problems associated with xylene are associated with inhalation of fumes from the volatile liquid. Since xylene is used as an ingredient in paints, lacquers, varnishes, inks, dyes, adhesives and cleaning fluids, or in its concentrated form as a degreaser and cleaning agent, workplace exposure to this carbon chemical is possible. According to the Canadian Center for Occupational Health and Safety, preliminary irritation of the eye, nose and throat can begin after three to five minutes of exposure at a concentration of 200 parts per million (ppm). At 700 ppm, xylene fumes can cause vomiting and nausea. In extreme concentrations of xylene (approximately 10,000 ppm), problems with coordination, loss of consciousness, respiratory failure and even death may occur.
Side Effects of Inhalation
Xylene, like many fumes from organic liquids, may in high doses cause pulmonary edema, which is a condition that causes the lungs to fill with fluid. At times, pulmonary edema can be fatal, but since this chemical is so easily detected by human senses, extreme problems with short-term exposure to xylene fumes are rare.
Long-term effects could be more of a problem with xylene. Because of the chemical's many common uses, employees in certain occupations may develop health problems after years of exposure to the lungs from low concentrations. Studies cited by the Canadian Center for Occupational Health and Safety suggest that concentrations as low as 21 ppm can cause neurological damage after seven years or more of daily exposure. Long-term effects might include headaches, irritability, depression, insomnia, tremors and memory loss. However, it should be emphasized that results in this area of study are inconclusive.
Xylene can be a skin irritant after contact is made with the chemical. In these situations xylene may cause redness and a burning sensation, but symptoms are reversible within an hour or two of exposure.
Irritations to the eyes may result from exposure to a vapor concentration of 200 ppm or more. Most eye irritations from xylene dissipate within a few hours of leaving the area. On occasion, xylene may cause corneal vacuoles, an irritating condition that may last as long as two weeks.