• The main volatile organic compounds found at gasoline stations are benzene, toluene, ethylbenzene, and xylene isomers (BTEX). (hindawi.com)
  • Regulatory Norm 7 (1978) provides that, in Brazil, biological monitoring of toluene and xylene is carried out by measuring the urinary metabolites hippuric acid (HA) and methylhippuric acid (MHA), respectively. (hindawi.com)
  • The objective of this study was to assess the exposure to toluene and xylene and to identify related signs and symptoms in gasoline station workers. (hindawi.com)
  • Gasoline station workers showed high levels of HA and MHA, reflecting high occupational exposure to the solvents toluene and xylene present in gasoline, demonstrating that changes in the current legislation and in the work environment are necessary to ensure better health protection for these workers. (hindawi.com)
  • This process, associated with gasoline distribution, can be an important source for emission of volatile organic compounds (VOCs) [ 2 ], with benzene, toluene, ethylbenzene, and xylene isomers (BTEX), the main volatile hydrocarbons originating from petroleum. (hindawi.com)
  • Ethylbenzene is classified as possibly carcinogenic to humans (Group 2B), while toluene and xylene have so far had poor evidence of carcinogenicity (Group 3) [ 7 ]. (hindawi.com)
  • Although there is still no evidence for the development of cancer due to toluene, acute exposure causes immediate excitability and euphoria, followed by a depressing response with disorientation, mood fluctuations, hallucinations, and ataxia [ 8 , 9 ]. (hindawi.com)
  • Toluene is known to be neurotoxic and some of the chronic effects observed after prolonged periods of exposure include memory/concentration problems, disturbance of emotional and psychomotor functions, hepatotoxicity, nephrotoxicity, and hearing loss, which can cause permanent brain damage or even lead to death [ 9 - 11 ]. (hindawi.com)
  • Xylenes are produced mainly as part of the BTX aromatics (benzene, toluene, and xylenes) extracted from the product of catalytic reforming known as reformate. (wikipedia.org)
  • Xylenes are produced by the methylation of toluene and benzene. (wikipedia.org)
  • A return visit was completed December 11 and 12, 2000, during which quantitative sampling was performed for major compounds of the jet fuel, such as benzene , toluene, and xylene. (cdc.gov)
  • Acute Exposures to p-Xylene and Toluene Alter Visual Information Processing (Journal Version). (epa.gov)
  • Long-Evans hooded rats were exposed to single doses of toluene (p.o.) at 0, 250, 500 and 1000 mg/kg, to p-xylene (p.o.) at 0, 125, 250, 500, 1000 and 2000 mg/kg, and to inhalation of p-xylene for 4 hrs at 0, 800 or 1600 ppm. (epa.gov)
  • The data indicated a significant depression in amplitude of FEP peak N3 at 250 mg/kg and higher dosages of toluene and p-xylene. (epa.gov)
  • The effects produced by oral administration of 500 mg/kg p-xylene or toluene lasted at least 8 hr, while the effect of inhaled p-xylene dissipated within 75 min of removal from the exposure. (epa.gov)
  • The effects of p-xylene and toluene on FEPs, while indicative of altered processing of visual information, may be secondary to changes in arousal or excitability. (epa.gov)
  • Volatile organic compounds (VOCs) off-gassing from synthetic materials, nitrogen dioxide and harmful outdoor VOCs such benzene, toluene, ethyl-benzene and xylene penetrate into the indoor environment through ventilation and are the main contributors to poor indoor air quality with health effects. (springer.com)
  • However, NIOSH recommends exposure to carcinogenic compounds, such as benzene , be kept to the lowest feasible levels. (cdc.gov)
  • Xylene exists as three isomers (ortho-, meta-, and para-xylene), which can be found singly or, more commonly, mixed in varying proportions. (cdc.gov)
  • The ratio of isomers can be shifted to favor the highly valued p-xylene via the patented UOP-Isomar process or by transalkylation of xylene with itself or trimethylbenzene. (wikipedia.org)
  • The physical properties of the isomers of xylene differ slightly. (wikipedia.org)
  • The demand for isophthalic acid is relatively modest, so m-xylene is rarely sought (and hence the utility of its conversion to the o- and p-isomers). (wikipedia.org)
  • 1992) concluded that indications of mild CNS effects noted in some individuals exposed to 100 ppm (442 mg/m3) provided the best available basis for setting an exposure limit for xylene isomers. (europa.eu)
  • The critical health effects underpinning the IOELV for xylene isomers were mild irritation of the eye and upper respiratory tract and mild CNS effects noted in some individuals exposed to 100 ppm (442 mg/m3). (europa.eu)
  • The findings were considered by the SEG to provide the best available basis for setting an exposure limit for xylene isomers. (europa.eu)
  • Application of an uncertainty factor of 2 gave an 8-hr TWA for xylene isomers of 50 ppm (221 mg/m3). (europa.eu)
  • Exposure levels of the xylene isomers associated with neurological effects in animals are well defined. (europa.eu)
  • Acute exposures to concentrations inducing behavioural changes included a 6 hour inhalation exposure to the individual xylene isomers at a concentration of 3000 ppm (Korsak, 1990). (europa.eu)
  • In animal studies xylene isomers (including mixed xylene) exhibit low acute toxicity by oral and dermal routes with the reported LD50 values all exceeding 2000 mg/kg bw. (europa.eu)
  • Multiple studies conducted in rats and mice consistently demonstrate that the oral LD50 for xylene isomers (including mixed xylene) exceeds 2000 mg/kg bw. (europa.eu)
  • Mixed xylenes refers to a mixture of the xylenes plus ethylbenzene. (wikipedia.org)
  • Commercial or laboratory-grade xylene produced usually contains about 40-65% of m-xylene and up to 20% each of o-xylene, p-xylene and ethylbenzene. (wikipedia.org)
  • Title : Occupational exposure to xylene Personal Author(s) : Hardin, Bryan D. Corporate Authors(s) : National Institute for Occupational Safety and Health. (cdc.gov)
  • Recommendations are made for a standard of occupational exposure to xylene (1330207), based on the health effects of exposure to the solvent. (cdc.gov)
  • The following resources provide information about occupational exposure to xylene. (cdc.gov)
  • Concentrations of jet fuel compounds were found to be well below established occupational exposure limits. (cdc.gov)
  • Concentrations of carbon monoxide in air were found to be above the ceiling limits for occupational exposure for two workers, most likely attributable to exposure to truck exhaust inside the mechanics' garage. (cdc.gov)
  • Exposure to carbon monoxide for all other workers was below occupational exposure limits. (cdc.gov)
  • The odor of xylene is detectable at concentrations as low as 0.08 to 3.7 ppm (parts of xylene per million parts of air) and can be tasted in water at 0.53 to 1.8 ppm. (wikipedia.org)
  • A number of studies addressing neurobehavioural effects of xylenes in rodents and humans have been reported, however these often use a limited range of exposure concentrations with some conflicting results and are therefore considered to be generally unreliable. (europa.eu)
  • Le benzène en particulier est classé cancérogène et une exposition à des concentrations supérieures à 64 g/m3 de benzène peut être fatale en 5-10 minutes. (umontreal.ca)
  • In the petroleum industry, xylene is also a frequent component of paraffin solvents, used when the tubing becomes clogged with paraffin wax. (wikipedia.org)
  • Xylenes are solvents used in industrial and consumer products, such as cleaning agents and paint thinners. (ewg.org)
  • Workers exposed to fuels had higher average levels of these exposure biomarkers (HA and MHA), which were also higher in convenience store workers than in filling station attendants. (hindawi.com)
  • A similar depression in peak N3 amplitude was observed following inhalation exposure to 1600 ppm p-xylene. (epa.gov)
  • Acute systemic toxicity can result from ingestion of xylene. (cdc.gov)
  • Sensory deficits resulting from exposure to p-xylene were observed in a key study of the acute neurotoxic effects (Dyer, 1988). (europa.eu)
  • Commercial grade xylene, in which m-xylene is usually the major constituent, is a clear, colorless liquid with a sweet, aromatic odor. (cdc.gov)
  • Xylene (C 8 H 10 ) is a colorless, flammable liquid with a sweet odor. (cdc.gov)
  • Persons exposed only to xylene vapor do not pose substantial risks of secondary contamination. (cdc.gov)
  • Persons whose clothing or skin is contaminated with liquid xylene can cause secondary contamination by direct contact or through off-gassing vapor. (cdc.gov)
  • Xylene vapor is heavier than air and may cause asphyxiation in enclosed, poorly ventilated, or low-lying areas. (cdc.gov)
  • Children exposed to the same levels of xylene vapor as adults may receive a larger dose because they have greater lung surface area:body weight ratios and increased minute volumes:weight ratios. (cdc.gov)
  • In addition, they may be exposed to higher levels than adults in the same location because of their short stature and the higher levels of xylene vapor found nearer to the ground. (cdc.gov)
  • Results of the confidential employee interviews and questionnaires, regarding previous employment, medical history, dermatitis, respiratory symptoms, and personal protective equipment use, revealed that employees reported respiratory and physical symptoms that are consistent with, but not specific for, workplace exposure to jet fuel vapor and jet exhaust. (cdc.gov)
  • Being benzylic and hence weakened, the C-H bonds of the methyl groups are susceptible to free-radical reactions, including halogenation to the corresponding xylene dichlorides (bis(chloromethyl)benzenes), while mono-bromination yields xylyl bromide, a tear gas agent. (wikipedia.org)
  • Xylene is less dense than water and will float on the surface of water. (cdc.gov)
  • A STEL of 100 ppm (442 mg/m3) was recommended to limit peak exposures which could result in eye and respiratory tract irritation. (europa.eu)
  • In humans critical effects of xylenes are irritation and CNS effects, with the overall NOAEC inhalation for the latter effect being 300 mg/m3. (europa.eu)
  • The EWG Health Guideline of 1,800 ppb for xylenes was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. (ewg.org)
  • Teratogenic effects can also be observed [ 14 ], affecting the development of embryos and fetuses during maternal exposure. (hindawi.com)
  • The azeotrope with water consists of 60% xylenes and boils at 94.5 °C. As with many alkylbenzene compounds, xylenes form complexes with various halocarbons. (wikipedia.org)
  • Results of the personal breathing zone sampling for jet fuel compounds were below applicable exposure limits set by the Occupational Safety and Health Administration (OSHA). (cdc.gov)
  • Therefore, recommendations are made in this report concerning proper work practices such as hygienic practices, personal protective equipment use, and engineering control use, to minimize exposure to such compounds. (cdc.gov)
  • Mixed xylene is considered harmful by inhalation. (europa.eu)
  • Xylene was first isolated and named in 1850 by the French chemist Auguste Cahours (1813-1891), having been discovered as a constituent of wood tar. (wikipedia.org)
  • Two individuals, however, each had one peak exposure above the NIOSH recommended ceiling limit for CO, most likely resulting from their proximity to exhaust from a running refueling truck. (cdc.gov)
  • Xylenes are used as a solvent in printing, rubber, and leather industries. (wikipedia.org)
  • Xylene is 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. (wikipedia.org)
  • Xylene is a clear, colorless liquid. (cdc.gov)
  • Xylene is among the 30 most abundantly produced chemicals in the United States. (cdc.gov)
  • These mutations can be caused by exposure to toxic chemicals, infections, inflammation and nutritional deficiencies. (drwendywells.com)
  • The level of exposure depends upon the dose, duration, and work being done. (cdc.gov)
  • Xylenes cause nervous system damage and may harm developing fetuses. (ewg.org)
  • Xylene is irritating to the skin, eyes, and respiratory tract. (cdc.gov)
  • Most exposures to xylene occur by inhalation and xylene is readily absorbed from the lungs. (cdc.gov)
  • Generally, two kinds of reactions occur with xylenes: those involving the methyl groups and those involving the ring C-H bonds. (wikipedia.org)
  • Exposure via ingestion and inhalation produces systemic toxicity. (cdc.gov)
  • The mechanism by which xylene produces toxicity is not known. (cdc.gov)
  • The legal limit for xylenes, established in 1991, was based on a toxicity study in laboratory animals conducted in the 1980s. (ewg.org)
  • The employees expressed concerns that potential exposure to jet fuel and aircraft exhaust may be related to health symptoms such as headache and respiratory problems. (cdc.gov)
  • The results indicated that the toxic effects of exposure to o- and m-xylene were more pronounced than those of p-xylene at the single exposure level evaluated (Korsak et al, 1994). (europa.eu)
  • I think the level of evidence that we currently have is enough to invoke the precautionary principal and take precautions to protect the public who live close to oil and gas development against the potential health effects of toxic exposure," said Epstein, whose city sits at the edge of another Texas shale play, the Permian Basin. (publicintegrity.org)
  • NIOSHTIC-2 search results for xylene -NIOSHTIC-2 is a searchable database of worker safety and health publications, documents, grant reports, and journal articles supported in whole or in part by NIOSH. (cdc.gov)
  • Visit NIOSH's page on Managing Chemical Safety in the Workplace to learn more about controlling chemical workplace exposures. (cdc.gov)
  • 1996) discussed the merits and methodology behind the LLNA assay, and presented tabulated results for a wide range of substances including mixed xylenes. (europa.eu)
  • Par ailleurs, la présence de traces de ces substances dans un biogaz entrave son utilisation comme source d'énergie renouvelable en causant des dommages coûteux à l'équipement. (umontreal.ca)
  • Workers may be harmed from exposure to xylene. (cdc.gov)
  • GLP status not known, data fromguideline studies, published in peer reviewed literature,no restrictions, fully adequate for assessment (although very limited data on evaluation of xylene in the LLNA included. (europa.eu)
  • Basketter and Kimber (2010) performed a weight of evidence evaluation of the sensitisation potential of mixed xylenes which included their own LLNA findings together with other chemical and biological considerations. (europa.eu)
  • Xylene is slowly absorbed through intact skin, but percutaneous absorption may contribute to total body burden. (cdc.gov)
  • Repeated or prolonged skin contact with liquid xylene can defat the skin, causing it to crack and peel. (cdc.gov)
  • however, xylene absorbed through the skin may contribute to body burden. (cdc.gov)
  • Xylene is not a skin sensitiser. (europa.eu)
  • This limit may not fully protect against harm to the brain and nervous system due to xylene exposure. (ewg.org)
  • The sensitisation potential of mixed xylenes when tested in the LLNA was described by Basketter et al. (europa.eu)
  • The sensitisation potential of mixed xylenes when tested in the standard local lymph node assay was reported by Basketter et al. (europa.eu)
  • It is generally referred to as Mixed, Total or Technical-Grade Xylene. (cdc.gov)
  • Xylenes form azeotropes with water and a variety of alcohols. (wikipedia.org)
  • The melting point ranges from −47.87 °C (−54.17 °F) (m-xylene) to 13.26 °C (55.87 °F) (p-xylene)-as usual, the para isomer's melting point is much higher because it packs more readily in the crystal structure. (wikipedia.org)
  • The Office of Research and Standards Development, National Institute for Occupational Safety and Health, had primary responsibility for development of the criteria and the recommednded standard for xylene. (cdc.gov)
  • And they all believe exposure to natural gas development triggered their health problems. (publicintegrity.org)
  • The major application of ortho-xylene is as a precursor to phthalate esters, used as plasticizer. (wikipedia.org)
  • Administration of mixed xylenes caused deaths at 6,000 mg/kg in each sex and at 4,000 mg/kg in males. (europa.eu)
  • 1999) concluded that a SI "cut-off" value of 3.5 would lead to greater specificity in the interpretation of LLNA results, and also reduce the occurrence of occasional false positive results such as that reported for mixed xylenes (Basketter and Kimber, 2010). (europa.eu)
  • In dentistry, xylene can be used to dissolve gutta percha, a material used for endodontics (root-canal treatments). (wikipedia.org)
  • Xylene reacts with strong oxidizers and strong acids. (cdc.gov)