In occupational exposure, xylene main entering the body through the respiratory tract. All of the isomers of xylene, the xylene manufacturers, the situation is the same as the lungs absorb its vapor, reached a total of 60% to 70% of the entire contact period, the capacity to absorb a relatively constant. Xylene solution can be absorbed through intact skin at an average rate of 2.25μg / (cm3 · min) (range 0.7 ~ 4.3μg / (cm3 · min)) is absorbed, xylene vapor percutaneous absorption and compared to direct contact with the liquid Insignificant. Xylene residues and accumulation is not serious, we have said above enter the body of xylene, in the human body can NADP (switch II) and NAD (switch - I) presence methacrylate acid, xylene prices, glycine and then combined to form a maleimide uric acid within 18 hours in almost all excreted. Even within three hours after the inhalation of the residue in 3% -6% of xylene lungs, but also in contact (half-life of 0.5 to 1 hour) were exhaled in vitro. Evaluation of exposure xylene residue trials, xylene Jinan, mainly in urine within a maleimide uric acid was also suggested in exhaled breath or blood xylene, but the results are not always accurate. Because methyl hippuric acid is not naturally present in the urine, and because it is almost all the stranded xylene metabolites, which in its existence is the best xylene exposure tests of confirmation. Xylene can be very durable exist in the drinking water. Tap water xylene concentration of 5mg / L, its odor intensity equivalent to 5, xylene unique odor will have over 7-8 days to disappear; Odor intensity need 4-5 days at three. River xylene odor maintain a shorter time, which is the initial level of concentration, generally 3-5 days can be retained. Some properties of crystals depends on molecules linked into binding solids. These forces typically involve the outermost electrons of atoms or molecules (or valence electrons) interactions. If the combination of strong, crystal has a higher melting point. If some of them weaker, the crystals have a lower melting point, it may be easier to bend and deform. If they are weak, crystals can only form at very low temperatures, then the energy molecule can be used much. There are four main key crystals. Ionic crystals by the positive and negative ions constitute, by gravity (ionic bonds) between different charges together. Sodium chloride is an example of ionic crystals. Atomic crystal (crystal covalently) of atoms or molecules share their valence electrons (covalent bond). Diamond, germanium and silicon is important covalent crystals. Metal crystal is a metal atom into an ion, Weifang xylene, surrounded by a free valence electrons, they can be easily transferred from one atom to another atom movement, the image can be described as immersed in a sea of ??free electrons (metal bond ??? When these electrons full motion in the same direction, their motion is called electric current. Molecule molecular crystals completely share their electrons. They are due to the binding molecule from one end to the other end there is a slight change in the electric field. Because of this weak bonding force (van der Waals forces and hydrogen bonding), these crystals in melts at low temperatures, and low hardness. A typical molecular crystal solid-state oxygen and ice. Cheung dry chemical (Figure) | paraxylene prices | Weifang Cheung provide dry xylene from Jinan Chemical Co. Jinan Cheung Dry Chemical Co. (www.xiangqianhuagong.com) (www.dilunyierchun.com) adhere to the "people-oriented" business philosophy, with a professional staff, and strive to provide the best products and services to contribute to society, and are welcome new and old customers throughout the visit, sincere cooperation for a better future. Xiang dry chemical - your trusted friend, Company Address: Industrial Road chemical market, Contact: Mr.