TLV-TWA 0.2 mg(Se)/m3 (ACGIH, MSHA,
and OSHA); IDLH 100 mg/m3.
物理描述：
Selenium is a reddish colored powder that may become black upon exposure to air. It is toxic by ingestion. It is used to manufacture electronic components and rubber.
颜色/状态：
Selenium exists in several allotropic forms. 3 are generally recognized ... Selenium can be prepd with either amorphous or crystalline structure. ... Amorphous is either red, in powder form or black, in vitreous form. Crystalline monoclinic selenium is deep red; crystalline hexagonal form, the most stable variety, is a metallic gray.
蒸汽压力：
1 Pa at 227 °C; 10 Pa at 279 °C; 100 Pa at 344 °C; 1 kPa at 431 °C; 10 kPa at 540 °C; 100 kPa at 685 °C
分解：
When heated to decomp ... emits toxic fumes of /selenium/.
粘度：
221 mPa-S (= cP) at 220 °C; 70 cP at 360 °C
腐蚀性：
Strongly corrosive, especially at high temperature.
燃烧热：
-225.1 kJ/mol at 298 K
汽化热：
59.7 kJ/mol
表面张力：
105.5 dyn/cm at 220 °C; 95.2 dyn/cm at 310 °C (liquid)
Selenium supplements are typically available in the form of sodium selenite which is metabolized to selenide through either glutathione conjugation and subsequent reduction by glutathione reductase enzymes or reduction by thioredoxin reductases. Selenide is further metabolized to selenocystein by cysteine synthases and to selenophosphate by selenophosphate synthases. Selenide is also metabolized progressively to methyl-selenol, dimethyl selenide, then trimethylselenonium. Selenocysteine is degraded to methyl-selenol, pyruvate and ammonia by cysteine beta lyase. Selenocystein reacts with oxygen to form selenocysteine selenoxide which spontaneously degrades to methylselenic acid, pyruvate and ammonia. Methylselenic acid can be converted to methylselenol via conjugation with thiol groups on proteins like glutathione.
来源:DrugBank
代谢
硒化合物在体内部分被还原为元素硒... 大部分被代谢为二甲基硒，通过肺部排出，散发出大蒜般的气味。
Selenium compounds are in part reduced in the body to elemental selenium... Much is metabolized to dimethyl selenide which is excreted by the lungs, imparting a garlic-like odor.
Selenium is an essential trace element and has been shown to be a natural component in the enzyme glutathione peroxidase and other proteins. Most selenium compounds are water-soluble and can efficiently be taken up in the intestine. Soluble as well as non-soluble compounds can be taken up by the lungs. When given in excess, selenium compounds are rapidly distributed to major organs of the body. ... Identified metabolites are trimethylselenide in urine and dimethylselenide in breath. ... in man ... toxic effects have been reported at 1 mg/dl. ... Toxic effects have been seen at blood levels ranging from 0.179 ug/ml-7.5 ug/ml. In most parts of the world normal urine levels do not exceed 0.03 ug/ml. Occupationally exposed workers usually excrete less than 0.1 ug/ml. The LD50 ranges between 1.5 and 6 mg/kg for many selenium compounds and animal species. The CNS seems to be the target organ ... but the liver, heart, and lungs may also be affected. A few cases of selenium poisoning in humans have been described ... either after consumption of selenium or after exposure via inhalation. Gastrointestinal and neurological symptoms predominated. Chronic poisoning due to long term exposure has been reported in livestock and humans from geographical areas where soil contains high levels of selenium. In rodent liver cirrhosis is a common effect while typical effects in domestic animals are: emaciation, deformation of hooves, loss of hair, and joint erosions. In humans consuming 5 mg selenium per day, hair and nail problems are very common. Skin lesions and depigmentation are also common signs of intoxication. In more severe cases neurological and gastrointestinal symptoms predominate. ... Several selenium compounds have been tested for possible carcinogenic potential. Selenium sulfide has been shown to induce liver cancer in two species while no convincing evidence of carcinogenicity has been presented for other selenium compounds. ... Some selenium compounds may induce DNA damage and some previous reports indicate a teratogenic potential ... . Selenium may prevent or alleviate toxic effects of arsenic, cadmium, mercury, platinum, and silver. Conversely, some of these metals protect against selenium toxicity.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌性证据
癌症分类：D组 不可归入人类致癌性类别
Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity
CLASSIFICATION: D; not classifiable as to human carcinogenicity. BASIS FOR CLASSIFICATION: Based on inadequate human data and inadequate evidence of carcinogenicity in animals. The evidence for various selenium compounds in animal and mutagenicity studies is conflicting and difficult to interpret; however, evidence for selenium sulfide is sufficient for a B2 (probable human carcinogen) classification. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Inadequate.
Classification of carcinogenicity: 1) evidence in humans: inadequate; 2) evidence in animals: inadequate. Summary evaluation of carcinogenic risk to humans 3: The agent is not classifiable as to its carcinogenicity to humans. /From table, Selenium and selenium compounds/
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌物分类
国际癌症研究机构致癌物：硒和硒化合物
IARC Carcinogenic Agent:Selenium and selenium compounds
来源:International Agency for Research on Cancer (IARC)
吸收、分配和排泄
吸收
口服生物利用度为90%，以L-硒代蛋氨酸形式给予。达峰时间为9.17小时。
Oral bioavailability of 90% when given as L-selenomethionine. Tmax of 9.17h.
Mainly excreted in urine as 1beta-methylseleno-N-acetyl-d-galactosamine and trimethylselenonium. The amount excreted as 1beta-methylseleno-N-acetyl-d-galactosamine plateaus at doses around 2microg after which the amount excreted as trimethylselenonium increases. Some selenium is also excreted in feces when given orally.
... The distribution and retention of inhaled selenious acid and selenium metal aerosols ... similar in size and chemical form to selenium aerosols that may be produced during fossil fuel combustion /were examined/. Beagle dogs were given 10 to 61 ug Se/kg of body weight by inhalation. Aerosols generated for the inhalation exposures were also collected and instilled into the upper respiratory tracts or stomachs of additional dogs to measure systemic absorption at these sites. Selenium-75, incorporated into the aerosols, was used to determine the Se content in the whole animal, excreta, and individual tissues as a function of time. Virtually all inhaled selenious acid aerosol was rapidly absorbed into the blood from the lungs, gastrointestinal tract, and the nasal membranes. Selenium metal aerosols were less rapidly absorbed. Selenium that was absorbed into the blood was translocated to the liver, kidney, spleen, and heart. Selenium-75 in these organs had a biological half-life of 30 to 40 days. Approximately 50% of the deposited Se was eliminated with a biological half life of 1.2 days. Urine was the major route of excretion, accounting for 70 to 80% of the excreted Se. The long-term component of the whole-body retention function for both inhaled aerosols had a half-life of about 34 days and accounted for about 20% of the initial Se dose. ... Although absorption of selenious acid into blood following inhalation was more rapid than absorption of selenium metal, once absorbed the disposition of both compounds was similar. 6845362
来源:Hazardous Substances Data Bank (HSDB)
安全信息
职业暴露等级：
C
职业暴露限值：
TWA: 0.2 mg/m3 [*Note: The REL also applies to other selenium compounds (as Se) except Selenium hexafluoride.]
A method of producing aminobenzimidazolones which comprises reacting a compound I having the general formula ##STR1## wherein X, Y and Z independently represent a substituent selected from the group consisting of a nitro group and an amino group, with carbon monoxide in solvent in the presence of selenium and an inorganic base or an organic base, and in the presence of water when the compound I has nitro groups, thereby providing a compound II having the general formula ##STR2##
Compounds of formula (I) and their pharmaceutically acceptable salts are provided as well as processes for the manufacture of such compounds. The compounds are useful in the treatment or prevention of inflammatory and allergic diseases.
Process for preparation of solid phase dispersion of photoconductive
申请人：Xerox Corporation
公开号：US04013530A1
公开（公告）日：1977-03-22
Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
Process for preparation of a solid phase dispersion of photoconductive
申请人：Xerox Corporation
公开号：US04030992A1
公开（公告）日：1977-06-21
Process for preparation of a solid phase dispersion of photoconductive materials in an insulating binder matrix from a film forming insulating polymeric resin and an organo-selenium compound capable of undergoing selective decomposition in response to an appropriate stimulus; whereby, elemental selenium is extruded from said organo-selenium compound and deposited in the binder matrix. Because this extrusion/deposition of elemental selenium can be performed selectively, it is possible to prepare binder films having photoconductive image patterns which are suitable for use in range extended and conventional xerography.
Therapeutic use of acyl glycerols and the nitrogen- and sulphur- containing analogues thereof
申请人：Darteil Raphael
公开号：US20060154984A1
公开（公告）日：2006-07-13
The invention relates to the use of acyl glycerols and the nitrogen- and sulfur-containing analogues thereof in the therapeutic field, particularly in human health. The inventive compounds have advantageous pharmacological properties and are particularly of use for the prevention or treatment of neurodegenerative diseases.
