Chromic acid, solid is a dark purplish red solid. It is soluble in water with the release of heat. The material itself is noncombustible but it will accelerate the burning of combustible materials. Its solution is corrosive to metals and tissue.
颜色/状态:
Dark purplish-red crystals /Anhydrous chromic acid/
沸点:
Decomposes at about 250 °C /Anhydrous chromic acid, chromic trioxide/
分解:
When heated to decomposition it emits smoke and irritating fumes.
腐蚀性:
Attacks most metals, particularly copper and brass. Attacks cloth, leather, and some plastics.
Skin contact with chromic acid can cause redness, pain, and severe skin burns. Chromic acid may cause severe burns to the eye and permanent eye damage. Severe and rapid corrosive burns of the mouth, gullet and gastrointestinal tract will result if chromic acid is swallowed. Symptoms include burning, choking, nausea, vomiting and severe pain. Chronic exposure to low levels of chromic acid can lead to chronic exposure to hexavalent chromium. Hexavalent chromium is a known carcinogen. Chronic inhalation especially has been linked to lung cancer. Hexavalent chromium is also known to cause reproductive and developmental defects. (A12)
IDENTIFICATION AND USE: Chromic acid forms dark purplish-red crystals. It is used as photographic chemical; aluminum anodizing reagent; chrome electroplating/zinc colorless conversion coatings reagent; side-chain oxidation reagent, and wood preservative. HUMAN EXPOSURE AND TOXICITY: Repeated or prolonged exposure to chromic acid or chromate dust or mist may cause an ulceration and perforation of the nasal septum. Respiratory irritation may occur with symptoms resembling asthma. Liver damage with yellow jaundice has been reported. Prolonged or repeated exposure of the skin may cause a skin rash. Allergic skin rash may also occur. Contact causes severe eye injury characterized by infiltration, vascularization, and opacification of the cornea. Full-thickness skin burns covering as little as 1% of the body surface area may lead to irreversible acute tubular necrosis secondary to acute chromium intoxication. The mortality rate is high if the burned area exceeds approximately 10% of the body surface. The correlation with duration of chrome bath work associated with exposure to chromium acid was positive only for cancers of the lung and bronchus in male workers. It was experimentally and epidemiologically confirmed that hexavalent chromium compounds act as carcinogens and cause specific biological effects on the respiratory system. These characteristics of hexavalent compounds might be attributable to the strong oxidizing potency and/or high permeability through the cell membrane. Furthermore, hexavalent compounds might be entirely different in biological action from trivalent compounds which are chemically most stable. ANIMAL STUDIES: There is limited evidence in experimental animals for the carcinogenicity of chromic acid. There was an increased incidence in abnormalities (cleft palate, cleft sternum, perforated sternum) in developmental studies in mice. In CHO cells, there was a significant increase in SCE with CrVI compounds. In the Ames test there was a dose-response for increase in revertant colonies for all CrVI compounds at 10-200 ug/plate with TA1537, TA98 and TA100. Addition of S9 did not affect mutation incidence. In other studies, when tested in Salmonella typhimurium strains TA1537, TA1538, TA98 and TA100 the S9 mix decreased the mutagenicity of CrVI compounds.
Chromic acid is highly corrosive and strongly oxidative. Many strong acids cause tissue burns through the denaturation of proteins and partial hydrolysis of proteins. Most proteins denature at pH values of less than 3-4. The large-scale denaturation of proteins, de-esterification of lipids and subsequent desiccation of tissues leads to chemical burns. . Symptoms include itching, bleaching or darkening of skin or tissues, blistering and burning sensations. Chromic acid also denatures proteins through inserting oxygen atoms into protein side chains. Chromic acid is also a source of chromium and especially hexavalent chromium. Hexavalent chromium compounds (including chromium trioxide, chromic acids, chromates, chlorochromates) are toxic and carcinogenic. For this reason, chromic acid oxidation is not used on an industrial scale except in the aerospace industry. Hexavalent chromium's carcinogenic effects are caused by its metabolites, pentavalent and trivalent chromium. The DNA damage may be caused by hydroxyl radicals produced during reoxidation of pentavalent chromium by hydrogen peroxide molecules present in the cell. Trivalent chromium may also form complexes with peptides, proteins, and DNA, resulting in DNA-protein crosslinks, DNA strand breaks, DNA-DNA interstrand crosslinks, chromium-DNA adducts, chromosomal aberrations and alterations in cellular signaling pathways. It has been shown to induce carcinogenesis by overstimulating cellular regulatory pathways and increasing peroxide levels by activating certain mitogen-activated protein kinases. It can also cause transcriptional repression by cross-linking histone deacetylase 1-DNA methyltransferase 1 complexes to CYP1A1 promoter chromatin, inhibiting histone modification. Chromium may increase its own toxicity by modifying metal regulatory transcription factor 1, causing the inhibition of zinc-induced metallothionein transcription. (A12, L16, A34, A35, A36)
Evaluation: There is sufficient evidence in humans for the carcinogenicity of chromium(VI) compounds as encountered in the chromate production, chromate pigment production and chromium plating industries. There is sufficient evidence in experimental animals for the carcinogenicity of calcium chromate, zinc chromates, strontium chromate and lead chromates. There is limited evidence in experimental animals for the carcinogenicity of chromium trioxide (chromic acid) and sodium dichromate. Overall evaluation: Chromium(VI) is carcinogenic to humans (Group 1). The Working Group made the overall evaluation on chromium(VI) compounds on the basis of the combined results of epidemiological studies, carcinogenicity studies in experimental animals, and several types of other relevant data which support the underlying concept that chromium(VI) ions generated at critical sites in the target cells are responsible for the carcinogenic action observed. /Chromium(VI) compounds/
Skin contact with chromic acid can cause redness, pain, and severe skin burns. Chromic acid may cause severe burns to the eye and permanent eye damage. Severe and rapid corrosive burns of the mouth, gullet and gastrointestinal tract will result if chromic acid is swallowed. Symptoms include burning, choking, nausea, vomiting and severe pain. Chronic exposure to low levels of chromic acid can lead to chronic exposure to hexavalent chromium. Hexavalent chromium is a known carcinogen. Chronic inhalation especially has been linked to lung cancer. Hexavalent chromium is also known to cause reproductive and developmental defects. (A12)
来源:Toxin and Toxin Target Database (T3DB)
吸收、分配和排泄
吸入高度水溶性的六价铬盐,如铬酸...可能导致全身吸收。
Inhalation of highly water-soluble hexavalent chromium salts, such as chromic acid, ... may result in systemic absorption.
Absorption of inhaled chromium cmpds takes place in the lung via transfer across cell membranes and in the GI tract from particles cleared from the lungs. Absorption after oral exposure in humans varies from essentially none for the highly insoluble chromium(III) cmpd chromic oxide, to 0.5-2.0% for chromium(III) cmpds in the diet, to approx 2-10% for chromium(VI) as potassium chromate. Dermal absorption depends on the physical and chemical properties of the cmpd, the vehicle, and the integrity of the skin. Concentrated soln of chromium(VI) cmpds such as potassium chromate can cause chemical burns and facilitate absorption. /Chromium cmpds/
1.周国泰,化学危险品安全技术全书,化学工业出版社,1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编,化学品毒性法规环境数据手册,中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989
[EN] PYRROLIDINE DERIVATIVES AS OXYTOCIN ANTAGONISTS<br/>[FR] DERIVES DE PYRROLIDINE UTILISES EN TANT QU'ANTAGONISTES DE L'OXYTOCINE
申请人:APPLIED RESEARCH SYSTEMS
公开号:WO2004005249A1
公开(公告)日:2004-01-15
The present invention relates to novel pyrrolidine derivative of formula (I), its geometrical isomers, its optically active forms as enantiomers, diastereomers, mixtures of these and its racemate forms, as well as salts thereof, wherein R1 is selected from the group comprising or consisting of H and C1-C6-alkyl, for the prevention and/or treatment of preterm labor, premature birth or dysmenorrhea.
AQUEOUS SOLUTIONS OF ORGANIC ACID CHROMIUM(III) SALTS AND PROCESS FOR PREPARATION THEREOF
申请人:Nippon Chemical Industrial Co., Ltd.
公开号:EP2039673A1
公开(公告)日:2009-03-25
An aqueous solution containing an organic acid chromium (III) salt represented by general formula: Crm(Ax)n, wherein A represents a residue left after proton removal from an organic acid; x represents a charge of A; and m and n represent integers satisfying equation 3m+xn=0, is disclosed. The aqueous solution contains the organic acid chromium (III) salt in a concentration of 6% by weight or higher in terms of Crm(Ax)n, has impurity ion concentrations of Na≤30 ppm, Fe≤20 ppm, Cl≤0.001%, SO4≤0.03%, and NO3≤20 ppm per 20 wt% concentration of Crm(Ax)n, and is substantially free from chromium (VI).
The invention concerns a 2′,2′-difluoro-2′-deoxycytidine derivative of general formula (I), wherein: R
1
, R
2
and R
3
, identical or different, represent independently of one another, a hydrogen atom or an at least C
18
hydrocarbon acyl radical and of such conformation that it is capable of providing the compound of general formula (I), a compacted form in a polar solvent medium, at least one of groups R
1
, R
2
and R
3
being other than a hydrogen atom.
[EN] PROCESS FOR THE PREPARATION OF METAL ACETYLACETONATES<br/>[FR] PROCEDE DE PREPARATION D'ACETYLACETONATES DE METAL
申请人:COUNCIL SCIENT IND RES
公开号:WO2004056737A1
公开(公告)日:2004-07-08
The present invention provides an improved, economical and environmmentally benign process for metal complexes of acetylacetone having the general formula, M(acac)n wherein M is a metal cation selected from the group consisting of Fe, Co, Ni, Cu, Zn, Al, Ca, Mg, Mo, Ru, Re, U, Th, Ce, Na, K, Rb, Cs, V, Cr, and Mn etc., n is an integer which corresponds to the electrovalence of M, are obtained by reacting the corresponding metal hydroxide, metal hydrated oxide or metal oxide with a stoichiometric amount of acetylacetone and separating the product.
本发明提供了一种改进的、经济的和环境友好的金属乙酰丙酮络合物的过程,其具有一般公式 M(acac)n,其中 M 是从 Fe、Co、Ni、Cu、Zn、Al、Ca、Mg、Mo、Ru、Re、U、Th、Ce、Na、K、Rb、Cs、V、Cr 和 Mn 等组成的金属阳离子中选择的,n 是与 M 的电价对应的整数,通过将相应的金属氢氧化物、金属水合氧化物或金属氧化物与等量的乙酰丙酮反应并分离产物获得。
Fluorine containing renin inhibitors
申请人:Pfizer Inc.
公开号:US04855303A1
公开(公告)日:1989-08-08
Polypeptides containing fluorinated cyclostatine derivatives as antihypertensive agents.