Huagongshe화공사 화학 정보 인쇄 보고서 · 연구 참고용
실리카겔
실리콘화합물실리카겔 · 규산겔 · 무정형합성실리카젤 · 산화규소 · 실리카겔 · 실리카수화물 · 침전된 규토 · COLLOIDAL SILICA
식별자 및 물리적 특성
| CAS No. | 112926-00-8 |
|---|---|
| 분자식 | O2Si |
| 평균 분자량 | 60.084 g/mol |
| 단동위원소 질량 | 59.96675577 g/mol |
| SMILES | O=[Si]=O |
| InChIKey | VYPSYNLAJGMNEJ-UHFFFAOYSA-N |
| PubChem CID | 24261 |
| ChEMBL | CHEMBL2108563 |
| ChEBI | CHEBI:30563 |
| EC No. | 231-545-4 |
| DTXSID | DTXSID1029677 |
| 현지명 | 실리카겔 |
화학 및 물리적 성질
| 극성 표면적 | 34.1 |
|---|---|
| 수소 결합 공여자 수 | 0 |
| 수소 결합 수용자 수 | 2 |
| 회전 가능 결합 수 | 0 |
| 무거운 원자 수 | 3 |
| 형식 전하 | 0 |
| 복잡도 | 18.3 |
| 물질 분류 | Mineral Dusts -> Other Mineral DustsMajor ion |
| 의약품 | Pharmaceuticals -> Used in Switzerland |
| 화장품 | Cosmetics ingredient -> Anticaking/AbsorbentsBaseBulking/ViscosityColorantConditioning/EmollientEmulsifierMoisturizing/HumectantOpacifying AgentOther (Specify)Preservative/StabilizerSolventCosmetic ingredients (Silica) -> CIR (Cosmetic Ingredient Review)AbrasiveViscosity controlling |
| SpringerMaterials Properties | electron density of states |
| 향료 | Fragrance Ingredient (Silica) -> IFRA transparency List |
| 농약 | RepellantsActive substance -> EU Pesticides database: Approved |
| 냄새 | Odorless냄새 없는 |
| 맛 | Tasteless |
| 식품 첨가물 | ANTICAKING AGENT OR FREE-FLOW AGENT, ANTIOXIDANT, COLOR OR COLORING ADJUNCT, DRYING AGENT, EMULSIFIER OR EMULSIFIER SALT, FLAVORING AGENT OR ADJUVANT, FORMULATION AID, HUMECTANT, LUBRICANT OR RELEASE AGENT, -> FDA Substance added to food |
| 밀도 | 2.2 (NIOSH, 2024) - Denser than waterwill sink2.2 @ 25 °C2.6Colorless crystals or white powderodorless and tastelessdensity: 2.2-2.6soluble in molten alkai when finely divided and amorphous /Silicon dioxide/Density = 2.20 g/cmRefractive index = 1.459Surface tension = 5.200 @ 298 K (calc)Thermal conductivity = 1.37 W/m-deg K at 298 deg KHeat of Formation = -903.2 kJ/mol at 298 deg KHeat Capacity = 37.94 J/mol-deg K at 298 deg KDielectric Constant = 3.8 /Corning 7940 fused silica/Density = 2.648 /alpha-Quartz/ /from table/ |
| Color/Form | Amorphous powderTransparent to gray powder (Note: Amorphous silica is the non-crystalline form of O2Si). ... solidSilica gel is a coherent, rigid, continuous three-dimensional network of spherical particles of colloidal microporous silica.Transparent crystals |
| 용해도 | Insoluble (NIOSH, 2024)The solubility of the various phases of silicas is very complex and depends upon several factors. Solubility increases with temperature and pH and is affected by the presence of trace metals. Particle size influences the rate of solubility. /Silica/Silica is rather poorly soluble in water although solubility is higher for the amorphous than for the crystalline morphologies. ... The external amorphous layer in quartz is more soluble than the crystalline underlying core.AMORPHOUS IS SOL IN ALKALIES, ESP WHEN FINELY DIVIDEDPractically insoluble in water or acids. Dissolves readily in HF, forming silicon tetrafluoride. |
| 녹는점 | 1610°C |
| 끓는 점 | 2230℃ |
| 인화점 | 23°C |
| 저장 조건 | 2-8°C |
| 물리적 상태 | 분말 또는 과립 |
| 비중 | 0.88g/ml |
| 색상 | 파란색 |
| pH | ~6.8 (10% in aq. suspension) |
| 용해도 | 물에 불용성 |
| Merck | 14,8493 |
| 화장품 원료 기능 | 불투명화흡착제연마제점도 조절고결방지제필러 |
| EPA | Silica gel, pptd., cryst.-free (112926-00-8) |
화학적 성질
white to off-white powder
안전 및 규제
| GHS 분류 | Not ClassifiedAggregated GHS information provided per 9127 reports by companies from 60 notifications to the ECHA C&L Inventory.This chemical does not meet GHS hazard criteria for 35% (889 of 2540) of reports.WarningH315 (56.3%): Causes skin irritation [Warning Skin corrosion/irritation]P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement) |
|---|---|
| 규제 정보 | Chemical: SilicaChemical: Cristobalite (SiO2)Chemical: Silica, vitreousChemical: Calcined diatomiteRegulation (EC) No 257/2010Commission Regulation (EC) No 2229/2004 |
| 기타 안전 정보 | IMAP assessments - Cristobalite (SiO2): Environment tier I assessmentIMAP assessments - Calcined diatomite: Environment tier I assessmentIMAP assessments - Silica, vitreous: Human health tier I assessmentIMAP assessments - Silica: Environment tier I assessment |
| 화재 위험 | Not combustible. |
| 건강 유해성 | Excerpt from NIOSH Pocket Guide for Silica, amorphous: |
| 유해성 요약 | Silica is another name for the chemical compound composed of silicon and oxygen with the chemical formula SiO2, or silicon dioxide. There are many forms of silica. All silica forms are identical in chemical composition, but have different atom arrangements. Silica compounds can be divided into two groups, crystalline (or c-silica) and amorphous silica (a-silica or non-crystalline silica). c-Silica compounds have structures with repeating patterns of silicon and oxygen. a-Silica chemical structures are more randomly linked when compared to c-silica. All forms of silica are odorless solids composed of silicon and oxygen atoms. Silica particles become suspended in air and form non-explosive dusts. Silica may combine with other metallic elements and oxides to form silicates.Silica, amorphous (7631-86-9) is not classifiable as to carcinogenicity to humans. [IARC] Documentation and TLV withdrawn in 2006 because of insufficient data[ACGIH] The main problem in assessing the risk of exposure to diatomaceous earth is its varying degree of contamination with crystalline silica. While the natural version usually contains about 1%, up to 60% may be present in flux-calcined amorphous silica. [Rom, p. 527] |
| FDA 요건 | The food additive silicon dioxide may be safely used in food in accordance with /specified/ conditions.Silicon dioxide may be safely used as a component of articles intended for use in packaging, transporting, or holding food in accordance with prescribed conditions.The food additive silicon dioxide may be safely used in animal feed in accordance with /specified/ conditions. |
| 반응성 그룹 | Siloxanes |
| Special Reports | USEPA/Office of Pesticide ProgramsReregistration Eligibility Decision Document - Silicon Dioxide and Silica Gel. September 1991. The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of December 2, 2003: http://www.epa.gov/pesticides/reregistration/status.htm] |
| EPA Safer Chemical | Chemical: Silica |
| FIFRA 요건 | Tolerance exemptions for minimal risk active and inert ingredients. Unless specifically excluded, residues resulting from the use of the following substances as either an inert or an active ingredient in a pesticide chemical formulation, including antimicrobial pesticide chemicals, are exempted from the requirement of a tolerance under FFDCA section 408, if such use is in accordance with good agricultural or manufacturing practices. Silica, amorphous, fumed (crystalline-free)silica, amorphous, precipitated and gelsilica gelsilica gel, precipitated, crystalline-free, silica, hydrateand silica, vitreous are included on this list.Residues of silicon dioxide, fumed, amorphous, are exempted from the requirement of a tolerance when used as a flow control, anticaking, and carrier agent in accordance with good agricultural practices as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest.Silicon dioxide, fumed, amorphous exempted from the requirement of a tolerance when used as a flow control, anticaking, and carrier agent in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only.As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA, as amended in 1988, were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern and List D pesticides of less concern. Silicon dioxide is found on List D. Case No: 4081Pesticide type: Insecticide,fungicide, antimicribialCase Status: RED Approved 09/91OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document .Active ingredient (AI): silicon dioxideAI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI..The U. S. Environmental Protection Agency (EPA) conducted a review of the scientific data base and other relevant information supporting the reregistration of silicon dioxide and silica gel and has determined that the data base is sufficient to conduct a reasonable risk assessment. In addition, the Agency has conducted a tolerance reassessment for silicon dioxide and silica gel and its conclusions are discussed in Section IIC. The data available to the EPA support the conclusion that the currently registered uses of silicon dioxide and silica gel will not result in unreasonable public health risks or effects to the environment. No further generic data are required. Accordingly, the EPA has determined that all products containing silicon dioxide and silica gel as the active ingredients are eligible for reregistration and will be reregistered when appropriate labeling and/or product specific data are submitted and/or cited. Before reregistering each product, the EPA is requiring product specific data to be submitted within eight months of the issuance of this document. After reviewing these data and the revised labels, the EPA will determine whether to reregister a product based on whether or not the conditions of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 3(c)(5) have been met. End use products containing silicon dioxide and silica gel in combination with other active ingredients will not be reregistered until those other active ingredients are determined to be eligible for reregistration. |
| OSHA Standards | The PEL for amorphous silica is expressed by a formula that reduces the amount of dust to which a worker can be exposed as the percentage of amorphous silica in the dust rises. The term SiO2 refers to the percentage of amorphous silica in the sample. When the amorphous silica content is at or below 5.33% the total dust (Particulates Not Otherwise Regulated) PEL of 15 mg/m3 should be used. |
| Reactivity Profile | SILICA, AMORPHOUS is a non-combustible solid. Generally unreactive chemically. Incompatible with fluorine, oxygen difluoride, chlorine trifluoride. Soluble in molten alkalis and reacts with most metallic oxides at high temperature. |
| 소화 | In case of fire in the surroundings, use appropriate extinguishing media. |
| 응급 조치 | Fresh air, rest.Rinse and then wash skin with water and soap.Rinse with plenty of water (remove contact lenses if easily possible).Rinse mouth. |
| 응급 처치 | Excerpt from NIOSH Pocket Guide for Silica, amorphous:(General first aid procedures) |
| 안전 보관 | Separated from strong oxidants. |
| 노출 관리 및 개인 보호 | TIH (Toxic Inhalation Hazard) - Term used to describe gases and volatile liquids that are toxic when inhaled. Some are TIH materials themselves, e.g., chlorine, and some release TIH gases when spilled in water, e.g., chlorosilanes. [ERG 2016].0.3 [mg/m3], respir. fraction (diatomaceous earth calcined, silica fume, and fused)[German Research Foundation (DFG)] |
| 보관 조건 | Avoid dusty atmosphere. /Cab-O-Sil*/PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/ |
| 정리 방법 | PRECAUTIONS FOR "CARCINOGENS": A high-efficiency particulate arrestor (HEPA) or charcoal filters can be used to minimize amt of carcinogen in exhausted air ventilated safety cabinets, lab hoods, glove boxes or animal rooms ... Filter housing that is designed so that used filters can be transferred into plastic bag without contaminating maintenance staff is avail commercially. Filters should be placed in plastic bags immediately after removal ... The plastic bag should be sealed immediately ... The sealed bag should be labelled properly ... Waste liquids ... should be placed or collected in proper containers for disposal. The lid should be secured & the bottles properly labelled. Once filled, bottles should be placed in plastic bag, so that outer surface ... is not contaminated ... The plastic bag should also be sealed & labelled. ... Broken glassware ... should be decontaminated by solvent extraction, by chemical destruction, or in specially designed incinerators. /Chemical Carcinogens/ |
| 처리 방법 | SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air qualitypotential migration in soil or watereffects on animal, aquatic, and plant lifeand conformance with environmental and public health regulations.PRECAUTIONS FOR "CARCINOGENS": There is no universal method of disposal that has been proved satisfactory for all carcinogenic compounds & specific methods of chem destruction ... published have not been tested on all kinds of carcinogen-containing waste. ... summary of avail methods & recommendations ... /given/ must be treated as guide only. /Chemical Carcinogens/PRECAUTIONS FOR "CARCINOGENS": ... Incineration may be only feasible method for disposal of contaminated laboratory waste from biological expt. However, not all incinerators are suitable for this purpose. The most efficient type ... is probably the gas-fired type, in which a first-stage combustion with a less than stoichiometric air:fuel ratio is followed by a second stage with excess air. Some ... are designed to accept ... aqueous & organic-solvent solutions, otherwise it is necessary ... to absorb soln onto suitable combustible material, such as sawdust. Alternatively, chem destruction may be used, esp when small quantities ... are to be destroyed in laboratory. /Chemical Carcinogens/PRECAUTIONS FOR "CARCINOGENS": HEPA (high-efficiency particulate arrestor) filters ... can be disposed of by incineration. For spent charcoal filters, the adsorbed material can be stripped off at high temp & carcinogenic wastes generated by this treatment conducted to & burned in an incinerator. ... LIQUID WASTE: ... Disposal should be carried out by incineration at temp that ... ensure complete combustion. SOLID WASTE: Carcasses of lab animals, cage litter & misc solid wastes ... should be disposed of by incineration at temp high enough to ensure destruction of chem carcinogens or their metabolites. /Chemical Carcinogens/For more Disposal Methods (Complete) data for CRYSTALLINE SILICA (6 total), please visit the HSDB record page. |
| 누출 처리 | Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water. |
| Preventive Measures | Wetting processes to control dusts must be used wherever feasible. Dust-producing operations should be segregated.SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.PRECAUTIONS FOR "CARCINOGENS": Smoking, drinking, eating, storage of food or of food & beverage containers or utensils, & the application of cosmetics should be prohibited in any laboratory. All personnel should remove gloves, if worn, after completion of procedures in which carcinogens have been used. They should ... wash ... hands, preferably using dispensers of liq detergent, & rinse ... thoroughly. Consideration should be given to appropriate methods for cleaning the skin, depending on nature of the contaminant. No standard procedure can be recommended, but the use of organic solvents should be avoided. Safety pipettes should be used for all pipetting. /Chemical Carcinogens/PRECAUTIONS FOR "CARCINOGENS": In animal laboratory, personnel should remove their outdoor clothes & wear protective suits (preferably disposable, one-piece & close-fitting at ankles & wrists), gloves, hair covering & overshoes. ... Clothing should be changed daily but ... discarded immediately if obvious contamination occurs ... /also,/ workers should shower immediately. In chemical laboratory, gloves & gowns should always be worn ... however, gloves should not be assumed to provide full protection. Carefully fitted masks or respirators may be necessary when working with particulates or gases, & disposable plastic aprons might provide addnl protection. If gowns are of distinctive color, this is a reminder that they should not be worn outside of lab. /Chemical Carcinogens/PRECAUTIONS FOR "CARCINOGENS": ... Operations connected with synth & purification ... should be carried out under well-ventilated hood. Analytical procedures ... should be carried out with care & vapors evolved during ... procedures should be removed. ... Expert advice should be obtained before existing fume cupboards are used ... & when new fume cupboards are installed. It is desirable that there be means for decreasing the rate of air extraction, so that carcinogenic powders can be handled without ... powder being blown around the hood. Glove boxes should be kept under negative air pressure. Air changes should be adequate, so that concn of vapors of volatile carcinogens will not occur. /Chemical Carcinogens/PRECAUTIONS FOR "CARCINOGENS": Vertical laminar-flow biological safety cabinets may be used for containment of in vitro procedures ... provided that the exhaust air flow is sufficient to provide an inward air flow at the face opening of the cabinet, & contaminated air plenums that are under positive pressure are leak-tight. Horizontal laminar-flow hoods or safety cabinets, where filtered air is blown across the working area towards the operator, should never be used ... Each cabinet or fume cupboard to be used ... should be tested before work is begun (eg, with fume bomb) & label fixed to it, giving date of test & avg air-flow measured. This test should be repeated periodically & after any structural changes. /Chemical Carcinogens/ |
| Eye Prevention | Wear safety goggles or eye protection in combination with breathing protection. |
| Inhalation Risk | A harmful concentration of airborne particles can be reached quickly when dispersed. |
| 독성학 정보 | CDC-ATSDR Toxicological Profile |
| 상호 작용 | Another form of amorphous silica, precipitated amorphous silica, /may/ form layers around quartz particles, which may facilitate the toxic action of quartz.Ameliorating effects of /poly-2-vinylpyridine-N-oxide/ PVNO were observed for pulmonary damage from colloidal SiO213 lead chromate-based pigments were assayed for mutagenicity and toxicity using Salmonella typhimurium TA100 with and without S9, both in the presence and absence of the chelating agent, nitrilotriacetic acid (NTA). In general, the use of NTA to solubilize the compounds resulted in /enhanced/ mutagenicity and/or toxicity ... . Encapsulation of pigments with amorphous silica rendered these pigments non-mutagenic and non-toxic, indicating that the active moieties were biologically unavailable to the bacteria.Lazaroid (U-75412E) scavenges .OH radicals generated by crystalline silica-mediated reaction from H2O2 and inhibits lipid peroxidation in macrophages induced by these particles.Occupational studies have found that the major source of co-morbidity with silicosis is infection by Mycobacterium tuberculosis (TB). |
| 표적 장기 | Cancer, Immunological (Immune System), Renal (Urinary System or Kidneys), Respiratory (From the Nose to the Lungs)Eyes, respiratory system |
| 생태독성 수치 | LC50 Carp >10,000 mg/l/72 hr /Conditions of bioassay not specified/ |
| 식품 조사 수치 | Amorphous silica (such as fumed silica) is incorporated in a variety of food productsas anti-caking agent at levels up to 2% by weight ... also as an anti-caking agent and as an excipient in pharmaceuticals. |
| 유해 작용 | Fibrogenic - Inducing tissue injury and fibrosis (scarring). |
| 노출 경로 | Exposure mainly occurs via inhalation.inhalation, skin and/or eye contact |
| 독성 요약 | The Panel concluded that synthetically-manufactured amorphous Silica ... safe in the present practices of use and concentration described in the safety assessment when formulated to be non-irritating.Safe for use in cosmetics, with qualificationsIDENTIFICATION: Quartz is a frequently occurring solid component of most natural mineral dusts. HUMAN EXPOSURE: Human exposures to quartz occur most often during occupational activities that involve the movement of earth, disturbance of silica containing products (masonry, concrete), or use or manufacture of silica containing products. Environmental exposure to ambient quartz dust can occur during natural, industrial and agricultural activities. Respirable quartz dust particles can be inhaled and deposited in the lung. There are many epidemiological studies of occupational cohorts exposed to respirable quartz dust. Silicosis, lung cancer and pulmonary tuberculosis are associated with occupational exposure to quartz dust. Statistically significant increases in deaths or cases of bronchitis, emphysema, chronic obstructive pulmonary disease, autoimmune related diseases (scleroderma, rheumatoid arthritis, systemic lupus erythematosus) and renal diseases have been reported. Silicosis is the critical effect for hazard identification and risk assessment. There are sufficient epidemiological data to allow the risk of silicosis to be quantitatively estimated, but not to permit accurate estimations of risks for other health effects. ANIMAL STUDIES: Quartz dust induces cellular inflammation in vivo. Short term experimental studies of rats have found that intratracheal instillation of quartz particles leads to the formation of discrete silicotic nodules in rats, mice and hamsters. Inhalation of aerosolized quartz particles impairs alveolar macrophage clearance functions and leads to progressive lesions and pneumonitis. Oxidative stress (formation of hydroxyl radicals, reactive oxygen species, or reactive nitrogen species) has been observed in rats after intratracheal instillation or inhalation of quartz. Many experimental in vitro studies have found the surface characteristics of the crystalline silica particle influence its fibrogenic activity and a number of features related to its cytotoxicity. Long term inhalation studies of rats and mice have shown that quartz particles produce cellular proliferation, nodule formation, suppressed immune functions and alveolar proteinosis. Experimental studies of rats reported the occurrence of adenocarcinomas and squamous cell carcinomas after the inhalation or intratracheal instillation of quartz. Pulmonary tumors were not observed in experiments with hamsters or mice. Quartz did not test positively in standard bacterial mutagenesis assays. In experimental studies of particles, results may vary depending on the test material, concentration administered and species tested. The experiments with quartz particles involved specimens from various sources, using various doses, particle sizes and species. Data on the reproductive and developmental effects of quartz in laboratory animals are not available. The adverse effects of quartz in aquatic organisms and terrestrial mammals have not been studied. |
| Signs and Symptoms | Cough.Redness.Redness. Pain.No acute symptoms expected.irritation eyes, pneumoconiosis |
| Ongoing Test Status | The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. /Silica, crystalline - quartz/ [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=14808-60-7] |
| Effluent Concentrations | Silica fume, generated unintentionally and emitted from electric arc furnaces may contaminate work environments in silicon, ferrosilicon and other silicon-containing alloy production.Fly ash from power stations and various manufacturing facilities (e.g., silicon, silicous carbide, silicon nitride, ferrosilicon industries) may contain significant amounts of amorphous and crystalline silicaAmorphous silica fibers were identified as smoke constituents in three of seven area samples located near burning sugar cane fields in HawaiiAmorphous silica fibers were observed in samples collected /near/rice farming operations in California |
| Medical Surveillance | Along with lengthy occupational silica exposure and respiratory symptoms, diagnosis of chronic silicosis is confirmed with a positive X ray. The radiology community has agreed on a grading convention developed by the International Labour Organization (ILO) for assessing the severity of silicosis lesions (International Labour Organization, 1980). The X-ray opacities can range from mild (up to 1.5 mm) to moderate (1.5 to 3.0 mm) to severe (3 to 10 mm). These opacities are different from the diffuse lung changes that occur with age and cigarette smoking, but over time differentiation may be difficult. Chronic silicosis in its simplest form can be detected by X ray in the absence of any physical symptoms or clinical abnormalities.PRECAUTIONS FOR "CARCINOGENS": Whenever medical surveillance is indicated, in particular when exposure to a carcinogen has occurred, ad hoc decisions should be taken concerning ... /cytogenetic and/or other/ tests that might become useful or mandatory. /Chemical Carcinogens/ |
| 직업 노출 등급(OEB) | B |
| 직업 노출 한계(OEL) | TWA: 6.0 mg/m3 |
| 수질 위해 등급(WGK) | 2 |
| TSCA 등재 상태 | Yes |
| RTECS 번호 | VV7315000 |
| 운송 번호(UN) | 1993 |
| 위험 문구(R) | 20-37-42/43-49-36/37-48/20-51/53-68-50/53-41-22-60 |
| 위험 표시 | Xi,T,N,Xn |
| 안전 문구(S) | 22-24/25-45-36/37-53-26-36-61-60-39 |
| 기존화학 물질 | KE-32733 |
| F 고인화성물질 | 3 |
| 위험 참고 사항 | Harmful/Irritant |
용도
출처
Silica gels are dispersions of colloidal silica obtained by a sol–gel process. The process consists in precipitating colloidal silica from an aqueous solution of sodium silicate by adding hydrochloric or sulfuric acid. The colloidal precipitate or gel consists mainly of hydrated silica (SiO2 .nH2 O). After filtration the precipitated silica is washed in order to remove residual salts and stabilized by adding ammonia or sodium hydroxide. The stabilized gel is then dried and later calcined to obtain an activated material, usually in the form of small beads.
용도
Silica gel was used on glass plates for preparative TLC and on aluminium sheets for analytical TLC. Silica gel was used in vacuum chromatography and TLC. Silica gel was used in column chromatography.
일반 설명
Silica gel is a rigid 3D network of colloidal silica. It is exclusively used as a support material for the active titanium(III) centers in Ziegler-Natta catalysts. Silica gel allows a controlled fragmentation lresulting in the formation of uniform polymer particles with narrow particle size distribution and high bulk density. Silica gel is classified as below:a. Aquagel - pores are filled with waterb. Xerogel - by the process of evaporation, aqueous phase in the pores are removedc. Aerogel - solvent removed by supercritical extraction