Sealed containers

Formed commercially by the polymerization of S, NajCOj and PhX in a sealed container at 275--370 C, substituted derivatives are known but not fully evaluated. Used as high-temperature adhesives, for laminates and in coatings. 

Static headspace GC/MS. The partitioning of volatile and semivolatile compounds between two phases in a sealed container. An aliquot of the headspace gas generated is injected onto a gas chromatographic column. This is followed by mass spectrometric analysis of compounds eluting from the gas chromatograph. 

The high purity anhydrous copper(II) fluoride must be stored ia a tightly closed or sealed container under an atmosphere of argon. The dihydrate may be stored ia polyethylene-lined fiber dmms. The ACGIH (1992—1993) adopted toxicity value for copper as Cu is 1 mg/m, and for fluorides a F , 2.5 mg/m. ... 

The estabhshment of safe thermal processes for preserving food in hermetically sealed containers depends on the slowest heating volume of the container. Heat-treated foods are called commercially sterile. Small numbers of viable, very heat-resistant thermophylic spores may be present even after heat treatment. Thermophylic spores do not germinate at normal storage temperatures. 

Dehydration Processing. Dehydration is one of the oldest means of preserving food. Microbes generally do not grow below a minimum water activity, of 0.65 defined as the equiHbrium relative humidity surrounding food ia a sealed container at a given temperature, ie, no microbes can... 

Phenyllithium can be used as a solution in ethyl ether, but because of its limited stabUity (t 2 = 12 d at 35° C) it is commercially available in solution in mixtures, usuaUy 70 30 wt % cyclohexane ethyl ether (117). In this particular mixture of solvents, a 20 wt % solution, free of chlorobenzene, is stable for at least four months under an inert atmosphere (argon or nitrogen) in sealed containers at room temperature. Phenyllithium is also available in dibutyl ether solution (117). It is classified as a flammable Hquid. 

Eig. 3. Isothermal section at 23 3°C of the system MgO-MgCl2 H2 0 showing phases in equiHbrium with vapor phases in sealed containers (65). 

The transducers are typically mounted on an outside wall of the cleaning tank, but may also be mounted on the inside of the tank below the solution level in a sealed container. Alkaline cleaning solutions are typically at the same concentration and temperature as for a normal immersion cleaner, but the time required to clean may be less because of the ultrasonic effect. Like electrocleaning, ultrasonic cleaning produces an extremely clean surface. The main drawback is the relatively high cost. 

The 4,4 -MDA is sold commercially with a diamine assay of 98 —99%. The major impurity is the 2,4 -MDA isomer, which can be present in amounts up to 3%. PMDA products are normally defined by hydrogen equivalent weight and viscosity. Typical products exhibit a 50 hydrogen equivalent weight and a viscosity of 80 140 mPa-s(=cP) at 70°C. PMDA products normally contain, in addition to the isomers and oligomers of MDA, small amounts of aniline, water, chlorides, and various alkylated amines. AH MDA products should be stored in sealed containers in a cool dry area. 

The concept of heat processing of foods in hermetically sealed containers was introduced in 1810 (23). The role of microorganisms was unknown at the time, and only the so-called agents of putrefaction were eliminated. 

Because of the multiple conjugated olefinic stmcture in the molecule, pure crystalline carotenoids are very sensitive to light and air and must be stored in sealed containers under vacuum or inert gas to prevent degradation. Thus, commercial utilization as food colorings was initially limited however, stable forms were developed and marketed as emulsions, oil solutions and suspensions, and spray-dried forms. 

Air cells are packaged with sealing tape over the air holes or in sealed containers. In the sealed state, they maintain their capacity well during storage... 

Commercially important soHd available chlorine bleaches are usually more stable than concentrated hypochlorite solutions. They decompose very slowly in sealed containers. But most of them decompose quickly as they absorb moisture from air or from other ingredients in a formulation. This may release hypochlorite that destroys other ingredients as well. 

Dry potassium cyanide in sealed containers is stable for many years. An aqueous solution of potassium cyanide is slowly converted to ammonia and potassium formate the decomposition rate accelerates with increasing temperature. However, at comparable temperatures the rate of conversion is far lower than that for sodium cyanide only about 25% as great. 

Dental Stones. Dental stones, produced from gypsum, are sold as dry powders in sealed containers. They are prepared for use by mixing with water, in proportions recommended by the manufacturer. 

Propylene Oxide. Propylene oxide [75-56-9] (qv), C H O, is a higher homologue of ethylene oxide that boils at 35°C. Propylene oxide is not as germicidaHy active as ethylene oxide (291), but has one distinct advantage it hydrolyzes to produce nontoxic propylene glycol (292), allowing use for treating foods. Three hours at 37°C reduced the microbial count of cocoa powder by 50—70% and molds by 90—99% (293). Powdered cosmetics and toiletries are treated with 1—2% of Hquid propylene oxide in sealed containers, and the temperature is raised to cause vaporization and increased activity (294). 

Hazardous Wastes Hazardous Wastes for deliveiy to a treatment or disposal facility normally are collected by the waste producer or a licensed, speciahzed hauler. Typically, the loading of collection vehicles is completed in one of two ways (1) wastes stored in large-capacity tanks are either drained or pumped into collection vehicles, and (2) wastes stored in sealed drums or other sealed containers are loaded by hand or by mechanical equipment onto flatbed trucks. To avoid accidents and possible loss of life, two collectors shoiild always be assigned when hazardous wastes are to be collected. 

Drum not sealed Seal containers as directed in operating properly. procedures Use new gaskets Provide correct tools for sealing drums CCPS G-3 CCPS G-15 CCPS G-22 CCPS G-29... 

The chloroform solution Is washed with water (2 x 250 ml) and stirred with glacial acetic acid (250 ml) for 1 hr (Note 6). The solution that results Is washed with water (2 x 250 mL), and the chloroform phase is treated with 1.5 L of hexane and kept at 2 C for 48 hr. The material which precipitates Is collected and dried at 0.1 ram In a desiccator (calcium chloride) for 5 hr to give p-methoxyphenyllead triacetate (20-22 g, 35-40%) as pale yellow crystals, mp 138-139°C (Note 7). The product may be kept for at least 3 weeks If stored at 2°C In a sealed container. 

Geraniol [106-24-1] M 154.3, b 230 , d 0.879, n 1.4766. Purified by ascending chromatography or by thin layer chromatography on plates of kieselguhr G with acetone/water/liquid paraffin (130 70 1) as solvent system. Hexane/ethyl acetate (1 4) is also suitable. Also purified by GLC on a silicone-treated column of Carbowax 20M (10%) on Chromosorb W (60-80 mesh). [Porter Pure Appl Chem 20 499 7969.] Stored in full, tightly sealed containers in the cool, protected from light. 

Calcium sulfate hemihydrate []0034-76-1 j M 145.2. Sol in H2O (0.2 parts/100 at 18.75°). Completely dehydrated >650°. Dry below 300° to give a solid with estimated pore size ca 38% of vol. Anhydrous CaS04 has high affinity for H2O and will absorb 6.6% of its weight of H2O to form the hemihydrate (gypsum). It sets to a hard mass with H2O, hence should be kept in a tightly sealed container. 

Trimethylsilyl)ethoxymethyl chloride (SEMCl) [76513-69-4] M 166.7, b 57-59"/8mm, d 0.942, n 1.4350. Dissolve in pentane, dry (MgS04), evaporate and dist residual oil in a vac. Stabilise with lOppm of diisopropylamine. Store under N2in a sealed container in a refrigerator. [Lipshutz and Pegram Tetrahedron Lett 21 3343 I980. ... 

Pure methanesulfinyl chloride boils at 48° (22 mm.) and 59° (42 mm.) and has 1.5038, d° 1.4044 and df 1.3706. On standing at room temperature, it slowly decomposes with the liberation of hydrogen chloride. It should not be stored for a long period in a tightly sealed container. 

Transfer of solids in sealed containers or plastic sacks in preset batch weights, so avoiding emptying for reweighing. 

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