Hazards, nature

Demand for thallium has decreased since the early 1980s because, wherever possible, substitute materials are used due to its hazardous nature. Annual production is very small, estimated to be 10,000 kg/yr. The principal domestic producer is Noah Chemical Division, Noah Industrial Corporation. Thallium is available in three grades 99.9%, 99.99%, and 99.999% pure. The 99.9% material is priced at 360/kg ( 17/kg 1969). 

Electiical classification. Article 500 of the National Electric-Code provides for the classification of the hazardous nature of the process area in which the measurement device will be installed. If the measurement device is not inherently compatible with this classification, suitable enclosures must be purchased and included in the installation costs. 

Rapid Manufacturing-Cost Estimates Fixed manufacturing costs are a func tion of the fixed-capital investment and are independent of the production rate of the plant. Property taxes or rates depend on location. They may be taken as 2 percent of the fixed-capital cost of the plant in the absence of specific data. The cost of insurance depends on both location and the hazardous nature of the materials handled. This cost is normally of the order of 1 percent of the fixed-capital cost of the plant. 

In spite of the hazardous nature of Sc4N4, this binary selenium nitride has been used for the synthesis of other Se-N compounds, all of which have sulfur analogues (Scheme 5.2). " However, safer alternatives to the use of Sc4N4, e.g., selenium-nitrogen halides and silicon-nitrogen-selenium reagents, are available for the development of Se-N chemistry. ... 

Because of the reactivity, instability and hazardous nature of O3 it is always generated on... 

Determining and specifying the required process performance and mechanical requirements, including the corrosive and hazardous nature and the moisture content of the fluids (gases/vapors) to be compressed, is important. 

An assessment of each element of the program of work is carried out using the Assessment of Potential Hazards Form APHl (see below), which is to be completed by the person responsible for the task to be carried out. This may include hot work cutting/grinding work on electrical systems working alone use of hazardous materials (e.g. chemicals, solvents, etc.) confined spaces or any other work which may be of a hazardous nature. 

Because of the hazardous nature of anhydrous hydrogen fluoride, adequate precautions should he taken to protect the head, eyes, and skin. Rubber gloves, an apron, and a plastic face mask are strongly recommended. All operations should be carried out in a hood. If hydrogen fluoride comes in contact with the skin, the contacted area should be thoroughly washed with water and then immersed in ice water while the patient is taken to a physi-... 

The hazardous nature of the pic rates is underscored in Urbanski s description of the construction of PA driers (Ref 11) ... 

Whilst some of these measures attempt to take account of the hazardous nature of by-products and effluent, they do not take account of the hazardous nature of any starting materials. The other major omission from these measures is any measurement of the energy involved. 

Materials input - covers all raw materials including water. The operator is required to show that unnecessarily hazardous materials are not being used and that adequate precautions are in place to prevent release or operator harm. In some cases an improvement programme may be required to reduce either the quantity or the hazardous nature of materials being used. 

PTC has been effectively used to reduce the hazardous nature of overall processes whilst the elimination of hazardous reagents has not been achieved, the volume required has been reduced. In reaction 4.4 sodium cyanide is normally required in excess, so at the end of the process great care must be taken to separate it from the product and either destroy it or recover it. In the PTC system the NaCN is for all practical purposes confined to the aqueous layer which can be simply separated from the organic layer and reused in the next batch. 

G. Quantity of flammable material the potential loss will be greater the greater the quantity of hazardous material in the process or in storage. The factor to apply depends on the physical state and hazardous nature of the process material, and the quantity of material. It varies from 0.1 to 3.0, and is determined from Figures 3, 4 and 5 in the Dow Guide. 

The conditions under which the material is tested are crucial. The top of the exposure chamber must be sealed and the tank should contain no free air space. A stirring mechanism in the tank keeps the leachate mixture homogeneous and a heater block keeps it at an elevated temperature as required for the test. Stress conditions of the material in the field should also be simulated as closely as possible. The original U.S. EPA Method 9090 test included a rack to hold specimens under stress conditions but was revised when some materials shrank in the leachate. Due to the hazardous nature of the material, testing should be performed in a contained environment and safety procedures should be rigorously followed. 

Because of the unavoidable tendency of granular solids to become triboelectrically charged when handled, it is no surprise that electrostatic phenomena are often quite pronounced in fluidized and spouted beds. The vigorous motion of fluidized particles—with constant particle-particle and particle-wall contacts—guarantees that electrical charging will take place. Electrostatic adhesion and cohesion, observed and recorded in the very earliest experimental investigations of fluidization, were immediately identified as experimental nuisances to be overcome. Somewhat later, the hazardous nature of electrostatics came to be appreciated. 

Hazard Class A series of nine descriptive terms that have been established by the UN Committee of Experts to categorize the hazardous nature of chemical, physical, and biological materials. These categories are flammable liquids, flammable solids, explosives, gases, oxidizers, radioactive materials, corrosives, poisonous and infectious substances, and dangerous substances. 

The collected papers of a symposium at Dallas, April 1956, cover all aspects of the handling, use and hazards of lithium, sodium, potassium, their alloys, oxides and hydrides, in 19 chapters [1], Interaction of all 5 alkali metals with water under various circumstances has been discussed comparatively [2], In a monograph covering properties, preparation, handling and applications of the enhanced reactivity of metals dispersed finely in hydrocarbon diluents, the hazardous nature of potassium dispersions, and especially of rubidium and caesium dispersions is stressed [3], Alkaline-earth metal dispersions are of relatively low hazard. Safety practices for small-scale storage, handling, heating and reactions of lithium potassium and sodium with water are reviewed [4],... 

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