Chemical substances identifying

Great Lakes Water Quality Board. 1983. An inventory of chemical substances identified in the Great Lakes ecosystem. Vol. 1. Summary Report to the Great Lakes Water Quality Board. Windsor Ontario, Canada 195. 

Service Index or Preferred Nomenclature in the Chemical Substance Identities section of the Inventory - or (ii) chemical substances identified in the... 

Company name] intends to manufacture or import the chemical substance identified in this notice, [insert chemical name], for commercial purposes. 

B) The Administrator shall, in prescribing a rule imder subparagraph (A) which fists any chemical substance, identify those uses, if any, which the Administrator determines, by rule under subsection (a)(2) of this section, would constitute a significant new use of such substance. 

International Joint Commission, An Inventory of Chemical Substances Identified in the Great Lakes Ecosystems, vols. 1-6, International Joint Commission, Windsor, Ont.,... 

Thus, if the user wants to look for literature including requested chemicals or reactions, it is possible to query the database by the first option Chemical Substance or Reaction , The compound can be entered as a query in three different ways drawing the chemical structure in a molecule editor (Chemical Structure) searching by names or identification number, such as the CAS Number (Structure Identifier) and searching by molecular formula (Figure 5-12). 

Registry File. This CAS file contains more than 11.8 million chemical substance records. About 8,000—14,000 records are added each week as new substances are identified by the CAS Registry System. The substance records contain CAS Registry Numbers, chemical names, stmctures, molecular formulas, ring data biosequence information, and classes for polymers. AH of this information may be displayed. 

A number of methods have been developed to introduce context to on-line databases, enabling searches to be refined to minimized false retrieval. One of the earliest techniques is proximity searching, in which two words are required to be adjacent, or within a limited distance from each other in text. The assignment of roles to chemical substances is a method of precoordinating concepts. A substance can be identified as a reactant, as a product, and in some systems in a number of additional roles. For example, by searching for documents in which formaldehyde is a product, documents in which it is a reactant, or in which it undergoes no reaction, are thus eliminated. 

Toxic Substances Control Act. EPA regulates the manufacture, use, and exposure to ha2ardous or toxic chemicals under a number of laws. Eor the chemical industry, the law of prime concern is the Toxic Substance Control Act (TSCA) (10), which was passed by the U.S. Congress in 1976. The two main goals of TSCA are acquisition of sufficient information to identify and evaluate potential ha2ards from chemical substances, and regulation of the production, use, distribution, and disposal of these substances. 

The Toxic Substances Control Act (TSCA) was enacted in 1976 to identify and control toxic chemical ha2ards to human health and the environment. One of the main provisions of TSCA was to estabUsh and maintain an inventory of all chemicals in commerce in the United States for the purpose of regulating any of the chemicals that might pose an unreasonable risk to human health or the environment. An initial inventory of chemicals was estabhshed by requiring companies to report to the United States Environmental Protection Agency (USEPA) all substances that were imported, manufactured, processed, distributed, or disposed of in the United States. Over 50,000 chemical substances were reported. PoUowing this initial inventory, introduction of all new chemical substances requires a Premanufacturing Notification (PMN) process. To be included in the PMN are the identity of the new chemical, the estimated first year and maximum production volume, manufacture and process information, a description of proposed use, potential release to the environment, possible human exposure to the new substance, and any health or environmental test data available at the time of submission. In the 10 years that TSCA has been in effect, the USEPA has received over 10,000 PMNs and up to 10% of the submissions each year are for dyes (382)... 

CRS provides information on chemical substances and how they are represented in the Environmental Protection Agency regulations and data systems. A search engine for chemicals by CAS number, name, molecular formula, chemical type, definition, or other data identifiers. 

The notion of a pnre chemical snbstance can be related to empirically identifiable properties (e.g. sharp melting and boiling temperatures) but is nowadays understood in theoretical terms that are abstract (Johnson, 2002 Taber, 2002a). So hydrogen, methane, diamond, sodium, sodium chloride and polythene - poly(ethene) - are all considered examples of single chemical substances, although they are very different... 

PBPK models improve the pharmacokinetic extrapolations used in risk assessments that identify the maximal (i.e., the safe) levels for human exposure to chemical substances (Andersen and Krishnan 1994). PBPK models provide a scientifically sound means to predict the target tissue dose of chemicals in humans who are exposed to environmental levels (for example, levels that might occur at hazardous waste sites) based on the results of studies where doses were higher or were administered in different species. Figure 3-4 shows a conceptualized representation of a PBPK model. 

The Chemical Substances Threshold Limit Values Committee classifies certain substances found in the occupational environment as either confirmed or suspected human carcinogens. The present listing of substances that have been identified as carcinogens takes two forms those for which a TLV has b n assigned and those for which environmental and exposure conditions have not been sufficiently defined to assign a TLV. Where a TLV has been assigned, it does not necessarily imply the existence of a biological threshold however, if exposures are controlled to this level, we would not expect to see a measurable increase in cancer incidence or mortality. 

The most widespread modem use of mass spectrometers is to identify chemical substances. When a molecule is placed in a mass spectrometer, the electrical discharge strips away one of its electrons. This so-called parent ion has virtually the same mass as the neutral molecule. If the mass of the parent ion is measured with high enough accuracy, the data can provide the molecular formula of the substance. 

Although there is no universal consensus as to the scale of production and use of chemical substances, it is estimated that the average annual world production of such substances is in excess of 450 million tonnes. Other estimates indicate that there are currently identified over five million distinct chemical compounds, with this number increasing at the rate of over a third of a million per year. Whilst many of these compounds are clearly not in everyday commercial or industrial use, it is estimated that at least 100,000 chemical substances can be considered to be in everyday use on a substantial scale, and that this number is being added to at the rate of at least several hundred per year, in the case of substances which are produced in quantities in excess of one tonne per year. 

The purpose of this section is to enable the reader to identify the potential stability properties of a chemical substance by simply analysing its structural formula. This will be made possible by listing the structural properties of unstable molecules. The reader will see the need to identify two types of structural properties those that bear the hallmarks of an unstable property and those whose presence can increase or alternatively reduce the risk of violent decomposition. Since the latter are the only ones in the molecule, they do not represent any danger for it in terms of stability. But when performing qualitative analysis, one also has to take into account the conditions under which the substance is handled. In addition to the structural properties, the analyst will have to carry out a study on the external risk factors. 

The lUPAC International Chemical Identifier (InChl ) is a nonproprietary identifier for chemical substances that can be used in printed and electronic data sources thus enabling easier linking of diverse data compilations. It was... 

The identification of chemical substances by examination of their spectra (singular, spectrum). Both infrared and ultraviolet spectroscopy are used in the study of rubber problems such as identifying the type of polymer or the nature of a contaminant. 

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