Chemical process safety properties

FIG. 23-3 The relationship between the various flammability properties. (D. A. Cro-wl and J. F. Louvar, Chemical Process Safety Fundamentals with Applications, 2d ed, 2002. Adapted by permission of Pearson Education, Inc., Upper Saddle River, N.J.)... 

In an ideal world, an easy-to-contact, responsive modifications man would be available for questions generated in Operations, Engineering, and Maintenance. This modifications man could be a Process Safety Engineer, Loss Prevention Engineer, or a mechanical or chemical engineer who has been trained in chemical process safety. Preferably, this individual would be an on-site plant employee, but he could be a company regional engineer, a property insurance consultant, or a contractor. The modifications man must understand basic loss-prevention principles of proper layout. 

As per the Center for Chemical Process Safety (CCPS), hazard is defined as, an inherent or physical characteristics that have potential for causing damage to people, property or environment, it is the combination of a hazardous material, an operating environment, and certain unplanned event that could result an accident. ... 

However, compared with the traditional analytical methods, the adoption of chromatographic methods represented a signihcant improvement in pharmaceutical analysis. This was because chromatographic methods had the advantages of method specihcity, the ability to separate and detect low-level impurities. Specihcity is especially important for methods intended for early-phase drug development when the chemical and physical properties of the active pharmaceutical ingredient (API) are not fully understood and the synthetic processes are not fully developed. Therefore the assurance of safety in clinical trials of an API relies heavily on the ability of analytical methods to detect and quantitate unknown impurities that may pose safety concerns. This task was not easily performed or simply could not be carried out by classic wet chemistry methods. Therefore, slowly, HPLC and GC established their places as the mainstream analytical methods in pharmaceutical analysis. 

Water has several anomalous features (e.g., density, being the only nontoxic and liquid "hydride" of the non-metals, melting point varying with pressure, etc.). Of direct importance for the aqueous biphasic process are the physiological (entries 2 and 4 of Table 5.1), economic (1,3,6,9), ecological/safety-related (2,3,4,9), process engineering (1,6,7,9,10,11,12), and chemical and physical properties (1,5,6,8,11,13) of water. The different properties interact and complement each other. Thus water, whose high... 

The safety of a chemical process can be achieved through internal (inherent) and external means. The inherent safety (Kletz, 1984) is related to the intrinsic properties of the process e.g. the use of safer chemicals and operations. The essence of the inherent safety is to avoid and remove hazards rather than to control them by added-on protective systems, which is the principle of external safety. The largest payoffs are achieved by verifying that inherent safety has been considered early and often in the process and engineering design (Lutz, 1997). 

The Chemical Inherent Safety Index deals with the hazards which are related to the chemical properties of substances in the process. The Index has been divided into subindices for reaction hazards and hazardous substances. 

In addition to the factual findings of the investigation, this incident helps to illustrate the importance of process safety information. AVhen unusual or unprecedented situations are encountered, every effort should be taken to understand the chemical properties and behavior of chemical substances before attempting their removal. The adhesive properties of the fly-ash/lime mixture were obviously affected by water and this led to a large release and structural failure. Had the development of formal procedures been attempted, the knowledge gap might have been identified and a dif-... 

Physico-chemical properties and evaluation of potential safety liabilities are important aspects of the library design process. Predicted properties like hERG liability (45), compound aqueous solubility, etc. (46-48) have been extensively studied and included in various library design strategies (49, 50) as a part of multiple constraints optimisation. We have therefore further extended the ProSAR concept to take the library property profile into account in the design process. Several in-house calculated properties are considered these include a compound novelty check (that checks in in-house and external compound databases to see if the compound is novel), predicted aqueous solubility... 

There are two aspects of this program that will effect the research and development investment decision. First, the costs of premanufacture notification (including testing costs) will increase the investment in R D necessary to develop and market new chemicals. The health and safety properties of a chemical must now be considered an intrinsic part of the new chemical development process, right alongside consideration of the substances commercial properties. Both are equal parts of the "total product". Tb the extent that this results in increased testing for health and environmental effects, the amount of investment required to achieve a given level of output from R D will also rise. 

Detailed safety checklists appear in books by Fawcett and Wood (Chap. 32, Bibliography 1.1, Part E) and Wells (pp. 239-257, Bibliography 1.1, Part E). These books and the large one by Lees (Bibliography 1.1, Part E) also provide entry into the vast literature of chemical process plant safety. Lees has particularly complete bibliographies. A standard reference on the properties of dangerous materials is the book by Sax (1984) (References, Section... 

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