Hazardous substances process safety

Melhem, G. A., and E. S. Shanley. 1997 On the Estimation of Hazard Potential for Chemical Substances, Process Safety Progress, 15(3), Pall. 

Highly Hazardous Chemical - Toxic, reactive, flammable, or explosive substances, as defined in Appendix A of 29 CFR 1910.119, "Process Safety Management of Highly Hazardous Chemicals."... 

Safety PI may drastically increase the safety of chemical processes. It is obvious that smaller is safer. For instance, material inventories will be lower, which is safer in case of hazardous substances. Moreover, keeping processes under control is easier because of PI, for instance, by efficient heat removal from exothermic reactions. 

Chemiefabrik in der Grojie eines Chips, Handdsblatt, May 1996 Vision of shoe box-sized micro reactors plant cells as model for micro-reactor development cost, performance, and safety advantages LIGA process numbering-up safety processing of hazardous substances [237]. 

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. 

The research described in this thesis deals with safety management in complex and high-risk organizations. Companies in the chemical process industry handling hazardous substances are chosen as the subject of study. In particular this thesis will focus on the current safety indication process, and how this safety indication process works and its shortfalls. An unreliable indication process, leads automatically to wrong reactions and measures to prevent possible accidents. Increased understanding of this process helps in providing a better basis from which effective measures to prevent accidents can be derived. 

In this research, the main focus is safety in a chemical company handling hazardous substances. The risks of accidents or other events during processes involving hazardous substances (flammable, toxic, or explosive) or activities where extreme conditions are used (like high/low pressures or high/low temperatures), are subject of this research. Process safety is the absence of risk from events with these hazardous substances and activities with extreme conditions. Non-process safety or process risk is often measured by accidents, incidents and near misses and this concept will be discussed in the following sub-Section. 

From Chapter 1 it appeared that all the existing safety management systems and tools cannot prevent accidents with hazardous substances in the chemical process industry. In this Chapter, the most commonly used safety indicators will be analysed to derive the set of deviations used for indicating. These deviations are then compared with deviations present in an accident trajectory prior to recent accidents. The differences between the two sets of deviations are then discussed to indicate why accidents still occur. These differences show shortcomings in current safety indicators and are used to set the criteria for a new safety indicator. 

NFPA developed Standard 704 as a tool for identification and evaluation of potential hazards during emergency response, not for application to chemical process safety. The instability rating is a part of this standard. It was not intended to be used to measure reactivity, but rather to measure the inherent instability of a pure substance or product under conditions expected for product storage. The instability rating does not measure the tendency of a substance or compound to react with other substances or any other process-specific factors, such as operating temperature, pressure, quantity handled, chemical concentration, impurities with catalytic effects, and compatibility with other chemicals onsite. 

CSB found significant gaps in OSHA process safety regulations designed to protect workers from highly hazardous chemicals, including reactive hazards. OSHA standards cover the hazards of some classes of substances, such as flammable and combustible liquids however, no OSHA standard specifically addresses reactive hazards. 

RMP requires covered processes to have a hazard assessment, a prevention program, and an emergency response program. The hazard assessment must evaluate the accidental release of regulated substances, including the worst case scenario. RMP contains requirements for prevention of accidental releases, which include the same basic elements as the OSHA PSM Standard. Therefore, the limitations described in Section 5.1.2.2 with respect to process safety information and process hazard analysis also apply to RMP. 

One of the best ways to determine that potential is to examine the Material Safety Data Sheets (MSDS), which by law in most jurisdictions must be provided by the manufacturer for any hazardous material used in the workplace and made available to the employees by plant management. The MSDS provides all the information necessary to determine the hazard potential and the requirements for control of any hazardous substance. Still other information can be found in the various guidelines published by the American Industrial Health Association, or by the U.S. National Safety Council, or by NIOSH (the U.S. National Institute for Occupational Safety and Health) or various other national, state, or provincial government bodies. (See Appendix II for information on sources.) Once you have an inventory, of course, you can start relating potential health problems to possible sources in particular areas. Also, in the process of preparing this report, you will begin to build an invaluable library that will stand you in good stead for further consideration of the problems at hand. 

The economic framework conditions for hazardous substance substitution have thus also changed considerably in the course of the past twenty years. Many commodities are produced today in globally organised supply chains the origin, quality and application conditions of process chemicals and product components is complex. Developing appropriate management systems for product quality and product safety requires considerable organisational innovation by the companies involved. 

In the 13 case studies documented processes and experiences of attempts to substitute hazardous substances in the 1980s and 1990s were examined. The aim of the choice of cases was to cover a wide spectrum of substitution conditions consumer-close and consumer-remote products, product auxiliary materials and process auxiliary materials, SMEs and large-scale industiy, environment, consumer and occupational health and safety subjects, technical and organisational iimova-tions. 

Hazardous substances—Safety measures. 2. Hazardous substances—Environmental aspects. 3. Chemical industries—Safety measures I. American Institute of Chemical Engineers. Center for Chemical Process Safety. 

The Occupational Safety and Health Administration s (OSHA) Hazard Communication Standard (29 CFR 1910.1200) of 1986 requires that employers at manufacturing facilities, and any other work place where toxic chemicals are handled or processed, be provided Material Safety Data Sheets (MSDS) for aU hazardous substances used in their facility, and to make these MSDSs available to all employees potentially exposed to these hazards. 

Commonly reported near misses include such events as exceeding operating limits, a release of a chemical or other hazardous substance that does not meet the threshold for a process safety incident metric, activation of relief valves, interlocks, or ruptured disks. Companies may establish near-miss metrics based on the specifics of their operation, based on their observations of frequent upsets or failures, or to track and correct observed unsafe practices or behaviors. 

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