Process hazards, knowledge

Hazards from combustion and runaway reactions play a leading role in many chemical process accidents. Knowledge of these reactions is essential for control of process hazards. It is important that loss of containment be avoided. For example ... 

While these responsibilities seem straightforward, there are numerous responsibilities that are intertwined and discrete. Both parties need to understand their individual responsibilities especially regarding process hazards, environmental concerns, communication, and technology/knowledge transfer. 

Parshall (1989) notes that product liability issues are complex and varied. An attorney knowledgeable in product liability issues may be an important contributor to process hazards discussions if such issues may affect the advisability of a proposed process chemistry. 

The use of any of the above techniques demands knowledge, experience, and flexibility. No prescriptive set of questions or key words or list is sufficient to cover all processes, hazards, and all impacted populations. As a research chemist reviews a chemistry and its potential application, there are advantages to maintaining an open mind when applying the various techniques designed to open up avenues of thought. The reader is referred to Chapter 7 for additional information and direction on the choice of process hazard review techniques. 

Designs should be based on knowledge of what the human body (and human nature) will do. Include educated operators in design reviews. The HAZOP methodology for process hazard analysis offers an excellent opportunity to identify design and procedural opportunities for inherently safer systems. After all, the OP in HAZOP stands for operability (COPS, 1992). For example, a safe start-up procedure that requires the operator to walk up and down the stairs three times to manipulate valves in the correct sequence can be made inherently safer by locating the valves so that operator has to walk up the stairs only once during the start-up. 

The evaluation of hazards in a process starts at the initial screening of the process parameters. Several technical issues that will need more attention will arise from this screening procedure. Hazard evaluation procedures, however, are no substitutes for engineering codes of practice and for design standards, but are used as supplementary ideas and concepts. A prerequisite for any process hazard evaluation is a full knowledge of the chemistry of the process (including potential unwanted side reactions) with supporting data. 

Document Chemical Reactivity Risks and Management Decisions Process Knowledge and Documentation Process Risk Management Process Safety Information Process Hazard Analysis Operating Procedures Operational Control... 

Risk assessment studies can be performed using whatever process information is available (CCPS 1992a). Obviously, the more information and knowledge that is available, the more thorough and valuable the risk study can be. For facilities that must meet regulatory requirements for process hazard analyses, certain process safety information (PSI) is required to be compiled and up to date before starting the analysis. 

Each of these considerations will not, of course, apply to every material and situation. To look at your operation in a systematic, rigorous way with a knowledgeable group of people, a process hazard analysis can be conducted. Books and outside consulting resources are available that can provide guidance and professional assistance when needed. 

Other avenues for increasing process safety knowledge exist. Previously unrecognized potential hazards and latent properties of materials are written about in industry and technical journals. Peer-reviewed research work in the area of process safety is published in several international scientific journals. Manufacturers and suppliers of process equipment often publicize previously unrecognized failure modes. Additional information on case histories can be found in Chapter 15. 

This Concept Series book supports several of the twelve elements of process safety enunciated in Guidelines for the Technical Management of Chemical Process Safety, including process knowledge and documentation, process risk management and enhancement of process safety knowledge. The purpose of the book is to assist designers and operators of chemical facilities to understand and reduce potential hazards associated with static electricity. 

Supported by the PSMT, the line organization develops a structured approach for performing process hazard analyses on a repetitive basis. One effective way to do this is to organize knowledgeable facility personnel into ad hoc Process Safety Review (PSR) teams. These teams, supplemented by outside specialists as required, are responsible for studying all processes, identifying all potential hazards, and recommending appropriate corrective or control measures. 

There are several points to be kept in mind when using physical testing as part of process hazard evaluation. First, the limitations of the test method should always be kept in mind. For example, it has been pointed out that different thermal stability tests give different exotherm detection temperatures. In most cases it is not possible to define an exact exotherm onset because the decomposition reaction s rate does not go to zero as the temperature is lowered. Overconfidence in test results can be just as much of a hazard as no knowledge at all if the limitations of the tests are forgotten. 

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