Hazard study 2 guidelines

This guide outlines a typical method for carrying out a process hazard study level 2 for a new or existing chemical process plant. It is based on guidelines originally prepared by IC I in the UK. For a more comprehensive treatment of hazard study procedures reference should be made to the hazard study guides listed in this book. 

Finally we take a look at some methods of determining SILs that may be used in the course of arriving at the SILs for each individual safety function. Various methods for determining SIL requirements have been developed in the past and most of these have now been captured into the lEC and ISA standards in the guideline sections. It s a subject that causes considerable difficulties in organizations, perhaps because it is not an exact science and there can be a lot of expense at stake. These methods depend on the quality of information flowing from the hazard studies and thus provide continuity in the safety life cycle. 

Use the hazard study 2 guidelines in Chapter 3 to identify potential risks. The study team should apply the guide diagram 1 to identify possible hazards and basic causes. Use guide diagram 2 to identify possible consequences. 

Humans and DomesticHnimals. Data from toxicology studies are used to evaluate hazards to humans from the use of pesticides (40 CFR 158.340 and Subdivision F Guidelines). 

Landfill leachate or gas condensate derived from listed waste. Landfill leachate and landfill gas condensate derived from previously disposed wastes that now meet the listing description of one or more of the petroleum refinery listed wastes would be regulated as a listed hazardous waste. However, U.S. EPA temporarily excluded such landfill leachate and gas condensate from the definition of hazardous waste provided their discharge is regulated under the CWA. The exclusion will remain effective while U.S. EPA studies how the landfill leachate and landfill gas condensate are currently managed, and the effect of future CWA effluent limitation guidelines for landfill wastewaters. 

As the project progresses, more information is available therefore, the review technique used can be different at each stage of the project. The use of various hazard evaluation techniques, such as checklist analyses, relative rankings, what-if analyses, and hazard and operability studies, is documented in Guidelines for Hazard Evaluation Procedures Second Edition with Worked Examples (CCPS, 1992). The need to use more quantitative techniques for hazard evaluation may be identified during these reviews, and become an action item for the project team. 

Bloom, A. D., Ed. "Guidelines for Studies of Human Populations Exposed to Reproductive Hazards " March of Dimes Birth Defects Foundation New York, 1981, passim. 

Regulatory guidelines require that there be maternal toxicity at the highest dosage level in embryo-fetal developmental toxicity studies. It is important to avoid excessive toxicity in these studies since it is known that marked maternal toxicity can cause secondary developmental toxicity (see discussion in Section 8.4.3, Association between Developmental and Maternal Toxicity ). This secondary developmental toxicity is irrelevant to the assessment of the developmental hazard of the test agent and thus simply confounds the interpretation of the data. 

A site specific study is the most comprehensive approach. Site specific studies to identify and quantify explosion hazards are usually conducted by the owner s process safety specialist or by specialty consultants. There are several steps which need to be taken, each of which may be done in a variety of ways. The steps are outlined below with some of the available methods. More detailed information is available in CCPS Building Guidelines and API RJ -752. 

Other examples of inductive tools that have limited application in incident investigation include failure mode and effects analysis (FMEA), hazard and operability study (HAZOP), and event tree analysis (ETA). These are detailed in the CCPS book, Guidelines for Hazard Evaluation Procedures... 

As mentioned previously, there are no test guideline methods for respiratory irritation. Good data, often clearly related to exposure levels, can be obtained on respiratory and mucous membrane irritation, from well-designed and well-reported inhalation studies in animals. Also the Alarie test (Alarie 1973, 1981), an experimental animal test assessing the concentration that results in a 50% reduction of the breathing frequency, may provide useful information on sensory irritation of the upper respiratory tract and the results may be used for hazard identification. 

In the hazard assessment, it is important to evaluate the toxicological database with regard to its adequacy. The adequacy of a study includes its validity and its relevance. The relevance refers to what has been studied in relation to what is needed for the hazard and risk assessment, and the validity refers to how the study was performed, e.g., conforming with a particular test guideline. The validity and the relevance of a study, or a whole database, has to be considered in relation to the reliability and thus the confidence. The data for hazard assessment are described in detail in Chapter 3. 

In the REMARK system, estimated effects (e.g., hazard ratios) with confidence intervals for the marker were recommended for univariant and key multivariable analyses, and a Kaplan-Meier plot was recommended to represent the effect of a tumor marker in a time-to-event outcome. The discussion section should interpret the results in the context of the pre-specified hypothesis and describe limitations of the study as well as implications for future research and clinical value. These guidelines were advocated for reporting of tumor marker studies in breast cancer research and treatment (63). 

Bloom AD (1981) Guidelines for reproductive studies in exposed human populations. Guideline for studies of human populations exposed to mutagenic and reproductive hazards. Report of Panel II. White Plains. New York, March of Dimes Birth Defects Foundation, pp 37-110. 

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