Hazard study 2 guidelines method

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. 

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. 

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. 

One effective method of obtaining information about zinc metabolism Is the use of radioactive tracers to study absorption, kinetics and body distribution following oral administration. Of course, as in all cases in which radionuclides are administered to human subjects, the hazard of such administration must be considered and balanced against the value of information expected from the study. The administered activity should be as low as possible consistent with obtaining adequate measurements. The studies reported here were carried out in accordance with approved protocols which followed relevant guidelines for studies of human subjects and with the informed consent of the participating subjects. 

Many hazards may be identified and controlled or eliminated through use of qualitative hazard analysis as defined in Guidelines for Hazard Evaluation Procedures, Second Edition (AICHE/CCPS, 1992). Qualitative studies typically identify potentially hazardous events and their causes. In some cases, where the risks are clearly excessive and the existing safeguards arc inadequate, corrective actions can be adequately identified with qualitative methods. CPQRA is used to help evaluate potential risks when qualitative methods cannot provide adequate understanding of the risks and more information is needed for risk management. It can also be used to evaluate alternative risk reduction strategies. 

Among the petrochemical industries the increasing concern in safety, led to one of the major industries, the British company ICI, in 1963, to put in place the conception of an analytical method that would allow the study of possible hazards and operability problems, in order to eliminate or correct them, thereby making the facilities and the respective operation safer (Kletz, T. 1999). Since then, this method named as HAZOP (hazard and operability study), has evolved to became the reference for the sector. The International Electrotechnical Commission published lEC 61882 2001—Hazard and operability studies (HAZOP) Application guide, providing guidelines, which became a benchmark since then for the preparation those studies. 

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