Hazard triangle

Preventive Explosion Protection The principle of preventive explosion protection comprises the reliable exclusion of one of the requirements necessary for the development of an explosion. In pictorial terms, therefore, at least one of the sides of the hazard triangle shown in Figure 26-33 will be broken open. 

FIG. 26-33 Hazard triangle principle of preventive explosion protection. 

Another way to technically define a hazard is A hazard is a set of inactive conditions, which consist of a Hazardous Source, an Initiating Mechanism and a Target-Threat Outcome, which leads to a mishap when the Initiating Mechanism is actualized. A hazard is a physical entity that characterizes a potential mishap. A hazard is a condition that is prerequisite to a mishap that is, it is a blueprint for a mishap. When a hazard exists, a hazard triangle is created (see discussion below). 

These three required components ot a hazard form what is known as the hazard triangle, which is illustrated in Figure 2.35. The hazard triangle conveys by the idea that a hazard consists ot three necessary and coupled components, each of which forms the side ot a triangle. All three sides of the triangle are... 

See Hazard and Hazard Triangle for additional related information. 

If any side of the hazard triangle is eliminated through risk mitigation techniques, the hazard and its associated risk are also eliminated. 

If none of the hazard triangle sides can be eliminated, the hazard UkeU-hood and/or severity must be controlled. 

The SSHA hazard column does not have to contain all three elements of a hazard HS, IMs, and TTO. The combined columns of the SSHA worksheet can contain all three components of a hazard. For example, it is acceptable to place the HE in the Hazard section, the IMs in the Cause section, and the outcome in the Effect section. The Hazard, Causes, and Effects columns should together completely describe the hazard. These columns should provide the three sides of the hazard triangle. 

Every identified hazard should have at least one corresponding SSR, as a minimum, which either eliminates or mitigates the hazard. Some hazards may require multiple SSRs for elimination or mitigation of the hazard. An SSR is the methodology by which system safety influences the design, and is thus the basis for the term DFS. SSRs relate very closely with the hazard triangle for... 

ISA RP 12.6. 1987. Installation of Intrinsically Safe Systems for Hazardous (Classified) Locations. (ANSI approved.) Instrument Society of America, Research Triangle Park, N.C. 

Cupitt LT. 1980. Fate of toxic and hazardous materials in the air environment. Research Triangle Park, NC U.S. Environmental Protection Agency, Office of Research and Development. EPA-600/3-80-084. NTIS No. PB80-221948. 

Magison, E.C., Electrical Instruments in Hazardous Locations. Third Edition, ISA, Research, Triangle Park, NC, 1978. 

Singh HB, Salas El, Smith A, et al. 1980. Atmospheric measurements of selected hazardous organic chemicals. Report to U.S. Environmental Protection Agency, Environmental Sciences Research Laboratory, Research Triangle Park, NC, by SRI International, Menlo Park, CA. 

Fig. 1. Triangular spacing between the major process components. Offices, control rooms, maintenance, and similar departments should be located outside the triangle. Distances A, B, and C should be carefully selected based on the nature of the process and local conditions. U, Loading and unloading zone for hazardous materials P, process plant S, storage space for hazardous materials.

US Environmental Protection Agency (1994) Technical Background Document to Support Rulemaking Pursuant to the Clean Air Act C Section 112(g). Ranking of Pollutants with Respect to Hazard to Human Health. EPAB450/3-92-010. Research Triangle Park, NC Emissions Standards Division, Office of Air Quality Planning and Standards. 

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