Control of the Hazard

The subsequent step is to identify the various scenarios which could cause loss of control of the hazard and result in an accident. This is perhaps the most difficult step in the procedure. Many accidents have been the result of improper characterization of the accident scenarios. For a reasonably complex chemical process, there might exist dozens, or even hundreds, of scenarios for each hazard. The essential part of the analysis is to select the scenarios which are deemed credible and worst case. 

Significant experiences (both positive and negative) documented or communicated so that potentially affected operations could make changes to management practices or the conduct of operations, eliminating the hazard or helping with control of the hazard... 

The levels of PPE discussed provide controls of the hazardous substance based on the degree of worker exposure. As we have discussed before, PPE is only acceptable as a hazard control measure in the following situations ... 

Heat transfer is a very widely used operation in chemical processing. Both heating and cooling affect the controllability of the hazards inlierent in chemical processing. Heat transfer equipment can produce temperatures ranging from -455 to 4000 F. 

Control of the hazards for example, by containment of flammable and toxic materials. 

Control of the hazard could well involve bunding the plant area so that any spills are contained. If the bunds slope to sumps or catch-pits, the surface area available for burning will be reduced. Other important control mechanisms will probably depend on the use of remotely operable shut-off valves on key pipelines (to stop the supply of fuel to any fire, and remotely operated because nobody will want to approach a fire to close valves manually). 

Control of the hazards by the most appropriate means for example, containment, substitution, improved maintenance, etc. 

However, potentially affected citizens may look at these quantitative descriptors as only partially describing the risk. They may consider a number of other factors such as the voluntariness, catastrophic potential, familiarity, and controllability of the hazard. Thus, contrary to the scientist, they may consider the one in a million risk to be more serious than the one in a thousand risk. Government officials are often reminded of this at public meetings, when people who smoke express great concern about very low levels of environmental contaminants which pose much lower health risks than smoking. 

Of partieular note in this ehapter are the hazard identification requirements sinee successful control of the hazards of ehemieals and ehemieal produets begins with the timely and aeeurate identification of those... 

The Occupational Safety and Health Review Commission (OSHRC) initially addressed the employer-employee relationship shortly after the OSH Act was enacted in the case titled Gilles v. Cotting, Inc. In this case, two employees of the primary contractor were killed in an accident created by and resulting from the actions of a subcontractor. OSHA issued one citation to the primary contractor and one citation to the subcontractor. OSHA subsequently vacated the citation to the primary contractor, finding the citation was improper and would impose liability outside the employment relationship. Over the years, the OSHRC, as well as the various federal Circuit Courts of Appeal, has addressed this issue primarily in the construction area, with focus on creation of the hazard and control of the hazard. In recent decisions and with the inception of the multiemployer woiksite rule, the scope of the duty to safeguard employees at the worksite has been substantially expanded."... 

Identify the hazards to determine the necessary controls of the hazards. 

HAZID calls for good participation from workforces but it is not possible to involve all, therefore discussion points may be circulated and feedback can be obtained. This feedback could be in the form of training and control of the hazards present. In this way, the workforce can be involved. The workforce may be involved in the following cases by sharing data and receiving feedback from them ... 

Hazard Control References cite any standards or norms that relate to the control of the hazard. The references will assist you in identifying which standards are the... 

Decisions at higher levels propagate down the hierarchy, and information about the current state of affairs propagates up the hierarchy. The interdependencies among the levels of the hierarchy are critical to the successful functioning of the system as a whole. If instructions from above are not formulated or not carried out, or if information from below is not collected or not conveyed, then the system may become unstable and start to lose control of the hazardous process it is intended to safeguard. 

In pre-industrial society, human muscles accounted for much of the energy used in production of goods and services. The individual and the work group had hands-on control of the hazards associated with these energies. At the same time, humans were at the mercy of nature and its hazards, as represented by weather extremes, wild animals, etc. Accidents were viewed as a phenomenon beyond human control. They were determined by fate or were a punishment for sin. 

Hakkinen (1958) presented a study on Finnish bus and tram drivers, in which the control of the hazards over a longer period of time was accomplished. The aim of Hakkinen s study was to investigate the value of certain psychological tests for detecting various levels of accident proneness. A group of 322 bus drivers and a group of 363 tram drivers exposed to the same traffic conditions for up to eight years were the subjects of this study. 

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