Zero accident rate

Nonprescriptive standards are, of necessity, performance-based because there is no external specific standard against which they can be assessed. Also, it is never possible to be in compliance. Ultimately, the only measure of success is success. Consequently, from a theoretical point of view, it is impossible to achieve compliance. The only truly acceptable level of safety is perfection. Yet, no matter how well run a facility may be a zero accident rate is a theoretically unattainable goal. Risk can never be zero. Indeed, if a facility operates for long enough, it is certain—statistically speaking— that there will be an accident. Therefore, management has to determine a level for acceptable safety. And because risk can never be zero, there are always ways of improving safety and operability. 

Encapsulation in containment vessels allows near zero emission rates to be reached in miniplants, e.g. by purging the reactor with an inert gas sent to a scrubber. This embedding of the miniplant should also dramatically reduce the risk of explosion or environmental contamination in case of an accident Even if modules of the miniplant are damaged or break, the robust encasement will be mechanically and chemically stable enough to prevent pollution. 

The hazard analysis of any industrial process impacts on risk assessment. Risk assessment involves the estimation of the frequency and consequences of a range of hazard scenarios and of individual and societal risk. The risk assessment process is shown in Figure 3.1. The risk criterion used in hazard analysis is the fatal accident rate (FAR). The FAR is defined as the number of fatalities per 108h exposure. The actual FAR in the U.K. was 3.5 in the chemical industry in 1975. No doubt the ideal FAR value should be zero, which is difficult to achieve in practice. 

The safety culture action principle, behavior based attitudes theory and accident triangle principles work together to promote the change of zero accidents concept to zero accidents objective from three indispensable aspects of idea , action and methods , as is shown in Figure 4. Three principles commonly guide zero accidents concept, which is one of the key elements of safety culture, to strengthen enterprise safety management, prevent accidents and lessen accident rate, as follows ... 

Zero accidents concept is very important for an enterprise to achieve zero accident objective and good safety performance. If all employees realize the importance of zero accidents concept, they will do well with every detail safety-related work, thus greatly reducing the accident rate to obtain better safety performance. 

Tests right before launch detected the zero roll rate, but there was no formal communication channel established for getting that information to those who could understand it. Instead, voice mail and email were used. The report is not clear, but either there was no formal anomaly reporting and tracking system or it was not known or used by the process participants. Several recent aerospace accidents have involved the bypassing of formal anomaly reporting channels and the substitution of informal email and other communication—with similar results. 

The way towards a zero-accident culture is long and diflicult in the constmction industry. Parallel to declining accident rates, the improvement gets more challenging, and from time to time there may appear increasing of losses. Prevention is first and foremost a human affair. Both managers and employees need to be continuously awakened and aware of the hazards and develop new ways to improve... 

In the first case, the pursuit of absolute safety, the concern is for the value of the numerator N, where N represents the number of a certain type of events, for instance accidents, incidents, injuries, lost time injury, unplanned outages rejection rate, etc. The goal is to reduce N to as small a value as is practicable, preferably zero if that is possible. In the pursuit of absolute safety, there is no concern for the number of complementary events, i.e., the number of cases where N does not occur. For example, if N is the number of times per year a train passes a red signal (SPAD), then the number of complementary events is the number of times during the same time period that a train stops at a red signal. Having N=0 as the ideal in practice means that safety is defined as the freedom from risk rather than as the freedom from unacceptable (or unaffordable) risk. The difference is by no means unimportant. 

Consider a distillation column whose heat input is being controlled in ratio to the feed rate. Throughout the normal operating range, this ratio would be maintained. But even if the feed should drop to zero, heat input must not, because it could cause loss of liquid in the trays. An excessively high heat input is also to be avoided, because flooding of the tower could result. To avoid the possibility of these accidents, high and low limiters can be used, as illustrated in Fig. 6.18. 

Condition I is obvious— with no activity of the population there should be no road deaths. Condition II goes back to Vision Zero (Tingvall, 1998) which means no fatalities in road accidents. Condition III takes account of the fact that there is a breakpoint within the series of road fatality rate numbers as a country develops. 

Current HSE fatality data indicates a UK rate of 10 (one fatality for every 10,000 actively employed construction workers per year). So actual fatalities due to construction activity do not appear to be unreasonable in relation to the HSE s tolerability limit. While zero fatality must always be the prime health and safety objective, the current level of fatalities taken alone, would not require that a special risk assessment be undertaken. Deaths arising from construction activity may not be at intolerable levels, but the position in regard to non-fatal accidents, both those causing major injuries and over-3-day injuries, is rather different. Current data here shows major incidents at an annual level of 10 (one major injury for every 1,000 actively employed construction workers per year). The data for over-3-day incidents indicates an annual level of 10 (one over-3-day injury for every 100 actively employed construction workers per year). 

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