Identifying lead hazards

Children may be exposed to lead from other hobby or recreational activities that are not as obviously dangerous. For example, two case studies (one in North Carolina and one in Arizona) of lead poisoning in children from homes in which environmental surveys indicated no identifiable lead hazards have been reported. More extensive investigations revealed that both children had been observed on several occasions with pool cue chalk in their mouths. Subsequent chemical analysis of 23 different types of pool cue chalk identified three types as having lead concentrations in excess of 7,000 mg/kg (Miller et al. 1996). 

Viverette L, Mielke HW, Brisco M, et al. 1996. Environmental health in minority and other underserved populations Benign methods for identifying lead hazards at day care centers of New Orleans. Environmental Geochemistry and Health 18(l) 41-45. 

The purpose of a hazard tree is to identify potential hazards, define the conditions necessary for each hazard, and identify the source for each condition. Thus, a chain of events can be established that forms a necessary series of required steps that results in the identified hazard. This is called a hazard tree. If any of the events leading to the hazard can be eliminated with absolute certainty, the hazard itself can be avoided. 

A hazard tree is constructed by first identifying potential hazards. Starting with the hazard itself, it is possible to determine the conditions necessary for this hazard to exist. For these conditions to exist, a source that creates that condition must exist and so forth. Using this reasoning, a hierarchy of events can be drawn, which becomes the hazard tree. In a hazard analysis an attempt is made, starting at the lowest level in the tree, to see if it is possible to break the chain leading to the hazard by elimi-... 

In the process of identifying chemical health hazards, tlie near term and long tenn fate of tlie hazard should be incorporated into tlie analysis. Near-term concerns relate primarily to tlie release of the chemical into the enviromnent. This leads to the general subject area of e.xposure assessment, including routes of e.xposure - a topic that is treated in e.xtensive detail in Cliapter 12. However, tlie fate of the chemical (hazard) following tlie point of human entry is another consideration when attempting to identify health hazards. An overview of tliis topic is presented here... 

This section discusses how a runaway reaction occurs and lists some of the process deviations that can lead to such a runaway. Equipment for identifying potentially hazardous process steps is reviewed, and general principles for inherently safe process design are given. 

To identify the hazards of the EUC in all modes of operation, the event sequences leading to the hazards, and the EUC risks associated with the hazards have to be analyzed (methods are well known like FTA, FMEA, FMECA, etc.)... 

The Administrative Measure on the Control of Pollution Caused by Electronic Information Products (China-RoHS) entered into force in March 2007.85 The legislation is applicable to import, manufacture, and sale of products in China. Products for export are specifically excluded. Many product types that are not within the scope of the EU RoHS are within the scope of the China RoHS and vice versa. In addition, the initial disclosure, declaration, and exemption requirements for a RoHS certificate in China are different from the EU RoHS. The same six hazardous substances are regulated (lead, cadmium, chromium(VI), mercury, PBBs, and PBDEs, with the exception of deca-BDE). The China RoHS is likely to be upgraded to national regulation and to be amended in the future to potentially cover more products. More detailed materials testing is required in the China RoHS and is accepted only if performed by certified Chinese laboratories. A table in the product documentation must identify which hazardous substances are contained and which components are present. 

Figure 4.1 Hazard Analysis to Identify Leading Indicators (BP, 2008)...

Using the augmented control structure, the remaining activities in STPA are to identify potentially hazardous control actions by each of the system components that could violate the safety constraints, determine the causal factors that could lead to these hazardous control actions, and prevent or control them in the system design. The process thus involves a top-down identification of scenarios in which the safety... 

Create a periodic audit system on the safety of operations and the state of the plant. Audit scope might be defined by such information as the hazard analysis, identified leading indicators of risk, and past incident/accident investigations. 

Use the hazard analysis and documentation created during development and passed to operations to identify leading indicators of migration toward states of higher risk. Establish feedback channels to detect the leading indicators and respond appropriately. 

To prevent the undesirable consequences of accidents, hazards that can lead to accidents must be identified. Effective hazard identification and control require a systematic, comprehensive, and precise analysis of the process system and its operation. Once hazards are recognized, the adequacy of the mechanisms to control the hazards is evaluated. If control mechanisms do not exist or are inadequate, this must recognized and actions recommended. Several of the benefits of using a HAZOP are the ... 

This approach may help in achieving safety and safe behavior in a work group. The group identifies the hazards, analyzes them, and implements appropriate controls. Their collective knowledge leads to a better and safer operation. Various individuals may help others master the details of their group responsibility. 

One of the leading process safety experts Dennis Hendershot often says You cannot manage a hazard that you do not know exists. He follows up by saying that hazard identification is a critical first step, but it is only the first step. Identifying a hazard does not mean that the risk from the hazard will actually be properly managed, but at least you have a chance. I doubt that the business truly understood horrific potential that existed. 

Easy to use (requires less experience) Can be quick May be customized Cost effective Still somewhat limited by team experience Repetition may lead to errors Minimum level of hazard identification May not identify new hazards Custom checklists for specific industries, processes, and companies Best applied to processes where hazards are well understood... 

The hazard and operability analysis (HAZOP) technique was developed to identify both hazards and operability problems in chemical process plants. An interdisciplinary team and an experienced team leader are required. In a HAZOP application, a process or operation is systematically reviewed to identify deviations from desired practices that could lead to adverse consequences. HAZOPs can be used at any stage in the life of a process. 

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