Hierarchy of controls

There are several steps which iadividuals and corporations can and should take to minimi2e the consequences of ha2ard occurrence, as well as risk to employees and the pubHc. Much of the legislation has adopted a hierarchy of controls that essentially fall iato two categories, ie, engineering and administrative (43,44). 

Figure 1. Hierarchy of control of gene expression. A total of about 50,000 to 100,000 genes are necessary to encode a mammal, most of which encode housekeeping, structural component, or terminal differentiation gene products. Transcription factor genes regulate expression of the lower-level genes and are in turn controlled by other upper-level transcription factors.

Hundreds of biochemical reactions take place even in the cells of relatively simple microorganisms. Living systems have evolved a sophisticated hierarchy of controls that permits them to maintain a stable intracellular environment. These controls ensure that substances required for maintenance and growth are produced in amounts that are adequate without being excessive. Biochemical controls have developed in such a way that the cell can make adjustments in response to a changing external environment. Adjustments are needed because the temperature, ionic strength, acid concentration, and concentration of nutrients present in the... 

Escherichia coli carries about 3,000 genes. Only a small fraction of the genome is actively transcribed at any given time. But all of the genes are in a state where they can be readily turned on or turned off in a reversible fashion. The level of transcription is regulated by a complex hierarchy of control elements. 

It seems likely that the pivotal events in the evolution of a differentiated cell reflect changes in gene expression that result from a complex hierarchy of controls. The key to understanding differentiation, therefore, is to identify the regulatory factors responsible for the controls involved in differentiation and to explain how they act. 

Follow the hierarchy of control to ensure that exposures are prevented or adequately controlled... 

Once the precautions that are needed to control exposures are determined, the next step is to compare the level of controls needed against what controls are already in place. There frequently are multiple control strategies that will minimize the potential for exposure. The determination of which control strategy is the best to use is determined by the hierarchy of control principle. Our particular approach to managing risk is to use this hierarchy to evaluate possible risk management approaches for a specific project in conjunction with a modified layer of protection analysis (LOPA) approach.5... 

Compliance with the Carcinogens Directive requires the employer to assess the risk of exposure, and the nature and degree of that risk. The hierarchy of control mechanisms, in descending order of preference, is ... 

Suitable risk control measures must be develqred and used. The hierarchy of control measures, from most to least preferred is ... 

Based on the identified hazards and standards set, controls are developed to ensure safe operating conditions. The control of chemical hazards is, in general, no different than controlling other hazards, i.e., radiological hazards. An integrated process to identify and apply the hierarchy of controls (engineering, administrative, and personal protective equipment), including pollution prevention/waste minimization options, should be in place as part of the site s ISMS. 

The control of chemical hazards at SNL is documented in the Primary Hazard Screen and Hazard Analysis process for every project or facility. Work-specific technical work documents provide more detailed chemical hazard controls. Hazard control is based on the hierarchy of controls engineering controls first, administrative controls next, and personal protective controls last. ES H subject matter experts provide input on appropriate controls to chemical users and their management. 

By describing accidents in terms of a hierarchy of control based on adaptive feedback mechanisms, adaptation plays a central role in the understanding and prevention of accidents. 

Some of the questions asked in following this hierarchy of control are ... 

A comparison of the ILO/OSH and the OSHA provisions for hazard prevention indicates that the ILO/OSH Guidelines are somewhat more detailed. They relate to both hazards and the risks that derive from them, and set forth actions to be taken in what originated in the United States as a hierarchy of controls, applied in an order of effectiveness. 

The hierarchy of controls should be used to reduce hazards in the workplace. Agree... 

Behavior-based safety does not recognize the most effective method of controlling hazards, which is through the application of the hierarchy of controls [p. 7]. (See The Safety Decision Hierarchy in Innovations in Safety Management Addressing Career Knowledge Needs.)... 

If the problem is behavioral, then behavioral solutions are appropriate. But if the problem is systemic, the proper thing to do is to apply tried and tested concepts of problem solving, within which the hierarchy of controls is interwoven. 

Risks are avoided, eliminated, or minimized through good engineering design. Basic methods used to prevent worker exposure to harmful chemical, physical, or biological agents by means of material substitution, equipment isolation, and material removal. Traditionally, a hierarchy of controls has been used as a means of determining how to implement feasible and effective controls. One representation of this hierarchy can be summarized as follows ... 

Organizations must use the concept known as hierarchy of controls to reduce, eliminate, and control hazards or hazardous processes. Hazard controls can also include actions such as using enclosure,... 

The third step is identifying, analyzing, and implementing risk controls. Important here are the priorities for controls, listed in Table 3-2. This list is called the Hierarchy of Controls. ... 

TABLE 3-2 Priorities for Hazard Controls the Hierarchy of Controls... 

It is worth discussing the workplace safety and health concept developed and implemented in the United Kingdom. Some of the Commonwealth countries, particularly Australia, have adopted this concept as well. The concept reduces the amount of regulation for safety and health details by the government. The concept relies on risk analysis and the hierarchy of controls (see Table 3-2) for companies, employers, and workers. It contrasts with the approach in the United States in which government agencies, such as... 

Australia adopted this approach with the National Occupational Health and Safety Strategy in 2002. The strategy involved the Commonwealth, six states, and two territories. A publication by Safe Work Australia illustrates how to manage workplace safety and health under the overall approach. The implementation extends to worker levels using risk analysis and the hierarchy of controls. Figure 5-1 provides an example of a worker-level card to help in decision-making. 

Table 3-2 introduced the choices for controlling hazards and the preferred order for controls. Recall that those choices and their order are called the Hierarchy of Controls for hazards. Some also refer to Table 3-2 as the Order of Precedence. This chapter will explore the hazard control choices further. 

A hazard control mentioned in several previous chapters is personal protective equipment. There are many activities requiring personal protective equipment (PPE) as a primary control. In the hierarchy of controls concept (Chapter 9), PPE is the last resort if one cannot eliminate or manage hazards. PPE applies when other engineering and administrative controls do not work and hazards remain. 

Although inherently safer technology (1ST) is the most effective major accident prevention approach in the hierarchy of controls, it is not enforced by the EPA through the General Duty Clause under die Clean Air Act" [25]. 

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