Potential Outcomes

When EPA rejects a request for a correction, it sends the submitter a denial letter with the reasons for the denial. In some situations, EPA will specify what additional information will be needed for it to reevaluate the request, and a second submittal may lead to an acceptance. If the correction is accepted, the correct substance identity is considered to be legally included in the TSCA Inventory retroactively to the time of the initial Inventory, or to the time when the substance was placed on the Inventory through submission of a Notice of Commencement. When an Inventory correction is accepted, the erroneously listed chemical remains on the Inventory until EPA makes a formal Federal Register announcement of its removal from the Inventory to avoid disrupting commercial activity by the unpublished deletion of a chemical listing upon which some companies may be relying. 

An example of the process through which substances might be removed from the Inventory can be illustrated by a proposed delisting of 38 substances 

Williamson E-mail. The e-mail makes this statement with respect to the initial Inventory only, but later adds that the corrections process has been adapted to deal with substances that were put on the Inventory by the PMN route. 

After reviewing the nine comments submitted in response to its announcement, EPA determined that two of the substances should not be removed from the Inventory because they had been in commercial production or importation prior to October 24,1994. The other 36 substances were deleted from the TSCA Inventory as of June 27,1995.  

While not an Inventory correction, and not involving removals of chemicals from the Inventory, the EPA provided similar relief to affected industry members in the case of monomer acid and its derivatives and Tall Oil Fatty Acid and its derivatives. The EPA concluded that it, and not a private party, had erroneously equated monomer acid with Tall Oil Fatty Acid in a 1985 letter to industry, and manufacturers had relied on the Inventory listings for 

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To determine the risk from a particular initiating event, the potential outcome or consequence of the event and the frequency of the outcome are... 

Figures 5-3 and 5-4 illustrate the potential outcomes of a gas and liquid release, respectively (CCPS, 2000). Unconfined vapor cloud explosions...

The warning icon points to a procedure or potential outcome that can be dangerous. We call it our Don t-Try-This-At-Home icon. 

Herein lies one of the difficulties of synthetic planning. We tend to learn organic reactions in the forward direction—that is, reactants A and B give product C. This type of information handling is a convergent process in that a set of conditions is imposed which leads to a limited number of potential outcomes—in most cases a single product ... 

However, no specific method of reducing heart failure is addressed, and heart failure itself has many potential outcomes. On the other hand, if the problem is addressed more narrowly, a more narrowly defined objective could be studied. For example, one may look to reduce the number of heart failure exacerbations related to noncompliance with medications. Additionally, other specific objectives may be included, such as increasing the quality of life of patients with heart failure, reducing the number of medications used by patients with heart failure, or making patients more aware of behavioral and dietary modifications related to heart failure. 

The U.S. EPA Design for Environment (DfE) program is in place to work in partnership with a broad range of stakeholders to better understand the environmental health and safety aspects of materials.92 One potential outcome of this is to reduce risk to people and the environment by preventing pollution. Three of the EPA s DfE programs include or are focused on flame-retardants. They include the following ... 

Risk management reviews the information and findings from risk appraisal (risk assessment and concern assessment) and the results and conclusions from tolerability and acceptability judgment (risk characterization and evaluation), in order to assess, evaluate and select appropriate risk management options. Starting point for risk management are three potential outcomes ... 

Four-patch models were also examined for sensitivity to initial conditions. The arrangements examined were a linear four-patch arrangement and a three-patch circular arrangement with the fourth patch attached to one patch of the circle as a tail (Figure 11.24). Other than the arrangement of the patches, all other features are the same as in previous models with degradable toxicants. End patches were dosed. A series of simulations was performed to examine the importance of initial population size upon the frequencies of potential outcomes. Initial population sizes for each of the patches were 100, 75, and 50 for simulations one, two, and three, respectively. 

Patterns should be in common. Although exact prediction may be problematic and the idea of recovery an illusion, certain patterns should be detectable. The increase in tolerance, often observed as pollution-induced community tolerance, is one such example. Several potential outcomes may be possible, but not every outcome. Perhaps, as a better understanding of the assembly of ecosystems develops, we can even predict the probabilities of the outcomes. Prediction of ecological impacts will resemble more the weather forecast than the Newtonian dynamics. 

Due to the complex nature of population modeling, it can be difficult to foresee all potential outcomes and prespecify the corresponding strategies. If some unexpected outcomes that were not prespecified occur, it may be best to decide on a solution as close as possible to one that would have been prespecified. An alternative could be conducting several reasonable analyses and examining the robustness of the conclusions. This might be fine in some circumstances, however, the number of analyses could easily become impractical and arguably inflate Type I error. 

R. J. Little and D. B. Rubin, Causal effects in clinical and epidemiological studies via potential outcomes concepts and analytical approaches. Anna Rev Public Health 21 121-245 (2000). 

Initiation by itself does not appear to be sufficient for neoplastic formation. Once initiated hepatocytes are formed, their fate has multiple potential outcomes ... 

The expected value is the average return weighted by the probability of each potential outcome 100(0.20) + 0(0.80) = 20. 

Similarly, following the Persian Gulf War (PGW), the Department of Defense (DoD) and the Department of Veterans Administration (DVA) faced basic questions of exposure, outcome, and association. These questions address exposures that were known or possible for the deployed cohort, the potential outcomes of importance that might be associated with such exposures, and the studies and actions undertaken to evaluate these associations. Multiple expert boards and committees have studied PGW veterans and health consequences of service in the Gulf (Table 9.2). The... 

There also needs to be consideration of how the packaging might perform if involved in an accident. As presented in Section 3.2.5, conditional release probabilities are applied in a risk analysis to represent the range of potential outcomes. These outcomes can range from no release to full package failure. While it is important to consider scenarios that can lead to a loss of containment, not all transportation accidents will result in a chemical release. 

Figure 3.2 Potential Outcomes of a HAZMAT Transportation Event...

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