The<unk>  is derived from data generated by SSTs, as so falls victim to the same errors and limitations. These limitations are described in detail in literature Using point estimates such as NOECs/LOECs reduces a data set containing many values down to an isometric, removing the rich visual information that allows the researcher to assess the reliability and variability in the data. Information such as the slope of the dose-response curve, from which NOECs are LOECs are derived, is lost. However, without NOECs and LOECs regulatory decisions are much harder to make. While<unk>  has drawbacks due to the uncertainty of the point estimates it uses to define it, it is still widely valued as a regulatory tool in making environmental assessments and policy decisions.<unk> s are based on tests with a number of different methodologies, which means that there can be significant variance among<unk> s.
Acute to chronic ratio
Multiple chemical sensitivity
Sufficient similarity
Incidence 
Holmes rebound phenomenon
Limited symptom attack
Clinical significance
Risk of mortality