The science behind determining a safe concentration to the environment is imperfect, statistically limited, and resource intensive.
While empirical methods are crucial to making scientific conclusions and informed decisions, best personal judgement is often the best tool to the regulator in allowing or prohibiting potentially toxic chemicals from entering the environment.
[2] It provides no new information, it simply converts AF values into whole integer numbers that are more easily comparable for researchers visually.
[3] Section 5 of the TSCA states that the EPA must respond to pre-manufacturing notices (PMN) 90 –180 days after submission by the manufacturer.
The EPA is responsible for identifying the substance, its proposed use, amount made, byproducts, exposure levels, and all existing environmental and health data necessary to prevent significant harm to the environment.
This essentially puts a huge burden on the EPA because chemical effects to the environment are extremely hard to predict simply based on single species toxicity tests (SST).
The results of acute and chronic toxicity testing form the basis of knowledge that regulators draw from in performing work related to ecological risk assessment and designing policy that defines how much of a chemical of interest should be allowed in certain environments.
While this sounds simple enough to the layperson, it is extremely difficult in practice due to a large number of modifying factors inextricably tied to toxicity tests and statistical analysis.
[8] Scientific methods for determining acute and chronic toxicity to organisms are inherently imperfect and non-uniform throughout the field of research, and the most useful tool for decision making by officials is more often than not best personal judgement.
This method uses computer software to estimate chronic toxicity, which provides similar information with much less effort and expense to the researcher.
While ACR 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.