No Perchlorate MCL
Last month, EPA reached a “preliminary determination” not to regulate perchlorate in drinking water. Unless EPA changes its position, there will be no national primary drinking water regulation or Maximum Contaminant Level (“MCL”) established for perchlorate. Perchlorate is frequently discovered in soil and water. It is also increasingly the subject of toxic tort litigation. The absence of a clear national standard like an MCL to define “injury” is an element of uncertainty in a toxic tort case and increases the litigation risk for both plaintiffs and defendants.
See Continue Reading for: why is perchlorate important; what are perchlorate sources; and why is the lack of a perchlorate MCL important.
Why Is Perchlorate Important? The Agency for Toxic Substances and Disease Registry reports that high levels of perchlorate may affect the thyroid gland. The thyroid gland provides hormones necessary for normal growth and development. The thyroid gland also affects the functioning of many organs in the body. Some studies have linked perchlorate exposure to thyroid problems in pregnant women, young children and newborns.
Perchlorate has been found in at least 49 Superfund sites. It has also been found at numerous other waste sites.
What Are Perchlorate Sources? Perchlorate is an ingredient in rocket fuel, fireworks, highway flares, some munitions and other explosive products. However, perchlorate is often discovered in locations where those items are not manufactured, stored or used. Perchlorate may also occur naturally according to EPA.
Why is the Lack of a Perchlorate MCL Important? An MCL is a widely accepted measure of a safe level of exposure to a chemical. In a toxic tort case, as a practical matter, a plaintiff has a stronger claim of injury if the chemical exposure at issue exceeds the MCL. Some courts regard an exceedance of the MCL as sufficient evidence in itself of an actionable injury. Similarly, a defendant may more easily argue absence of injury when the exposure does not exceed the MCL. Several courts have dismissed plaintiff’s claims based on a factual finding that the relevant MCL was not exceeded.
Absent an MCL for perchlorate, there is no uniform national measure of safe exposure to perchlorate. Some states, but probably not all states, will promulgate their own standards. Inevitably, those state standards will vary, permitting a situation where a specific level of exposure is a violation of the standard in one state but of no significance in the neighboring state. Risk assessments and toxicological profiles and reports issued by different scientific and regulatory agencies may also vary in their conclusions regarding safety of specific exposure levels.
As a result, toxic tort litigants must understand the scientific literature and the different possible standards and be prepared to litigate about which standard is the appropriate test to determine if a specific exposure is an actionable injury. For both sides, it will be critical to have experts in toxicology, risk assessment or similar fields who can explain the competing standards and studies and assist the judge or jury in sorting through them.
