CCL 5 Chemical Contaminants

¹ Chemical Abstracts Service Registry Number; a unique identifier assigned by the Chemical Abstracts Service (a division of the American Chemical Society) to every chemical substance (organic and inorganic compounds, polymers elements, nuclear particles, etc.) in the open scientific literature. It contains up to 10 digits, separated by hyphens into three parts.

² Distributed Structure Searchable Toxicity (DSSTox) Substance Identifier; a unique substance identifier assigned in EPA’s CompTox Chemicals Dashboard, where a substance can be any single chemical, mixture or polymer.

 ³ Toxins naturally produced and released by some species of cyanobacteria (previously known as "blue-green algae"). The group of cyanotoxins includes, but is not limited to: anatoxin-a, cylindrospermopsin, microcystins, and saxitoxin.

⁴ This group includes 23 unregulated DBPs. 

⁵ For the purpose of CCL 5, the structural definition of per- and polyfluoroalkyl substances (PFAS) includes chemicals that contain at least one of these three structures (except for PFOA and PFOS which are already in the regulatory process):

1. R-(CF2)-CF(R′)R′′, where both the CF2 and CF moieties are saturated carbons, and none of the R groups can be hydrogen
2. R-CF2OCF2-R′, where both the CF2 moieties are saturated carbons, and none of the R groups can be hydrogen
3. CF3C(CF3)RR′, where all the carbons are saturated, and none of the R groups can be hydrogen