Toxaphene

Toxaphene is a technical mixture containing hundreds of polychlorinated camphenes with chlorination levels ranging from Cl₅ to Cl₁₂, although most target congeners range from Cl₆ to Cl₁₀. First introduced in the US in 1947, toxaphene was primarily used as an insecticide for cotton and soybean crops. The use of toxaphene in the US was restricted in 1982 and banned entirely in 1990, although it is still permitted for use in very defined circumstances in certain US territories. Restrictions and bans in most of the world were harmonized with the ratification of the first Stockholm Convention on Persistent Organic Pollutants¹³ (also known as the POPs Treaty) in 2004.

Commercial toxaphene is considerably more complex than commercial PCB mixes such as aroclors and kanechlors. Synthesis and isolation of individual toxaphene congeners is correspondingly difficult, making production of standards for routine analysis more challenging. Although EPA Method 8276 was published in 2010, it has often been difficult to obtain standards for the analytes listed in that method. All eight unlabeled compounds cited in M8276 can now be ordered from CIL, in addition to five others, both ¹³C labeled and unlabeled, not cited in the method. A mixture of the eight target analytes referenced in M8276² (Hx-Sed, Hp-Sed, Parlar 26, Parlar 40, Parlar 41, Parlar 44, Parlar 50, and Parlar 62) is currently in production.

References

1. The 12 initial POPs under the Stockholm Convention
2. US EPA Method 8276

Toxaphene Congeners