Perfluorinated alkyl substances (PFAS) have come to attention recently due to their widespread presence in the environment, recalcitrance, and potential negative health associations. Because of the long-term production of PFAS using ECF, which created branched isomers as byproducts in addition to the intended linear product, branched isomers of PFAS account for a significant portion of PFAS load in the environment. The distribution of isomers is not consistent in the environment, however. Geographic location appears to be a major factor in determining the isomer makeup of PFAS in surface and groundwater as well as in humans and animals. This is largely to differences in production methods; a region that produced PFAS via ECF for many years would have a higher ratio of branched isomers than one that produces PFAS using telomerization. In addition, the different structures of branched PFAS isomers as compared to linear PFAS appear to affect transport in the environment. Research suggests that linear PFAS sorb preferentially to soil and sediments, whereas branched isomers are more likely to remain in water. The higher polarity of the branched structure explains this difference. Studies in humans and animals show that most animals preferentially accumulate the linear PFOS isomer, but humans appear to preferentially accumulate the branched isomers as they are often found in human serum at percentages higher than that of ECF product. In addition, some studies have indicated that linear and branched PFAS isomers have some unique negative health associations. Very few studies, however, account for linear and branched PFAS separately.

由于全氟烷基物质（PFAS）在环境中的广泛存在，顽固性以及潜在的不良健康关联，最近已引起关注。由于使用ECF长期生产PFAS，除预期的线性产物外，它还会产生支链异构体作为副产物，因此PFAS的支链异构体占环境中PFAS负荷的很大一部分。但是，异构体在环境中的分布不一致。地理位置似乎是决定地表水，地下水以及人和动物中PFAS异构体组成的主要因素。这主要是由于生产方法的不同；与通过端粒化生产PFAS的地区相比，通过ECF多年生产PFAS的地区的支链异构体比例更高。此外，与线性PFAS相比，支链PFAS异构体的不同结构似乎会影响环境中的运输。研究表明，线性PFAS优先吸附在土壤和沉积物上，而支链异构体更可能保留在水中。分支结构的较高极性解释了这种差异。对人类和动物的研究表明，大多数动物会优先积累线性PFOS异构体，但人类似乎会优先积累支链异构体，因为它们通常在人血清中的含量高于ECF产品的百分比。此外，一些研究表明，线性和支链PFAS异构体具有某些独特的负面健康关联。但是，很少有研究单独解释线性和分支PFAS。