Poly- and perfluoroalkyl substances (PFASs) are a family of anthropogenic chemicals widely used in the commercial and industrial applications due to their unique properties of stability, hydrophobicity and lipophobicity. Traditionally, PFASs are produced via two major manufacturing processes: electrochemical fluorination (ECF) and telomerization. Due to their persistence, toxicity and bioaccumulation, ECF-associated chemicals perfluorooctane sulfonic acid (PFOS), its salts and perfluorooctane sulfonyl fluoride (POSF) are placed into the Annex B of the Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) in 2009. The ECF production has also been phased out gradually in the developed countries. However, the production of fluorotelomer alcohols (FTOHs) by telomerization has increased significantly. Recent studies have demonstrated that the biotransformation and abiotic transformation of FTOHs yielded perfluocarboxylic acids (PFCAs), which may be router for the ubiquitous distribution of PFCAs. Besides, some of the FTOHs intermediate metabolites have been demonstrated to be able to covalently bind with various biomolecules and thereby cause serious toxicity, while the final metabolites are showed to cause hepatotoxicity and renal toxicity. Recently, the environmental problems related to FTOHs have become the hotspots in environmental science, toxicology and epidemiology. This paper reviews the research progress on the production status, environmental occurrence, and the toxicities of FTOHs and the related metabolites. Finally, the currently existing problems and trends are discussed.

Contents
1 Introduction
2 Production status and human exposure of FTOHs
2.1 Production status
2.2 Human exposure of PFAAs
3 Environmental occurrence of FTOHs
3.1 Basic properties
3.2 Analytical methods
3.3 Environmental occurrence
4 Toxicological studies
4.1 Biotransformation of FTOHs
4.2 Toxicities of FTOHs and the related metabolites
5 Conclusion and outlook