What are PFAS?
Per- and polyfluoroalkyl substances (PFAS), including perfluorooctylcarboxylic acid (pfoa) and perfluorooctylsulfonic acid (pfos) (see Figure 1 for the structures of the two substances), are a class of synthetic substances with a carbon chain structure in which the hydrogen atoms have been partially or completely replaced by fluorine atoms. Although these chemicals are called "persistent chemicals" (once in the human body, they persist for a long time and are difficult to remove), they have been manufactured and used in factories around the world since the 1940s.
As surfactants, pfas are widely used in a variety of industrial and consumer products. Along with its wide application in industrial production and life, the emission of pfas in the natural environment has been increasing, and at the same time, the presence of these anthropogenic pollutants in natural and treated waters, human and animal organisms has posed a great environmental challenge, and has also triggered a wide range of environmental problems. The high-energy c-f bonds in pfas molecules make them chemically, thermally. At the same time, the biological properties are stable and it is difficult to be hydrolyzed, photolyzed and biodegraded, so it will persist in the environment. At present, pfass has become a global pollutant. In recent years, pfass has been widely detected in many regions of the world and in a variety of environmental media, and its widespread detection in various sea areas, especially in polar regions, indicates that it has the ability to migrate over long distances.
PFOS and PFOSF are listed as persistent organic pollutants (POPs) under the Stockholm Convention. in 2009, the U.S. Environmental Protection Agency (epa) added them to the Candidate List of drinking water contaminants. In addition, in 2016 epa established a health advisory level of 70 ng/l for the sum of pfoa and pfos in drinking water. pfos was also added to directive 2013/39/eu as a priority pollutant to be monitored and regulated in surface water throughout Europe.
Globally, most natural water bodies are contaminated with varying degrees of pfoa and pfos at concentrations ranging from 0.1-3640 ng/l and 0.005-527 ng/l, respectively.
Toxicological studies have shown that typical pfas are environmentally persistent, bioaccumulative, and multitoxic. The results of many studies have shown that pfass exposure can cause a variety of toxic effects, including hepatotoxicity, reproductive developmental toxicity, immunotoxicity and other toxic effects, and there is a certain correlation with a variety of human health problems and diseases. In view of the hazards of long-chain pfass, such as environmental persistence, long-range transport, bioaccumulation and multiple toxicities, which seriously threaten the ecological environment and human health, many countries or regions around the world have successively introduced relevant regulations restricting the production and use of pfass.
Therefore, Filterelated's expert team has been continuously researching on PFAS, and finally developed a solution that can filter PFAS from water, contributing to the global healthy drinking water.