Why are PFAS a concern and how are they regulated?
13 June 2023
What makes PFAS a substance of concern?
While PFAS, consisting of thousands of individual compounds, have been used in both industrial purposes and everyday consumer items for decades, concern over their harmfulness started to increase in the 1990s and early 2000s, when reports of PFAS in environmental samples started to appear around the world. Nowadays, PFAS can be globally found in soils, surface and rain waters, groundwater, air and biota, including humans. One of the biggest issues with PFAS is that they are extremely persistent or degrade into persistent PFAS (PFAS that degrade into other PFAS are called precursors). Due to this high persistency, PFAS are also often referred to as “forever chemicals”, which illustrates well the trans-generation nature of the PFAS problem.
In addition to persistency, many PFAS can be transported long distances from the original source of contamination via air and sea currents, making PFAS emissions a transnational issue. Consequently, PFAS have also been found in remote pristine sites, such as the polar regions and high-altitude mountainous areas. Several PFAS have also been found to bioaccumulate into organisms and biomagnify, meaning that concentrations of PFAS increase when going up in the food chain, which poses a risk also to people consuming fish and other contaminated sea food. PFAS have also been found in drinking water, and for example the drinking water of multiple Swedish municipalities has been found to be highly contaminated by PFAS originating mostly from fire-fighting training sites. Consequently, high PFAS concentrations have been found in the blood of people who have consumed the polluted water.
Simultaneously with reports of PFAS contamination across the globe, understanding of the harmful health effects of PFAS has increased. PFAS have been found to disrupt reproduction and cause developmental effects in children. They can also act as immunosuppressants, causing for example reduced response to vaccines. PFAS are also carcinogenic, meaning that exposure to them can increase the risk of developing certain cancers. PFAS have also been suspected of acting as endocrine disrupting chemicals even at low concentrations. However, the full health risks of PFAS exposure are poorly known due to, for example, the high number of different compounds, their mixture effects, and potentially different modes of action and effects during different life stages of a person.
Regulations and restrictions
The initial attention on PFAS was focused on two compounds, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). These two compounds have been used in large quantities, for example in aqueous film forming foams (AFFFs), used as fire extinguishers, and in the production of fluoropolymers, such as Teflon. Wide-spread environmental contamination by PFOS and PFOA was reported in the 1990s and 2000s. Concern over the environmental and health risks caused by these compounds led to voluntary phase-outs by the fluorochemical industry, and finally in 2009 to the inclusion of PFOS, its salts and related compounds in the international Stockholm Convention on Persistent Organic Pollutants (POPs) in 2009, which is an international treaty restricting the use of harmful chemicals.
Since then, also PFOA and perfluorohexane sulfonate (PFHxS) have been listed in the Stockholm Convention for elimination (the ban on PFHxS coming into force at the end of 2023). Currently, so-called long-chain perfluorocarboxylic acids (PFCAs), with carbon chain lengths from 9 to 21 are on the Convention candidate list. In the EU, the Stockholm Convention is implemented through the POP regulation. In addition, PFCAs with chain lengths from nine to 14, their salts and precursors are restricted also in the EU/EEA area under REACH regulation since February 2023. Several PFAS compounds are also on the list of Substances of Very High Concern (SVHC), which obliges manufacturers and importers to give a declaration of the presence of a chemical if the content of the substance exceeds 0.1% of the weight of the product and give guidance on safe use.
Due to restrictions on the production and use of PFAS such as PFOS and PFOA, their emissions to the environment have declined. However, due to their persistence, the already emitted PFAS remain in the environment. Also, as individual PFAS have been banned, the chemical industry has replaced them with other unregulated PFAS with similar chemical properties. In many cases, replacement substances have often proved to be at least as problematic as their predecessors. The phenomenon where a harmful chemical is replaced with another harmful chemical is called ‘regrettable substitution’. For example, HPFO-DA, a substance used to replace PFOA in fluoropolymer productions, has been included in the SVHC list due to health and environmental concerns related to the substance.
It has been widely agreed, due to regrettable substitution, and the sheer number of potential PFAS, most of which cannot even be analyzed in environmental samples with existing analysis techniques, that environmental problems caused by PFAS cannot be solved with bans and restrictions based on individual substances. In 2022, a proposal of a group-based ban of production and use of PFAS in other than non-essential purposes was presented to the European Chemicals Agency (ECHA) by Denmark, Germany, Netherlands, Norway, and Sweden. The proposal defines PFAS as substances containing certain fluorinated carbon moieties, rather than defining them based on structures of individual PFAS molecules. This definition also includes fluoropolymers, such as polytetrafluoroethylene (PTFE), which is used for example in Teflon. Due to the high number of compounds included in the definition, the sheer scale of this group-based restriction would be historical.
Current work and how EMPEREST project addresses PFAS
While the group-based ban of PFAS will go through the consultation and evaluation phases, both regulatory work on the PFAS problem will continue. Currently, ECHA is working on a proposal to ban the use of PFAS in fire-fighting foams, which are currently one of the largest direct sources of PFAS in the environment. Also, the revised Urban Wastewater Directive (UWD) will give new requirements for wastewater treatment plants regarding the monitoring and removal of certain micropollutants, including PFAS, in urban wastewater. As wastewater treatment techniques currently in wide use are not efficient at removing PFAS and many other micropollutants, research and testing on new micropollutant removal techniques are needed for wastewater treatment plants to be able to implement the UWD requirements in the future. In EMPEREST, a mobile wastewater treatment container will be used to test different ways of removing PFAS from the wastewater, so treatment plants in the future can invest in the most effective and cost-efficient technologies.
Simultaneously with the regulative work, the work on understanding the full scale of the PFAS problem continues. In the Baltic Sea region, the monitoring of the PFAS in the environment is currently not harmonized, meaning data gaps in the occurrence and concentrations of these substances in many parts of the region. One of the goals of the EMPEREST project is to make a harmonized monitoring scheme for the Baltic Sea countries. In addition to the monitoring scheme, EMPEREST will develop a PFAS risk assessment tool for municipalities, as well as training materials about the PFAS issue. The aim of the monitoring scheme, risk assessment tool and the training package is to help municipalities and other regulatory institutions to recognize hot-spot areas of PFAS contamination, and to help them to direct protective and mitigative measures in most effective way for better protection of the environment and human health. You can read more about the work EMPEREST does in future posts.
Turku University of Applied Sciences