Key Questions Answered by Daniel de Graaf, German Environment Agency (UBA). PFAS (Per- and polyfluoroalkyl substances), commonly known as “forever chemicals,” are increasingly recognized as a significant threat to environmental and human health. Their application in refrigerants and the formation of trifluoroacetic acid (TFA), a highly durable breakdown product, have garnered rising concern. In this interview, Daniel de Graaf from the German Environment Agency (UBA) provides his expert insights on the risks, environmental impacts, and regulatory discussions surrounding PFAS. We posed eleven detailed questions to him, delving into the science behind PFAS, their prevalence in everyday items, and the measures being taken at the European level.
1. Could you explain what PFAS are and why they are called "forever chemicals"?
PFAS stands for per- and polyfluoroalkyl substances – a large group of synthetic chemicals found in many every day and industrial products. What makes them unique – and concerning – is that they don’t degrade at all or not completely in nature. Once released into the environment, they or their breakdown products can remain there for decades or even thousands of years. That’s why they’re often referred to as “forever chemicals.”
Today, scientists have identified around 10,000 different PFAS. One of the most studied is PFOA (perfluorooctanoic acid), which was widely used in the past.
2. What is TFA, and how does it relate to PFAS in refrigerants?
TFA, or trifluoroacetic acid, is a particularly persistent and mobile substance that belongs to the PFAS group. Its chemical structure makes it more acidic than everyday vinegar, and studies have linked it to liver and reproductive toxicity. Although TFA is used in some industrial processes, most of it ends up in the environment unintentionally. It forms when certain fluorinated refrigerants – especially R 134a and R 1234yf – break down in the atmosphere. R 1234yf is especially concerning, as it turns almost entirely into TFA. Today, these refrigerants are the main source of TFA pollution, next to some pesticides.
3. What are the main sources of PFAS?
PFAS are used in a wide range of applications including cosmetics, food packaging, carpets, textiles, firefighting foams, coatings, pharmaceuticals, pesticides, and refrigerants. Because of this broad use, they are emitted into the environment through many different sources. TFA, as a specific PFAS compound, is now considered the most widespread PFAS pollutant globally.
4. What are the environmental risks associated with PFAS/TFA?
Due to their persistence, PFAS build up in the environment – in soil, water bodies, groundwater, and even in living organisms. This is especially concerning because these substances don’t occur naturally and can interfere with ecosystems. While many PFAS haven’t yet been fully studied, some are already known to harm both wildlife and human health.
5. What are the human health impacts of PFAS?
Toxic effects of PFAS have been observed in animal testing and confirmed in some human studies (especially PFOA, PFOS, PFHxS, and PFNA). These PFAS can interfere with hormonal systems (endocrine disruption), damage the nervous system, affect reproductive health, and may promote cancer. They also cause oxidative stress and liver toxicity in rodents.
6. Are all PFAS chemicals equally harmful, or do some pose greater risks than others?
No – PFAS compounds vary significantly in their structure, mobility, and toxicity. Some are highly harmful, while others are considered less risky. For example, the refrigerant R 134a itself is not classified as toxic. However, its breakdown product, TFA, does show toxic effects. This shows the need to consider both the original substance and its degradation products.
7. Which PFAS are present in maritime container refrigerants (like R-134a and R-1234yf)?
The refrigerants R 134a and R 1234yf, commonly used in refrigerated maritime containers, are both PFAS under the proposed EU definition. When released into the atmosphere, they degrade to form TFA – with R 134a resulting in about 7–20% TFA formation, and R 1234yf in nearly 100%. Other refrigerant blends such as R 404A (which includes R 143a, R 125, and R134a) and R513A (a mixture of R1234yf and R134a) are also classified as PFAS.
8. Can you explain the proposed restrictions on PFAS especially concerning refrigerants like R-134a?
A group of five EU countries – Denmark, Germany, the Netherlands, Norway and Sweden – has proposed a broad restriction on PFAS according to the EU REACH regulation (Regulation (EC) No 1907/2006). Under this proposal, almost all fluorinated refrigerants would be restricted once the regulation comes into force (expected around 2028). For transport refrigeration specifically, there is a proposed transition period of 6.5 years – meaning that from approximately 2035 on, new refrigeration equipment using fluorinated refrigerants could no longer be sold in the EU.
9. What is the German Environment Agency’s role in the global efforts to regulate and reduce PFAS emissions, particularly in the context of refrigerants?
We work alongside other authorities on PFAS regulation and promote alternatives to fluorinated refrigerants. One challenge has been that earlier climate policies (like the EU F-gas Regulation) encouraged the switch from high-GWP refrigerants (like R 134a) to lower-GWP options such as R 1234yf – but this unintentionally increased TFA emissions. The German Environment Agency supports the proposed PFAS restriction as an opportunity to end TFA emissions and is actively researching natural refrigerants for use in refrigeration, air conditioning, and heat pumps.
10. Are there any PFAS in natural refrigerants like propane and CO2?
No. Natural refrigerants such as propane (R290) and CO₂ (R744) are not fluorinated and therefore do not belong to the PFAS group. They are PFAS-free and considered safer for both the climate and the environment.
11. What advice would you give to cargo owners, retailers or operators whose supply chains rely heavily on current refrigerants like R-134a and R-1234yf?
It’s important to plan a transition towards fluorine-free refrigerants. Natural alternatives such as CO₂ and hydrocarbons (like propane) are already being tested in maritime containers and are commercially available in other transport cooling systems. The industry – particularly system manufacturers – should invest in further developing and scaling up solutions based on natural refrigerants.
The interview follows Daniel’s presentation during the webinar Greener Reefers – The Future of Refrigerated Maritime Transport webinar organised by the Greener Reefers Transition Alliance and conducted by the Kuehne Climate Center (opens in a new window). The Greener Reefers (opens in a new window)Transition Alliance is founded in the margins of the COP 28 by the Kuehne Climate Center and the GIZ implemented project Greener Reefers. The Greener Reefers project is financed through the International Climate Initiative by German Federal Ministry for the Environment, Climate Action, Nature Conservation and Nuclear Safety and Consumer Protection (BMUKN).