The question of what bottled water is truly free of per- and polyfluoroalkyl substances (PFAS) is a growing concern for consumers seeking safer drinking sources. PFAS are a large family of synthetic chemicals, often called “forever chemicals” because they do not easily break down in the environment or the human body. Widespread use in industrial and consumer products since the 1940s has led to their pervasive presence in water sources globally. Understanding how these substances enter the water supply and what standards define a “PFAS-free” product is essential for making informed purchasing decisions.
Understanding PFAS Contamination Sources
PFAS contamination in bottled water primarily originates from the source water used by the bottling company. Many groundwater and surface water sources, including natural springs, have become contaminated due to decades of environmental pollution from industrial sites and the widespread use of products containing these chemicals, such as firefighting foams. These stable chemicals travel long distances through soil and water, eventually infiltrating the aquifers and reservoirs that serve as bottling sources.
Approximately 25% of bottled water uses the same municipal water sources as public tap water systems. If the municipal supply is contaminated, the bottled product will also contain PFAS unless the water is subjected to advanced treatment processes like reverse osmosis. While source water is the main entry point, there is a secondary concern about potential leaching from the packaging materials themselves. However, the greatest risk of contamination remains tied to the quality of the raw water source.
Regulatory Landscape and Defining “PFAS-Free”
The regulation of PFAS in drinking water is handled by two separate federal bodies, leading to a complex regulatory environment. The U.S. Environmental Protection Agency (EPA) sets standards for public tap water, while the Food and Drug Administration (FDA) oversees bottled water as a packaged food product. In April 2024, the EPA finalized legally enforceable Maximum Contaminant Levels (MCLs) for six specific types of PFAS, including PFOA and PFOS, setting the limit for each at four parts per trillion (ppt).
This new EPA standard triggers a requirement for the FDA to evaluate the need for a corresponding standard for bottled water within 180 days. Currently, “PFAS-free” is an industry-driven term, not a universally certified legal status enforced by the FDA. The term typically signifies that PFAS compounds were not detected or were found to be below the Minimum Reporting Level (MRL) of the testing method used. Industry groups, such as the International Bottled Water Association (IBWA), have established their own guidelines, requiring member brands to test for 18 types of PFAS and maintain levels below 5 ppt for any single compound. Parts per trillion (ppt) indicates an extremely small concentration, like one drop of water in 20 Olympic-sized swimming pools.
Bottled Water Brands and Testing Results
Third-party testing organizations frequently conduct independent studies to assess the PFAS content across popular bottled water brands, providing a clearer picture for consumers. Results from a 2020 Consumer Reports study, which tested 47 brands, indicated that detectable levels of PFAS were present in a majority of samples, though most were below the IBWA’s voluntary limit of 5 ppt. The testing revealed a noticeable difference between water types, with purified or treated waters generally showing lower levels than spring or mineral waters.
Brands that employ advanced purification methods, such as reverse osmosis, often consistently test below detection limits. Conversely, spring and carbonated waters, which rely on a natural source and minimal treatment, showed higher variability. For example, the 2020 testing found that some sparkling water brands, including Topo Chico and Polar, had levels as high as 9.76 ppt and 6.41 ppt, respectively, exceeding the 5 ppt industry guideline. Consumers should prioritize brands that transparently provide recent, verifiable testing data or state they use purification methods known to remove these contaminants, such as reverse osmosis.
Home Water Filtration as a PFAS Solution
For individuals concerned about both tap and bottled water contamination, installing a home water filtration system offers a proactive and consistent solution. The most effective methods for removing PFAS from residential water are activated carbon filters and reverse osmosis (RO) systems. Under-sink RO systems are generally the most effective, demonstrating the ability to achieve near-complete removal, often reducing PFAS levels by 94% or more.
Activated carbon (AC) filters, commonly found in pitcher or refrigerator units, are also effective but show more variable performance. While AC filters can remove an average of 73% of PFAS compounds, their efficiency is lower for the shorter-chain versions of the chemicals. When selecting a filtration system, consumers should look for certifications from organizations like NSF International. Specifically, look for NSF/ANSI Standard 53 for carbon filtration and NSF/ANSI Standard 58 for reverse osmosis, which verify the product for PFAS reduction. Regular maintenance, including timely filter replacement, is necessary for any system to retain its effectiveness over time.