Per- and polyfluoroalkyl substances (PFAS), often called “forever chemicals,” are a growing public health concern due to their extreme persistence and widespread presence. The public often seeks bottled water, believing it to be safer than tap water. These synthetic compounds are found in countless consumer and industrial products, leading to pervasive global contamination that extends to various water sources, including those used for commercial bottling. Understanding the nature of these chemicals, how they enter bottled water, and what levels are being detected is necessary to evaluate the potential exposure risk.
Defining Per- and Polyfluoroalkyl Substances (PFAS)
PFAS are a large family of over 12,000 synthetic organic chemicals manufactured globally since the 1940s. Their defining characteristic is the incredibly strong bond between carbon and fluorine atoms, making them highly resistant to heat, water, oil, and most degradation processes. This stability is why they are nicknamed “forever chemicals,” as they persist in the environment and the human body for long periods. Historically, the unique properties of PFAS were exploited in numerous industrial and commercial applications, such as non-stick coatings, water-repellent fabrics, and specialized firefighting foams. Their use led to their eventual release into the environment through manufacturing discharge and waste disposal, allowing them to accumulate in soil, air, and water supplies worldwide.
Contamination Pathways in Bottled Water
PFAS primarily enter bottled water through the source water utilized by bottlers. A significant portion of bottled water comes from groundwater, such as wells and aquifers, or from municipal supplies. These sources are vulnerable to contamination from industrial sites, military bases, or areas where firefighting foam was used. If the source water is contaminated, the bottled product will contain PFAS unless advanced treatment methods are employed.
Natural mineral or spring waters, which are less processed, often contain higher PFAS concentrations, reflecting the quality of their original source. Purified bottled water typically undergoes effective removal processes like reverse osmosis or carbon filtration, resulting in lower detectable levels. The plastic packaging itself, usually polyethylene terephthalate (PET), is not considered a primary source of PFAS contamination, although some less common packaging processes have historically involved fluorinated compounds that could potentially leach into the water.
Testing Results and Detectable Levels of PFAS
Testing has confirmed the presence of PFAS in various bottled water brands, though concentrations are generally low and highly variable. Studies conducted by non-governmental organizations and academic researchers have detected PFAS in a substantial number of tested bottled water products. For instance, one study testing over 100 bottled water samples in the U.S. detected PFAS in 39 of them, with concentrations varying widely between brands.
Recent testing by the U.S. Food and Drug Administration (FDA) of 197 domestic and imported samples found detectable levels in ten. The measured concentrations in these FDA tests were below the Maximum Contaminant Levels (MCLs) established for public drinking water by the Environmental Protection Agency (EPA). The International Bottled Water Association (IBWA) requires member companies to meet a limit of 5 parts per trillion (ppt) for any single PFAS compound and 10 ppt for a mixture of two or more.
Health Effects of Long-Term PFAS Exposure
Exposure to PFAS has been associated with a range of potential health consequences following chronic, low-level ingestion. Because these chemicals bioaccumulate in the human body, the concern is centered on the long-term effects of this persistent presence. Epidemiological studies have consistently linked PFAS exposure to a compromised immune system, leading to a reduced ability to fight infections and a decreased response to vaccines.
PFAS exposure is also associated with endocrine disruption and metabolic issues, including changes in liver function, such as elevated cholesterol levels, and disruption of thyroid hormone levels. Furthermore, research suggests potential links between certain PFAS and an increased risk for specific cancers, including kidney and testicular cancers, as well as developmental effects in children.
Regulatory Standards and Reducing Personal Exposure
The regulatory landscape for PFAS in drinking water is evolving but currently differs between tap water and bottled water. The EPA, which regulates tap water, has finalized legally enforceable Maximum Contaminant Levels (MCLs) for six PFAS compounds, including PFOA and PFOS, setting limits as low as 4 ppt for some individual chemicals. Bottled water is regulated as a packaged food product by the FDA, but federal law mandates that its regulations must be as protective of public health as tap water regulations.
Reducing Personal Exposure
For consumers looking to reduce their exposure, several actionable steps can be taken. Individuals concerned about municipal tap water should check their local water utility’s water quality report for PFAS testing results. To filter water at home, point-of-use systems incorporating reverse osmosis (RO) technology or granular activated carbon (GAC) filters are generally effective at reducing PFAS levels. When purchasing bottled water, looking for purified water brands, which are more likely to have undergone effective filtration treatments like reverse osmosis, may help minimize potential exposure.