Phthalates in Water: What You Need To Know

Growing awareness about environmental contaminants has brought increased attention to phthalates — synthetic chemicals widely used in plastic products. These compounds have raised concerns due to their ability to leach into the air, food and water.

According to the Minnesota Department of Health, food, house dust, and consumer products are far greater contributors to human exposure than drinking water and even then, for most people, these exposures are below a level that would be a health concern. Still, phthalates in water may contribute to your overall environmental exposure. Understanding how they get there, and what to do about it, is an important step for water-conscious consumers.

In this blog, we’ll break down:

• What phthalates are and how they enter water sources
• The current research and potential health implications
• Where phthalates are most commonly found
• What you can do to reduce exposure at home

What Are Phthalates?

Phthalates are a group of synthetic (or man-made) chemicals used primarily to make plastics more flexible and durable. They’re commonly found in products made from polyvinyl chloride (PVC), including packaging, plastic tubing, flooring and hundreds of everyday medical, household and consumer items, according to the U.S. Environmental Protection Agency (EPA).

While exposures from food, consumer products and household dust remain the most significant sources of phthalates, water is part of the cumulative picture — especially for those actively trying to reduce their chemical exposure.

Why Are Phthalates So Common?

Unlike some chemical additives, phthalates aren’t chemically bonded to the plastics they’re used in. This means they can migrate into the surrounding environment, including food, air and water — especially when products are heated, aged or damaged. For instance, a 2024 study noted the leaching potential of phthalates from household materials under everyday conditions.

Additionally, because of their broad use, phthalates are pervasive in modern environments, and trace amounts can show up in surface water, groundwater and even rainwater.

What Are the Health Concerns With Phthalates in Water?

Phthalates are classified as endocrine-disrupting compounds, which means they can interfere with the body’s hormone systems, even at low doses. Chronic phthalate exposure has been linked to a wide range of health issues, including:

• Reproductive system disruptions
• Developmental abnormalities
• Metabolic disorders such as insulin resistance and obesity
• Altered thyroid hormone levels, and more

These risks are particularly concerning for vulnerable populations like pregnant people, infants and young children. Because early development depends heavily on hormonal regulation, even small changes caused by phthalates may have long-lasting effects.

While drinking water is not the primary source of phthalate exposure, it can still contribute to your overall exposure. Phthalates in tap water, surface water or water bottles may be present at trace levels, but those levels add up alongside other environmental sources.

By focusing on overall water quality and limiting avoidable plastic exposure, consumers can take meaningful steps toward reducing cumulative risk.

Are There Regulations on Phthalate Levels in Drinking Water?

To understand the regulations around phthalates, it’s important to understand that there are several different types of phthalates, such as:

• DEHP (Di-2-ethylhexyl phthalate): A widely used plasticizer in PVC products such as pipes, containers and children’s toys
• DEHA (Di-2-ethylhexyl adipate): Similar to DEHP, found in food packaging and flexible plastics
• DBP (Di-n-butyl phthalate): Used in adhesives, printing inks and sealants
• Dimethoate: While not a plasticizer, it’s a pesticide that shares chemical behavior and relevance in water quality discussions due to its solubility and health impacts

In the United States, the EPA has set a Maximum Contaminant Level (MCL) for DEHP in drinking water at 0.006 milligrams per liter (mg/L). This is the highest concentration allowed for public water systems and is based on evidence that long-term exposure above this level may cause health problems, particularly affecting the liver and reproductive system. The U.S. Food and Drug Administration (FDA) applies the same allowable level for DEHP in bottled water sold across the states.

The EPA has also expressed concern about other phthalate esters, including butyl benzyl phthalate, dimethyl phthalate and 2-ethylhexyl phthalate, due to their potential to act as endocrine disruptors and contribute to environmental pollution. Through the Toxic Substances Control Act (TSCA), the EPA is actively evaluating the risks associated with several phthalate compounds.

In Canada, Health Canada has taken a more preventive approach, banning the use of DEHP in:

• Cosmetic products
• Children’s toys and care articles
• Certain medical devices

While DEHP is regulated in drinking water, other phthalates like DEP and DBP are increasingly monitored due to their persistence in aquatic environments. This leaching process underscores why phthalates are not just a plastic problem — they’re a water quality consideration, too.

Where Do Phthalates Come From?

Phthalates can enter water sources through several environmental pathways, including:

Plastic Containers

One common concern is water stored in plastic containers. Elevated temperatures, such as those found in cars or outdoor storage, can increase phthalate contamination, particularly diethyl phthalate and DEHP. In one study, phthalate concentrations in plastic water bottles increased after being stored in sunlight or warm conditions for extended periods.

Aging Plastic Pipes and Infrastructure

Tap water may also carry trace phthalates from aging municipal infrastructure. Older water systems that use plastic pipes, PVC seals or outdated treatment components can introduce small amounts of phthalate esters into the water supply.

Industrial Waste and Landfill Runoff

Environmental runoff is another source. As plastic waste breaks down in landfills or littered areas, industrial wastewater and stormwater runoff can carry phthalates into surface water and groundwater. A review of global phthalate pollution found that rivers near urban and agricultural zones often show measurable levels of phthalate compounds due to improper plastic disposal and plastic consumption trends.

Rainwater Contamination

Phthalates don’t stay grounded. Studies show rainwater in urban areas can carry airborne particles from industrial emissions or degraded plastic products into reservoirs. Agricultural regions face similar risks, where rainwater washes phthalates from plastic mulch or irrigation systems into local water sources.

How Can You Reduce Your Phthalate Exposure?

While you can’t eliminate environmental exposure entirely, there are several ways to reduce your contact with phthalates in water and other sources:

1. Avoid Overly Processed Foods

Phthalates often contaminate foods through plastic packaging and processing equipment. A 2024 study linked diets high in processed foods to elevated phthalate levels. Whenever possible, opt for fresh, unpackaged produce.

2. Choose Phthalate-Free Products

Check labels on cosmetics, toys and food packaging. Avoid plastics labeled #3 (PVC) or “vinyl,” as these commonly contain phthalates. The Minnesota Department of Health advises against microwaving or storing hot foods in #3 plastics, which accelerates chemical leaching.

3. Ditch Single-Use Plastic Bottles

Switch to glass or stainless-steel containers for drinking water. Bottled water, particularly in PET bottles, is more likely to contain phthalates after long storage periods.

4. Upgrade Outdated Plumbing

Some older water systems still use PVC piping or components that may contribute trace phthalates. Consider a professional water consultation if you suspect your home’s infrastructure may be contributing to chemical exposure.

5. Install a Reverse Osmosis System

Reverse osmosis systems are widely used to reduce a range of chemical contaminants in drinking water. Independent studies show RO filtration can effectively reduce phthalates, depending on the membrane and system configuration.

Cleaner Water Starts With Clarity

Phthalates in water may only account for a small portion of your overall exposure, but they reflect a broader concern: what’s in your water, and how can you improve it?

Understanding your water quality is the first step toward safer, cleaner drinking water. While Culligan does not test for phthalates specifically, our in-home water consultation can help identify other potential issues — like hardness, chlorine, total dissolved solids (TDS) and more — and guide you to the right water filtration or softening system for your home.

Ready to take control? Schedule a free in-home water consultation with Culligan to explore customized solutions, from reverse osmosis systems to whole-home filtration.