What is Di(2-ethylhexyl) phthalate* and Why Does It Matter?

Di(2-ethylhexyl) phthalate, commonly known as DEHP, is a synthetic chemical used to make plastics soft and flexible. It belongs to a family of chemicals called phthalates, which manufacturers add to PVC plastic to keep it from becoming brittle. DEHP enters drinking water primarily through aging plastic pipes, industrial discharge, and the breakdown of plastic materials in water treatment infrastructure. Landfill runoff and manufacturing wastewater can also carry DEHP into rivers and groundwater sources that feed municipal water systems.

The health concerns around DEHP are significant, particularly for children and pregnant women. DEHP is an endocrine disruptor, meaning it interferes with the body's hormone system. According to the EPA, long-term exposure is linked to liver damage, reproductive harm, and developmental problems in children. Animal studies have shown DEHP can affect the liver, kidneys, and reproductive organs at relatively low doses. The Environmental Working Group (EWG) considers it especially dangerous during pregnancy, when developing fetuses are most vulnerable to hormonal interference. Even low-level, long-term exposure adds up — and that's what makes it worth paying attention to.

The EPA has set a legal limit for DEHP in drinking water at 6 parts per billion (ppb). On the surface, that sounds protective. But the EWG's health guideline is far stricter — just 0.4 ppb — based on the most current research on reproductive and developmental harm. Across the 288 water systems where DEHP was detected, the average level measured 0.293 ppb. That's below the EPA's legal limit, but it sits uncomfortably close to the EWG's health-based guideline. Two of those 288 systems actually exceeded the EWG threshold, with the highest recorded level reaching 3.6 ppb — nine times above what the EWG considers safe. Legal doesn't always mean risk-free.

Geographically, Texas leads the country with DEHP detected in 110 water systems — more than any other state by a wide margin. New York follows with 31 systems, then New Jersey with 22, Illinois with 16, and Colorado with 15. The heavy presence in Texas and the Northeast likely reflects a combination of aging water infrastructure, industrial activity, and the sheer size of those states' water networks. Older pipes and distribution systems are more prone to leaching plastic-related chemicals into water as materials degrade over time. States with large manufacturing sectors also tend to see higher rates of industrial chemical contamination in nearby water sources.

The good news is that DEHP is very effectively removed by the right filtration system. Reverse osmosis (RO) filtration removes up to 99% of DEHP from drinking water, making it one of the most reliable options for households concerned about this contaminant. Activated carbon filters also reduce DEHP levels significantly, though not always to the same degree as RO. If your water comes from one of the 288 systems where DEHP has been detected — especially in Texas, New York, or New Jersey — it's worth taking action rather than waiting for a regulatory update. Echo Water's reverse osmosis systems are designed to target exactly these kinds of synthetic chemical contaminants, giving your family a reliable layer of protection at the tap. Start by checking your annual Consumer Confidence Report, which your water utility is required to provide. That report will tell you whether DEHP has been detected in your specific system and at what levels.

Regulatory Standards for Di(2-ethylhexyl) phthalate*

Cities With the Highest Di(2-ethylhexyl) phthalate* Levels

States Most Affected by Di(2-ethylhexyl) phthalate*

Frequently Asked Questions

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