Phenol, p-tert-butyl- in Drinking Water
Found in 38 water systems • Detected
Updated September 2026 • Data from EWG & EPA
What is Phenol, p-tert-butyl- and Why Does It Matter?
PHENOL, P-TERT-BUTYL-: WHAT YOU NEED TO KNOW
What Is p-tert-Butylphenol and Where Does It Come From?
p-tert-Butylphenol (commonly called p-tert-butyl phenol or PTBP) is a synthetic chemical used primarily in manufacturing plastics, resins, and industrial coatings. It's also found in some personal care products, adhesives, and antioxidant formulations. When these products break down or are improperly disposed of, PTBP can leach into groundwater and eventually contaminate drinking water supplies. Industrial facilities and landfills near water sources pose the greatest risk, as do areas with aging or compromised water infrastructure that allows chemicals to seep into pipes.
The chemical enters water systems through both point sources—like industrial discharge—and nonpoint sources, including runoff from manufacturing areas and improper waste disposal. Because PTBP is persistent in the environment, it doesn't break down quickly once it enters water. This means contamination can persist for years, even after the original source is removed.
Health Effects and Exposure Risks
Limited human health studies exist specifically for p-tert-butylphenol, but research on similar phenolic compounds shows potential concerns. Animal studies suggest that PTBP may affect the endocrine system—the network of glands that controls hormones—at high doses. The EPA has not established a maximum contaminant level (MCL) for this chemical, meaning federal drinking water standards don't currently address it.
According to available toxicology data, short-term exposure to low levels of PTBP in drinking water carries minimal documented risk. However, long-term exposure to higher concentrations warrants caution, particularly for children and pregnant women, whose developing systems are more sensitive to chemical exposure. The Environmental Working Group (EWG) has not published a specific health guideline for PTBP, but the chemical's potential endocrine-disrupting properties make it worth minimizing whenever possible.
Current Regulations and Guidelines
This is where the regulatory picture gets murky. The EPA has not set a legally enforceable drinking water limit for p-tert-butylphenol, which means water utilities aren't required to test for it or remove it. The chemical doesn't appear on the EPA's Contaminant Candidate List, the official roster of substances under consideration for future regulation. This regulatory gap means PTBP can be present in tap water with no legal requirement for disclosure or treatment.
Some states have begun monitoring PTBP independently. Texas, where all 38 detected cases of this contaminant have been found, shows the highest concentration at 9.7 parts per billion (ppb), with an average of 3.248 ppb across systems. For context, the EPA's drinking water standards for regulated chemicals typically range from 0.5 to 10 ppb, suggesting Texas levels warrant attention even without federal mandates.
Why Texas Is the Hotspot
Texas's concentration of PTBP detections almost certainly reflects both the state's significant petrochemical and manufacturing industries and its extensive groundwater-dependent water systems. The state's chemical production facilities, particularly in the Gulf Coast region, use phenolic compounds extensively. Additionally, Texas's reliance on groundwater aquifers means contamination from industrial sources can spread widely and persist longer than in surface-water-dependent regions.
How to Remove p-tert-Butylphenol From Your Water
Activated carbon filtration effectively removes PTBP and similar organic chemicals. Both whole-home carbon filters and point-of-use systems (like under-sink filters) can reduce this contaminant significantly. Reverse osmosis systems provide even more comprehensive removal, blocking PTBP along with other synthetic chemicals. If you live in Texas or use well water, testing your water for PTBP is a smart first step—knowing your baseline helps you choose the right filtration approach. An Echo Water test can identify whether this chemical is present in your home's water supply, giving you the information needed to decide on treatment.
Regulatory Standards for Phenol, p-tert-butyl-
| Standard | Level | Notes |
|---|---|---|
| Average Detected Level | 3.25 ppb | Across all tested systems |
| Highest Detected Level | 9.70 ppb | Worst-case system |
Cities With the Highest Phenol, p-tert-butyl- Levels
| # | City | Detected Level | People Served |
|---|---|---|---|
| 1 | Priddy, TX | 9.70 ppb | 0 |
| 2 | Temple, TX | 4.40 ppb | 4,125 |
| 3 | Houston, TX | 3.90 ppb | 488 |
| 4 | Somerville, TX | 3.90 ppb | 338 |
| 5 | Lorena, TX | 3.60 ppb | 1,776 |
| 6 | Hewitt, TX | 3.40 ppb | 16,978 |
| 7 | Smithville, TX | 3.40 ppb | 90 |
| 8 | Jarrell, TX | 3.15 ppb | 0 |
| 9 | Troy, TX | 3.10 ppb | 2,350 |
| 10 | Snook, TX | 3.10 ppb | 980 |
| 11 | Belton, TX | 3.07 ppb | 25,466 |
| 12 | Copperas Cove, TX | 3.07 ppb | 37,225 |
| 13 | Harker Heights, TX | 3.07 ppb | 34,834 |
| 14 | Killeen, TX | 3.07 ppb | 151,261 |
| 15 | Fort Hood, TX | 3.07 ppb | 35,669 |
States Most Affected by Phenol, p-tert-butyl-
How to Remove Phenol, p-tert-butyl- From Your Water
Reverse osmosis (RO) systems are generally the most effective at removing a wide range of contaminants from drinking water.
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Shop Hydrogen FlaskFrequently Asked Questions
Is Phenol, p-tert-butyl- in my drinking water?
Phenol, p-tert-butyl- was detected in 38 water systems across the US. Check your city's water quality report to see if it affects your water supply.
What are the health effects of Phenol, p-tert-butyl- in water?
Phenol, p-tert-butyl- has been associated with various health concerns at elevated levels. The EWG has set health guidelines that are typically stricter than EPA legal limits.
Which city has the most Phenol, p-tert-butyl- in its water?
Based on our analysis, Priddy, TX has the highest detected levels of Phenol, p-tert-butyl- in its water supply.
How do I remove Phenol, p-tert-butyl- from my water?
Reverse osmosis (RO) systems are generally the most effective at removing this contaminant. Check the filtration recommendations section for specific guidance.
Related Contaminant Guides
Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)
Last updated: September 2026
Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.
