DBP
2950Total Trihalomethanes
The health basis on which the EPA sets this contaminant's legal limit. Reported verbatim from the regulatory record — it is not a diagnosis or a prediction about any individual.
Long-term exposure increases bladder-cancer risk; disinfection byproduct of chlorination.
- Maximum contaminant level
- 80 µg/LLegal MCLEnforceable federal limit
- Health goal
- 0.0 µg/LHealth goal (MCLG)No safe exposure level
- Category
- DBPCategory
- Reporting unit
- µg/LReporting unit
Regulatory basis
How Total Trihalomethanes is regulated
What the enforceable limit actually obliges a utility to do, and how it differs from the health-based goal it is measured against.
Two different numbers govern Total Trihalomethanes, and they are not interchangeable. The Maximum Contaminant Level (MCL) is 80 µg/L — the enforceable ceiling. A system reporting above it is in violation and owes its customers notification and corrective action. The health goal (MCLG) is 0 and is not enforceable.
The health goal is zero. EPA sets a goal of zero when it has not identified a level at which the contaminant is known or expected to be free of the effects the standard was written to address. Zero is not attainable as an enforceable standard with available treatment technology and cost, so the MCL was set at 80 µg/L instead — the level EPA judged feasible. The practical consequence: a utility can report Total Trihalomethanes anywhere between zero and 80 µg/L and be fully compliant while still sitting above the health goal. “No violation” and “at the goal” are different statements about the same water.
Results are reported in µg/L. A laboratory result and the limits above are only comparable when both are expressed in that same unit — a value in a different unit will be off by orders of magnitude. WaterQualityLens groups Total Trihalomethanes under DBP for navigation; the grouping is ours, the limits are the regulator’s.
The record for Total Trihalomethanes
- Enforceable limit (MCL)
- 80 µg/L
- Health goal (MCLG)
- 0
- Reporting unit
- µg/L
- Category
- DBP
- Contaminant code
- 2950
Limits as published by EPA and state primacy agencies. This page reports regulatory and certification records; it does not assess anyone’s exposure and makes no health prediction.
Certification scope
Which certifications actually remove Total Trihalomethanes
Only NSF/ANSI 53, 58 and 401 are health-contaminant standards. A product certified only to Standard 42 (aesthetics) or 372 (lead-free materials) has not been verified to reduce Total Trihalomethanes, however the box is worded.
NSF/ANSI 53
Counts — health standardHealth effects: lead, VOCs, cysts, chromium, and (post-P473) PFAS reduction.
2 filters in our registry hold an independently verified NSF/ANSI 53 claim for Total Trihalomethanes, listed below.
NSF/ANSI 58
Counts — health standardReverse osmosis: dissolved inorganics, arsenic, hexavalent chromium, and total PFAS.
No filter in our registry holds a verified NSF/ANSI 58 claim for Total Trihalomethanes. That means we hold no certification record — not that the standard could never cover it.
NSF/ANSI 401
Counts — health standardEmerging/incidental compounds: pharmaceuticals and select trace contaminants.
No filter in our registry holds a verified NSF/ANSI 401 claim for Total Trihalomethanes. That means we hold no certification record — not that the standard could never cover it.
NSF/ANSI 42
Does not count — not a health standardAesthetic effects: chlorine, taste, odor, particulates. No health-contaminant protection.
6 registry products carry an NSF/ANSI 42 claim referencing Total Trihalomethanes — and it still does not mean the product was verified to reduce Total Trihalomethanes from your water. Read it as a taste-and-odour claim only.
NSF/ANSI 372
Does not count — not a health standardLead-free materials (manufacturing content only). Not a water-treatment claim.
No registry product lists Total Trihalomethanes under NSF/ANSI 372. It would not count as verification of Total Trihalomethanes reduction in any case.
Counts are of active products in the WaterQualityLens filter registry holding a verified claim for contaminant code 2950 under that standard, as recorded by the certifying body (NSF, WQA, or IAPMO). Certification is granted per contaminant, not per product: a filter certified to Standard 53 for one contaminant is not thereby certified for Total Trihalomethanes.
Entity graph
Systems reporting Total Trihalomethanes
Water systems in our coverage whose most recent published sample set includes Total Trihalomethanes. Each value carries its sample date and the agency that reported it.
Certified reduction · commercial placements
Filters verified to reduce Total Trihalomethanes
These filters hold an independent NSF/ANSI health certification (Standard 53, 58, or 401) specifically for Total Trihalomethanes. Certification against a health standard means an accredited lab verified the filter reduces this contaminant — a materials-only claim such as NSF 42 or 372 does not.
- Verified PartnerAquaTru
Classic Countertop RO
AT-CLASSICCountertop RO$449NSF/ANSI 53Certified by NSF
- Verified PartnerWaterdrop
G3P800 Under-Sink RO
WD-G3P800Under-sink RO$549NSF/ANSI 53Certified by NSF
Hardware links are affiliate placements marked “Verified Partner.” Products appear here solely because they hold an independently verified NSF/ANSI health certification for Total Trihalomethanes; commercial arrangements never affect this list.