This one has the lowest legal limit of any volatile organic chemical on the EPA’s list — 2 parts per billion — and there’s a reason. Vinyl chloride is a known human carcinogen, and the cancer it causes is liver cancer.
What it is. Vinyl chloride is a colorless gas used to make PVC — polyvinyl chloride, the plastic in pipes, siding, and countless products. It’s also what TCE and PCE turn into when they break down underground, which means old solvent plumes can generate vinyl chloride years after the original spill.
Where it comes from. Three routes: industrial discharge from plastics and chemical plants, leaching from PVC pipes (especially older ones), and the breakdown of other chlorinated solvents already sitting in the groundwater. That last one catches people off guard — you investigate a TCE spill and find vinyl chloride where the TCE used to be.
The health picture, honestly. Liver cancer is the headline — the evidence from workers and animal studies is solid. At high exposures it’s also tied to liver damage and nerve effects. The EPA set the legal limit at 2 ppb with a health goal of zero — and even that 2 ppb reflects what labs can reliably measure, not a level where risk disappears. Keep it as low as you can get it.
How to test. Same playbook as the other VOCs: a lab test (EPA Method 524.2 or 502.2) from a state-certified lab. City water folks, check the annual water quality report. Well owners near industrial areas, old dry cleaners, or anywhere with a solvent history — test.
What removes it. Granular activated carbon and aeration — the EPA’s best available technologies for vinyl chloride. A whole-house GAC system at the point of entry, with aeration ahead of it when test numbers run high.
What does NOT remove it. Pitcher filters. Boiling — it just drives a volatile chemical into the air. Water softeners, UV, chlorine. Same story as its solvent cousins: this is a whole-house problem.
What I’d buy: Treatment type: whole-house granular activated carbon filtration, NSF or WQA listed, at the point of entry — with aeration ahead of it if your numbers are high. Retest after install and on a schedule. Carbon has a lifespan, and you need to know when it’s spent.
Vinyl chloride doesn’t give you a second warning — by the time you know it’s there, it’s been there a while. Test if the history around your well gives you any reason at all. Then treat the whole house and verify.
Curious what’s in your tap? Start with What’s In Your Water?
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