Kirkland Signature Purified Water Plastic Bottle
Near you
Kirkland Signature is carried at Costco stores. Find one within 25 miles.
Summary
Kirkland Signature Purified Water scores 42/100. Independent testing flagged Total Trihalomethanes (THMs) at roughly 9 times the legal limit — chronic exposure to THMs is linked to reproductive harm and endocrine/hormone disruption. Sourced from municipal supply, treated with micron filtration, RO, and ozone sanitation, but elevated disinfection byproducts persist. Plastic bottle drives a likely-microplastic risk; pH 5.9.
At a glance
Contaminants 1
Source: Independent third-party laboratory testing
Microplastics Detected Moderate
Detected at a moderate level — a meaningful fraction of health-based exposure limits. Worth factoring in if this product is used regularly. Plastic bottle packaging contributes to a likely microplastic exposure risk over time.
Independent third-party testing.
Key ingredients 2
Total TrihalomethanesVery Bad
Total Trihalomethanes detected at approximately 9× the legal limit. Chronic exposure to THMs is linked to reproductive system damage and hormone disruption, in addition to long-recognized cancer risk.
See more about Total Trihalomethanes →Nitrate0.1 mg/LGood
Nitrate (as NO3) detected at 0.1 mg/L, below EWG's strict health guideline of 0.62 mg/L.
See more about Nitrate →Processing
Unprocessed or Minimally Processed Foods
Get the full breakdown in the Scout app
Scan any product to see lab results, healthy alternatives, and your personalized analysis.
Download on theApp Store