Ongoing experiment — Round 1 of 3
We Tested 7 Bottled Water Brands for Microplastics. All 7 Had Them.
Liquid Death, Fiji, Crystal Geyser, Dasani, Evian, San Pellegrino, and Path — tested using Nile Red fluorescence microscopy in our LA lab. Every single one tested positive for particles consistent with microplastics, with a fluorescence signature matching PET (water-bottle plastic).
Including the aluminum cans. More on that below.
The Experiment
We're testing the same 7 brands over 3 months under different storage conditions. Same methodology each time. Here's the plan:
March 2026
Fresh off the shelf, room temperature
April 2026
Same batch, 30 days at room temperature
May 2026
Same batch, 30 days in a hot car
The question everyone asks: does water get worse the longer it sits in plastic? We're going to find out.
Round 1 — March 2026
Fresh Off the Shelf
All 7 brands purchased from grocery stores in Los Angeles. Tested within 48 hours of purchase using our standard Nile Red fluorescence process.
Liquid Death
Aluminum canAluminum cans have PET-based interior linings
Fiji
Plastic bottleCrystal Geyser
Plastic bottlePath
Aluminum canPET-lined aluminum can
San Pellegrino
Plastic bottleEvian
Plastic bottleDasani
Plastic bottleRanked: which bottled water has the least microplastics
From least to most particle load in Round 1. Path read lowest at 106, Dasani highest at 143 — but every brand tested positive, so “least” means lowest load, not none.
- 1PathLeast (lowest reading)106
- 2San PellegrinoPositive — mid-band
- 3EvianPositive — mid-band
- 4FijiPositive — mid-band
- 5Crystal GeyserPositive — 106–143 band
- 6Liquid Death141
- 7DasaniMost (highest reading)143
The aluminum can finding
Liquid Death and Path both come in aluminum cans. Most people assume aluminum = no plastic. But aluminum cans have a thin plastic lining inside to prevent the metal from reacting with the liquid. That lining is made of PET-based plastic. Both brands matched our PET training signature — the classifier identified them as water bottle plastic without being told what container they came from.
All testing performed at our LA lab using peer-reviewed Nile Red fluorescence methodology. See how we test →
Is there a safe bottled water without microplastics?
Short answer: not among the brands we tested. All seven came back positive for particles consistent with microplastics, and every one matched the same PET signature — the plastic the bottles and can linings are made of. There is no clean option here, only degrees of particle load.
If you're asking which bottled water has the least microplastics, Path had the lowest reading in Round 1 and Dasani the highest — but the spread between brands was narrow, and “least” is not the same as “none.” The container is the common thread: a plastic bottle or a PET-lined aluminum can. The full brand-by-brand ranking is on the complete bottled water study.
The honest takeaway: switching brands doesn't get you to zero. The only way to know what's actually in the water you drink — bottled, tap, or filtered — is to test it. That's why we built an at-home kit that uses the same Nile Red method as this study.
Next Up: Does Heat Make It Worse?
In Round 2, we're testing the same brands after sitting at room temperature for 30 days. In Round 3, we'll leave them in a hot car in an LA summer.
If you've ever left a water bottle in your car and drank it later — Round 3 is for you.
Results updated monthly. Check back in April for Round 2.