Testing microplastics in tap water vs bottled water can be done through several scientific methods. Heres a breakdown of how its tested, what differences typically emerge, and how you might approach such a test practically (if youre considering doing it or commissioning one).
Sample Collection
Collect at least 1 liter of each sample (tap and bottled).
Use glass or stainless steel containers to avoid plastic contamination.
Filtration
Water is filtered through very fine filter paper (usually 0.45 m or smaller).
This captures particles, including microplastics.
Digestion (Optional)
Organic material in the sample is chemically digested (e.g., with hydrogen peroxide) to isolate plastic particles.
Microscopy + Spectroscopy
Use microscopes (light or fluorescence) to visually identify particles.
Use FTIR (Fourier-transform infrared spectroscopy) or Raman spectroscopy to confirm if particles are plastic and identify the type (e.g., PET, PE, PP).
Water Type | Avg. Microplastic Particles per Liter (approx.) | Common Polymers Found |
---|---|---|
Tap Water | 020 particles/L (depending on country/region) | PE, PP, nylon |
Bottled Water | 50300+ particles/L (much higher on average) | PET, PP (from bottle/cap) |
A 2018 study by Orb Media tested 259 bottles and found 93% contained microplastics.
You can:
Send samples to a lab that does environmental or food-grade microplastic testing. Labs charge from $300$1,000 per sample.
DIY with microscopes and filter paper possible but less accurate and only visual (no polymer ID).
Example certified labs:
Eurofins (Global)
ALS Environmental
SGS
Microplastic Lab (Europe-based specialized service)
Bottled water typically contains more microplastics than tap water, largely from packaging.
Testing requires careful filtration, identification, and polymer analysis.
For accurate results, use lab-based FTIR/Raman testing.