Frequently Asked Questions

Microplastics are tiny fragments of plastic smaller than 5mm. The ones we detect in tap water are typically much smaller — often 50x thinner than a human hair. They come from degrading plastic pipes, containers, textiles, and other sources. They're invisible to the naked eye and undetectable by consumer water testing kits.

We can't make safety claims. There is currently no federal safety standard for microplastics in drinking water. Research on the health effects of ingesting microplastics is still ongoing. What we can tell you is exactly how many particles are in your specific sample, so you can make informed decisions.

Multiple sources contribute. Aging plastic water mains and service lines can shed particles. Internal household plumbing (PVC, PEX, CPVC) is another source. Some particles may originate from water treatment facilities. Our data suggests that building age and plumbing type can significantly affect particle counts — the same municipal water supply can produce very different results at different homes.

Municipal water utilities test for regulated contaminants like lead, bacteria, and chlorine. Microplastics are not currently regulated under the Safe Drinking Water Act, so there's no requirement to test for them. California has passed legislation to develop monitoring standards, but implementation is still in progress.

We use fluorescence microscopy with Nile Red staining. Nile Red is a dye that binds to plastic polymers. Under specific wavelengths of light, the plastic particles fluoresce bright orange, making them clearly visible against a dark background. This is the same method marine biologists have used for years to detect plastics in ocean water.

From when we receive your sample, results are typically ready within 48 hours. You'll receive a high-resolution fluorescence microscopy image of your sample along with a particle count and tier classification.

Yes. Many people submit two samples — one from their unfiltered tap and one from their filter (RO, Berkey, Brita, etc.). This gives you a direct before/after comparison. Some of the most interesting results on the map are filter comparisons.

We currently focus on Los Angeles County, but we accept samples from anywhere in the US. The map is centered on LA because that's where we have the most density, but we're expanding as more people contribute.

Traditional lab tests (like SimpleLab) use GC/MS analysis and cost $600+. You get a PDF with numbers. Our approach uses fluorescence microscopy — you get a high-resolution image where you can actually see the plastic particles. Visual proof, not just data.

Particle counts represent the number of fluorescing (suspected microplastic) particles found in your 100ml sample. We classify results into three tiers:

• Low (0–5 particles) — Minimal contamination detected
• Moderate (6–15 particles) — Some contamination present
• High (16+ particles) — Elevated contamination levels

These tiers are relative benchmarks based on our dataset. No federal standard exists yet.

A high count doesn't necessarily mean your water is unsafe — we just don't know yet. Some practical steps people take: using a reverse osmosis (RO) filter (which our data shows significantly reduces particle counts), running water for 30 seconds before drinking, or testing again to see if results vary. You might also consider testing your filter's output to see how effective it is.

Yes. Water quality can change based on time of day, water pressure, recent plumbing work in your area, and seasonal factors. A single sample is a snapshot, not a comprehensive assessment. That said, homes with high counts tend to consistently show elevated levels, and homes with low counts tend to stay low.

Results are published on the map at the neighborhood level — we never share your exact address. The goal is to build a useful community resource. If you have concerns about privacy, reach out and we're happy to discuss.