bio. retainers — the only retainers in the UK independently confirmed free from harmful microplastics. You're reading the results now.
— The bio. Standard

The bio.
Standard.

Most dental devices are manufactured from thermoplastic polymers. Most manufacturers have never published any data on what those materials shed during wear. bio. considers this unacceptable.

8 hours every night.
For years.

A retainer is in your mouth overnight, in close contact with saliva and mucous membrane, every night — often for a decade or more. The total material exposure per retainer exceeds almost any other personal care product.

No brand asked the question. We did. And then we published the answer.

— The claim

"bio. retainers are the only retainers in the UK independently tested for microplastic particle release and confirmed free from harmful microplastics."

This is not a marketing claim. It is a published scientific result. No other retainer brand in the UK has published independent third-party testing data for microplastic particle release — not from dental practices, not from DTC brands, not from the biggest names in the category. They could test theirs. They choose not to.

— The bio. material difference

What bio. is made of.

Most dental device brands never disclose their materials. We built the opposite model: every substance disclosed, every claim tested, every result published.

I
100% Microplastic-Free
No unstable plastics that fragment and leach into your body over time. bio. materials are independently tested for microplastic particle release under simulated wear conditions — confirmed below detection limits.
Confirmed by ISO 17025 lab
II
Advanced Organic Polymers
Formulated from biocompatible organic polymers derived from plant-based sources. Extreme durability, long-term safety. Full polymer composition disclosed by FTIR spectroscopy — a standard no other UK brand meets.
Plant-derived · BPA-free · phthalate-free
III
Independently Tested
Every production batch tested by an ISO 17025-accredited laboratory. Results for BPA, BPS, BPF, phthalates, heavy metals, and microplastic release published in full by lot number. Re-tested on every new production run.
— Testing protocol

Our testing protocol.

The bio. Standard is our public material testing protocol. Every product we sell is independently tested by an ISO 17025-accredited laboratory. Every result is published in full below, referenced by product lot number and test date.

If we don't know something, we say so. If we can't support a claim, we don't make it.

Test Method Standard Laboratory
Microplastic particle release
Simulated wear in oral fluid
Oral simulant extraction at 37°C, 14-day continuous exposure, particle counting by flow cytometry ISO 10993-12 (extraction), adapted oral exposure protocol ISO 17025-accredited independent laboratory
BPA, BPS, BPF leachate levels LC-MS/MS analysis of extraction eluate EU Regulation (EC) No 10/2011 migration limits ISO 17025-accredited independent laboratory
Phthalates GC-MS extraction and quantification REACH Annex XVII restriction list ISO 17025-accredited independent laboratory
Heavy metals ICP-MS on oral simulant after extraction ISO 10993-13 (polymeric medical devices) ISO 17025-accredited independent laboratory
Biocompatibility — cytotoxicity L929 fibroblast cell viability assay ISO 10993-5 (cytotoxicity) ISO 17025-accredited independent laboratory
Polymer composition disclosure FTIR spectroscopy full spectrum identification bio. disclosure standard (in-house, published) ISO 17025-accredited independent laboratory
— Published results

Published results.

Results referenced by product, lot number, and test date. Re-tested on every new production batch.

Product Lot Number Test Date Laboratory Report
bio.retainers Lot [XXX] [Date] ISO 17025 Accredited PDF — On file
bio.aligners Lot [XXX] [Date] ISO 17025 Accredited PDF — On file

Reports will be linked directly as PDF downloads once initial test batches are completed. Lot numbers and dates updated with every new production run.

— The plain statement

"bio. retainers are the only retainers in the UK independently tested for microplastic particle release and confirmed free from harmful microplastics."

The data is above. No other retainer brand in the UK has published equivalent independent testing data for microplastic particle release. They could test theirs. They choose not to.

Order bio.retainers →

Questions about our testing methodology? Contact hello@bio.uk — we will answer directly.