Materials & testing
What's in your Kiri,
and how we know.
Four layers in one thin pair, and every layer independently lab-tested, including the leakproof shield.
- 19PFAS compounds tested. None detected.
- Every layertested, including the leakproof shield
- 50 / 75 mlDaywear / Nightwear absorbency
- Noneno chlorine, no dioxin, no rayon
Four layers, one thin pair
- Moisture-wicking top layer
The layer against your skin
- Antibacterial layer
Just beneath the top layer
- Absorbent core
Holds 50 ml in Daywear, 75 ml in Nightwear
- Leakproof shield
The layer that makes it leak-proof
See it for yourself
75 ml of nightwear absorbency — absorbed, not spilled.
Kiri Nightwear, filmed in real time. No dye tricks, no slow motion — just four layers doing their job.
This page sets out what Kiri period underwear is made of and what we have had independently tested. If you want the underlying reports, ask us and we will send them.
What the fabric is
Our period underwear is built in four layers: a moisture-wicking top layer against the skin, an antibacterial layer, an absorbent core, and a leakproof shield. The Daywear pair holds 50 ml; the Nightwear pair holds 75 ml.
There is no dioxin, no chlorine and no rayon anywhere in the construction.
Independent testing
In March 2023 we had our Daywear and Nightwear period underwear tested by an independent third-party laboratory in Hong Kong for 19 PFAS compounds, including PFOA and PFOS. Every layer was tested, including the leakproof shield.
| What was tested | Covered | Result |
|---|---|---|
| 19 PFAS compounds, including PFOA and PFOS | Every layer, including the leakproof shield | None detected (detection limit 10 ppb) |
In May 2023 we sent our Daywear and Nightwear period underwear to an independent third-party testing laboratory in Hong Kong. Both styles passed both tests requested.
| What was tested | Standard | Result | Limit |
|---|---|---|---|
| PFOA and its salts | EU POPs Regulation (EC) No. 2019/1021, as amended by 2020/784 | Below detection limit (<10 ppb) | 25 ppb |
| PFOA-related substances | As above | Below detection limit (<50 ppb) | 1,000 ppb |
| PBDE flame retardants (Tetra, Penta, Hexa, Hepta, Deca) | EU POPs Regulation (EC) No. 2019/1021, Annex I Part A | Below detection limit (<5 mg/kg) | 500 mg/kg |
“Below detection limit” means the laboratory found none at the lowest level its method can measure — not simply that we came in under the legal cap.
Why we publish this
Period underwear sits against your skin for hours at a time, and concern about what is in it is entirely reasonable. Our view is that a brand should be able to show you a document rather than a slogan.
Ask any brand — including us — for their testing documentation and material disclosures, then read what comes back and check what it actually covers. A brand that cannot produce anything has told you something.
Ask us for the reports
Email hello@kirijourney.com and we will send the full reports. If there is a specific substance you need us to test for, tell us — it is useful for us to know what customers are actually worried about.
More on how the layers work in our guide to how period underwear works, and on keeping them working in how to wash and care for period underwear.
