Guide to safety and security in period products
Here you can learn everything about the risks of period products, what studies and research show, and how to choose safe products like period underwear without dangerous chemicals.
Why period product safety is important
De seneste år er der kommet markant mere opmærksomhed på sikkerheden i menstruationsprodukter. Mange søger i dag på spørgsmål som:
- Are tampons safe?
- PFAS in pads
- Tungmetaller i tamponer
- Er menstruationsprodukter sikre?
Det er ikke tilfældigt.
Menstruationsprodukter bruges i gennemsnit ca. én uge hver måned – ofte i op mod 40 år af en menstruerendes liv. Nogle produkter, som tamponer og kopper, anvendes desuden inde i kroppen i mange timer ad gangen.
Vi skal turde at stille højere krav til både lovgivning og producenter.
Research finds critical content in period products
Several international studies have raised questions about ingredients in traditional menstrual products in recent years.
American studies have detected traces of heavy metals in certain tampons, and Nordic media have reported findings of lead, among other things, in products on the Scandinavian market.
There has also been focus on the discovery of PFAS (per- and polyfluoroalkyl substances) in some menstrual panties.
In addition, experts have pointed to challenges with the use of biocides – for example, nanosilver – in textiles, including menstrual panties.
The increasing focus is therefore not about creating fear – but about transparency, documentation and informed choices for us as consumers.
Sources: NIEHS , VG.no , UC Berkele
What harmful substances can be found in period products?
Biocides & antibacterial chemicals
Biocides such as nanosilver are used in menstrual panties to reduce any odors.
The Danish Environmental Protection Agency does not recommend that these be used in areas near mucous membranes, where the chemicals can be absorbed and accumulate in the body.
The FDA believes that nanosilver can help kill the healthy bacteria in the vagina (lactobacillus) that help fight infections. This can promote a viable environment for harmful bacteria, potentially leading to a variety of infections, pelvic diseases, and pregnancy complications.
Source: Mapping and
health and environmental assessment of biocidal active substances in clothing - Danish Environmental Protection Agency
PFAS (per- and polyfluoroalkyl substances)
PFAS (per- and polyfluoroalkyl substances) are a group of synthetic chemicals, also called “forever chemicals” because they break down very slowly in nature and can accumulate in the body. They have previously been used to give textiles a water and liquid-repellent effect.
Several studies have linked certain PFAS substances to endocrine disruption and other health risks.
Therefore, there is increasing focus on avoiding PFAS in products that are used close to the body – including menstrual products.
Source: NY Times
Lead and dioxin
Found in certain pads and tampons.
Lead can occur as contamination from raw materials or production, while dioxins have historically been associated with cotton bleaching processes.
Even in low concentrations, these substances are of concern because menstrual products are used regularly over many years – and in some cases inside the body.
Long-term exposure to lead is associated with effects on the nervous system and hormonal balance, while dioxins are classified as potentially carcinogenic.
How do I choose safe period products?
The increasing focus on unwanted chemicals and heavy metals in menstrual products calls for greater transparency, testing and stricter regulation of ingredients in menstrual products.
But until this is introduced via legal requirements, you can do the following:
〰️ Avoid menstrual panties that mention "antibacterial" treatment, "stay fresh" treatment or similar. If you are bothered by odor in your menstrual panties, use a special detergent like Bloody Clean, which is also Allergy Certified .
〰️ If possible, buy organic pads and tampons, which in VG's study contained the least lead and arsenic.
〰️ Buy menstrual pads and cups made of medical silicone from manufacturers in the EU.
〰️ Ask brands to send results from testing their menstrual products.
We have our absorbent underwear tested for, among other things, PFAS by a third party in Germany.
"Do your panties contain PFAS or biocides?"
Hvad gør Flow for at sikre trygge menstruationsprodukter?
Kvalitetskrav til vores produkter
Først og fremmest: At tilsætte kemiske behandlinger til menstruationstrusser er unødvendigt.
Dine menstruationstrusser fra Flow virker pga. vævninger i stof - ligesom dit sportstøj Med en god vaskerutine og fx et vaskemiddel til menstruationstrusser som Bloody Clean, så er du godt på vej.
🩸 Alle stoffer vi bruger er Oeko-tex certificerede. Når vi bruger bomuld er det altid økologisk bomuld.
🩸 Hvis vi bruger polyester, er der tale om virgin polyester, som har længere fibre og derfor mindre risiko for at shedde og skabe mikroplastik.
🩸 Vi er i proces med at skære betragteligt ned for mængden af polyester i vores absorberende indlæg. Det ser du allerede i fx vores Period Flow Shorts, som er gode til natten.
We test systematically
Dine menstruationstrusser fra Flow virker pga. vævninger i stof. Ikke pga. af nogen former for kemi. Alle stoffer vi bruger er Oeko-tex certificerede.
Vi bruger ikke nanosølv eller PFAS i vores trusser heller. Og vi tester alle vores trusser for PFAS hos tredjepart i Tyskland hvert andet år.
Vi har senest i 2023 fået anmærkningen "No detectable levels" af PFAS og andre biocider. Det vil sige; der var ingen målbare mængder i trusserne.
Men at sige "Fri for PFAS" - det er vildledende. Det er det 'uhyggelige' ved PFAS, det er stoffer som er alle vegne i vores miljø. Så selv om vi ikke bevidst har kommet PFAS-kemikalier i vores trusser, så kan de have rørt ved noget, der har PFAS på sig.
Safety and quality we are proud of
Period underwear
FAQ about period product safety
What is period underwear?
Period underwear are is reusable type of panties with a built-in absorbent layer that collects menstrual blood. They can be used as an alternative or supplement to tampons, cups or pads.
How do period panties work?
Period underwear typically consist of several layers: a layer that fits snugly against the body, an absorbent core, and a protective membrane. The layers wick fluid away from the skin and keep it contained.
Read our full guide to period underwear here →
Read our full guide to period swimwear here →
How much can period underwear absorb?
Absorbency depends on the model and flow type. There are panties for light, moderate and heavy bleeding, and some models are suitable for nighttime use.
Find our selection of period underwear right here →
Can period underwear be used alone?
Yes, for light to moderate bleeding they can often be used alone. For heavy periods you may need to combine with a cup, disc or tampon for extra security.
Can you bathe with period underwear?
Regular period panties are not designed for bathing.
For swimming, there are specially developed period swimwear, see our selection here →
How do I wash period underwear?
Rinse in cold water after use and wash at low temperature without fabric softener. Air dry to maintain absorbency and longevity.
Read more about washing your period panties here →
Is period underwear safe?
Most period underwear is considered safe, especially if they are free of PFAS and not added biocides. It is important to choose products with transparency about materials and testing.
What about PFAS in period underwear?
PFAS are a group of so-called "forever chemicals" that can accumulate in the body and have been linked to health risks. Therefore, there is increasing focus on avoiding PFAS in products used close to the body.
What about heavy metals like lead?
Traces of heavy metals such as lead have been found in some menstrual products. Long-term exposure is a concern because the products are used regularly over many years.
What about biocides and nanosilver?
Biocides such as nanosilver are added to some textiles to inhibit bacterial growth. There is debate about their impact on the skin microbiome and the environment, which has increased focus on alternatives without added biocides.