Here at Nam & Ko, we strive to be as transparent as possible. In this spirit, we wanted to share our design process for making the n1 nanofiber filter.
What is the n1 nanofiber filter?
The n1 is a disposable filter made from a material called nanofiber. It’s designed to be worn with a Nam & Ko mask.
Why did we make the n1 nanofiber filter?
Filters increase the protection of a cloth face mask. We wanted to give our customers the option to wear a filter with their mask for extra peace of mind.
Why did we pick nanofiber?
We wanted to find filter material that met 3 criteria:
1. It should filter comparable to a non-medical KN95 from the grocery store
2. It should be non-toxic
3. It should be breathable
We first looked at readily available filter materials:
- Coffee filter? Breathable, but only 14% filter efficient
- 2.5PM carbon filters? These were designed to filter at 2.5 microns (hence the name). The gold standard for face mask testing is 0.3 microns.
- HEPA vacuum filter? Very filter efficient at 0.3 microns. But this type of material could be manufactured with hazardous fiberglass.
Here’s how it performed against our checklist:
1. Was it filter efficient? To answer this question, we sent the filters for testing at 4C Air, an air filtration company that had been testing donated masks on behalf of hospitals. Here were the results:
Nanofiber scored better than the non-medical KN95 from a local supermarket. It also tested better than the box of non-medical surgical masks from Walgreens.
2. Was it non-toxic? To answer this question, we sourced material that had been already tested for safety from toxic substances. The manufacturer was based in South Korea and had used protocols listed in the National Institute of Environmental Research Notice 2018–71.
3. Was it breathable? Very. I wore an s1 face mask with a filter for 6 hours on the train. My boyfriend preferred wearing n1 filters to the gym over his KN95s.
Some last thoughts
Our masks and filters are non-medical.
We want to emphasize that our filters and the masks we bought for testing are non-medical. These are the types of masks you can buy at Walgreens so that medical PPE is reserved for healthcare workers.
What’s the difference between medical and non-medical? Medical masks are designed to be used in clinical settings. Every product must perform according to strict standards. In contrast, non-medical masks vary significantly in performance according to the CDC.
As a small business, we cannot QC every filter to guarantee performance. It was never our goal to make medical masks. Our mission has been to make great masks and filters for the public — so they can look good and keep our community safe.
We also used protocol to mimic the CDC NPPTL guidelines for testing masks in response to COVID-19. You may see other brands like using tests like BFE or PFE. It’s easier to score high on these tests, which is why brands use them. But these tests aren’t recommended by the CDC when evaluating face masks for pandemic response.
Nanofiber is an emerging technology.
Nanofiber is the new kid on the block. It encompasses a wide range of materials, from plastics to fabrics. Its use is already widespread in exciting areas like tissue engineering and surgical application. We are learning that working safely within the larger field of nanotechnology requires regulation.
Personally, I wear my face mask without a filter most of the time. If I’m going to take the subway, I throw on a filter.
Our hope is that by being as transparent as possible, we share some of our learnings.
Stay safe and well — we’re all in this together.
Alice | Founder of Nam & Ko