Unraveling The Secrets Of Closed-Loop SeaCell Clothing
Bamboo viscose is not sustainable. SeaCell is. Here’s the difference.
What Does “Closed-Loop” Mean In Clothing?
At its core, a closed-loop system is a way of making yarn where resources are reused and recycled instead of being flushed into waterways.
On the other hand, in an open-loop system, toxic chemicals are used and discarded, polluting rivers and endangering workers.
Traditional bamboo viscose rayon is the most common version of open-loop fabric that you’ll find. It’s in a lot of athletic clothes and often framed as sustainable. However, viscose is made through a cocktail of caustic chemicals, including sodium hydroxide, sulfuric acid, and carbon disulfide (CS₂).
In large amounts to dissolve cellulose so it can be reformed into fibers that are not recycled between uses. Instead, they get washed down the drain… and into the environment.
Here is how the three fibers compare on how they are made and what their production leaves behind.
| SeaCell | Bamboo Viscose | Conventional Cotton | |
|---|---|---|---|
| Production System | Closed loop: the solvent is recovered and reused | Open loop: chemicals discarded after one use | Farmed fiber; no solvent spinning step |
| Processing Chemistry | One organic solvent, recognized as non-toxic | Sodium hydroxide, sulfuric acid, and carbon disulfide | Needs more dye than lyocell-class fibers (Uren 2024) |
| Documented Pollution | No solvent released into the environment | Severe pollution reported near production regions (Changing Markets Foundation) | 11% of world pesticide use, 24% of insecticide use |
| End Of Life | Compostable alongside natural fibers | Biodegradable cellulose, but its process chemicals are discarded | Biodegradable natural fiber |
The short version of the table above: SeaCell recovers and reuses a non-toxic solvent in a closed loop, while conventional bamboo viscose discards sodium hydroxide, sulfuric acid, and carbon disulfide after a single use. It is that open loop, not the bamboo plant itself, that makes the fabric unsustainable.
Circular Fabric Spotlight: What Is SeaCell Fabric?
Now, how does SeaCell fashionably fit into the conversation? What is it exactly?
It’s made by reconstructing cellulose (plant cells) and then spinning it into fibers that can be blended with other materials like cotton and wool or spun on its own into yarn.
It’s made in a closed-loop, which does not release solvents into the environment, unlike viscose. An organic solvent is used throughout the entire closed-loop process, and the Forest Stewardship Council has recognized the solvent as non-toxic. SeaCell combines two different plant fibers, seaweed (obviously) and wood pulp harvested from eucalyptus tree farms.
Seaweed is regeneratively farmed from the cool blue fjords of Iceland every 4 years. Similar to how yaks graze, we only take the tops of the plant, leaving the lower sections to regenerate.
The wood pulp comes from Eucalyptus and Beech Trees, two fast-growing trees that require little water.
These trees are harvested in Europe from Forest Stewardship Council (FSC) certified tree farms. The FSC certification means that a newly planted tree must replace every tree used in the production of SeaCell.
Seaweed grows quickly without pesticides or farmland, in contrast to eucalyptus and beech trees that grow more slowly. And while SeaCell does still utilize some wood pulp, the addition of seaweed cuts this down significantly, reducing strain on much more slowly replenishable resources in favor of a constantly renewable one.
All this results in a fabric that, in my experience, wears like a second skin. It’s light, breathable, and soft enough to keep you comfortable on its own or layered under a sweater.
During my wear test of my new SeaCell T-shirt, it felt weightless but far from flimsy.
I also appreciate that the SeaCell is not only healthy for the body due to lack of toxic processing, but also kind to sensitive skin like mine. The fiber is hypoallergenic, and the seaweed content is believed to retain antioxidants that may soothe and protect. While I couldn’t measure that claim firsthand, I can say the fabric remained gentle and irritation-free throughout long hours of wear.
Why Closed-Loop Fabric Systems Matter
The difference between closed-loop and open-loop production isn’t just a technicality; it’s the dividing line between textiles that protect ecosystems and people, and those that actively harm them.
The chemicals flushed away after a single use in an open-loop system find their way into rivers and groundwater, poisoning aquatic ecosystems and leaching into farmland. Communities downstream bear the brunt, with water supplies contaminated by toxic residues that can take years to break down.
Viscose production, for instance, has been linked to severe pollution in regions of China, India, and Indonesia, where entire waterways have turned lifeless from unchecked industrial discharge, according to the Changing Markets Foundation’s Dirty Fashion report.
At the Aditya Birla viscose factory in India, investigations reported by The Independent revealed water near discharge pipes was “extremely polluted,” failing local water quality standards, with downstream communities suffering health effects and environmental degradation.
Besides water pollution, air pollution is also a major consequence. Carbon disulfide can volatilize, contributing to atmospheric emissions that affect both ecosystem health and air quality nearby.
The social impact is just as critical, especially considering many factories have inadequate or nonexistent protective equipment.
Carbon disulfide in particular is known to cause neurological damage, reproductive and hormone issues, and in severe cases, death, according to published occupational-health research. One study of rayon workers in Taiwan exposed to carbon disulfide found that among exposed workers, 43.4% had hypertension compared to 7.1% in the controls (Chang et al., American Journal of Industrial Medicine, 2007).
This is where closed-loop systems make a major difference. No toxic chemicals. No wasted resources. And because the resulting fibers are still compostable at the end of their life alongside purely natural materials like yak wool, they offer a rare example of true circularity in fashion.
SeaCell is a material that gives back to the earth rather than lingering as microplastics.
Oliver Charles And The Future Of Zero-Waste Clothing
Closed-loop fabrics aren’t just a niche innovation; they’re a blueprint for where the fashion industry could (and should) be headed.
As demand for transparency grows, brands that embrace circularity will be better positioned to lead the charge toward a fashion economy where waste is designed out of the system.
Oliver Charles has already carved out a reputation for elevating wardrobe staples through thoughtful material choices. By introducing a new SeaCell line into their lineup, they’re expanding that philosophy beyond sweaters and into year-round basics.
Their approach shows that sustainability doesn’t have to be a side category. It can be woven into everyday essentials. With their commitment to closed-loop cellulosics and pure, natural fibers, Oliver Charles is helping prove that circular fashion, both in terms of fiber production and end-of-life disposal, isn’t a trend, but a future standard.
Frequently Asked Questions
Is Bamboo Viscose Actually Sustainable?
No. Traditional bamboo viscose rayon is the most common open-loop fabric, made with a cocktail of caustic chemicals (sodium hydroxide, sulfuric acid, and carbon disulfide) that dissolve cellulose and are then washed down the drain rather than recycled. Despite often being framed as sustainable, viscose production has been linked to severe pollution in regions of China, India, and Indonesia.
What Is SeaCell Fabric Made From?
SeaCell combines two plant fibers: seaweed regeneratively farmed in the fjords of Iceland, harvested every 4 years by taking only the tops of the plants, and wood pulp from fast-growing eucalyptus and beech trees. The trees come from Forest Stewardship Council (FSC) certified European tree farms, where every tree used in production must be replaced with a newly planted one.
Does SeaCell Break Down At The End Of Its Life?
Yes. Because SeaCell fibers are spun from plant cellulose in a closed-loop process, the finished fabric is still compostable at the end of its life, alongside purely natural materials like yak wool. Rather than lingering in the environment as microplastics, a SeaCell garment gives back to the earth once it is finally retired.
How Does A SeaCell T-Shirt Feel To Wear?
In the author’s wear test, the SeaCell T-shirt wore like a second skin: light, breathable, and soft. It felt weightless but far from flimsy, comfortable on its own or layered under a sweater. The fabric stayed gentle and irritation-free through long hours of wear, including on the author’s sensitive skin.
Own less, own better. Start with an Oliver Charles sweater.
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