Sargassum is a brown macroalgae that floats freely across tropical and subtropical oceans worldwide. Unlike most seaweed, it does not attach to the seafloor — it lives its entire life cycle at the ocean surface, forming vast floating mats that can stretch for hundreds of kilometres. It is one of the most abundant biomasses on earth, and until recently, it was considered almost entirely a nuisance.
That is changing. Sargassum is now being processed into a range of materials — including packaging foam — as industry looks for bio-based alternatives to petroleum-derived plastics. Here is what you need to know.
Key Facts About Sargassum
Where Sargassum Comes From
The largest concentration of sargassum is in the Sargasso Sea — a region of the North Atlantic bounded by ocean currents — which gives the seaweed its name. But sargassum blooms have expanded significantly since the early 2010s, driven by warming ocean temperatures and nutrient runoff. Today, massive sargassum mats wash ashore across the Caribbean, West Africa, and the Gulf of Mexico every year.
In many coastal communities, sargassum arrival is a significant environmental and economic problem. Decomposing mats damage coral reefs, harm marine life, and devastate tourism in beach-dependent economies. Governments in Mexico, Barbados, and several West African nations have spent tens of millions of dollars on sargassum removal programmes.
The opportunity: what is an environmental liability on the beach can become a valuable raw material at a processing facility. Converting sargassum into packaging foam transforms a waste stream into a supply chain — and removes the biomass from coastal ecosystems where it causes harm.
Why Sargassum Works as a Packaging Material
Sargassum has several properties that make it interesting as a packaging feedstock:
- High fibre content — sargassum contains structural fibres that provide mechanical strength when processed into foam or moulded formats
- Natural binders — alginates and other polysaccharides in sargassum cell walls act as natural binders when processed, reducing the need for synthetic additives
- Low moisture retention after drying — dried and processed sargassum foam maintains dimensional stability under standard storage and transit conditions
- Renewable and abundant — unlike agricultural biomass, sargassum does not compete with food production for land or freshwater
How Sargassum Is Converted Into Foam
Is Sargassum Foam Better Than EPS?
The honest answer is: it depends on the application. EPS is a mature, optimised material with decades of performance data and an established supply chain. Sargassum foam is early-stage — performance data is building, and commercial scale is at pilot level.
What sargassum foam offers that EPS cannot is regulatory compliance after 2030. Under the EU PPWR, EPS foam inserts will no longer be compliant for packaging sold in the EU market. Sargassum foam, with ≥85% biobased content, is positioned to meet the PPWR bio-based content and recyclability requirements that EPS fails.
For packaging engineers and procurement teams evaluating the transition away from EPS, sargassum foam is one of the few bio-based alternatives that combines ocean-origin feedstock, a low density range comparable to EPS, and a smooth white surface finish suitable for premium packaging applications.
See and feel it for yourself
Request a physical sample kit — standard, high-density, and low-density sargassum foam grades. €50 per sample, shipped worldwide.
Order sample kit →