Sustonable's EIC Accelerator Plastic Bottle Stone, 7 Years On

The company behind Sustonable has three names in the public record. The Dutch business register lists it as Innovative Stone Technologies B.V., registration number 61695858, with the trading name INNSTECH, according to OpenCorporates and North Data. CORDIS spells the grant holder "Innovative Technologies Stone BV", with the words in a different order, at the same address in Alphen aan den Rijn, according to the project fact sheet. The European Commission's list of 5 June 2019 winners names it simply "INNSTECH", in Amsterdam. Sustonable is the product, the brand, the project acronym and the web address, and today the company presents itself under that name on its website.

The material is a thin slab of crushed mineral bonded with recycled PET from plastic bottles instead of the resins used in engineered quartz stone. In the June 2019 cut-off of the EIC SME Instrument Phase 2, the Horizon 2020 pilot of what became the EIC Accelerator, the company won an EU contribution of €2,162,758.50 towards a €3,089,655 project to upgrade its production line and qualify the material for kitchen countertops. The project ran from 15 November 2019 to 14 November 2021. It was grant only, and the Commission's list names INNSTECH as the sole company of the project.

Where the Company Stands Now

The company is active. North Data records balance sheets for 2022, 2023 and 2024, the last two published on 5 May 2026, and lists no insolvency, according to North Data; OpenCorporates lists the company as active. The figures in those balance sheets are behind a paywall and could not be checked for this article, so equity, losses and staff numbers are not reported here.

The website gives two addresses: the registered office in Alphen aan den Rijn and a site in the Polatlı Organised Industrial Zone near Ankara, labelled "Sustonable Türkiye", according to the company's news page. A CORDIS Results in Brief article published in April 2022 had already reported that INNSTECH "has now commissioned a demonstration production line to be located in Turkey", according to CORDIS. The Turkish operating entity, its owners and its capacity could not be identified in the sources checked.

Recent company news points the same way. In October 2025 Sustonable said it had been named "Startup of the Year" at the Sustainable Business Awards in Istanbul, an award its head of marketing accepted, and in July 2025 it announced REACH compliance, according to Sustonable. The award could not be confirmed with the organiser. In a September 2025 interview, the CEO told the Society of British and International Interior Design that the company was "now fully focused on the UK market", according to SBID.

How Bottle Stone Differs From Quartz Slabs

Engineered stone, the quartz slabs sold for kitchen worktops, is crushed quartz held together by petroleum-based resin and pressed into thick, heavy slabs. INNSTECH's process uses recycled PET as "the only binder material, without any volatile chemical solvents", and makes thinner, lighter slabs, according to the company's Phase 1 report. The company says each square metre uses about 100 PET bottles, a figure repeated by CORDIS and SBID. Designs are applied by sublimation printing, which lets the same base slab imitate marble, terrazzo, concrete or wood, according to Sustonable.

The recipe has changed. The 2019 project describes quartz and recycled PET; the company's current environmental product declaration, published on 18 April 2025 and valid until April 2030, covers a "rGlass+rPET+Feldspar" surface, with recycled glass and feldspar, according to Environdec. An earlier declaration for the product, registered as S-P-03743, expired on 17 May 2026, according to Environdec.

The headline efficiency claims have also moved. The 2019 project objective said the slab uses "only 20% of the raw materials" of engineered stone; the 2022 CORDIS article quoted "only 50 % of the raw materials"; and the company's 2025 news said "70% less raw material". The three figures cannot all describe the same product, and none of them has been independently tested in a public source.

What the EIC Project Promised, and What the Record Shows

The Phase 1 feasibility study, a €50,000 grant from February to May 2019, set out the plan. The pilot plant had produced about 450 slabs of 250 by 80 cm, and the product "is not 100% qualified for kitchen countertops yet". Phase 2 was to add a proprietary surface-hardening layer so the product "will qualify on all criteria for kitchen countertops", raise output from 7,000 m² a month on one shift to 23,000 m² a month on three shifts (given as 250,000 m² a year), and demonstrate recycling with a take-back system, according to the Phase 1 report. The Phase 2 objective added a medium-scale plant of 400,000 m² a year, revenue of €48.4 million in 2027, and said the Dutch countertop leader Dekker had "signed up as a co-investor" to sell and install the material, according to CORDIS.

The final report, covering November 2020 to November 2021, is frank. The production line was commissioned and trial production of 10,000 m² was run. But "the SUSTONABLE product does not fully meet the engineered stone requirements yet", it says; it was accepted as a kitchen worktop by the Danish fabricator DFI Geisler, while with Dekker Zevenhuizen the company was discussing selling the current product "with a different sub-brand" and continuing development. A first recycling test with cutting and polishing waste worked, and "the process is now commercially ready", though capacity and efficiency "needs to be improved", according to the Phase 2 report. The project ended on its scheduled date. Holland Circular Hotspot dates the first customer deliveries to October 2021, a month before the project closed, according to its case study.

1. Qualify for all kitchen countertop criteriaPartlyFinal report: does not fully meet engineered stone requirements; accepted by DFI Geisler.
2. Production line commissioned and in useDelivered10,000 m² trial production; first customers from October 2021.
3. 250,000 m² a year capacityNot achievedNo capacity figure announced by the company or others.
4. Recycling and take-back systemPartlyWaste recycling test succeeded; no take-back scheme reported.
5. Sales through DekkerNot achievedOnly talks reported in 2021 and 2022; no launch announced.
6. €48.4M revenue in 2027UnverifiedNo revenue figure is public.

The grant also covered a related company. CORDIS lists Sustonable Stone Technologies SL in Paiporta, near Valencia, as a linked third party that received €77,875 of the EU contribution, according to CORDIS. Founded in 2018 with Innovative Stone Technologies as proprietor, it changed its name to Bison European Partners SL in June 2023, when its directors since 2018 were replaced by a corporate director, according to North Data. Its current business is listed as wholesale trade.

What It Has Achieved Since

The product has found buyers, mostly for walls rather than kitchens. The largest named project is Terminal 1 of Lisbon airport, where wall panels in a custom "Lisbon Terrazzo" design were installed for the operator ANA, using about 35,000 PET bottles, according to the Solar Impulse Foundation, which dates the project to 2025; SBID and the company also list the project. The website names other installations, including employee restrooms at IKEA in the Netherlands, the Amsterdam RAI convention centre and University Hospital Groningen, according to Sustonable; these could not be confirmed with the clients.

The Solar Impulse Foundation, which first labelled the solution in August 2018, now rates it as at commercial scale-up with multiple commercial applications, and records the company's price claim of "10 to 20% less than traditional engineered stone", according to its profile. In the 2019 project, the claim was "up to 50% cheaper".

No equity round, investor or acquisition has been announced in the sources checked. Holland Circular Hotspot says the founders were joined by Dekker Zevenhuizen in 2017 and by Shibumi International DMCC in 2019, without giving terms, according to its case study; no second source was found. The company is not in the EIC Fund portfolio, which is consistent with a grant-only award. Besides the two SUSTONABLE grants, North Data and CORDIS show no other EU project of the company.

Why It Matters for European Policy

INNSTECH's material sits under two EU priorities. The Commission's Circular Economy Action Plan names plastics and construction among its key value chains. But the bottle-grade PET the company relies on is increasingly needed by the drinks industry itself: the Single-Use Plastics Directive requires PET beverage bottles to contain at least 25% recycled plastic from 2025 and all plastic beverage bottles at least 30% from 2030, as summaries of the directive also set out. Turning bottles into slabs competes with turning them back into bottles.

Engineered stone is also under health scrutiny. Australia banned the manufacture, supply and installation of engineered stone benchtops, panels and slabs from 1 July 2024 over silicosis among stone workers, according to the Australian Institute of Health and Safety. A lighter alternative made with less mineral would fit that shift, but the crystalline silica content of Sustonable's current formula is not stated in the sources checked. The European production base has also moved: the Phase 2 plan was to scale manufacturing with a Dutch partner, while the company's production address is now outside the EU.

The Verdict

INNSTECH has not been asked for comment for this article. It is based entirely on public records and published statements, linked throughout.