Marta Sacristan – TOLSA
The flame retardancy industry is undergoing a profound transformation. Driven by price volatility, regulatory pressure and sustainability goals, manufacturers are urgently seeking alternatives to antimony trioxide (ATO), a substance long used as a synergist in halogen-based flame retardant systems but now listed as a Substance of Very High Concern (SVHC) by the European Chemicals Agency (ECHA).
In 2024 alone, ATO prices surged by more than 800%, with availability tightening due to geopolitical and environmental constraints.
In this context, Tolsa, a European company with long-standing expertise in functional additives and sustainable technologies, has developed a line of ATO-free, halogenfree flame-retardant synergists under the Adins® trademark. These materials are a complete solution for fire retardancy, because they allow us not only to eliminate the ATO from the formulations, but also improve several flame retardant properties at the same time.
They eliminate dripping, reduce the heat release and flame propagation and they also work as a smoke suppressant.
THE ROLE OF SYNERGISTS IN MODERN FLAME RETARDANT SYSTEMS
ATO has traditionally played a key role as a synergist, particularly in combination with halogenated flame retardants. However, growing environmental and health concerns have led the industry toward halogenfree flame-retardant (HFFR) systems, especially in protective coatings, architectural paints, and intumescent formulations for construction and infrastructure.
In paints and coatings, flame retardant performance is not only about meeting regulatory thresholds but also about ensuring durability, surface stability, and long-term material protection.
This makes the search for efficient, ATO-free synergists even more critical.
ADINS®: MECHANISMS AND PERFORMANCE
The fire-retardant effect of Adins® is primarily attributed to its ability to promote a denser, more compact char during the fire.
This barrier slows down the release of flammable gases, reduces oxygen ingress, and thereby suppresses flame propagation. Additionally, ADINS® contributes to:
CASE STUDIES AND VALIDATION
Adins® has been validated in paints and coatings designed to comply with strict fire safety regulations, such as those applied in building materials, transportation, and infrastructure.
In intumescent coating systems, the addition of these additives improves char structure, reducing peak heat release and smoke output while enhancing the stability of the expanded protective layer. In architectural paints, these additives also contribute to long-term film durability, maintaining surface properties while embedding fire safety benefits into the formulation.
SUSTAINABILITY AND REGIONAL SUPPLY ADVANTAGES
Tolsa’s flame retardancy solutions are developed and manufactured entirely in Europe, ensuring a secure and stable supply chain for flame retardant synergists.
This local production capability provides European manufacturers with shorter lead times, allowing for quicker delivery and improved responsiveness to market demands.
Additionally, producing within Europe supports better alignment with increasingly stringent sustainability goals by reducing transportation-related emissions and enabling greater control over environmental impact.
Beyond the technical benefits, this shift to European manufacturing offers a strategic advantage by reducing exposure to geopolitical uncertainties that can disrupt global raw material supplies.
It helps manufacturers mitigate risks, optimize operational costs, and better prepare for evolving fire safety regulations.
As the flame retardancy industry transitions away from antimony-based solutions, synergists such as Tolsa’s Adins® series offer a technically viable and sustainable path forward. By enhancing fire performance across several axes – char formation, heat release, and smoke suppression – these materials not only replace ATO but can exceed its capabilities when properly formulated. The case for ATO-free flame retardancy is no longer a matter of regulatory compliance or cost alone.
It represents an opportunity for innovation in materials science – one that aligns fire safety, sustainability, and supply resilience in a single solution.
