Flame retardant solutions

Flame retardant solutions for wood, paper, cardboard, insulation, and filter media

Modern construction relies on renewable materials such as wood, cellulose, and natural fibre insulation. While these materials bring clear sustainability benefits, they also increase the risk of fire. Kiilto develops safe, bio-based flame retardants that remain invisible in use, helping manufacturers meet European fire safety standards without compromising on aesthetics or production efficiency.

Flame retardants for wood, paper and cardboard, insulation, and filter media
Enable up to EN 13501-1 Class B fire performance
Safe and sustainable formulations, including new bio-based options
Aesthetic, neutral, and production-friendly — no staining, stickiness, or odour

Applications for flame retardants

Kiilto flame retardants are developed mainly for cellulose-based materials used indoors. We also offer solutions for selected non-cellulosic materials such as nonwovens and resins. Flame retardants can be custom-tailored for any industrial application method and process, ensuring both fire performance and production efficiency.

Flame retardants for Wood

Plywood, veneers and various wood materials

Flame retardants for Paper & Cardboard

Specialty papers and cardboard in different weights and forms

Flame redardants for Insulation

Natural fibre based insulation boards and acoustic panels

Flame retardants for Filter media

Filter media and other nonwoven applications

Invisible protection with visible results

A flame retardant should never compromise the look, feel, and function of a material. Kiilto flame retardants are:

Aesthetically neutral: No staining, yellowing, or colour change
Non-sticky: No machine clogging or residue
Odour-free: Keeping indoor air free from unwanted odours
Reliable: Effective when needed, invisible in everyday use

From halogen to bio-based and beyond

Flame retardants have evolved from halogen-based to phosphorus-based, and now to bio-based solutions. Kiilto is among the pioneers in this transition, already capable of developing 100% bio-based formulations without compromising performance.

Kiilto flame retardants can be custom-tailored for any industrial application method and process, ensuring both fire performance and production efficiency.

Fire classes explained

In Europe, building materials are tested and classified for fire performance according to the EN 13501-1 standard.

Class A1/A2 – Non-combustible or nearly non-combustible (stone, steel, gypsum)
Class B – Very limited contribution to fire (typical target class for wood, cellulose-based insulation, acoustic panels, etc.)
Class C – Limited contribution to fire (often acceptable for insulation products in certain applications)
Class D – Acceptable contribution to fire (sometimes sufficient for paper and cardboard applications)
Class E – Limited fire performance; tested only with a small-flame exposure (accepted only in specific cases)
Class F – No performance determined (or fails to meet Class E)

In construction, Class B is generally the target class, and Kiilto flame retardants can help materials achieve it. However, final classification always depends on the product application.

Why partner with Kiilto?

Proven expertise
Backed by over 15 years of flame retardant innovation and a century of chemical expertise, we are a partner you can rely on.

Sustainability leadership
We are pioneers in bio-based flame retardants, fully aligned with European regulations and always aiming for M1 classification – the Nordic standard for low-emission building materials.

Unnoticeable, yet effective protection
Our flame retardants are the most aesthetic on the market: no staining, no odour, no stickiness.

Partnership approach
We test, tailor, and scale solutions together with our customers.

From lab to production: how we support your process

It’s not enough for a flame retardant to work in the lab — it must deliver the same results on production lines. Kiilto supports you through every step:

Laboratory testing, including cone calorimeter and SBI (Single Burning Item) tests. In each case, we adapt our tests and methods to the customer’s needs.
Pilot-scale application and optimisation
Full production trials with hands-on support
Tailored formulations to meet process and product requirements

All R&D is based in Finland, with extensive lab and pilot-scale testing facilities. We also collaborate with research organisations and customers across Europe to test and tailor our solutions.