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Exolit® AP line for fire protection coatings
advance the world’s fire safety
with our ammonium polyphosphates

Nearly half a century of proven success in protecting lives and assets

Ammonium polyphosphate is a powerful polymeric flame retardant made in Germany since 1975. As the basis of our Exolit® AP products, it can provide non-toxic fire safety properties to flame retardant and fire-resistant intumescent coatings as well as to other products.

A great team player in intumescent systems – with many additional benefits

High-quality additives such as our Exolit® AP 422, Exolit® AP 418 (TP), Exolit® AP 435 and Exolit® AP 462 products are vital parts of many intumescent systems and fire protection coatings. Thin layers of intumescent coatings enable fire resistance times of up to 4 hours, protecting load-bearing steel structures, cables, wood and plastics, as well as textiles and paper.

When used in intumescent systems or with synergists in various fiber reinforced thermosets or polyurethane foams, our products support solutions like light-weight composites for transportation and construction, and feature non-migration of the used flame retardant. Also capable of adding excellent flame retardancy to polyolefins, all Exolit® AP products are characterized by very low smoke density and a favorable health and environmental profile.

Find out more about our Exolit AP® solutions

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Watch our on-demand webinar via European Coatings Clariant's new Exolit® solutions for fire protective water- and solvent-borne coatings

Based on more than 40 years of experience in the manufacturing of ammonium polyphosphate and its application in various fields Clariant has developed two new halogen-free flame retardants for water- and solvent-borne coatings. Exolit® AP 435 lowers your formulation viscosity, supports easy and constant production and product quality and keeps your water-based formulations flowable, even at low temperatures. Exolit® AP 418 (TP) improves the fire protection performance by offering an earlier on-setting reaction in solvent-based formulations.

Head of Technical Service Flame Retardants Coatings, Clariant

How Exolit® AP flame retardants can make steel structures resist fires

Graphic showing how an intumescent coating with Exolit® AP swells in fire and protects steel beams for up to three hours.

Sustainable fire protection,
key benefits of our Exolit® ap portfolio


Halogen-free, non-toxic, phosphorus-based solutions produced with 100% green electricity, of which several carry Clariant’s sustainability label EcoTain®


Compounds with a long track record, coming in a consistent quality that ensures steady production processes


Products available for waterborne, solvent-based as well as 2K-formulations, all being easily incorporated during the dispersion stage

Are Exolit® AP flame retardants a good fit for fire protection systems? Volker Thewes can warmly recommend them

»The development of new intumescent coatings for fire protection of structural steel is particularly complex. Therefore, the selection of environmentally friendly, halogen-free and sustainable flame retardants, like the Exolit® AP range, is essential!«

Portrait of Volker Thewes from the Rudolf Hensel company
Volker Thewes
Managing Director, Rudolf Hensel GmbH

Looking for first-rate fire safety just go by the numbers

Years of experience
in developing intumescent
system applications
Longer fire resistance time
can be achieved by solvent-
based intumescent coatings
made with Exolit® AP 418
Longer shelf life
possible for waterborne
intumescent coatings with
Exolit® AP 435 compared to
coatings using standard

Advanced fire protection coatings with our EXOLIT® AP line

  • Exolit® AP 422
    Exolit AP 422 is a fine-particle ammonium polyphosphate (phase II) produced by a special method. The product is largely insoluble in water and completely insoluble in organic solvents. It is colorless, non-hygroscopic and non-flammable.
  • Exolit® AP 435
    Exolit® AP 435 is a fine-particle ammonium polyphosphate (phase II) optimized for low viscosity in aqueous suspension and intumescent coatings. The product is largely insoluble in water and completely insoluble in organic solvents. It is colorless, non-hygroscopic and non-flammable.
  • Exolit® AP 418 (TP)
    Halogen-free Exolit® AP 418 (TP), especially designed for solvent-based intumescent coatings, offers longer fire resistance time (FRT) compared to conventional solutions by exhibiting an earlier on-set temperature. Therefore, a lower dry film thickness (DFT) for achieving the desired FRT is required compared to standard formulations. In addition, the protection of combustible and heat sensitive substrates is improved. Clariant’s well-known ammonium polyphosphate offers the consistent quality to produce and offer a stable intumescent coating. Exolit AP® 418 (TP) is a free flowing white powder with low solubility in water. Additionally, it is completely insoluble in organic solvents. The product is non-hygroscopic and non-flammable.

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