Aluminium Hydroxide

Aluminium hydroxide is one of the most important mineral flame retardants worldwide. It is environmentally friendly and has a high efficiency as a smoke suppressant. HYDRAFIL® is made from bauxite in accordance with the Bayer process. One of the unique things about these grades from Quarzwerke are the organosilane surface treatments, which allow for higher loadings to be achieved per unit viscosity build - with better mechanical properties.

Aside from the flame retardant behaviour it also has a high degree of whiteness and a low hardness. It is commonly used in cold cure PMMA worktops for its improvement in composite strength, breaking elongation and excellent steam resistance.


    • Aluminium hydroxide powders with various organosilane surface treatments possible.

    • d50 particle size ranging from 2 - 24 microns.

    • High degree of whiteness (Y > 94).

    • Low Mohs hardness of 3.

    • Thermal coefficient of expansion of 15 x 10-6K-1.


    • Flame retardant properties. Highly efficient smoke suppressant.

    • Non abrasive during processing.

    • Enhances the strength, elongation and steam resistance of composites.

Typical Applications

    • Cables.

    • Textile applications.

    • Solid surface composites made of PMMA.

    • Epoxy casting resins.

    • SMC/BMC and latex.

Featured grades with technical datasheets

A brief overview of the key grades is given below. You will find the Technical Datasheets (TDS) available for download. If you are looking for a Safety Datasheet (SDS) or Product Safety Information (PSI) then please get in touch by phone or via the contact buttons at the top of the page.

Should you not find what you are looking for here then please note that we have further grades available besides these. One of our Technical Sales team will be happy to help. All of the sales team are technically qualified and will be able to advise you on which product to choose. You can either call us, email us or fill in a quick form at the top of the page to get us to call you (Request a Callback). A sample can be requested via the button at the top of the page as well. Please note that by providing us with your contact details, you are agreeing for us to potentially contact you.

Related brochures & technical literature

You will find some of the key product brochures available for download below. There are more brochures available upon request. If you would like to discuss your enquiry further then please get in contact by phone or by filling in the "Request a Callback" form at the top of the page. Someone from the technical sales team will then call you within 24 hours, to discuss your project further.

HYDRAFIL® 744-300 MST in Cold Curing PMMA Casting Resin

Aluminium hydroxide improves the strength, elongation and steam resistance of PMMA composites.

HYDRAFIL® 744-300 MST in Cold Curing PMMA Casting Resin Brochure /