Flame Retardants

ATH - Aluminium hydroxide

Why use ATH?Iscaflam® ATH (Aluminium hydroxide, sometimes known as Aluminium trihydrate or Aluminium trihydroxide) is a fine powder flame retardant additive suitable for a multitude of flame retardant applications. Iscaflam® ATH is derived from bauxite ore, and as such it is a highly stable mineral flame retardant that has possess little health or environmental hazards.

Mode of actionIscaflam® ATH works both by a cooling and diluting effect during decomposition on exposure to heat.

Cooling As Iscaflam® ATH decomposes (at approximately 180 °C+) it converts to aluminium oxides and water vapour. This process absorbs large amounts of heat (around 1300 Jg-1). Absorption of heat in this way delays the onset of combustion and can often prevent a fire starting in the early stages of development.


Dilution - In order for a fire to develop and sustain combustion, flammable gasses from the decomposition of the substrate must mix with atmospheric oxygen in the presence of heat. This causes the gases (formed by pyrolysis) to oxidise which releases the heat required for continued pyrolysis of the substrate. Iscaflam® ATH releases water vapour into the flammable gas mix, diluting the concentrations to the point where sustained combustion is not possible.

Physical/Chemical Characteristics
Property Result (typical)
Bulk density 871 (g/l)
d50(Cilas) 12.29 m
> 90 m 0.09 %
Moisture 0.07 (%)

Typical use scenarios

Iscaflam® ATH can be used as a flame retardant in paper milling, plastic master batch, and many other polymeric substrates where addition of fillers is feasible. It is added as a solid fine white powder which imparts low levels of opacity. Typical addition rates are 5 - 30 %. In cases where lower addition rates are required, Phosphate based flame retardants are recommended.


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