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Huber's Alumina Trihydrate (ATH)
Huber supplies a halogen-free Alumina Trihydrate (ATH) grade that will fit almost any flame retardant or smoke suppression application or need in the marketplace. Our scientists have developed and formulated a wide variety of alumina trihydrate grades:
Particle sizes ranging from 0.25 to 80 microns
Untreated and surface treated grades
Ground ATH
Precipitated ATH (high purity; low electrical conductivity)
How ATH Works as a Fire Retardant
Thermal Decomposition Reaction (Endothermic):
2Al(OH)3 + HEAT → Al2O3 + 3H2O Starting @220ºC Consuming 280 cal/g
Alumina Trihydrate (ATH) Properties
| Physical Form |
Powder |
| Particle Morphology |
Hexagonal Platelet |
| Color |
White |
| Specific Gravity g/cm3 |
2.42 |
| pH Value |
9 - 10 |
| Hardness, Mohs |
2.5 – 3.5 |
| Refractive Index |
1.57 |
| Temperature of Decomposition |
220°C / 428°F |
| Heat of Decomposition, cal/g |
280 |
| Theoretical loss on ignition, % |
34.6 |
Ground Aluminum Hydroxide
Cost-effective fire retardant
Wide range of particle sizes (1-50 microns)
Irregular particle morphology, wide particle size distribution
Higher surface area
Available with surface treatments
(including vinyl, alkyl, phenyl)
Precipitated Aluminum Hydroxide
Regular crystal shape, narrower particle size distribution
Lower surface area, higher chemical purity
Select grades available with silane surface treatments
(including vinyl, alkyl, phenyl)
Halogen-Free Flame Retardant
& Smoke Suppressant Applications
