Specialty Additives Available to Source

Aluminum Hydroxide

ATH
CAS 21645-51-2 · MF AlH3O3 · MW 78.004 g/mol

Aluminum Hydroxide (ATH) is an inorganic specialty additive that appears as a white, gelatinous precipitate and serves dual functional roles as a filling/extending agent and flame retardant. This aluminum trihydroxide compound is utilized across coatings & construction, plastics & polymers, textiles, and water treatment industries for its flame retardancy properties…

SDS / TDS Download
CAS Number
21645-51-2
Molecular Formula
AlH3O3
Molecular Weight
78.004 g/mol
Material Family
Specialty Additives
Functional Roles
Physical Properties
physical_description
White solid in various forms; [ICSC] White odorless granules; Slightly soluble in water; [MSDSonline]
color/form
Usually obtained in white, bulky, amorphous powder
melting_point
300 u00b0C
solubility
Practically insoluble in water, but soluble in alkaline aqueous solutions or in HCl, H2SO4 and other strong acids in the presence of some water.
density
White, gelatinous precipitate. Constants variable with the composition, density approximately 2.4. Insoluble in water and alcohol, soluble in acid and alkali. /Aluminum hydroxide gel/
vapor_pressure
Vapor pressure, Pa at 20 u00b0C:
stability/shelf_life
Less sensitive than trialkylaminums to oxidation upon exposure to air. /Alkylaluminum halides/
refractive_index
Monoclinic crystal system; Mohs hardness: 3; Index of refraction: 1.57 (least index); 1.57 (intermediate index); 1.59 (greatest index) /Gibbsite/
dissociation_constants
Aluminum hydroxide is capable of reacting as either an acid or a base
other_experimental_properties
So-called aluminum hydroxide is actually mixture of aluminum hydroxide and aluminum oxide hydrates and it usually contains some fixed carbon dioxide (ie, carbonate).
GHS / SDS Safety Warning
Irritant
  • H315 (19.7%): Causes skin irritation [Warning Skin corrosion/irritation]
  • H319 (21%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]
  • H335 (19.8%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]
Chemical Identity
CAS Number21645-51-2
IUPAC Namealuminum trihydroxide
InChI KeyWNROFYMDJYEPJX-UHFFFAOYSA-K
PubChem CID 10176082
INCI NameCI 77002
Synonyms & Trade Names
Hydrated alumina Amphojel aluminum hydrate Dried aluminium hydroxide Aluminum hydroxide, dried ALternaGEL Aluminium hydroxide, dried Alu-Cap Aluminum hydroxide gel, dried Aluminium hydroxide gel, dried Alcoa C 30BF Hydroxyde d' aluminium Aluminum(III) hydroxide aluminium(III) hydroxide 5QB0T2IUN0
Full Description

Aluminum Hydroxide (ATH) is an inorganic specialty additive that appears as a white, gelatinous precipitate and serves dual functional roles as a filling/extending agent and flame retardant. This aluminum trihydroxide compound is utilized across coatings & construction, plastics & polymers, textiles, and water treatment industries for its flame retardancy properties and ability to extend material performance. With a molecular formula of AlH3O3 and melting point of 300°C, it is practically insoluble in water but soluble in alkaline aqueous solutions.