Potassium aluminum sulfate dodecahydrate

  • Alum
Formula
KAl(SO4)2.12H2O
Structure
Description
White, odorless powder or colorless crystals.
Uses
Used as a mordant in dyeing, in tawing skins and as a coagulating agent for latex. Used in the gypsum industry as a hardening agent and setting accelerator for the production of marble cement and alabaster plaster. Used as a styptic pencil; as a catalyst in the production of ammonia; and as a food additive. Used in the pharmaceutical and cosmetics industries as an astringent and antiseptic.

Registry Numbers and Inventories.
CAS
7784-24-9
EC (EINECS/ELINCS)
233-141-3
R 36/38
RTECS
WS5690000
RTECS class
Reproductive Effector
Merck
12,373
Beilstein/Gmelin
425482 (G)
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
AlKO8S2 . 12 H2O
Formula mass
474.39
Melting point, °C
92.5
Decomposition point, °C
~100
Vapor density (air=1)
16.4
Evaporization number
Probably zero
Density
1.72 g/cm3 (20 C)
Solubility in water
139 g/L (20 C)
Dielectric constant
3.8 (20 C)

Hazards and Protection.
Storage
Store in a cool, dry place. Keep containers tightly closed. Keep away from strong bases.
D2B
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Wash clothing before reuse. Discard contaminated shoes.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Clean up spills immediately, using the appropriate protective equipment. Sweep up, then place into a suitable container for disposal. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents, steel, aluminum, copper, zinc.
Decomposition
Oxides of sulfur, aluminum oxide, oxides of potassium.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. To extinguish fire, use water, dry chemical, chemical foam, or alcohol-resistant foam. Use agent most appropriate to extinguish fire.
Health
1
 
Flammability
0
 
 
Reactivity
0
 

Health.
Poison_Class
5 (Substances and products with a low hazard& potential)
Exposure effects
   Ingestion
Ingestion of large amounts may cause gastrointestinal irritation.
   Inhalation
Dust is irritating to the respiratory tract.
   Skin
Contact with skin causes irritation and possible burns, especially if the skin is wet or moist.
   Eyes
Causes eye irritation.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid if irritation or symptoms occur.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid if cough or other symptoms appear.
   Skin
Get medical aid. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
HS Code
2833 30 00