Phosphorous acid, Orthophosphorus, Phosphonsure, Tri hydroxy phosphine,  Ortho phosphorous acid, Phosphorus trihydroxide, PHOSPHOROUS ACID,REAGENT, 13598-36-2 

Phosphorous acid, Orthophosphorus, Phosphonsure, Tri hydroxy phosphine,  Ortho phosphorous acid, Phosphorus trihydroxide, PHOSPHOROUS ACID,REAGENT, 13598-36-2 

Phosphorous acid

CAS: 13598-36-2

Molecular Formula: H3O3P

Names and Identifiers

Physico-chemical Properties

Risk and Safety

Hazard Symbols	C - Corrosive
Risk Codes	R22 - Harmful if swallowed R35 - Causes severe burns
Safety Description	S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)
UN IDs	UN 2834 8/PG 3
WGK Germany	1
RTECS	SZ6400000
FLUKA BRAND F CODES	3
TSCA	Yes
HS Code	28092019
Hazard Class	8
Packing Group	III

Upstream Downstream Industry

Nature

colorless crystals. The relative density of 1.651(21.2 deg C). Melting Point 73,6. Boiling point 200 degrees C (decomposition). Soluble in water and alcohol. In the air slowly oxidized to orthophosphoric acid, heated to 180 deg C when the decomposition of orthophosphoric acid and phosphine (highly toxic). Phosphorous acid is a dibasic acid, and its acidity is slightly stronger than that of phosphoric acid. It has strong reducibility, easily reduces Ag ions to metal silver, and can reduce sulfuric acid to sulfur dioxide. Strong hygroscopicity and deliquescence, corrosive.

Preparation Method

The industrial production methods include the hydrolysis of phosphorus trichloride and The phosphite method.
Hydrolysis method: phosphorus trichloride is slowly added with water under stirring for hydrolysis reaction to generate phosphorous acid, which is refined, cooled, crystallized and decolorized to obtain phosphorous acid product. The hydrogen chloride produced in the production process is recycled and can be made into hydrochloric acid.

Use

is the raw material for the manufacture of phosphite, and is also the raw material for the manufacture of plastic stabilizers (such as: dibasic lead phosphite) and organophosphorus pesticides. Used as a stabilizer for polycarbonate. Also used as an antioxidant for nylon 1010.

Safety

is a Class II inorganic acid corrosion articles, risk code: GB 8.1 class 81520. UNN0.2854; IMDG CODE page 8205, class 8.1. Should be stored in a cool, ventilated, dry warehouse. The package is sealed, and it is strictly prohibited to be subjected to moisture and inverted, and it is not allowed to be stored and transported together with alkali substances, toxic substances, H porogen and other easily corrosive substances. Transport should be protected from rain and sunlight; Marine transport should not be placed on the deck. When loading and unloading should be light, not roll and inverted, to prevent damage to the package. Three-ply drum for export packaging, lined with two layers of polyethylene plastic bags, each net weight 50kg. Polyethylene plastic drum for domestic packaging, 30kg net weight per barrel. Or an iron drum lined with two layers of polyethylene plastic bags, each net weight 25kg. The package shall be marked with "corrosive items. When fire occurs, sand and dry powder can be used to kill
Firearm suppression. Toxicity and protection: see industrial phosphoric acid.

Reference Information