Specifications of Sodium Hydroxide USP NF Grade
Caustic Soda Pellets
NaOH 40.00 CAS 1310-73-2

Sodium Hydroxide contains not less than 95.0 percent and not more than 100.5 percent of total alkali, calculated as NaOH, including not more than 3.0 percent of Na2CO3.
Caution: Exercise great care in handling Sodium Hydroxide, as it rapidly destroys tissues.

Identification: A solution (1 in 25) responds to the tests for Sodium.
Insoluble substances and organic matter: A solution (1 in 20) is complete, clear, and colorless to slightly colored.
Potassium: Acidify 5 mL of a solution (1 in 20) with 6 N acetic acid, then add 5 drops of sodium cobalt nitrite: no precipitate is formed.
Heavy metals: the limit is 0.003%.

Specifications of Sodium Hydroxide BP Ph Eur Grade
Caustic Soda Pellets
NaOH --- 40.00

DEFINITION
Content: 97.0 per cent to 100.5 per cent Sodium Hydroxide.

CHARACTERS
Appearance: White or almost white, crystalline masses, supplied as pellets, sticks or slabs, deliquescent, readily absorbing carbon dioxide.
Solubility: Very soluble in water, freely soluble in ethanol (96 per cent).

IDENTIFICATION
A. pH minimum 11.0.
B. 2 ml of solution S gives reaction of sodium.

TESTS
Solution S: Carry out the procedure described below with caution. Dissolve 5.0 g in 12 ml of distilled water. Add 17 ml of hydrochloric acid R1, adjust to pH 7 with 1 M hydrochloric acid and dilute to 50 ml with distilled water.
Appearance of solution: The solution is clear and colourless.
Dissolve 1.0 g in 10 ml of water.
Carbonates: Maximum 2.0 per cent, calculated as Na2CO3 as determined in the assay.
Chlorides: Maximum 50 ppm.
Sulphate: Maximum 50 ppm.
Iron: Maximum 10 ppm, determined on solution S.
Heavy metals: Maximum 20 ppm.

Specifications of Sodium Hydroxide FCC Food Grade
Caustic Soda Pellets
NaOH Formula weight 40.00
INS: 524 CAS: 1310-73-2

DESCRIPTION
Sodium Hydroxide occurs as white or nearly white pellets, flakes, sticks, fused masses, or other forms. Upon exposure to air it readily absorbs carbon dioxide and moisture. One gram dissolves in 1 mL of water. It is freely soluble in alcohol.
Function: pH control agent.

REQUIREMENTS
Identification: A 1:25 aqueous solution gives positive tests for Sodium.
Assay: Not less than 95.0% and not more than 100.5% of total alkali, calculated as NaOH.
Arsenic: Not more than 3 mg/kg.
Carbonate: (as Na2CO3) Not more than 3.0%.
Insoluble Substances and Organic Matter: Passes test.
Lead: Not more than 2 mg/kg.
Mercury: Not more than 0.1 mg/kg.