ANNEX I

E 520 ALUMINIUM SULPHATE

Synonyms

Alum

Definition

Chemical name

Aluminium sulphate

Einecs

233-135-0

Chemical formula

Al2(SO4)3

Molecular weight

342,13

Assay

Content not less than 99,5 % on the ignited basis

Description

White powder, shining plates or crystalline fragments

Identification

A.

Positive tests for aluminium and for sulphate

B.

pH of a 5 % solution 2,9 or above

C.

Solubility

Freely soluble in water, insoluble in ethanol

Purity

Loss on ignition

Not more than 5 % (500 oC, 3h)

Alkalies and alkaline earths

Not more than 0,4 %

Selenium

Not more than 30 mg/kg

Fluoride

Not more than 30 mg/kg

Arsenic

Not more than 3 mg/kg

Lead

Not more than 10 mg/kg

Mercury

Not more than 1 mg/kg