Structure of 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside (CAS NO.7240-90-6):

Empirical Formula: C₁₄H₁₄BrClNO₆
Molecular Weight: 407.6216 
EINECS: 230-640-8
Nominal Mass: 406 Da
Average Mass: 407.6216 Da
Monoisotopic Mass: 405.969843 Da 
Flash Point: 375.9 °C
Enthalpy of Vaporization: 107.33 kJ/mol
Boiling Point: 698 °C at 760 mmHg
Vapour Pressure: 1.89E-20 mmHg at 25 °C
Melting point: 230 °C
Storage tempreture: 2-8 °C
Sensitive: Moisture & light sensitive
Appearance: White powder
IUPAC Name: (2S,3R,4S,5R,6R)-2-[(5-Bromo-4-chloro-1H-indol-3-yl)oxy]-6-(hydroxymethyl)oxane-3,4,5-triol
Canonical SMILES: C1=CC(=C(C2=C1NC=C2OC3C(C(C(C(O3)CO)O)O)O)Cl)Br
Isomeric SMILES: C1=CC(=C(C2=C1NC=C2O[C@H]3[C@@H]([C@H]([C@H]([C@H](O3)CO)O)O)O)Cl)Br
InChI: InChI=1S/C14H15BrClNO6/c15-5-1-2-6-9(10(5)16)7(3-17-6)22-14-13(21)12(20)11(19)8(4-18)23-14/h1-3,8,11-14,17-21H,4H2/t8-,11+,12+,13-,14-/m1/s1
InChIKey: OPIFSICVWOWJMJ-AEOCFKNESA-N
Product Category of 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside (CAS NO.7240-90-6): Enzyme substrates;Carbohydrates & Derivatives;Fluorescent Labels & Indicators;Labeling and Diagnostics Reagents

 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside (CAS NO.7240-90-6) is used to indicate whether a cell expresses the β-galactosidase enzyme in gene cloning, and may be used as a reporter in combination with growth media containing X-gal. It is used to determine E. coli and coliform content in drinking water samples, and also can be used in molecular biology.

Hazard Codes of 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside (CAS NO.7240-90-6): Xi
Risk Statements: 36/37/38 
R36/37/38:Irritating to eyes, respiratory system and skin.
Safety Statements: 24/25-37/39-26
 S24/25:Avoid contact with skin and eyes. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S37/39:Wear suitable gloves and eye/face protection.
WGK Germany: 3
F: 8-10-21

 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside , its cas register number is 7240-90-6. It also can be called X-Gal . It is an organic compound consisting of galactoside linked to indole. It is hazardous, so the first aid measures and others should be known. Such as: When on the skin: first, should flush skin with plenty of water immediately for at least 15 minutes while removing contaminated clothing. Secondly, get medical aid. Or in the eyes: Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Then get medical aid soon. While, it's inhaled: Remove from exposure and move to fresh air immediately. Give artificial respiration while not breathing. When breathing is difficult, give oxygen. And as soon as to get medical aid. Then you have the ingesting of the product: Wash mouth out with water, and get medical aid immediately.
In addition, 5-Bromo-4-chloro-3-indolyl-beta-D-galactoside (CAS NO.7240-90-6) is not compatible with strong oxidizing agents, and you must not take it with incompatible materials, light, moisture, excess heat. And also prevent it to broken down into hazardous decomposition products: Hydrogen chloride, nitrogen oxides, carbon monoxide, carbon dioxide, hydrogen bromide.