Product Identification

Product Name

2-Mercapto-5-methylbenzimidazole

Synonyms

2-Mercapto-5-methylbenzimidazole
5-Methyl-1,3-dihydrobenzimidazole-2-thione
5-Methyl-2-benzimidazolethiol
5-Methyl-2-mercaptobenzimidazole

CAS

27231-36-3

Formula

C8H8N2S

Molecular Weight

164.22

EINECS

248-350-5

Beilstein/Gmelin

5083

Beilstein Reference

5-24-02-00466

Physical and Chemical Properties

Appearance

Beige - off white powder.

Melting Point

220

Boiling Point

349

Partition Coefficient

2.11

First Aid Measures

Ingestion

Never give anything by mouth to an unconscious person. Get medical aid. Do NOT induce vomiting. If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water. Wash mouth out with water.

Inhalation

Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.

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.

Handling and Storage

Storage

Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.

Handling

Wash thoroughly after handling. Use with adequate ventilation. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation. Wash clothing before reuse.

Hazards Identification

Ingestion

May cause gastrointestinal irritation with nausea, vomiting and diarrhea. The toxicological properties of this substance have not been fully investigated. Mercaptans may cause nausea and headache. Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis, cold extremities and rapid pulse.

Inhalation

Causes respiratory tract irritation. The toxicological properties of this substance have not been fully investigated. Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis, cold extremities and rapid pulse. Mercaptans may cause nausea and headache.

Skin

Causes skin irritation.

Eyes

Causes eye irritation.

EC Safety Phrase

S 22 24/25

Exposure Controls/Personal Protection

Personal 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.

Fire Fighting Measures

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. Extinguishing media: Use agent most appropriate to extinguish fire. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam.

Accidental Release Measures

Small spills/leaks

Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Provide ventilation.

Stability and Reactivity

Incompatibilities

Oxidizing agents.

Stability

Stable at room temperature in closed containers under normal storage and handling conditions.

Decomposition

Nitrogen oxides, carbon monoxide, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide.