2-Mercaptobenzoic acid

  • o-Thiosalicylic acid
  • 2-Sulfanylbenzoic acid
  • Thiophenol-2-carboxylic acid
Formula
C7H6O2S
Structure
Description
Yellow powder. With a stench.
Uses
Manufacture of thioindigo dyes, reagent for determination of iron.

Registry Numbers and Inventories.
CAS
147-93-3
EC (EINECS/ELINCS)
205-704-3
EC Class
irritant
R 36/37/38
S 22 26 36
RTECS
DH3325000
RTECS class
Other
UN (DOT)
3335
Merck
12,9498
Beilstein/Gmelin
508507
Beilstein Reference
4-10-00-00272
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C7H6O2S
Formula mass
154.19
Melting point, °C
165 - 166
Boiling point, °C
230 (0.02 torr)
Density
1.489 g/cm3 (20 C)
Solubility in water
Very soluble
pKa/pKb
3.50 (pKa)

Hazards and Protection.
Storage
Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Do not expose to air. Store protected from light. Store under an inert atmosphere.
Handling
Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation. Store protected from light. Handle under an inert atmosphere. Store protected from air.
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
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Clean up spills immediately, using the appropriate protective equipment. Sweep up, then place into a suitable container for disposal. Avoid generating dusty conditions. Provide ventilation. Place under an inert atmosphere.
Stability
Stable at room temperature in closed containers under normal storage and handling conditions.
Incompatibilities
Oxidizing agents.
Decomposition
Carbon monoxide, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide.

Fire.
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.
Health
1
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure effects
Irritating to eyes, respiratory system and skin.
   Ingestion
Causes 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. The toxicological properties of this material have not been fully investigated.
   Eyes
Causes eye irritation.

First aid
 
   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.
   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
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
UN number
3335
Response guide
HS Code
2930 90 70