4-Hydroxybenzoic acid

  • p-Hydroxybenzoic acid
  • 4-Carboxyphenol
  • p-Salicylic acid
  • Paraben-acid
Formula
C7H6O3
Structure
Description
White to off-white.
Uses
Substance is used in org.

Registry Numbers and Inventories.
CAS
99-96-7
EC (EINECS/ELINCS)
202-804-9
EC Class
irritant
R 36/37/38
RTECS
DH1925000
RTECS class
Drug
Merck
13,4837
Beilstein/Gmelin
970950
Beilstein Reference
4-10-00-00345
Swiss Giftliste 1
G-3234
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C7H6O3
Formula mass
138.12
Melting point, °C
210 - 211
Boiling point, °C
336
Vapor pressure, mmHg
4E-5 (25 C)
Vapor density (air=1)
1.46
Density
1.398 g/cm3
Solubility in water
Very soluble
Refractive index
1.530
pKa/pKb
4.57 (pKa)
Partition coefficient, pKow
1.58
Heat of fusion
31.44 kJ/mol
Heat of vaporization
61.1 kJ/mol

Hazards and Protection.
Storage
Store in a cool, dry place. Keep container closed when not in use.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Avoid contact with eyes, skin, and clothing. Avoid ingestion and inhalation.
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 and clothing to prevent skin exposure. Clothing: Wear appropriate protective clothing to minimize contact with skin.
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.
Disposal code
4
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
171
Autoignition, °C
250
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. To extinguish fire, use water, dry chemical, chemical foam, or alcohol-resistant foam.

Health.
Poison_Class
4
Exposure effects
   Ingestion
May cause irritation of the digestive tract. Ingestion of large amounts may cause systemic effects such as nausea, stomach pain, rapid breathing, sweating, convulsions, coma, cardiovascular collapse and possible death.
   Inhalation
Dust is irritating to the respiratory tract. May cause effects similar to those described for ingestion.
   Skin
May cause skin irritation.
   Eyes
May cause severe eye irritation. May result in corneal injury.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Get medical aid immediately.
   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 if irritation develops or persists. Flush skin with plenty of soap and water.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
HS Code
2918 29 30