Malic acid

  • Apple acid
  • Pomalus Acid
  • Deoxytetraric acid
  • Hydroxysuccinic acid
  • Hydroxyethane-1,2-dicarboxylic acid
  • Butanedioic acid, hydroxy-
Formula
C4H6O5
Structure
Description
White free-flowing, odorless crystals.
Uses
Manufacture of various esters and salts, wine manufacture, chelating agent, food acidulant, flavoring.

Registry Numbers and Inventories.
CAS
6915-15-7
EC (EINECS/ELINCS)
230-022-8
EC Class
irritant
R 37/38 41
S 26 36/37/39
RTECS
ON7175000
RTECS class
Primary Irritant
Merck
13,5730
Beilstein/Gmelin
1723539
Beilstein Reference
4-03-00-01123
EPA OPP
51101
Swiss Giftliste 1
G-5101
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C4H6O5
Formula mass
134.09
Melting point, °C
131 - 132
Boiling point, °C
306
Decomposition point, °C
150
Vapor pressure, mmHg
7E-5
Density
1.601 g/cm3 (20 C)
Solubility in water
580 g/L
pKa/pKb
3.61 (pKa)
Partition coefficient, pKow
-1.26
Heat of vaporization
63.4 kJ/mol
Heat of combustion
-1338 kJ/mol

Hazards and Protection.
Storage
Store in a cool, dry well-ventilated place. Keep container sealed to avoid contamination and spillage.
Handling
Wear dust filter mask when handling. Uuse PVC or plastic gloves, safety goggles or face shield. Wear other impervious protective clothing to minimise exposure. Avoid contact with eyes, skin and clothing. Wash hands and face thoroughly after handling and before work breaks, eating, drinking, smoking and using toilet facilities.
Protection
Chemical splash goggles in compliance with OSHA regulations are advised; however, OSHA regulations also permit other type safety glasses. Whre chemical resistant gloves. To prevent repeated or prolonged skin contact, wear impervious clothing and boots.
Respirators
Dust filter mask
Small spills/leaks
Clean up personnel should wear protective clothing and breathing apparatus if dust environment exists. Avoid discharge to drains, sewers and watercourses.
Stability
Stable.
Incompatibilities
Strong oxidizing agents.
Decomposition
Decomposition products include fumes of carbon monoxide and carbon dioxide. Maleic acid or maleic anhydride may be formed as decomposition products.

Fire.
Flash Point,°C
153
Autoignition, °C
349
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. Use agent most appropriate to extinguish fire.
Combustion products
-320.1 kcal/mole

Health.
Poison_Class
4
Exposure effects
Abnormal neuropsychologic function has been reported following hydrochloric acid exposure from a leaking tanker truck.
   Ingestion
Symptoms of exposure may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea and vomiting.
   Inhalation
May irritate mucous membranes.
   Skin
Malic acid dust and aqueous solutions may irritate the skin.
   Eyes
Malic acid dust and aqueous solutions may cause lachrymation (flow of tears) and irritation to the eyes.

First aid
 
   Ingestion
Seek medical attention. If individual is drowsy or unconscious, do not give anything by mouth; place individual on the left side with the head down. Contact a physician, medical facility, or poison control center for advice about whether to induce vomiting. If possible, do not leave individual unattended.
   Inhalation
If symptoms develop, move individual away from exposure and into fresh air. If symptoms persist, seek medical attention. If breathing is difficult, administer oxygen. Keep person warm and quiet; seek immediate medical attention.
   Skin
Remove contaminated clothing, wash exposed area with copious amounts of water. A physician should examine the area if irritation or pain persists.
   Eyes
If symptoms develop, immediately move individual away from exposure and into fresh air. Flush eyes gently with water for at least 15 minutes while holding eyelids apart; seek immediate medical attention.

Transport.
4. Organic acids
HS Code
2918 19 80