Isopentanoic acid

  • 3-Methylbutanoic acid
  • Isovaleric acid
Formula
(CH3)2CHCH2COOH
Structure
Description
Dense, clear, colorless liquid with a disagreeable, rancid-cheese odor.
Uses
Fragrance ingredient in perfumes, flavor ingredient in perfumes, non-alc beverages, foods, chemical intermediate for sedatives.

Registry Numbers and Inventories.
CAS
503-74-2
EC (EINECS/ELINCS)
207-975-3
EC Class
corrosive
R 22 24 34
S 26 36/37/39 45
RTECS
NY1400000
RTECS class
Primary Irritant
UN (DOT)
1760
Merck
12,5251
Beilstein/Gmelin
1098522
Beilstein Reference
4-02-00-00895
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C5H10O2
Formula mass
102.13
Melting point, °C
-33
Boiling point, °C
177
Vapor pressure, mmHg
0.55 (25 C)
Saturation Concentration
487 ppm (0.05%) at 20 C; 1300 ppm (0.132%) at 34 C (calculated)
Critical temperature
356
Critical pressure
33.56
Density
0.9467 g/cm3 (0 C)
Solubility in water
Soluble
Viscosity
2.73 cp (15 C)
Refractive index
1.40263 (15 C)
pKa/pKb
4.77 (pKa)
Partition coefficient, pKow
1.16
Heat of vaporization
45.4 kJ/mol
Heat of combustion
-2834 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
B3 D2B
Handling
Wash thoroughly after handling. Use with adequate ventilation. Do not get in eyes, on skin, or on clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid ingestion and inhalation. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
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
Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Remove all sources of ignition. Do not get water inside containers.
Disposal code
4
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Oxidizing agents.
Decomposition
Carbon monoxide, carbon dioxide.

Fire.
Flash Point,°C
71
Autoignition, °C
440
Upper exp. limit, %
6.8
Lower exp. limit, %
1.6
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Combustible Liquid. Containers may explode when heated. Extinguishing media: Use water spray to cool fire-exposed containers. Do NOT get water inside containers. For small fires, use dry chemical, carbon dioxide, or water spray. For large fires, use dry chemical, carbon dioxide, alcohol-resistant foam, or water spray. Cool containers with flooding quantities of water until well after fire is out.
Fire potential
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Hazards
Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Health
3
 
Flammability
2
 
 
Reactivity
0
 

Health.
Exposure effects
   Ingestion
May cause severe gastrointestinal tract irritation with nausea, vomiting and possible burns. May be harmful if swallowed.
   Inhalation
May cause severe respiratory tract irritation and possible burns. Vapors may cause dizziness or suffocation.
   Skin
Harmful if absorbed through the skin. Causes skin burns.
   Eyes
Causes eye burns.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Possible aspiration hazard. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration.
   Skin
Get medical aid immediately. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Discard contaminated clothing in a manner which limits further exposure.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed.

Transport.
UN number
1760
Response guide
Hazard class
8
Packing Group
I; II; III
 
4. Organic acids
HS Code
2915 60 90
 
Std. Transport #
4932040