Dehydroacetic acid

  • 3-Acetyl-4-hydroxy-6-methyl-2h-pyran-2-one
  • 2-Acetyl-5-hydroxy-3-oxo-4-hexenoic acid delta-lactone
  • 3-Acetyl-6-methyldihydropyrandione-2,4
  • 3-Acetyl-6-methylpyrandione-2,4
  • 3-Acetyl-6-methyl-2H-pyran-2,4(3H)-dione
  • 3-Acetyl-6-methyl-2,4-pyrandione
Formula
C8H8O4
Structure
Description
Needles from water, rhombic needles or prisms from alcohol. Odorless.
Uses
Organic synthesis, as plasticizer, bactericide, fungicide, in antienzyme toothpastes, to reduce pickle bloating.

Registry Numbers and Inventories.
CAS
520-45-6
EC (EINECS/ELINCS)
208-293-9
EC Index Number
607-163-00-2
EC Class
Harmful
RTECS
UP8050000
RTECS class
Agricultural Chemical and Pesticide; Tumorigen
UN (DOT)
1325
Merck
13,2885
Beilstein/Gmelin
6129
Beilstein Reference
4-17-00-06699
EPA OPP
27801
Swiss Giftliste 1
G-1476
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C8H8O4
Formula mass
168.15
Melting point, °C
108
Boiling point, °C
333
Vapor pressure, mmHg
0.0001 (25 C)
Vapor density (air=1)
5.8
Solubility in water
Very soluble
Refractive index
1.4379 (20 C)
pKa/pKb
5.39 (pKa)
Partition coefficient, pKow
0.35
Heat of vaporization
61.3 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Make no contact with the spilled material. ELIMINATE all ignition sources and ground all equipment. With clean shovel place material into clean, dry container and cover loosely; move containers from spill area.
Disposal code
4
Stability
Moderately volatile in steam.

Fire.
Flash Point,°C
151
Fire fighting
Water or foam may cause frothing.
Fire potential
Slight fire hazard.
Combustion products
Fire may produce irritating and/or toxic gases.
Health
1
 
Flammability
1
 
 
Reactivity
0
 

Health.
Poison_Class
4
Exposure effects
The toxological properties of this substance have not been fully investigated.
   Skin
May cause burns.
   Eyes
See Skin.

First aid
 
   Ingestion
The possible benefit of early removal of some ingested material by cautious gastric lavage must be weighed against potential complications of bleeding or perforation. Activated charcoal activated charcoal binds most toxic agents and can decrease their systemic absorption if administered soon after ingestion. Activated charcoal: administer charcoal as a slurry (240 ml water/30 g charcoal). Usual dose: 25 to 100 g in adults/adolescents.
   Inhalation
Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with beta2 agonist and corticosteroid aerosols.
   Skin
Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush with running water for at least 20 minutes. Wash skin with soap and water.
   Eyes
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.

Transport.
UN number
1325
Response guide
Hazard class
4.1
Packing Group
II; III
 
HS Code
2932 29 80