2,3-Dihydropyran

  • 3,4-Dihydro-2H-pyran
  • Dihydropyran
Formula
C5H8O
Structure
Description
A clear colorless liquid with an ethereal odor.

Registry Numbers and Inventories.
CAS
110-87-2
EC (EINECS/ELINCS)
203-810-4
EC Class
highly flammable, irritant, harmful
R 11 36/38
S 16 26 33 36
RTECS
UP7700000
UN (DOT)
2376
Beilstein/Gmelin
103493
Beilstein Reference
5-17-01-00181
Swiss Giftliste 1
G-8075
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C5H8O
Formula mass
84.12
Melting point, °C
-70
Boiling point, °C
86
Vapor pressure, mmHg
74 (25 C)
Vapor density (air=1)
2.9
Critical temperature
314
Critical pressure
48.7
Density
0.923 g/cm3 (20 C)
Solubility in water
Soluble
Refractive index
1.4402 (19 C)
Partition coefficient, pKow
1.06
Heat of vaporization
31.3 kJ/mol
Heat of combustion
-2955 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from heat and flame. Keep away from sources of ignition. Store in a cool, dry place. Store in a tightly closed container. Flammables-area.
Handling
Wash thoroughly after handling. Wash hands before eating. Remove contaminated clothing and wash before reuse. Use only in a well ventilated area. Avoid contact with skin and eyes. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. 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. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, using the appropriate protective equipment. Scoop up with a nonsparking tool, then place into a suitable container for disposal. Cover with an activated carbon adsorbent and place into a closed container for disposal. Remove all sources of ignition. Provide ventilation.
Disposal code
1
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Oxidizing agents, strong acids, and alcohols.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
-16
Autoignition, °C
240
Upper exp. limit, %
13.8
Lower exp. limit, %
1.1
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 water spray to keep fire-exposed containers cool. Water may be ineffective. Material is lighter than water and a fire may be spread by the use of water. May polymerize explosively when involved in a fire. Containers may explode when heated. Extinguishing media: For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog or alcohol-resistant foam. Do NOT use straight streams of water. Cool containers with flooding quantities of water until well after fire is out.
Fire potential
HIGHLY FLAMMABLE.
Hazards
Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. May polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
2
 
Flammability
3
 
 
Reactivity
0
 

Health.
Poison_Class
3
Exposure effects
The toxological properties of this substance have not been fully investigated.
   Ingestion
Causes gastrointestinal irritation with nausea, vomiting and diarrhea. The toxicological properties of this substance have not been fully investigated.
   Inhalation
Causes respiratory tract irritation. The toxicological properties of this substance have not been fully investigated. Vapors may cause dizziness or suffocation.
   Skin
Causes skin irritation.
   Eyes
Causes eye irritation.

First aid
 
   Ingestion
Do NOT induce vomiting. 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. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   Skin
Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Get medical aid if irritation develops or persists. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
UN number
2376
Response guide
Hazard class
3
Packing Group
II
 
HS Code
2932 99 95
 
Std. Transport #
4908240