Product Identification

Product Name

3,4-Dihydro-2H-pyran

Synonyms

3,4-Dihydro-2H-pyran
Dihydropyran

CAS

110-87-2

Formula

C5H8O

Molecular Weight

84.12

EINECS

203-810-4

RTECS

UP7700000

Beilstein/Gmelin

103493

Beilstein Reference

5-17-01-00181

EC Class

highly flammable, irritant, harmful

Physical and Chemical Properties

Appearance

A clear colorless liquid with an ethereal odor.

Solubility in water

Soluble

Melting Point

-70

Boiling Point

86

Vapor Pressure

74 (25 C)

Density

0.923 g/cm3 (20 C)

Partition Coefficient

1.06

Heat Of Vaporization

31.3 kJ/mol

Heat Of Combustion

-2955 kJ/mol

Usage

This cyclic ether is used to protect alcohols in organic synthesis.

Vapor Density

2.9

Refractive Index

1.4402 (19 C)

First Aid Measures

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.

Handling and Storage

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.

Hazards Identification

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.

Ingestion

Causes gastrointestinal irritation with nausea, vomiting and diarrhea. The toxicological properties of this substance have not been fully investigated.

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.

EC Risk Phrase

R 11 36/38

EC Safety Phrase

S 16 26 33 36

UN (DOT)

2376

Exposure Controls/Personal Protection

Personal 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.

Exposure Effects

The toxological properties of this substance have not been fully investigated.

Poison Class

3

Fire Fighting Measures

Flash Point

-16

Autoignition

240

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.

Upper exp. limit

13.8

Lower exp. limit

1.1

Fire Potential

HIGHLY FLAMMABLE.

Accidental Release Measures

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.

Stability and Reactivity

Disposal Code

1

Incompatibilities

Oxidizing agents, strong acids, and alcohols.

Stability

Stable under normal temperatures and pressures.

Decomposition

Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Combustion Products

Fire may produce irritating, corrosive and/or toxic gases.

Transport Information

UN Number

2376

Hazard Class

3

Packing Group

II

HS Code

2932 99 95