Cytosine

  • 4-Amino-2-hydroxypyrimidine
  • 4-Amino-2(1H)-pyrimidinone
  • 4-Amino-2-oxo-1,2-dihydropyrimidine
  • Cytosinimine
  • 4-Aminouracil
Formula
C4H5N3O
Structure
Description
White solid.
Uses
Nitrogenous base.

Registry Numbers and Inventories.
CAS
71-30-7
EC (EINECS/ELINCS)
200-749-5
S 22 24/25
RTECS
UW7350150
RTECS class
Mutagen
Merck
13,2824
Beilstein/Gmelin
2637
Beilstein Reference
4-25-00-03654
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C4H5N3O
Formula mass
111.10
Melting point, °C
313 - 316
Vapor pressure, mmHg
0.01 (232 C)
Density
0.98631 - 0.99771 g/cm3 (55 - 25 C)
Solubility in water
Very soluble
pKa/pKb
9.40 (pKb)
Partition coefficient, pKow
-1.65

Hazards and Protection.
Storage
Store in a cool, dry place. Store in a tightly closed container.
Handling
Use with adequate ventilation. Avoid contact with skin and eyes. Avoid ingestion and inhalation.
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 minimize contact with skin.
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
Vacuum or sweep up material and place into a suitable disposal container.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Carbon monoxide, oxides of nitrogen, carbon dioxide.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. To extinguish fire use water spray, dry chemical, carbon dioxide, or chemical foam.

Health.
Exposure effects
   Ingestion
No hazard expected in normal industrial use. Ingestion of large amounts may cause gastrointestinal irritation.
   Inhalation
No hazard expected in normal industrial use. May cause respiratory tract irritation.
   Skin
May cause skin irritation.
   Eyes
May cause eye irritation.

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. Get medical aid if irritation or symptoms occur.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid if cough or other symptoms appear.
   Skin
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.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. If irritation develops, get medical aid.

Transport.