Selenium dioxide

  • Selenium oxide
  • Selenium(IV) oxide
Formula
SeO2
Structure
Description
A white or creamy-white volatile lustrous crystal or crystalline powder with a pungent sour smell.
Uses
In the manufacture of other selenium compounds.

Registry Numbers and Inventories.
CAS
7446-08-4
EC (EINECS/ELINCS)
231-194-7
EC Index Number
034-002-00-8
EC Class
toxic, dangerous for the environment
R 23/25 33 50/53
S 20/21 28 45 60 61
RTECS
VS8575000
RTECS class
Mutagen; Reproductive Effector
UN (DOT)
2811
Merck
12,8576
Beilstein/Gmelin
25580 (G)
RCRA
D010
Swiss Giftliste 1
G-2846
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
O2Se
Formula mass
110.96
Sublimation point, °C
315
Vapor pressure, mmHg
12.5
Odor Threshold Odor threshold 2.0 ppm
Density
3.95 g/cm3
Solubility in water
384 g/L

Hazards and Protection.
Storage
Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep containers tightly closed. Do not get water inside containers.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Minimize dust generation and accumulation. Do not get in eyes, on skin, or on clothing. Keep container tightly closed. Do not ingest or inhale.
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
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Provide ventilation.
Disposal code
17
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Selenium/selenium oxides, selenious acid.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Substance is noncombustible. Reacts with water to form corrosive acids. Extinguishing media: Substance is noncombustible; use agent most appropriate to extinguish surrounding fire.
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
0
 
 
Reactivity
0
 

Health.
Exposure limit(s)
TLV (as Se): ppm; 0.2 mg/m3 (ACGIH 1990-1991). PDK (as Se): 0.1 mg/m3 (USSR 1977).
Poison_Class
1
Exposure effects
May cause liver and kidney damage. May cause anemia and other blood cell abnormalities. Repeated exposure may cause damage to the spleen. Chronic exposure to selenium may cause central nervous system effects, digestive tract disturbances, pallor, garlic breath, Chronic exposure to selenium may cause pallor, garlic breath, metallic taste, anemia, liver and spleen damage.
   Ingestion
Harmful if swallowed. May cause severe gastrointestinal tract irritation with nausea, vomiting and possible burns. May cause liver and kidney damage. May cause effects similar to those of acute inhalation.
   Inhalation
Inhalation of high concentrations may cause central nervous system effects characterized by headache, dizziness, unconsciousness and coma. Causes respiratory tract irritation. Inhalation of fumes may cause metal fume fever, which is characterized by flu-like symptoms with metallic taste, fever, chills, cough, weakness, chest pain, muscle pain and increased white blood cell count. May cause spleen and liver damage.
   Skin
Causes skin burns. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. Causes redness and pain.
   Eyes
Causes severe eye burns. May result in corneal injury. May cause pink, puffy eyelids due to an allergic reaction.

First aid
 
   Ingestion
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 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.
   Skin
Get medical aid immediately. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Discard contaminated clothing in a manner which limits further exposure.
   Eyes
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
2811
Response guide
Hazard class
6.1
Packing Group
I; II; III
 
USCG CHRIS Code
SLD
 
HS Code
2811 29 90
 
Std. Transport #
4923340