Melting point :315 °C (subl.)(lit.)
Boiling point :684.9 °C(lit.)
Density :4.81 g/mL at 25 °C(lit.)
vapor pressure :1 mm Hg ( 157 °C)
refractive index :nD20 <1.76
Flash point :315°C
storage temp. :Store below +30°C.
solubility :H₂O: soluble
form :powder
color :white
Specific Gravity :3.95
PH :2 (10g/l, H2O, 20℃)
Water Solubility :38.4 g/100 mL (14 ºC)
Sublimation :315 ºC
Merck :14,8434
crystal system :square
Space group :P42/mbc
Lattice constant :

a/nm	b/nm	c/nm	α/o	β/o	γ/o	V/nm3
0.83622	0.83622	0.50612	90	90	90	0.3539

Exposure limits :ACGIH: TWA 0.2 mg/m3
NIOSH: IDLH 1 mg/m3; TWA 0.2 mg/m3 Stability :Stable. Incompatible with organic materials, strong acids, ammonia, nitric acid, halogen acids. Protect from moisture.
CAS DataBase Reference :7446-08-4(CAS DataBase Reference)
NIST Chemistry Reference :Selenium dioxide(7446-08-4)
EPA Substance Registry System :Selenium dioxide (7446-08-4)

Symbol(GHS):
Signal word:	Danger
Hazard statements:	Code Hazard statements Hazard class Category Signal word Pictogram P-Codes H373 May cause damage to organs through prolonged or repeated exposure Specific target organ toxicity, repeated exposure Category 2 Warning P260, P314, P501 H410 Very toxic to aquatic life with long lasting effects Hazardous to the aquatic environment, long-term hazard Category 1 Warning P273, P391, P501
Precautionary statements:	P273 Avoid release to the environment. P314 Get medical advice/attention if you feel unwell.