CAS No.:7783-07-5

TOXICITY DATA with REFERENCE：

Organism	Test Type	Route	Reported Dose (Normalized Dose)	Effect	Source
guinea pig	LC50	inhalation	300ppb/8H (0.3ppm)	Sense organs and special senses: other changes: olfaction sense organs and special senses: conjunctive irritation: eye gastrointestinal: other changes	"Toxicology of Drugs and Chemicals," Deichmann, W.B., New York, Academic Press, Inc., 1969Vol. -, Pg. 320, 1969.
rat	LCLo	inhalation	20mg/m3/1H (20mg/m3)		Clinical Toxicology. Vol. 17, Pg. 171, 1980.

Consensus Reports：

Selenium and its compounds are on the Community Right-To-Know List. EPA Extremely Hazardous Substances List. Reported in EPA TSCA Inventory.

SAFETY PROFILE：

A deadly poison by inhalation. Very poisonous irritant to skin, eyes, and mucous membranes. Causes central nervous system effects in humans. An allergen. Can cause damage to the lungs and liver as well as conjunctivitis. It has been found that repeated exposures to concentrations of 0.3 ppm prove fatal to experimental animals by causing a pneumonitis, as well as injury to the liver and spleen. Causes garlic odor of breath, dizziness, nausea. Concentrations of 0.3 ppm are readily detected by odor, but there is no noticeable irritant effect at that level. Concentrations of 1.5 ppm or higher are strongly irritating to the eyes and nasal passages.
As in the case of hydrogen sulfide, the odor of hydrogen selenide in concentrations below 1 ppm disappears rapidly because of olfactory fatigue. The odor and irritating effects do not offer a dependable warning to workers who may be exposed to gradually increasing amounts and therefore become used to it. Due to its extreme toxicity and irritating effects, it seldom is allowed to reach a concentration in which it is flammable in air. Very little data are available on possible chronic effects of this material, but it is logical to assume that when the concentration of this gas is low enough to avoid the irritant effects, only the systemic effects will be noticeable.
Dangerous fire hazard when exposed to heat or flame; will react vigorously with powerful oxidizing agents, such as H₂O₂, HNO₃. Dangerous; forms explosive mixtures with air; keep away from heat and open flame. See also SELENIUM COMPOUNDS and HYDRIDES.
RIDADR: 2202
HazardClass: 2.3

Standards and Recommendations：

OSHA PEL: TWA 0.05 ppm (Se)
ACGIH TLV: TWA 0.05 ppm (Se)
DFG MAK: 0.05 ppm (0.17 mg/m³)
DOT Classification:  2.3; Label: Poison Gas, Flammable Gas

Analytical Methods：