| EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
| production method | preparation method 1 put selenium into a stainless steel container, heat and melt it and make it boil and reflux, under a pressure of 200kPa, to boil The selenium is bubbled with hydrogen. At this time, the reaction gas mixture contains more than 40% hydrogen selenide. When the gas mixture cools, selenium condenses into a solid and is removed through a filter. Then the gas mixture is frozen to -40°C, at which time H 2 Se has been solidified, and almost all of the hydrogen in it is discharged from the reaction device. The remaining trace hydrogen in the product can be removed by low-temperature distillation. The purity of the hydrogen selenide obtained is determined by the purity of the raw material. Method 2 Hydrolysis of selenide in the laboratory can easily produce hydrogen selenide. Al 2 Se 3+6H 2 O → 3H 2 Se + 2Al(OH) 3 The pure and dry Al2Se3 solid is placed in a flask with a gas outlet pipe and an inlet pipe and a dropping funnel, which is connected with a drying device and a condensing device. The drying device is composed of a U-shaped tube equipped with anhydrous CaCl 2 and a U-shaped tube equipped with phosphorus pentoxide and glass wool. The U-shaped tube is followed by two cold traps cooled to -78°C. First, dry nitrogen without oxygen is introduced to drain the air in the device, and then the newly boiled and cooled distilled water is dripped from the drip funnel with nitrogen slowly introduced. Adjust the dripping speed to make the reaction proceed smoothly. When the reaction speed is appropriate, the flask only slightly heats up. When the rate of gas generation slows down, a small amount of dilute hydrochloric acid can be added. The H2Se gas generated in the reaction condenses in a cold trap. Hydrogen selenide can be condensed into a liquid and stored at low temperature, or it can be stored in a burnt glass bottle in a gaseous state. |
| category | toxic gas |
| toxicity classification | highly toxic |
| acute toxicity | inhalation-rat LCL0: 20 mg/m3/1 hour |
| explosive hazard characteristics | blastable when mixed with air |
| flammable hazard characteristics | flammable; toxic selenium oxide gas emitted from the fire site |
| storage and transportation characteristics | warehouse ventilation and low temperature drying; separate from oxidant, metal and combustible materials |
| fire extinguishing agent | water |
| occupational standard | TCV-TWA 0.2 mg (selenium)/m3; STEL 0.2 mg (selenium)/m3 |
| toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
| immediate life-threatening and health concentration | 1 ppm |
