The chemical I have chosen is Silicon Tetrahydride, and the CAS number on the Ontario EOL for this chemical is 7803-62-5.
Hazardous physical/chemical properties:
The basic properties for Silicon Tetrahydride are:
Molecular Name: H4Si
Melting Point: -185 °C
Boiling Point: -112 °C
Density: 1.114 g/mL at 25 °C(lit.)
Vapor Density: 1.1 (vs air)
Silicon Tetrahydride is a chemical that can be flammable and is a lethal gas when exposed in air. Becuase of its physical and chemical properties vapor density it can easily cause fire in air at room temperature or at a temperature that is slightly raised. This chemical can irritate the eyes, skin, and the mucous membrane, and also is very toxic if inhaled. It can be hazardous to humans because the vapors that are released can cause dizziness, or nausea, and if it comes in contact with any type of gas it may cause burns, frost bites, or injury. The chemical is reactive and not compatable with any oxidizing materials. Also, due to it being extremely flammable, the containers may explode when in fire so be aware of surroundings..
Routes of entry:
One way this chemical enters the body is though inhalation or ingestation and can be toxic if inhaled at high concentration. This is because Silicon Tetrahydride is a gas which can be exposed in the air, and is said to be lighter then air. Which is why it can enter the body if inhaled.
Another way Silicon Tetrahydride may enter the body is through skin contact or eye contact. It can enter through the skin depending on how much of the chemical is released into the air and if and if eyes are rubbed. There is no other way of entry into the body and is mainly harmful to the eyes or skin.
Effects on the body:
Due to this chemical being highly flammable and poisonous it can be hazardous to the body if exposed through breathing or though skin or eye contact. The short term health effects that may occur if inhaled are that it may irritate the nose, throat, and lungs. Also it can cause nausea because of the headaches and dizziness. May burn or irritate when in contact with skin eyes and even cause eye damage. The long term effects of Silicon Tetrahydride can last for months or even years being cancerous or being hazardous to reproduction, although not much research supports this. Caution shall still be taken.
Sources of exposure:
Silicon tetrahydride is used in the production of amorphous silicon and for semiconductors. This chemical is essentially stored in tightly closed containers, in areas that are to be cool, dry, and well-ventilated.
The measures that need to be taken in the workplace regarding the hazardous chemical Silicon Tetrahydide are essential for everyone’s safety. Beginning with pre-contact controls, engineering control is the most effective way to reduce the exposure to this chemical. Choosing to enclose the operations or to isolate is the best protection measure that can be taken. Also, installing local exhaust ventilators when the chemical released is another great measure. part of the control measures is to also evaluate how hazardous the substance is and how much of it is released, and if it is harmful when in contact with eyes or skin, and when inhaled. Other controls are to have workers trained on how to handle and deal with this chemical, and to have knowledge of the work practices to reduce exposure to the chemical. First is to change any clothing which may have been contaminated immediately, second if any skin contact wash or shower your body from any chemical.
The measures that need to be taken after contact with Silicon Tetrahydride when there is a fire hazard is that let it burn unless the gas leak can be stopped. If there is a small fire use the CO2 extinguisher and not the halon one. Due to high flammability containers may also explode. If the chemical is leaked then everyone who is not wearing protective equipment should be evacuated until area is cleaned. If there is a larger fire or spills then call the fire department immediately . For the purpose of first aid measures, if any frostbite or burns are caused then immediately seek medical attention and try warming up the areas of frozen tissues.