Is Silicon Carbide Toxic To Humans?

Silicon carbide is a non-metallic chemical having the molecular formula SiC. It is made up of covalent connections between silicon and carbon atoms and has a lot of great qualities.Silicon carbide is a non-metallic chemical having the molecular formula SiC. It is made up of covalent connections between silicon and carbon atoms and has a lot of great qualities.

Properties And Structure Of Silicon Carbide

I) The composition of materials

The fundamental unit of silicon carbide’s crystal structure is the silicon-carbon tetrahedron, which has silicon atoms in the centre and carbon atoms surrounding them. About 70% of the crystal contains silicon, and the remaining 30% is carbon. With covalent bonds making up 88% of the bonding mode, silicon carbide crystals have one primary bonding mode. Bonding between carbon and silicon atoms results in electron transport on the shell layer, which creates sp3 hybridisation. This hybridisation increases the stability of the silicon carbide structure and gives it structural traits that are comparable to those of diamond.

The two primary crystal structures of silicon carbide are α-SiC, which is a hexagonal or rhombohedral structure and is commonly referred to as hexagonal silicon carbide, and β-SiC, which is a cubic silicon carbide that is similar to a zinc blende and is called β-SiC. Subsequent research revealed that β-SiC has many polymorphs and that, beyond 2100°C, it changes into α-SiC.

II) Chemical and physical characteristics

1. Physical characteristics: Silicon carbide has a density of 3.21g/cm³. While it is readily soluble in molten potassium and sodium hydroxide and insoluble in water, it is insoluble in iron. There is hardly much thermal expansion coefficient. The average thermal expansion coefficient, for a temperature range of 25 to 1400℃, is about equal to 4.4×10⁻⁵/℃. It is possible to interpret the extremely high thermal conductivity as 0.015–0.023 cal/cm⁃⁃⃼sec.

High-purity silicon carbide exhibits a decrease in resistance as temperature rises in terms of conductivity. Silicon carbide with impurity aluminium has a nonlinear volt-ampere characteristic curve and a high conductivity that grows quickly as the electric field strength increases. This material has potential applications as a semiconductor. Only a few materials are harder than silicon carbide in terms of hardness. varying crystal plane directions have quite varying densities, and as the temperature rises, densities progressively diminish.

2. Chemical characteristics: The oxidisability and chemical stability of silicon carbide are good. Thermodynamic calculations show that although silicon carbide is easily oxidised, the oxidation-generated silicon dioxide forms a thin coating that inhibits the oxidation process. In the air, it begins to oxidise at about 800°C, and as the temperature rises, the rate of oxidation accelerates quickly. At approximately 1600°C, the oxidation nearly stops.

Strong acid resistance characterises silicon carbide. Below 2000°C, it usually doesn’t react with acidic solutions. Silicon carbide does not react when heated with HCl, HF, H₂SO₄, HNO₃, etc. At extremely low temperatures, silicon carbide can be broken down by concentrated phosphoric acid. The resistance of silicon carbide to alkali is low. It readily interacts with molten alkali and alkali metal sulphates at temperatures exceeding 1000°C.

Relationship Between Silicon Carbide And Human Health

There are currently only a few research on how silicon carbide affects human health. There are several industrial applications for silicon carbide, including abrasives, chemicals, refractory materials, etc., but little research has been done on the material’s direct toxicity to humans.

Based on its qualities, silicon carbide exhibits great hardness and chemical stability. Since silicon carbide is normally insoluble in water, it is unlikely that it will enter the human body through water in the surrounding environment. Furthermore, silicon carbide only undergoes oxidation reactions in certain high-temperature circumstances and is highly stable in the air.

However, breathing in silicon carbide dust during particular industrial manufacturing processes may have some effects on the respiratory system. Long-term dust inhalation can result in respiratory conditions like pneumoconiosis, even if there isn’t enough proof to conclude that silicon carbide is harmful in and of itself. Similar to other dust particles, breathing in too much of it can harm the lungs and have an impact on how well the body functions.

Furthermore, semiconductor materials and other electronic devices are made using silicon carbide. However, as of right now, no research has demonstrated that using silicon carbide in these applications will directly harm people’s health.

Generally speaking, not much research has been done on how silicon carbide affects human health, and its toxicity is still unknown. To safeguard employees’ health, suitable precautions should be adopted in industrial production to prevent silicon carbide dust inhalation.