Silicon, Silica, Silicates, Silicones

What is the difference? The mathematics of exposure

Silicon is a chemical element. It is the second most abundant element in the earth’s crust after oxygen. Compounds of silicon and other elements form a range of substances including silica, silanes, silicates, and silicones. Naturally, silicon usually occurs as silica.

Silica is a compound of silicon and oxygen known as silicon dioxide. It occurs in sand, quartz and opal. Silica can exist as crystalline and amorphous forms. The prolonged inhalation of fine crystalline silica dust, even at low concentrations, is associated with silicosis. Amorphous silica is much less pathogenic than crystalline forms. Silica dust is formed in many processes connected with the construction industry, such as cutting, drilling or grinding cement or sandstone. Long term inhalation of fine silica dust causes irritation to the lung tissue. Early symptoms include breathlessness during exercise. Over a period of 10 to 20 years silicosis develops. Once the disease has begun it will continue to progress even if the person is removed from further exposure. There is no known cure. People with silicosis are at greater risk of developing lung cancer.

Silicates are compounds of silicon, oxygen and metals. Silicates are found in granite, asbestos and feldspars. Long chain silicates are found in asbestos. Exposure to asbestos can have long term adverse heath effects, although not all silicates have such an adverse effect.

Silicones are synthetic polymers with a linear repeating silicon-oxygen backbone. Organic groups attached directly to the silicon atoms prevent formation of the three dimensional network found in silica. Certain organic groups can cross link two or more of these backbones, enabling a wide range of products to be manufactured, including silicone rubber, silicone gels and silicone oils. A common silicone polymer is polydimethylsiloxane

Monomeric silicon based chemical structures similar to carbon based structures are known as silanes. They are commonly used as chemical coupling agents.

The adverse health effects of silica and asbestos are multiplied by simultaneous exposure to other irritants such as tobacco smoke. It might be noted here that:

1. As a rule the risk associated with exposure to carcinogens is proportional to  the amount of material the person is exposed to, that is the Dose, D,    and the duration of exposure, d, to the fourth power. Hence a long exposure to small doses is much worse than a short term exposure to a big dose.
2. It can easily be assumed that everything must always add up to 100% but this is not the case. While the effect may be 100%, say death from lung cancer, the causes may add up to more than 100%. That is, any of the causes such as asbestos or smoking can produce the effect alone, but they can have an additive or multiplier effect when exposure is to all of them together.

 

Contact GETEX for assistance with Silicon, Silica, Silicates, and Silicones

GETEX operates 24/7. Your call will be handled by experienced people with authority who can help you. We do not use message services.

Download the Silicon, Silica, Silicates, and Silicones Information Sheet (PDF)