Is food-grade silicone biodegradable? (3 applications of food-grade silicone)

This article shall look into the biodegradability of food-grade silicone.

It shall also cover other areas such as :

  • Properties of silicone.
  • Polymorphism of silicone.
  • Biodegradation process.
  • Eco-friendliness of food-grade silicone.

Is food-grade silicone biodegradable?

No, food-grade silicone is non-biodegradable. Silicone is a naturally occurring mineral that is not susceptible to microbial degradation.

The mineral silicon is made up of silicon and oxygen, they are chemically bonded together to form silica. Silica is almost in its simplest and therefore, can not be degraded further by microorganisms.

What is biodegradation?.

Biodegradation is the process by which naturally occurring organic materials are broken down by microorganisms such as bacteria and fungi into small particles which are not harmful to the environment.

Biodegradation is carried out by different agents such as UV radiation, light, wind, and water but the most effective agents of biodegradation are bacteria and fungi.

Biodegradation occurs in three distinct stages: biodeterioration, bio-fragmentation, and assimilation.

The biodeterioration process loosens up the structure of the organic substance. For instance, the cell wall of plants is weakened by light, wind, water, and UV radiation.

Bio-fragmentation involves the breakdown of organic matter into smaller, nontoxic particles by bacteria and fungi, releasing water and carbon dioxide in the process.

Assimilation is the last stage of biodegradation and it involves the microorganisms taking up the products of bio-fragmentation into their biological machinery to be used to make energy.

Biodegradation can either involve the microorganisms using oxygen, aerobic biodegradation or it can involve the microorganisms which do not use oxygen, anaerobic biodegradation.

Aerobic biodegradation breaks down organic matter into small biomass, producing carbon dioxide and water.

Anaerobic biodegradation breaks down organic matter into small biomass and in the process carbon dioxide and methane gases are produced.

Aerobic biodegradation occurs at a faster rate than anaerobic biodegradation whereas anaerobic respiration is more efficient and produces more gases and other products.

What is food-grade silicone?

This is a type of silicone material that is safe for application with foodstuff. 

It is used to make storage packages that store food that begins as a liquid and then solidifies. 

It is a material of choice that is non-toxic and does not stain food, dishes, or cookware. It is easily removable from used items.

Silicone is used to make mold shapes which the foodstuffs take when stored in them, such foods include chocolate, butter, gelatin, cheese, and candies.

It is used as a food package to keep from coming into contact with untidy surfaces while being transported across the industrial assembly channel.

What are forms of food-grade silicone?

Food grade silicone comes in different forms for different purposes. 

It can be found as a tube mold where food such as cake icing is squeezed through it to assume the shape of the tube.

It also can come in the form of a thinner line. The thinner line silicone is poured over a cast surface upon which it will solidify into the shape of that surface.

It can be found in a thick form like clay where small and flat objects can be squeezed through the thick silicone to form molds.

Food grade silicone can occur as a liquid or fumes. This form is mainly used as a lubricant in food packaging, and also protects the food from toxic conditions.

Food grade silicone in liquid or fumes formed is highly flammable when it is exposed to direct flame and therefore one ought to be careful.

What are the components of food-grade silicone?

Non-toxic food-grade silicone is made from silicon dioxide.

Silicone dioxide is also called silica. It has a chemical formula of SiO2. Silica is naturally found in animals and nature as quartz. It is the major component of sand; a product used to make glasses.

Applications of silica.

Silica is used in the following ways:

  • It is used in construction on the production of concrete and cement.
  • Silica is used to make glasses.
  • It is used in hydraulic fracturing of formations that contain shale gas.
  • In making telecommuting optical fibers.
  • Used in making ceramics such as porcelain, earthenware, and stoneware.
  • Used as an anti-caking agent.
  • Used as an anti-aging agent in asphalt binders.
  • It is used as a finishing agent for juice, wine, and beer.
  • It is used as the hard abrasive part of the toothpaste.
  • It is used in making semiconductors.
  • It is used as a defoamer agent.
  • It is used as a high-temperature thermal protection fabric 
  • It is used in the extraction of RNA and DNA.
  • It can be used to make fiberglass.

Toxicity of silica.

Silica is normally non-toxic. However, inhaling small particles of silica can lead to silicosis, bronchitis, or lung cancer.

Inhaling silica also increases the risk of systemic autoimmune diseases such as lupus erythematosus and rheumatoid arthritis.

What is silica polymorphism?

Silica polymorphism is the ability of silica to exist in different crystalline forms.

There are several forms in which silica can be found in nature, they include:

  • Keatite.
  • Moganite.
  • Coesite.
  • Stishovite.
  • Seifertite.
  • Melanophlogite.
  • 2D silica.
  • Alpha quartz.
  • Beta quartz
  • Alpha tridymite.
  • Beta tridymite.
  • Alpha cristobalite.
  • Beta cristobalite.

The polymorphs may differ in shape and color.

  • Quartz- This is the most abundant polymorph of silica and the second most abundant mineral in the Earth’s crust after feldspar.

The mineral occurs in crystalline structures of tetrahedral shape. It occurs in two forms, alpha quartz, and beta quartz. 

The transition from alpha quartz to beta quartz occurs at temperatures of 573⁰ Celsius.

Quartz is used in making jewelry and hardstone carvings.

  • Keatite– This is a tetragonal polymorph of silica.
  • Moganite- This is a polymorph of silica with a monoclinic crystal system.

It has the same formula as quartz but a different crystal structure.

  • Coesite- This polymorph of silica is formed when very high pressure and high temperatures are applied to quartz. 
  • Stishovite- This is an extremely hard and dense tetragonal form of silica. It is a rare form on the Earth’s surface but is common in the Earth’s mantle.

It was first synthesized by Sergey M. Stishov in 1961. 

It is separated from quartz by using hydrogen fluoride because it does not react with it.

  • Seifertite– This is one of the densest forms of silica. It is formed from tridymite or cristobalite by heating. 
  • Tridymite– This is a high-temperature polymorph of silica. It occurs as a white or colorless, pseudo-hexagonal crystal. It can also be found as scales in the cavities of felsic volcanic rocks.
  • Melanophlogite– This is a polymorph of silica that is very rare. It has a zeolite-like porous structure and therefore it is less dense.

It contains crystals of sulfur and calcite and organic compounds. Its name is derived from the darkening that occurs when its organic compound is heated.

It is thermally stable, stable even under,800⁰ Celsius. Temperatures above 800⁰C convert it to cristobalite.

  • Cristobalite- This is a polymorph of silica that is formed under very high temperatures. It is used in dentistry making teeth models and also as a component of alginate impression material.

It has the same formula as quartz but with a different crystal structure. It appears as a white octahedral in acidic volcanic rocks. It is only stable at temperatures above 1470⁰ Celsius.

  • 2D silica- This is a polymorph of silica with hexagonal crystals. It occurs in 2 forms, graphene-like sheets and SiO4 tetrahedral. It can be used in electronic appliances as the thinnest gate dielectric.

Is food-grade silicone eco-friendly?

Yes, using the end product silicone is eco-friendly.

According to an article on silicone eco-friendliness, Silicone is non-biodegradable, but it can be recycled by taking silicone wastes to recycling industries.

Silicone also helps reduce the use of plastics which are the biggest pollutants to the environment. 

However, the process of producing silicone involves burning sand which burns organic matter in the sand, producing carbon emissions. Carbon is a greenhouse gas that causes global warming.  


This article has answered the question of the biodegradability of food-grade silicone.

It has also covered other areas like:

  • Properties and uses of silicone.
  • Components of silicone.
  • The polymorphs of silica.
  • Eco-friendliness of food-grade silicone.

For any questions or comments please use the comment section below.

Frequently Asked Questions FAQs): is food-grade silicone biodegradable?

Is silicone recyclable?

Yes, silicone can be taken to recycling industries where it will be effectively recycled.

Is silicone better than plastic?

Silicone is more versatile and has more durability than plastics. What is more? It does not emit carbon like plastics do and therefore does not pollute the environment. So yes, silicone is better than plastic.

Is silicone toxic to humans?

No, silicone has been approved by the Food and Drug Administration (FDA) body as being non-toxic.


Eco Team. (March 1, 2021). Is Silicone Eco-Friendly? Facts Most People Don’t Know.

Retrieved from:

Starre Vartan. (May 24, 2021). Is Silicone Biodegradable?: Environment, Recycling, and waste.

Retrieved from:’t%20biodegradable,choice%2C%20which%20is%20partially%20true.

Skinner BJ, Appleman DE (1963). “Melanophlogite, a cubic polymorph of silica” (PDF). Am. Mineral. 48: 854–867.

De La Rocha C, Conley DJ (2017). “Mystical Crystals of Silica”. Silica Stories. Cham: Springer. pp. 50–55. doi:10.1007/978-3-319-

Leave a Comment