From Sand to Shelf: Is Silicone Eco-Friendly?

Silicone has seamlessly integrated into our daily lives, lauded for its heat resistance, pliability, and longevity. Silicone's environmental footprint is more significant than many realise because it relies on non-renewable hydrocarbons for production and has challenges in recycling and biodegradability. 

This ubiquitous material, found in everything from kitchenware to medical devices, has long been celebrated for its durability and versatility.

Despite its inert nature when incinerated, silicone's end-of-life treatment is not without complications, necessitating specialised recycling processes that are not widely accessible. Moreover, the recent bans on certain silicone compounds in the EU highlight the growing regulatory and consumer push towards more sustainable materials. 

But as we become more environmentally conscious, it's important to ask: Is silicone bad for the environment? This article aims to dissect the environmental implications of silicone, examining its production process, longevity, and end-of-life disposal. 

Due to its unique properties, silicone, often confused with the element silicon, is a versatile polymer widely used across various industries. It consists of repeating siloxane units (−O−R2Si−O−SiR2−, where R = organic group), varying in consistency from liquid to gel to rubber to hard plastic. 

Silicone is a synthetic polymer made from silica, a natural substance found in sand. Unlike plastics derived from petroleum, it offers a range of benefits due to its chemical composition and physical properties. It can withstand high and low temperatures without degrading, making it ideal for cooking, baking, and food storage products. These items are less likely to scratch, discolour, or break than their plastic counterparts, leading to a longer lifespan and potentially less waste.

The most common form of silicone is linear polydimethylsiloxane (PDMS), known for its oil-like consistency. Silicone's applications include sealants, adhesives, lubricants, medicine, cooking utensils, thermal and electrical insulation, and personal care products like skincare and hair conditioners. 

To put this in perspective, it is a synthetic polymer of silicon, oxygen, and other elements, often carbon and hydrogen. It's known for its heat resistance, durability, and flexibility.

Silicone's versatility allows it to be used in a myriad of applications across various industries:

The environmental impact of silicone is multifaceted, involving considerations of its production, use, and disposal. The production uses hydrocarbons derived from petroleum, raising concerns about sustainability and carbon emissions. 

This means that the material is not biodegradable, and recycling facilities for silicone are scarce. However, it is less likely to be discarded than plastic due to its durability. While not the most eco-friendly material, it is a far more suitable alternative to plastic, especially in applications where products are used multiple times.

The silicone market in 2023 indicates a continued demand for its products. The growth is due to significant construction, transportation, and electronics contributions. The Asia Pacific region is leading in silicone production and consumption, followed by North America and Europe. 

Despite the environmental concerns, the demand has continued to rise, driven by its superior properties and applications in various sectors.

According to a study commissioned by the Global Silicones Council, silicones generate greenhouse gas emission reductions that outweigh the impacts of production and end-of-life disposal by a factor of 9. This means that for every ton of CO2 emitted, the use of silicones allows for savings of 9 times greater.

Silicone's production is not environmentally benign. It involves the use of hydrocarbons derived from petroleum, a non-renewable resource. The process requires high temperatures, which typically consume significant energy, often from fossil fuels. It may release siloxanes at temperatures above 300 °F, harming the environment. Furthermore, it is not biodegradable. 

While it is more durable and less likely to be discarded than plastic, it can persist in the environment for hundreds of years once it reaches the end of its life. Recycling silicone is technically possible but challenging, as it requires specialised facilities that are not widely available.

Silicone's environmental footprint is multifaceted:

The global silicone market was estimated at £ 17.06 billion in 2023 and is expected to grow at a compound annual growth rate (CAGR) of 6.0% from 2024 to 2030. This growth indicates an increasing production and use of silicone, which could exacerbate its environmental impact. 

Globally, production and disposal contribute to non-renewable resource depletion, carbon emissions, and landfill waste. However, specific global figures on its total annual environmental impact are challenging to quantify due to the diversity of its applications and the opacity of production data.

Daily, the widespread use of silicone in consumer products leads to incremental contributions to environmental degradation, primarily through energy consumption in production and challenges in waste management.

Each product use indirectly supports the demand for petroleum-derived materials and energy-intensive manufacturing processes. However, its durability means that, compared to single-use plastics, silicone items may offer a slightly better environmental trade-off by reducing the frequency of replacements.

The silicone market is expected to continue its growth trajectory, with projections indicating a rise from 3.01 million tons in 2024 to 3.87 million tons by 2029, growing at a compound annual growth rate (CAGR) of 5.15%.

In 2022, a few key players dominated the global landscape of production. China led the world in silicon production with a staggering output, significantly outpacing other countries. Following China, Russia and Brazil held second and third positions, contributing to the global supply of critical raw materials for silicone production. However, the production is concentrated in a few countries worldwide, with China leading the pack significantly. 

Silicone is produced in a few countries worldwide. According to the latest data, the top silicone-producing countries are:

These countries have capitalised on their resources and industrial capabilities to lead the production market.

Here's a concise overview of the top silicone-producing economies based on the latest data from Statista and Wikipedia:

The Asia Pacific region leads the market, holding more than 45.18% of the market share in 2023, primarily due to strong demand from construction, electrical & electronics, and personal care industries. Europe and North America follow, with significant contributions to the market, driven by advancements in construction and the healthcare industry. 

The market is characterised by the presence of several major players, including:

These companies are engaged in continuous innovation and strategic expansions to maintain their market positions and meet the growing demand.

Silicone isn't the most environmentally friendly material, but it's a suitable alternative to plastic. As a robust material, it lasts longer than plastic. Reusing products is an easy way to act more sustainably. For example, silicone menstrual cups or food storage bags can significantly reduce the amount of waste generated over time compared to their disposable counterparts. 

This makes it a good option for eco-conscious businesses and consumers who want to avoid plastic-based products.

Silicone does not decompose or biodegrade in a traditional sense. This material, made primarily from silica found in sand, is celebrated for its durability and resistance to extreme temperatures, but it does not break down easily in the environment. 

Unlike organic matter, which breaks down into natural substances over time, its chemical structure prevents it from being broken down by bacteria or organisms in the environment. This means that silicone products can linger for decades, potentially leading to accumulation in landfills and natural habitats.

While not the perfect material, it is still celebrated as an alternative for reducing plastic pollution and promoting sustainability in various applications. 

However, its non-biodegradability and the challenges associated with recycling present significant environmental concerns. 

When considering the environmental friendliness of materials, it's essential to weigh their entire lifecycle, from production to disposal. Bioplastics, such as polylactic acid (PLA), are presented as biodegradable alternatives with similar properties to silicone for specific applications like food packaging. 

These materials are made from renewable resources and can degrade much shorter than silicone, offering key environmental advantages. However, choosing between silicone and biodegradable alternatives often involves balancing functionality, durability, and the material's environmental footprint.

While silicone is not acutely toxic, it can cause immune responses and toxic effects when it enters the body. Silicone is considered biocompatible, meaning it does not typically cause a reaction when it comes into contact with body tissues. 

However, when silicone particles enter the body, such as through silicone breast implants (SBIs), the immune system can be triggered, leading to potential toxic effects.

According to a review of silicone toxicology by the National Center for Biotechnology Information (NCBI), its compounds have been studied for over 50 years, and the results suggest that they have low toxicity. The review states that silicone fluids with a viscosity of 350 cS were described as having exceedingly low toxicity in a 1950 study. By then-current standards of toxicology, silicone fluids were considered harmless, devoid of any obvious acute toxic potential, and thus presumably safe.

In addition, some studies have raised concerns about certain types of silicones (siloxanes) like volatile cyclic methylsiloxanes D4 (Octamethylcyclotetrasiloxane), D5 (Decamethylcyclopentasiloxane) and D6 (Dodecamethylcyclohexasiloxane) which are persistent, bioaccumulative, and toxic. These compounds have been found to disrupt hormones and act like estrogen, and there is evidence of carcinogenic, mutagenic, and reproductive toxicity in animal studies.

The European Chemicals Agency has recommended phasing out these compounds due to their environmental persistence and potential for bioaccumulation.

For wash-off cosmetic uses, an EU restriction entered into force in 2022 to restrict formulations containing D4 or D5 in quantities of more or equal to 0.1 % w/w. 

Silicone should not be ingested or used at temperatures above 428°F (220°C). 

Recycling is difficult, and most recycling facilities do not accept it. Though it can be recycled, the process is not as straightforward as recycling materials like glass or paper.

Recycling is less widespread or streamlined than recycling more common materials like PET plastics or glass. The process usually involves mechanical shredding into smaller pieces, followed by high-temperature processing to break the silicone into reusable polymers. However, these methods are not universally available and can be cost-prohibitive, limiting their application.

The global silicone recycling market was valued at approximately £43 million in 2022 and is expected to grow to about £57 million by 2029, with a compound annual growth rate (CAGR) of 4.1%. Despite the challenges, this growth indicates a rising awareness and effort to recycle the product.

One of the main challenges in recycling silicone is the lack of widespread facilities capable of processing it. This would lead to its potential disposal in landfills, which can take centuries to break down. 

The primary barriers to silicone recycling include:

However, some companies like (EcoUSA and TerraCycle) and organisations offer take-back programs or specialised recycling services to address this issue. 

Despite these challenges, there are promising developments aimed at making silicone recycling more feasible and efficient:

While it offers certain environmental benefits over plastic, such as durability and the absence of toxic chemicals, it has drawbacks. The production process is not sustainable due to its reliance on fossil fuels, and the material's lack of biodegradability and challenges in recycling contribute to environmental concerns. 

The limited infrastructure for silicone recycling means that most end-of-life products are either incinerated, which releases CO2, or landfilled, where they persist without biodegrading. This situation presents a significant sustainability challenge.

Therefore, while it can be a better alternative to single-use plastics, it is not the most sustainable material available, and its use should be considered carefully. 

Silicone is often considered more environmentally friendly than plastic due to its durability and not breaking down into harmful microplastics. Unlike plastic, it does not require mining for crude oil for its production, and it is made from sand, a more abundant resource.

Bioplastics, such as polylactic acid (PLA), offer similar properties to silicone with key environmental advantages, including better biodegradability. Glass, another alternative, is highly recyclable and does not contain chemicals that could leach into food or the environment. However, its fragility can limit its use in some applications.

Considering the environmental impact of silicone, seeking alternatives might be a prudent choice. Biodegradable and compostable materials, such as natural rubber or plant-based polymers, offer sustainable options that break down more easily without harming the environment.

Glass, for example, is more sustainable due to its recyclability and the abundance of natural resources required for its production. 

Bioplastics, made from natural materials, are a more eco-friendly alternative in some applications and can be used in food packaging. They offer several key environmental advantages, including being biodegradable and made from renewable resources.

Silicone is not necessarily better than its alternatives. 

While silicone offers exceptional functionality, durability, and resistance to extreme temperatures, its environmental drawbacks cannot be overlooked. Silicone is not biodegradable and is challenging to recycle, contributing to environmental pollution. 

On the other hand, the alternatives mentioned above provide similar benefits with a significantly lower environmental impact. They are derived from natural or renewable resources, are biodegradable, and do not contribute to aquatic pollution.

Silicone's production is energy-intensive, producing higher CO2 emissions than some natural materials. However, its durability and resistance to extreme temperatures can lead to a lower overall environmental impact over its lifecycle.

However, these findings should be approached with caution due to potential biases and the difficulty in accurately measuring GHG emissions of silicone.

In contrast, plastics, often compared to silicones, contribute significantly to global GHG emissions, accounting for 3.4% of the total.

On the other hand, paper products have a relatively smaller carbon footprint, estimated at less than 1% of human carbon emissions in the US. 

The glass industry also has a notable carbon footprint, with container glass plants in the U.S. reporting direct emissions of 2.92 million metric tons of CO2.

Silicone, a synthetic material composed of silicon, oxygen, carbon, and hydrogen, is known for its versatility and is used in various industries. 

Here are some key statistics, facts, and figures about silicone and its market.