Why Do Silicone Cases Turn Yellow [And How To Prevent It]

Are you wondering why silicone cases are turning yellow over time?

This yellowing occurs as a result of a chemical reaction within the silicone material, causing it to change color.

Continue reading if you want to deepen your knowledge about this issue, and more importantly, how to prevent it.

hand holding yellow phone case

Why do silicone cases turn yellow?

These are the main reasons why silicone cases turn yellow:

  • UV radiation and yellowing
  • Oxidation processes in silicone
  • Impact of temperature on silicone
  • Chemical reactions with airborne substances
  • Quality of silicone materials
  • Role of additives in silicone
  • Humidity and moisture effects

Let’s check them out in more detail and see what you can do about them.

UV radiation and yellowing

Exposure to UV (ultraviolet) radiation is a key factor in the yellowing of silicone cases. UV rays from sunlight contain energy that can trigger chemical reactions in the silicone material, leading to a change in color over time. This yellowing phenomenon is a result of the degradation of the silicone’s molecular structure caused by UV radiation.

How to mitigate the impact of UV radiation and yellowing on clear phone cases

Opt for cases labeled as UV-resistant, designed to withstand sunlight exposure. Avoid direct sunlight for extended periods and store your phone in shaded areas when not in use.

Regularly clean the case with a mild soap solution to remove contaminants contributing to yellowing. Applying a UV-blocking screen protector on your phone’s screen can reduce UV exposure to the case.

Oxidation processes in silicone

Oxidation processes in silicone refer to chemical reactions that occur as silicone materials come into contact with oxygen over time. Oxygen molecules can react with the silicone polymer chains, leading to changes in the material’s optical properties, including color. This oxidative yellowing is a common occurrence in many silicone products as they age and are exposed to the atmosphere.


If you have multiple clear cases, rotate their usage to distribute wear evenly. Additionally, some manufacturers offer warranties against yellowing, so investing in a case with such coverage may provide added protection for your clear phone case.

Impact of temperature on silicone

The impact of temperature on silicone is significant, as temperature variations can affect the physical properties of silicone materials, including their color. Silicone cases may experience color changes, including yellowing when exposed to extreme temperatures. High temperatures can accelerate chemical reactions within the silicone, potentially leading to discoloration and degradation of the material.

Very low temperatures can make silicone more brittle and prone to damage, which can also affect its appearance over time. Proper storage and use within recommended temperature ranges can help mitigate these effects and preserve the appearance of silicone cases.

How to decrease the impact of temperature on silicone

Avoid exposing your phone and case to extreme heat, as high temperatures can also accelerate oxidation. Consider placing silica gel packets inside your phone case to absorb moisture and reduce oxidation.

Chemical reactions with airborne substances

from clear to yellow phone case

Airborne pollutants and contaminants, such as gases and particles, can come into contact with the silicone surface. Some of these substances may react with the silicone material, leading to discoloration. This chemical interaction can be exacerbated by environmental factors like humidity and temperature, making it important to protect silicone cases from exposure to such contaminants to minimize yellowing.


Keep your phone and case away from harsh chemicals, such as household cleaning agents or solvents, as exposure to these substances can accelerate yellowing.

Quality of silicone materials

Higher-quality silicone materials often incorporate additives and formulations designed to resist yellowing caused by UV radiation and chemical exposure. These premium materials are more resistant to color changes and tend to maintain their original appearance for longer periods.

In contrast, lower-quality or poorly formulated silicone materials may be more prone to yellowing, making it important for consumers to consider the quality of silicone when selecting cases for their devices.


Choose well-established and reputable brands known for their commitment to quality. Read customer reviews and check for certifications like RoHS or REACH, which attest to environmental and safety standards. Examine the product’s specifications and materials list, ensuring that silicone is a primary component and that there’s transparency about the materials used.

Role of additives in silicone

Manufacturers often incorporate additives to enhance the performance and durability of silicone materials. Specifically regarding yellowing, UV stabilizers, and anti-oxidants are common additives used to mitigate the effects of UV radiation and oxidation, both of which can lead to discoloration. UV stabilizers protect silicone from the harmful effects of sunlight, reducing the likelihood of yellowing over time.

Anti-oxidants help prevent oxidation-related color changes in silicone by minimizing chemical reactions with oxygen. The presence and quality of these additives can vary among different silicone products, affecting their resistance to yellowing and overall longevity.


Some clear silicone cases come with special clear coatings designed to resist yellowing and oxidation. Look for cases with these features for added protection.

Humidity and moisture effects

hand holding 3 old phone cases

High humidity levels can increase the likelihood of water vapor coming into contact with silicone surfaces. Over time, this moisture exposure can promote chemical reactions within the silicone material, leading to discoloration, including yellowing. Additionally, moisture can facilitate the growth of mold or mildew on silicone surfaces, which may also impact their appearance. Proper storage and care, including keeping silicone cases dry and protected from excessive humidity, can help mitigate these effects and preserve their original color.

How to decrease the humidity and moisture effect on your clear phone case

If you expect to be in a particularly humid or wet environment, consider using a waterproof bag or pouch specifically designed for smartphones. These cases provide a high level of protection against moisture.

Storing silicone cases properly

Here are some tips for storing silicone cases effectively.

  • Clean and Dry: Before storing, ensure that the silicone case is clean and dry. Any dirt or moisture left on the case can contribute to discoloration and mold growth.
  • Cool, Dry Location: Store silicone cases in a cool, dry place away from direct sunlight and extreme temperatures. Excessive heat and UV radiation can accelerate yellowing.
  • Avoid Airtight Containers: Silicone cases should be stored in containers or pouches that allow for some air circulation. Avoid airtight or vacuum-sealed containers as they can trap moisture.
  • Elevate from Surfaces: When placing silicone cases on shelves or in drawers, elevate them from direct contact with surfaces. This prevents potential color transfer and allows air circulation.
  • Keep Away from Humidity: If storing in a humid environment, consider using moisture-absorbing products like silica gel packets to reduce humidity levels inside storage containers.
  • Rotate Usage: If you have multiple silicone cases, consider rotating their usage to prevent extended periods of storage, which can lead to uneven color changes.
  • Regular Inspection: Periodically inspect stored silicone cases for any signs of yellowing or damage. Early detection can help address issues before they worsen.
  • Avoid Contact with Other Materials: Prevent direct contact between silicone cases and materials that may cause color transfer, such as fabrics with strong dyes.

Cleaning and maintenance impact

This is how proper cleaning and maintenance can preserve the appearance and longevity of silicone cases.

Cleaning and Maintenance ImpactPositive ImpactNegative Impact
Removal of ContaminantsRemoves dust and dirt.Harsh cleaning agents can damage the surface.
Prevention of Mold GrowthPrevents mold and mildew growth.Moisture trapped during cleaning may promote yellowing.
UV ProtectionSome cleaners contain UV protectants.Neglecting cleaning allows contaminants to accumulate.

Natural aging of silicone

As silicone ages, its molecular structure can change, leading to alterations in its optical properties, including color. While some yellowing due to natural aging is expected, proper care and maintenance can help slow down this process and extend the lifespan of silicone cases while maintaining their appearance.

My experience

My personal experience tells me that not all of them turn yellow/brown!

When I got my new phone, I desperately needed a case and got the cheaper clear case because it’s just a case to me, and didn’t care much at the time. My girlfriend has had her phone case for much longer (I bought it for her when we were getting her new phone and it was way more expensive than my case) and it hasn’t turned yellow at all, while mine turned brown in less than a year.

The more expensive flexible clear cases tend to be made of higher quality thermoplastic urethane that is UV stabilized so it won’t degrade and turn brown. They are pricier but damn I am jealous of my girlfriend’s clear phone case right now.

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I love all things tech, so I decided to make a blog about technology, electronics, gadgets, accessories, and all the various items we use every day that make our lives easier. I like doing a lot of research on various models and brands, looking for great value and performance, both through data and experience.