Is that transparent phone case you bought starting to look a tad yellow around the edges? Unfortunately, this is an all-too common scenario and it´s important to know both why it occurs AND how to deal with it!
Quick summary (how to clean a clear case that has turned yellow) – if your phone case has just started to yellow or if you think that the main culprit might be plain old dirt, give it a thorough scrub with water and dishwashing soap. For more stubborn stains, soak the case in vinegar and baking soda OR cover with hydrogen peroxide (this should always be a last resort)!
Why do phone cases turn yellow?
There are various reasons why clear phone cases turn yellow, ranging from exposure to certain chemicals to the presence of microorganisms such as fungi and bacteria. In 99% of instances, however, phone case discoloration is the result of exposure to sunlight and UV rays.
This isn´t all that surprising if you think about the effect that sunlight has on other materials. I´m sure we´ve all left something outside for too long and experienced color fading, be it an item of clothing, a childhood toy or just something that you ´lost´ in a long-forgotten nook of the garden!
Unfortunately, both plastics commonly used to make clear phone cases (TPU and polycarbonate) are negatively affected by UV rays.
According to the science buffs over at Zeus, even the slightest impurity in polycarbonate (the go-to material for transparent hard cases) ´will initiate color instability´.
When oxygen is present (pretty much always, then!), a process called photo-oxidization occurs. This causes both yellowing AND the breaking of chemical bonds, which leads to a brittle structure.
So, not only is yellowing a sight for sore eyes, but it is also a sign of degradation.
Don´t believe me? Give these before and after exposure snaps an eyeball –
So, do all clear cases turn yellow?
Well, it depends on the material the case is made from.
The vast majority of clear cases are made from either TPU (a soft, flexible polymer) or polycarbonate (a tough, rigid polymer) and both are susceptible to photo-oxidization (i.e. they both go yellow when exposed to UV rays).
There are, though, other options on the market which are less likely to turn an unsightly shade of yellow –
The ´Clear Case´ by Pela is made with ´plant materials´ and doesn´t suffer the same sickly yellow fate as its poor plastic counterparts!
More progressive companies make use of anti-yellowing agents in their cases. Basically, they add things called ´UV stabilizers´ during the manufacturing process; these absorb the UV radiation and prevent it from damaging the polymer itself.
Both Speck´s ´Presidio Perfect-Clear´ and Apple´s ´Clear Case´ are made from ´anti-yellowing materials´ … so no need to fret about yellowing if your phone´s wrapped in either of these!
How long does it take for a clear case to turn yellow?
Well, it´s almost impossible to say as each case is different AND there are a number of factors which determine the rate of yellowing –
1 Treatment of case – if you and your phone case spend the weekends basking in the sun, definitely don´t expect it to stay clear forever!
2 Quality of plastic – cheap plastics contain more impurities and are therefore more susceptible to color change and degradation.
3 Presence of ´UV Stabilizers´ – these work to counter the effects of photodegradation.
As you can see, there are many different variables at play so it´s kind of difficult to give an exact timeframe.
In general, the cheaper the case, the faster it´s likely to turn yellow!
Ways to clean a clear phone case
´Basic´ cleaning method -
The following method is perfect if your phone is starting to look yellow or if you think it might just be a little dirty.
You will need:
slightly yellowed phone case
1 cup / mug full of warm water + a few drops of dish washing soap
1 Dip toothbrush in soapy water
2 Apply to case and scrub affected area until clean
3 Rinse and dry
NOTE – this method is unlikely to be effective if discoloration is due to sunlight
The vinegar & baking soda method -
This is one of the best ways to clean your yellowed phone case WITHOUT using bleach or peroxide.
You will need:
yellowed phone case
container (or sink)
2 tablespoons baking soda
1 cup vinegar
1 cup water
1 Place old, yellowed phone case in a container or sink
2 Cover with 2 tablespoons of baking soda, 1 cup of vinegar and 1 cup of water
3 Let sit for 1-2 hours (or until the case starts to look ´clear´ again)
4 Brush the case down with an old toothbrush, this should remove any residue
5 Rinse with water and admire your (hopefully successful) handiwork!
The peroxide method -
Peroxide is incredibly effective when it comes to waging war against yellowed plastic.
You probably already know that it´s popular with hairdressers and blonde-haired surfer dudes, but it´s also a UV stabilizer which means that it will actually work to reverse the yellowing process!
Please be careful when using peroxide as it can be corrosive to both hands and skin, we recommend the use of gloves at all times.
You will need:
old, yellowed phone case
gloves (maybe goggles)
hydrogen peroxide 12%
1 Put on gloves and maybe even goggles if you´re using uber-strong peroxide
2 Coat phone case with a thin layer of peroxide
3 Place in ziplock bag and leave to sit in sun for 1-2 hours, turning over at half hour intervals
4 Rinse and dry phone case, check if desired effect has been achieved
5 Repeat process if necessary, checking / turning over phone case at half hour intervals
NOTE – it is advisable to test the effect of the peroxide on your case BEFORE going the full hog (just as a hairdresser would do if you were getting your hair dyed). Just apply a little peroxide to the corner of your case and follow the steps above.
The ´bleach bath´ -
If all else fails or you don´t want to use peroxide, you can try the ´bleach bath´ method. Again, bleach is an extremely strong chemical so use it sparingly and with care!
You will need:
old, yellowed phone case
1 Fill a container or sink with 10 parts water, 1 part bleach
2 Place phone case in container (don´t forget to put on your gloves)
3 Soak until clear again
4 Rinse and dry
NOTE – the use of bleach (and peroxide) should be a last resort and is only recommended if you´re really set on ´saving´ a particular case. Please bear in mind that excess bleach will ruin your case!
How can yellowing be avoided?
Most ´plastic´ phone cases will experience some yellowing, especially with heavy use.
The above methods should help to address the issue in most instances and, considering all that´s going on in the world, it´s probably a good idea to give your phone case a quick scrub down anyway!
Really the best way to avoid yellowing is to purchase a case manufactured using anti-yellowing agents. Remember that yellowing is actually a sign of degradation and, well, we really need our phone case to be tough and durable … it´s there to PROTECT our device, after all!
It might cost you a little more at the time, but a well-made case may save you a dime in the long run!
Erika is a Mexico City based stylist and self-confessed phone case fanatic! She´s been building up her case collection ever since she got her hands on her first iPhone! Her husband reckons that she has more cases than she does clothes!