Do Crocs Shrink In The Sun?

As of the time of writing this article, (December) this is a problem only our friends in Australia and all other places in the Southern Hemisphere have to deal with. Our mates in Oz also have another kind of croc to deal with. If only they could shrink! Some kinds of shoes such as Nike Slides have been known to shrink up when exposed to high heat. Can that happen to Crocs as well?

“Crocs” by Mark Crawley, Flickr is licensed under CC BY 2.0

Can Crocs Shrink In The Sun?

They can shrink. A combination of heat and humidity can cause the resin polymer that the shoes are made out of to shrink up.

How Long Does It Take For Crocs To Shrink In The Sun?

If it’s hot enough, Crocs can shrink in just thirty minutes. Keep your Crocs in a cool, shady place when you aren’t wearing them. Heat and humidity can cause them to shrink a bit while you are wearing them, but the foot inside them stretches the material out faster than it shrinks.

Why Do Crocs Shrink In The Sun?

Crocs are constructed out of a foam resin known as Croslite, which is constructed out of a polymer known as ethylene-vinyl acetate (EVA). The atomic polymer chains that make up the polystyrene are crowded together and randomly bunched together.

Heating this material plus the rolling and cooling process in manufacture makes them straighten out and form into a more orderly configuration. However, nature thrives on chaos. When the polystyrene is heated again, the molecular arrangement gets out of order.

Other Reasons That Cause Crocs To Shrink

A combination of heat and humidity can lead to consolidation shrinking. This causes the polymers to lose tension. Plastic is a poor conductor of heat. Heat causes the molecules to contract and the material to shrink. In manufacture, heat is applied but in a controlled mold. With nothing to guide the size and shape of the Croc, it just shrivels up.

How To Unshrink Crocs That Have Shrunk?

  • Boil a large pot full of water.
  • Throw the Crocs in for forty-five seconds.
  • Take them out to cool off for a bit.
  • While they are still rather warm, put them on.
  • You may want to wear two pairs of socks while doing this.
  • Wear the Crocs for a while until they conform to the size of your foot.

Are Crocs Fireproof?

Well, I wouldn’t recommend fighting a fire in them. The Croslite that Crocs are made out of is not made with fire retardant chemicals or plasticizers such as phthalates. Heat in Australia can warp railway tracks and melt bitumen streets, but no worries! The Crocs won’t melt! Not unless you actually put them in a fire or an oven.

Can Crocs Melt In The Sun?

They can warp and shrink, but you’d have to get them pretty hot to melt. Some people report their Crocs sticking to hot pavements if standing still for too long. So just keep walking!

At What Temperature Do Crocs Melt?

The melting point of plastic is 338 degrees Fahrenheit or 170 degrees Celsius. Because Croslite has chemical similarities to plastic, we can assume they will melt at this temperature too. The hottest place on Earth, Death Valley, California, has had temperatures recorded as high as 134.1 degrees Fahrenheit or 56.7 degrees Celsius.

Even that is far lower than the melting point of plastic. As long as you don’t try to walk on hot coals with them, you will probably be OK. Spilling gasoline on Crocs will also melt them. Be careful when using caustic chemicals around Crocs.

What Are Crocs Made Out Of?

They are made out of Croslite, a material made and patented specifically by the Crocs brand. Croslite is a proprietary Closed Cell Resin material that is not exactly plastic and not exactly rubber.

The exact formulation of this material is a guarded secret, much like KFC’s seven herbs and spices. It is known that closed-cell foam is made by the process of subjecting a rubber compound to a gas underneath a high pressure.

However, only the head honchos at Crocs know exactly what Croslite is made out of along with the precise ratio of rubber compound and gas. They want to keep that patent in order to hold on to their rights over Croslite. If it’s not Croslite, it’s not Crocs.

Are Crocs Eco Friendly?

They are not made with any animal products, so vegans will like them. However, because Croslite is so unique it cannot be recycled. It does not biodegrade easily, but it is so durable it may be a while before the Crocs see a landfill.

There is, of course, the inevitable industrial waste caused by any artificial manufacture. Crocs do have a humanitarian mission to distribute second-hand Crocs to those in need. They call it recycling, but it’s more like reusing. Still one of the three R’s.

Are Crocs Toxic In Any Way?

As Crocs are very secretive about the Croslite formula, it’s hard to say exactly what’s in it. Crocs will reveal what’s not in it. Croslite does not contain allergens such as rubber, latex, ethyl mercury, or thimerosal.

It does not contain BPA or Phthalates nor does it contain colophony, abietic acid, chromium, bisphenol A or neomycin. It seems doubtful that the Crocs have anything toxic. However, they are unsafe to wear in certain situations such as on an escalator. Use discretion.


Crocs are not going anywhere soon. Remember when I lost it a little over the ridiculousness of KFC scented Crocs? They all sold out! Not only did every pair get sold but pairs were being scalped on eBay for $250. Someone is buying them!

Recently, Crocs has released the fifth collaboration. Never mind, it’s already sold out. It only took five days. This is because Crocs is innovative with its shoes which helped it gain popularity all over the world.

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