Cutting open a watermelon and finding cracks inside can be surprising. Social media posts often claim these marks are caused by dangerous chemicals, but experts say that is not always true.

In many cases, internal cracking happens naturally. Changes in weather, uneven watering, rapid growth, or the fruit becoming overripe can all create hollow spaces or splits in the flesh.

One chemical often mentioned online is chlorfenuron, a plant growth regulator used in some places to encourage fruit growth. While it can sometimes affect the texture of a watermelon, regulations and safety standards vary from country to country.

Scientists say there is no clear evidence that internal cracks alone mean a watermelon is unsafe to eat. More often, the biggest concern is simple spoilage rather than chemical exposure.

When buying a watermelon, choose one that feels heavy for its size, has a firm rind, and a creamy yellow spot where it rested on the ground. After cutting it open, check that it smells fresh and has a crisp texture.

If the watermelon has only a few internal cracks but looks and smells normal, it is generally safe to enjoy. However, if you notice mold, a sour odor, sliminess, or an unusual taste, it is best to throw it away and choose another one.