How Long Do Helium Balloons Last?

A group of different colored balloons during a birthday celebration. — After a few hours, helium starts to leak out, causing the balloon to deflate. Flashpop / Getty Images

We've all been there — you get a bunch of helium balloons for a party, and the next day, they're half-deflated and drooping sadly in the corner. So, how long do helium balloons last?

First, it's important to understand that helium leaks out of balloons. Helium is a very small atom, and latex is pretty porous at the scale of a helium atom (if you ever go looking to buy balloons, you will see that there are "helium-grade" balloons, which are typically thicker and less porous).

The weight balance that keeps a balloon afloat does not leave a lot of room for leakage, so once a little leaks out, the balloon falls. But there are a few factors to consider beyond that. Let's dive deeper into the world of balloons and helium.

Diffusion: How Helium-filled Balloons Deflate

Helium atoms are incredibly tiny, and the material of the balloon, whether it's latex or foil, has microscopic pores that the helium atoms can slip through. This process is actually called "diffusion." Over time, the helium molecules escape through these pores, causing the balloon to lose its buoyancy and eventually fall to the ground.

Latex Balloons vs. Foil Balloons

There are two main types of balloons: latex balloons and foil balloons. Latex balloons are made from a natural rubber material, while foil balloons, also known as mylar balloons, are made from a thin layer of plastic coated with a layer of metallic foil.

Latex helium balloons are more porous than foil balloons, which means helium escapes more quickly from latex balloons. On average, a latex balloon filled with helium will start to lose its lift after about 6 to 8 hours, while a foil helium balloon can stay afloat for several days or even weeks.

The Role of Temperature

Temperature also plays a crucial role in how long helium balloons last. Helium gas expands in hot weather and contracts in cold weather. So, if you leave your helium-filled balloons in a hot car or under the hot sun, the helium will expand, and the balloon may pop. On the other hand, cold temperatures can cause the helium to contract, making balloons in a cold room shrink and droop.

To maximize the float time of your helium balloons, it's best to keep them in a room-temperature, air-conditioned room.

Tips to Extend the Life of Your Helium Balloons

While helium balloons are bound to deflate eventually, there are a few tips and tricks you can use to extend their float time.

Use Hi-Float

Hi-Float is a liquid solution that you use to can coat the inside of the balloon before filling it with helium. It creates a barrier that helps to reduce the rate at which the helium escapes from the balloon. Using Hi-Float can extend the float time of latex balloons from a few hours to several days.

Choose Bigger Balloons

Larger balloons have a greater volume, which means they can hold more helium. More helium means more lift, and it will take longer for enough helium to escape to cause the balloon to fall. So, if you want your bubble balloons to last longer for those birthday parties or baby showers, choose larger balloons.

Keep Balloons Indoors

As mentioned above, different weather conditions can affect the float time of helium balloons. Keeping your balloons indoors — away from the hot sun, cold weather and wind — will help them last longer.

A Dwindling Resource

Did you know that helium is a nonrenewable resource? It's extracted from natural gas fields, and once it's gone, it's gone for good. So, while helium-filled balloons are a lot of fun (especially for small children), it's important to use helium responsibly and consider alternatives when possible.

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