Many parents whose children love slime are asking are you allowed to take slime on a plane? The short answer is Yes. But bare in mind that slime is considered a liquid so if you have it in your carry on baggage then it needs to go with your other liquids and lotions in your one-liter zip bag.
How to pass airport security with slime in your carry-on bag
Can slime pass through security safely at the airport in a carry-on bag? Yes, but you need to keep in mind that slime or putty is a liquid.
According to TSA (Transportation Security Administration), passengers are allowed to carry liquids, gels, and aerosols in small containers that are 3.4 ounces (100 milliliters) or smaller. Passengers are limited to one quart-size (1 liter) transparent plastic bag of liquids, gels, and aerosols. The same rule applies all over the world for air travel. Some common items in this category include drinks, toothpaste, shampoo, cosmetic creams, and gels.
So in order to pass security with the slime in your carry-on baggage, you will need to first place the slime into a container that is smaller than 3.4 ounces (100 ml) and then place that container into a see-through plastic bag with all the other liquids. Make sure the container is labeled with the volume and it’s under the limit. It doesn’t matter if the container has less than 3.4 ounces of liquid in it, it’s the container size which counts.
It shouldn’t matter is the slime homemade DIY slime or is it something available in a store. The tricky part would be having a small enough container and having the container labeled with the volume. Many commercially sold slimes will not have the volume labeled on it.
TSA has a What can I bring section listing over 400 items, but slime or putty is not on the list. They do have also a service called AskTSA and the response from them is: yes, but only if the slime is 3.4 ounces or less and is carried with the passenger’s liquids.
Why is slime considered a liquid?
Slime doesn’t feel liquid like water but it’s not either solid like wood. I think we can all easily agree it’s not a gas.
There are four states of matter: solid, gas, liquid and plasma.
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure.
A solid object does not flow to take on the shape of its container and it doesn’t expand to fill the entire available volume like a gas. A solid is characterized by structural rigidity and resistance to a force applied to the surface.
Plasma is a state of matter in which an ionized gaseous substance becomes highly electrically conductive to the point that long-range electric and magnetic fields dominate the behavior of the matter.
Based on the above descriptions slime fits best into the description a liquid since slime conforms to the shape of its container. However, to be precise slime is a non-Newtonian fluid. This means that the viscosity, or resistance, of the fluid changes as you apply a stronger force. Stepping on the fluid with a larger force will make it behave more like a solid but standing still will lower the force and make you sink and the fluid behaves more like a liquid. We are more familiar with substances which change state due to temperature like freezing water into ice (solid) or boiling water into steam (gas). Non-Newtonian fluids are unique in the sense that they change states very rapidly based on the force applied to them.
From the perspective of flying slime is considered a liquid as other non-Newtonian fluids like shampoo, toothpaste, and honey.