Quite often (from my own experience anyway), one of the safety rules in a school (high school or university) laboratory is that the students must wear leather shoes.
I like to demonstrate some of the safety rules, so my question is, what is an effective and safe experiment to demonstrate the safety of wearing leather shoes while experimenting in the chemical lab?
*This is in comparison to say sneakers or canvas shoes
The simplest thing to do is to sacrifice two pairs of shoes, one with leather uppers and the other with canvas/cloth/whatever. Put something inside the shoes to represent "feet". Do something nasty to each pair, like pour concentrated acid over them (using secondary containment to avoid spills and splashes!). Then, extract your indicator and compare (assuming the different in damage to the shoes was not enough). You can also try lighting them on fire (though canvas shoes probably have fire-retardant compounds added), or seeing how long it takes water to soak through (leather will win here).
And, whatever you do, record it to video so that next time you only need to play the video and not buy more shoes. If this is for your students, I would make sure you appear in the video to increase "authenticity".
Use directly shoes could be not so practical and reproducible. I will try to find first to figure out which experiment could be more convincing. So why don't take many little piece of leather, cotton and synthetic fiber and make some general test (maybe useful even for clothes). These are what is passing through my mind.
One of the most important thing is that substance drop over the shoes don't get in touch with the skin. So you could measure the contact angle of polar and non polar liquids over different "shoes textile" and find which has the lower one. For permeability there are also some simple instrument you can buy.
Even if this is more difficult to perform you could try to make your own system with a little hot plate and some thermocouples to see which materials do not conduct heat or is less flammable. One simple test could be the Clothes iron test (this in fact doesn't exist) you can palace a piece of different shoes textile and place it beneath the clothes iron measure the time at which it burns.
Why don't you put a little piece of textile over a piece of paper with an acid-base indicator and then put a known amount of acid or base over it if you do it in a glass table you can monitor when the acid reach the other side watching when the paper change color.
Pieces of broken glass could cut the textile so you could perform some test for determinate which textile is more hard to penetrate.
