What is cheap rug backing

I bought some rugs from walmart. I used one under an office chair. After a few years I lifted up the rug and it had a ton of "powder" under neath it as if someone spiled a can of baby power under it. It was the rug backing, It seems the chair wheels pulverized the backing of the rug.

I want to buy a new rug but I do not want to have the same problem. I’m sure the dust was very unhealthy to breath too.

What is this backing called and is it just for very cheap rugs? It is hard to tell on some rugs if they have this backing from the limited pictures they give. I’m trying to find a good rug that isn’t too expensive to protect the hardwood floor.

Best I can tell is that these types of rugs are called tufted rugs and the backing is latex and this is what the powder was.