Micro carbon residue

So, you know how sometimes when you cook food or use a candle, there can be some black stuff left behind after the heat goes away? That black stuff is called carbon residue.

Micro carbon residue is when there is a teeny tiny amount of this black stuff left over after something is burned. Like, so small you can't even see it without a special tool.

It might not seem like a big deal, but micro carbon residue can actually hurt things like engines or machines. It can build up over time and make the machine work poorly or even stop working altogether. So it's important to make sure things are burning cleanly and not leaving behind any of that black stuff, even in microscopic amounts.