All the appliances mentioned are rated to be used with appropriate extension cords, and cords are sold at retail for such use.
They're not well marked at Home Depot, you have to bother to look for the right gauge, the cables aren't even necessarily in the right place, and if you don't know jack about being an electrician, it's easy to buy a cheap 2-prong 18-gauge indoor-rated cable for use outside in a wildly inappropriate fashion. No one at Home Depot is going to stop you and ask what you're about to do with the cable.
yes, For people with half of a clue, it's possible to buy the right cable and be safe, but we have to plan for the lowest common denominator, and tell people that extension cords are just extension cords when they come in all sorts of flavors, some of which are happy to burn your house down, is irresponsible.
The store brand, which is general most prominent, gauge is color coded: 6AWG - Gray / 12AWG - Yellow / 14AWG - Pink / 16AWG - Orange. There's one exception to this where 14 AWG cable is using orange labeling normally used on 16AWG wire but that's the opposite of a safety issue.
And they have generally have the rated amperage for the length of the cable.
If you're coming from the paint department, how are you to know that the color is material? I just like orange, it's my favorite color.
My point was gauge and maximum rated amperage are on the label.