Wow! You guys been having some fun since I was in here last!
As to the standards, in MHO even though DOT is as I would suspect, minimalist and even been reported to be simply bought for a price.
Any helmet affords protection, to varying degrees. From a fake helmet used in States to give the appearance of "compliance" to the "high end" ones. You will do better with one than without one in an accident.
Anything that absorbs ANY of the initial energies in a crash are that much less than what is in acted upon your body. The less the better and it is in those times that it MAY make the difference in a favorable outcome. And that is what any safety gear does, absorb energy. Glasses absorb the energies of a bug hitting you (or as mentioned, your skin absorbs it!) Leather, and plastic absorb the heat and force and reduce it to whatever degree before it as it's way on you, and some is obviously better than none.
I should be getting my new Skid Lid tomorrow, for those days when I just don't mind getting hit by bugs and want to feel the softer side of the world rushing at me, and still have a little protection if the harder side of the world decides to assault me!
For a potentially cantankerous subject, ya'll been playing pretty nice in the sand box!