No, to be able to put the standard EPA labeling for average NRR rating you must follow the same testing standards.
Further, the low profile sets like the MSA Sordins are designed for use with helmets, and with command, by tactical teams. The low profile, and comm controls, require they sacrifice noise reduction.
There are some who have claimed the MSA Sordins perform well at the important frequencies, but that is not true when compared to larger (and less expensive) darkroom.
Here is are links to previous posts where I showed the MSA Sordins greatly underperformed compared to less expensive Peltors:
https://pistol-forum.com/showthread....tor#post913219
https://pistol-forum.com/showthread....tor#post789234
If you're part of a tac team, and need to wear very low profile head gear with a helmet, get the gear designed for that. However, if you want quality ear pro to protect your hearing, and not wearing a helmet, get something that provides better protection.
Also, when not using a helmet you can use radios with the Peltor 100, 300, 500, and RangeGuard headsets, along with the Howard Leight electronic earpro, as they all accept a 3.5mm auxiliary cord, and can be connected to radios. I've done it before and it works great.