Welcome to A.S.!
US only has one chaps standard: ASTM 1897. It's Pass/Fail. Some chaps might be more protective than others, but the standard does not distinguish between them. The USFS has it's own specification, but that is a separate issue.
EU has EN381, with 3 chain speeds and 3 levels of coverage ('A', 'B', 'C', '1', '2', '3'). But, they mostly wear pants over there.
Canada has its own standard: ASTM F3325, with different levels of coverage.
For personal use, you can buy any of them. For workplace use, '
they' might want to see US standards in Washington state.
A helpful article on the differences is on the Clogger site:
https://blog.goclogger.com/the-clogger-guide-to-global-chainsaw-protection-standards/
Philbert