Why does an ASIN have a different HAZMAT status when comparing it on two amazon marketplaces

Why does an ASIN have a different HAZMAT status when comparing it on two amazon marketplaces

ASIN's are evaluated differently between all the different Amazon marketplaces (Amazon.com, Amazon.ca, etc.) 

For example, an ASIN on Amazon.com will already have sellers sending the product into the FBA warehouse so Amazon has identified it as a hazmat product whereas the same ASIN on Amazon.ca did not have any FBA Sellers so Amazon has yet to identify its hazmat status.