It maybe a Hazmat issue with everyone. It's not that the supplier do not want to ship, it's the shipping companies who won't. I've not been able to bring Hazmat items into Canada ( ie paint) via an out of country source and only because of the shipping companies hazmat polices.
Here's what Caswel state under their policies.
"Hazardous Goods: Some of our products are classified as hazardous goods by the US DOT, Transport Canada & IATA. These products will incur an additional charge when shipped by ground, and cannot be shipped by air or internationally"