It is legal. I dont' have the regulations here, but they are interpreted differently by different airlines. Every couple of weeks I send from 30 to 80 samples (100 ml each) by DHL. I have to have sealable bottles, and a cardboard box. FedEx and UPS will not ship, as they use American Airlines from Bolivia to Miami.
I have quoted air shipment from the U.S. on pails, and it can be done, but is not cheap (3 pails for $750 freight). A freight forwarder can handle it.
I have to include the MSDS sheets.