Never mind, for now, about legal rules, just use good, common sense rules. And that includes putting the powder back in its original container, everytime you quit loading.
As of now, you likely have only one type of powder, but someday you may have several. The most common type of serious accident from reloading comes from accidentally loading the wrong powder. Get in the habit of doing it right.
When you are ready to dispense powder in the cases, get the proper powder from where you store it and fill your powder measure. Then set the container of powder in plain view on your loading bench. When you are through loading, put the powder back in its container and put away the container of powder.
There should only be one type of powder on your loading bench at a time, and that is the powder you are using at the moment.
