Powdered rosin
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
The classification and grade of any rosin sold in commerce in a powdered or finely broken condition shall be stated in the invoice or contract of sale in accordance with the kind and grade of the rosin before it was powdered or broken. For the purpose of preventing coalescence there may be incorporated in such article a limited and necessary quantity of inert, nonresinous foreign material: Provided, That the nature and quantity of such inert material shall be stated on the label.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.