If your headbands are more of a hair styling accessory the COC or GCC from the bead manufacturers sufficient until Feb 10th 2010, if you are able to get them. If the headband is more of a jewelry style, ala Princess Diana, then the pieces must be tested now.
Natural salt and freshwater pearls are exempt, but there has been no concise answer from the government if this includes dyed natural pearls. Glass and plastic "pearls" would need testing to prove that they are under the lead limit, since lead is commonly added as a stabilizer to the colorant for both these types of beads.
As for the size I'm personally still trying to find an easy to understand version of the small parts law, where they spell out in plain measurements what is too small and too large to be choked on. here's the links I have on this
Small Parts Regulations Summary
http://www.cpsc.gov/BUSINFO/regsumsmallparts.pdf Small Parts labeling
http://www.cpsc.gov/BUSINFO/label.pdf You may also want to read these complete from a hard copy print highlighting the parts that are important to your products.
CPSIA guidance for small businesses/crafters includes a quick glance guide Table : B exempt raw material list
http://www.cpsc.gov/about/cpsia/smbus/cpsiasbguide.pdfThe current overview of the "final" determination of raw materials for exepmtion ( a more indepth version than Table B)
http://www.cpsc.gov/businfo/frnotices/fr09/leaddeterminationsfinalrule-draft.pdf
