Bismuth yellow
From PyroGuide
Formula: Bi2O3
Synonyms: Bismuth(III)oxide
Description: It is used in crackling stars (Dragon's eggs) as a non-toxic substitute for toxic lead compounds. For this purpose it is mixed with magnalium and copper oxide.
Hazards: Harmful by inhalation, in contact with skin and if swallowed. Wear suitable protective clothing when working with Bismuth yellow, such as dust mask and latex gloves.
Sources: Bismuth yellow can be found at various Pyro supplies. The major defect is the comparatively high price of bismuth.