Soluble glutinous rice starch SGRSEdit
Description: Soluble glutinous rice starch more commonly referred to as 'SGRS ' is a binder used by the Japanese star makers. SGRS is used as a water-soluble binder in many of Takeo Shimizu's formulas. This is not just because SGRS is more easily obtained in Japan than cornstarch derivatives like dextrin . SGRS does indeed have superior binding characteristics than dextrin, and somewhat less of it can be used than dextrin in most formulas.Edit
Hazards: Soluble glutinous rice starch is not particularly toxic or dangerous.
Sources: Soluble glutinous rice starch can be hard to come by, but can be made at home:
"Glutinous rice is polished and soaked in cold water for a week. This is then steamed in a steam basket and pounded into a cohesive mass. The mass is stretched into a thin plate like a squashed cake, which is parched at a suitable temperature. The parched cake is ground into a fine powder. The powder is somewhat brownish, but has a large cohesion power and is perfectly gelatinized in combination with water. This is the most useful binding agent for firework stars." - Shimizu