3 x 1LB Bags Kromopan Alginate Dust Free Class A Type 1Benefits & Features Kromopan 1 Lb. Pouch. Color Changing Alginate, Dust Free. With the chromatic phase indicator, you visually control the different working phases. Stable hydrocolloid class A alginate. Keeps its shape up to 100 hours. Thixotropic. Fast set, in-mouth setting time is about 30 seconds.