From the Hikari website:

"An excellent diet for all smaller freshwater fish, some reptiles & turtles.

Hikari’s extensive, multi-step sterilization process assures unequalled product quality. Free from harmful parasites, unwanted bacteria and foul odor, Bio-Pure frozen foods are another example of Hikari’s product quality commitment. Tubifex Worms are an excellent choice when a supplemental higher protein natural food or treat is desirable. Gut loaded with Bio-encapsulated multi-vitamins, packed in pure water and our no-touch™ cubes for ease of use, they are an excellent choice for most smaller fish, selected reptiles and turtles."