>> >I'd call the manufacturer to be sure, but I suspect the sponge will
>break
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>suppose it may eventually break down in the stomach but a sponge is
>made of rubber and would probably take a long time to break down.
Sponges are made of all kinds of materials, including Phylum Porifera,
the aquatic animals.
IIRC, and I may not, these things are a polyamide or polyacrylamide
gel, the stuff used for gel electrophoresis. It's pretty inert
chemically, but I don't know if it can rot, be digested, or dissolve
in stomach acid. I expanded one inside a small jar (pickled dinosaur),
and it hasn't shown any visible change after several years in tap water.
This material is also used in potting soils to hold moisture, and consumers
are sometimes alarmed to see gelatinous blobs emerge from their hanging
baskets.
I wouldn't let a little kid get his hands on them until they are
expanded. Before that, close adult supervision only. Of course, you
should exercise close supervision of little kids in the bathtub anyway.