Science

These bacteria are soil bacteria, so they're already in the environment. It seems like they produce biocement in small quantities and under specific conditions, so the real innovation here seems to be packaging them in a "just add water"-style container.

As for the worst that could happen? I suppose misuse of the packaged bacteria might cause the bacteria to leech into the soil and throw off the balance of the soil microbes in the area, which may or may not lead to poor soil quality