Sponge bomb

The sponge bomb is a non-lethal, non-explosive chemical device developed by the Israel Defense Forces to seal tunnels, tested around 2021. It is housed in a small plastic container with a metal partition separating two liquid reagents, isocyanate and polyol resin, which are combined by placing the device or throwing it at a target; the mixture then expands rapidly, up to sixty times its original volume, before hardening into solid foam. During initial testing, hazardous handling of the chemicals caused some Israeli soldiers to lose their eyesight. It follows earlier military use of expanding foam, such as foam previously used by United States forces for crowd control. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/