The U.S. Coast Guard has issued a Safety Alert reporting
that the Ikaros model Mark II Man-Overboard Smoke Signal may explode if the igniter mechanism is reinserted after ignition has commenced. The device is designed to automatically ignite when pulled from its bracket. It is used with a number of ring lifebuoys and is generally detached when the lifebuoy is deployed. Owners and operators should consider replacing the model Mark II with the new model Mark III, which includes a pressure relief mechanism to prevent explosion due to pressure build-up. In the meantime, owners and operators are encouraged to install warning placards advising crewmembers to not return the smoke signal to its bracket following ignition.
Source: HK Law