In the 1976 movie "Marathon Man," the bad guy Szell (Laurence Olivier) is torturing Babe (Dustin Hoffman) and repeatedly asks his victim: "Is it safe yet?" to find out if he can cash in some stolen diamonds.

If you're cleaning your home aquarium, or if you work in a store that sells fish and coral, that's a question you might want to ask yourself, too. If not, you could risk some pretty torturous (or even lethal) symptoms, including fever, respiratory distress, nausea and achiness.

According to the Centers for Disease Control and Prevention, in Alaska alone between 2012 and 2014 there were at least 10 reported cases of palytoxin poisoning caused by exposure to a type of coral, zoanthid, found in home aquariums.

Frequent incidents in Europe recently led Italian researchers to confirm the hazard that the coral poses.

Some marine hobbyists may be aware of Palythoa zoanthid's potential hazards, but fall victim anyway. That's because as the coral grows, it attaches to rocks and the sides of the aquarium and can be tough to remove. Scraping, cutting, applying chemicals or just using hot water to clean the tank can release the nasty palytoxins.

Whenever cleaning the tank or handling the coral, wear protective eye gear, gloves, and a mask or ventilator to avoid breathing it in.

Keep the coral contained in the tank; small crumbs can fall onto the floor and spread the irritant. And don't let children handle it.