Stepping on a sea urchin or handling one can result in an intensely painful puncture wound. The spines are strong enough to penetrate a wet suit or puncture the soles of tennis shoes. If a spine breaks off in the wound, the wound can fester and become badly infected. Frequently a patient will have to have the spines removed surgically. While some sea urchins can also inject venom through fang-like jaws, California sea urchins are not venomous.
Some sea urchins produce a toxin during mating season that makes sea urchins dangerous to eat.
Unless you know what you are doing, leave sea urchins alone. Under no circumstance is this web site meant to replace the expert advice of a qualified poison specialist or physician.