The Center for Science in the Public Interest (CSPI) is notorious for its hyperbolic and big-brother like public health campaigns. From trans fats to sugary sodas, CSPI’s efforts have always been more scare than science. A case in point is its perennial lobbying to get the Food and Drug Administration to mandate mercury warning signs wherever fish is sold.

The FDA has already stated that the CSPI-endorsed warnings would be misleading. In August 2005, then Commissioner Lester Crawford said CSPI’s plan would be “without any scientific basis as to the possible harm caused by the particular foods in question, or as to the amounts of such foods that would be required to cause this harm.”

In other words, CSPI has forgotten the golden rule of determining toxicity: the dose makes the poison. And, as we’ve told you before, the mercury levels in the vast majority of fish are well below the FDA’s “Action Level,” which is itself ten-times lower than the lowest level associated with negative health effects. So you’d have to eat a ridiculously large amount of fish to suffer even mild adverse effects.

That means that warning labels would probably do more harm than good. As Paul Dawson, a food chemist at Clemson University, put it recently: “We don’t want to scare people away from eating fish. Too much of certain types is bad for you, but moderation is key. Too much of anything is bad for you … But posting signs that warn against eating fish seems extreme to me.”