There's a Fungus Amoung Us

I've lost one planter of spinach and green onions, thanks to my dog, who dug them up. And now the wet spring we've had are threatening my mid-summer harvest of tomatoes. There's a fungus on the leaves and we don't have much of a choice of fungicides here. My husband bought one that a friend of mine said was banned in her state because it was shown to be too harmful when applied to vegetables.
So why is the same thing available in Arkansas? If it's too toxic for people in Pennsylvania, wouldn't it not be toxic to people here?
I will buy a bottle marked "Good for organic gardening," but it makes me wonder.