I can't speak for toxicity, but I used BM Iron Clad on a metal outbuilding in country (previously painted) and also on wood trim + doors. It's only been 3 years but I'm very pleased with how it's doing so far, still looks fresh and new. It just behaves like a paint that's going to hold up well. It's pricier tho, think I paid abt $40/gal? Maybe a bit more. BM Iron Clad latex. (They also make an oil based formula. I was using white and didn't want to risk any yellowing, so went with latex formula.)