Its funny..The fish didn't even get a tumor when they floated to the surface. 2.5 ppm is the LD-50, The best part about this was that INSU used an environmental freindly tube, I-Plus, composite tube with steam cure....less resin therefore less disruptive (a law of physics?). A fish fry is a great treat with styrene and organic peroxides (sweet tasting, floral smell).