Many slug baits are made of metaldehyde, a chemical that is toxic to the nervous system. Often these baits also contain bran or molasses to make the bait more attractive to slugs. These ingredients also make the slug bait tastier to pets. ...
Slug baits containing iron phosphate, according to the U.S. Environmental Protection Agency (EPA), have no unreasonable adverse effects to human health, and show a lack of toxicity to birds, fish and non-target insects. http://www.pesticide.org/slugs.html
Several types of snail and slug bait products are available. Baits containing the active ingredient metaldehyde are most common. Metaldehyde baits are particularly poisonous to dogs and cats, and the pelleted form is especially attractive to dogs. ...
A recently registered snail and slug bait, iron phosphate (available under many trade names including Sluggo and Escar-Go), has the advantage of being safe for use around domestic animals, children, birds, fish, and other wildlife http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74...
"slug (bait OR baits)" - 45,200 (.uk 2010, .edu 571)
"snail (bait OR baits)" - 48,100 (.uk 15,000, .edu 297)
"slug pellets" - 46,300 (.uk 22,400, .edu 66)
"snail pellets" - 668 (.uk 146, .edu 17)
"snail granules" - 547 (.uk 4, .edu 0)
"slug granules" - 331 (.uk 5, .edu 1)