Safe to pets, wildlife and children, this a 100% natural product with no additives or chemicals. It has a dual action; it is a long lasting physical barrier which slugs and snails will not cross, and if they do try to brave it, the granules suck the slime from them, stopping them in their tracks. No need to replace after rain, and can be worked into the soil at the end of the season. Use in conjunction with Nemaslug (see Biological Pest Control) for full control. 3.7 litre pack protects up to 300 plants.