HIPRF stands for Herbicides, Insecticides, Pesticides, Rodenticides and Fungicides. These are chemicals that are used to deal with weeds, insects, spiders, slugs, mice and fungus. They are used in all sorts of places, particularly outside, on lawns, pathways and driveways.
You do not know how often you are picking up these chemicals on your shoes. If you wear shoes in your house, you are introducing them onto your floor and into the dust that you breath. HIPRFs are toxins that are designed to kill lifeforms. Hence they can present health risks, particularly to children.