The safest silverfish killer makes it to the top, and it's Safer Brand Diatomaceous Earth. It is made with the crushed and powdered shells of fossilized diatoms that are safe to use, non-toxic and can be used around kids and pets. Simply sprinkle the diatomaceous earth around known silverfish habitats and let it work. Although the particles resemble dust to us, they are actually tiny razor blades to insects. When they either ingest the particles or merely walk over them, the diatomaceous earth slices through their exoskeleton which causes the insect to dehydrate. It works best when distributed in dry areas, and can be used both indoors and outdoors with equal effectiveness.
For the most trusted name in silverfish control, get Dekko Silverfish Paks and rid your household of the insect pests. This solution has been around for decades and is the most widely used and widely known remedy for silverfish infestation. The "paks" are essentially sugar-type paper packets filled with boric acid. When placed in areas with known silverfish activity, the silverfish will eat through the paper packet and begin to ingest the boric acid inside. It works much like diatomaceous earth in that it dehydrates the silverfish inside and out. Although boric acid can be toxic, because these are packaged and therefore contained for use, it is safer than regular unpackaged powders and it is just as effective.
If you are looking for a pyrethrin-based compound that will rid your home of silverfish, Control Solutions D-Fense Dust is the product for you. Using the pyrethrin-based ingredient deltamethrin, it is a natural form of insecticide that disrupts the nervous system of silverfish. Dust areas of known silverfish activity, and when the silverfish walk over it, it will stick to their bodies and be absorbed by either contact or during cleaning of their bodies. Since it is synthesized from chrysanthemums, it is relatively safe as poisoning agents go, it is water soluble and washes off readily with water, but care must be taken when spreading the dust so that you don't inhale it. Always wear rubber gloves when dusting, and keep it away from kids and pets.
One of the safer dusts on this list is Nibor-D Borate Dust. It uses boron, which is considered a green substance pesticide, to interfere with silverfish metabolism. They ingest the dust and then can no longer process food. Essentially, they starve to death no matter how mush they eat. It is considered safe to use around kids and pets because mammals can effectively process borate dust and eliminate from their systems, although in very large amounts it can still become toxic. Dust areas where silverfish roam and in a few weeks, the silverfish will be eliminated. Simple, safe and effective.
For a reliable and time-tested silverfish killer, J.T. Eaton Answer Boric Acid Insecticidal Dust has proven results for decades. Boric acid is one of the standard silverfish killers. When sprinkled where silverfish are known to congregate, the particles are abrasive to the exoskeleton both inside and out. It also acts much like borate powder in that it doesn't allow proper digestion of food, literally starving and dehydrating a silverfish to death. It is relatively safe to use, but always wear gloves when broadcasting the powder, and never inhale it as you go. It is simple to spread and effective, and has a proven track record that is the standard for silverfish elimination.