You would expect a natural insecticide to be perfectly safe for people and pets. The truth is that some cause irritations or burns or are even toxic to humans and animals. If you are going to use a natural insecticide, you should be aware of whether it causes problems beyond the pest.
Rotenone is a natural insecticide. It is made from derris plant roots. While it is fairly safe for people, it does harm fish. If you use it, you should take precautions to keep it away from water where you have fish. Rotenone is somewhat toxic to warm-blooded animals. It is even somewhat toxic to humans. You should therefore protect yourself during application of the natural insecticide. The good news is that it doesn't affect the safety of vegetables grown using it.
A natural insecticide that causes eye and respiratory irritations is Sabadillia. Although it causes discomfort, it is not toxic. However, you should take care not to breathe it in when using it. A mask should be worn.
Dried peppers can be ground and mixed with water to make a spray. This is used as a natural insecticide. However, it too can cause eye and respiratory irritation. The crucial time to be concerned is when you are grinding the peppers.
Termite control products that contain nicotine sulfates are actually more toxic to mammals than synthetic products are. These natural insecticides should be used with caution by an experienced exterminator. Some people use nicotine either in a commercially made product or they make it on their own from tobacco leaves. They use this natural insecticide for many different insects. The trouble is that it is toxic to people. You can't breathe the vapors. You'll want to avoid letting it touch your skin.
On the other hand, many a natural insecticide is completely harmless to people and pets. Boric acid is so safe that it can be used in areas where children play. It is toxic only to insects. Diatomaceous Earth is a very popular natural insecticide that is safe for all mammals, including people. Bacillus thurengiensis, Bt, is safe for use on plants as well. It does not harm humans or animals.
Orange, lime, and grapefruit oils are being developed as products to be used as natural insecticides in Third World countries. They are very good at killing many different insects. At the same time, they are completely non-toxic to humans. The natural insecticide from the neem tree is not just non-toxic. It has actually been used as an antiseptic. It has also been used by herbalists to treat many diseases. It has been used for over forty years.
If you use a natural insecticide that contains harmful ingredients, you need to be sure to use it properly. If it is a commercial preparation, follow instructions on the label and use in recommended amounts. It is also important to be aware of how long you need to wait between use of the product and harvesting the crop.
Some kinds of natural insecticide are harmful to people and/or pets. Some are not. The key is to know which natural insecticide you are dealing with. Then, be sure you know everything about it.