Are organic pesticides really safe?
Derived from natural sources, organic pesticides often have less residue than synthetics and break down quickly, so they usually have a lower environmental impact. But they can still be just as toxic to people and nontarget species as synthetic ones. For instance, diatomaceous earth has a number of eco-friendly insecticidal uses, but breathing the dust can cause irritation in the lungs. And natural fungicides containing copper are commonly used on fruit trees, but when overused, copper can accumulate in the soil in levels toxic to plants, requiring years to remove by adding organic matter and lime.
Just as with any synthetic pesticide, you should always carefully read the label, wear protective clothing and weigh options regarding the number of applications for effectiveness and environmental impact. Use proper protective equipment, such as a dust mask and neoprene gloves, when applying any pesticide, organic or synthetic.