When used correctly, neem oil is safe for humans and pets. This natural pesticide is organic and breaks down quickly. Direct contact with the oil may cause mild skin or eye irritation. Avoid inhaling or ingesting neem oil and wash hands well after using. Minimize exposure and wear protective clothing for broader applications. Wash fruits or vegetables thoroughly that are sprayed with neem oil before consumption. Neem oil may be somewhat toxic to fish and other aquatic life, so caution should be taken around ponds or streams.