West Nile Virus: Questions and Answers
How to Stay Safe This Summer as West Nile Spreads
We know that DEET is the most effective way to prevent against West Nile, but some people have concerns using it. Do any of the more natural products work?
There are a number of EPA-registered products that provide relatively long-lasting protection. Those include DEET [...] as well as some products called picaridin, oil of lemon eucalyptus, and IR3535. Oil of lemon eucalyptus and IR3535 are derived from natural materials, and they are classified as bio-pesticides by EPA.
No matter which of these products you're going to use, the most important thing is that you read the directions for that specific repellent because even the amount of that active [ingredient] that's in the product that you're using will vary, so you want to follow the directions as to how much to apply and how often to reapply it.
DEET, of all the products, has the longest track record and information regarding its effectiveness and safety. I can understand that some people want to use other products, but there are no specific concerns that we have with regards to the use of DEET when it's used according to the label.