I work for the DEET Education program, Washington, and I am a Mom, too.  DEET  is NOT toxic to bugs–it does not kill them. The Am. Academy of Pediatrics guidance is that these products can be used on infants as young as 8 weeks of age in concentrations up to 30%.   This conveys the level of confidence that the medical/scientific community has in the safety and efficacy of these repellents.  If you choose not to use DEET, at least pick one of the three other EPA-registered active ingredients. These have been tested for safety and efficacy. (Essential oils have not.)   Where there are endemic vector-borne diseases, you want something that works. These other three registered ingredients are picaridin, oil of lemon eucalyptus, and IR3535.  For ticks, the CDC recommends a minimum 20% concentration DEET-based repellent.  For mosquitoes, lower concentrations work. Essential oils work only about 20 minutes for mosquitoes…and are known to cause skin issues for many people (sensitivity).  As for DEET safety profiles, the CDC website notes that women who are pregnant who live in areas were vector-borne diseases are endemic (West Nile virus, EEE, dengue, and all of the others) can use these products.  The urban legends associated with DEET are just that.  If you want the science information, call me at 800-789-3300. I will be happy to share and discuss.  The most commonly reported adverse event with DEET-based products is stinging of the eyes (ingredients generally include alcohol).  Splashing with water alleviates that issue entirely should it occur. Always follow label directions for use no matter what product you choose.  Hope this information helps dispel some of the concerns…or at least gives some additional perspectives for consideration.