Governed by the Environmental Protection Agency (EPA), insect repellents may be required to list active ingredients, but the "EPA does not require a complete declaration of 'inactive or inert' ingredients" nor a list of "the identities of inert ingredients on product labels." The label is only required to list the percent composition of inert ingredients.
Furthermore, because only active ingredients require registration for safety and effectiveness, scented inactive ingredients may present concerns for patients with fragrance sensitivity. Case reports documenting insect repellent contact dermatitis have identified various botanical and fragrance chemical ingredients, such as citronellol, lemon oil, eucalyptus oil, and neem oil.
Skin Therapy Letter. 2021;26(5):1-6. © 2021 SkinCareGuide.com