Toxicological trivia from November 02, 2009: The main advantages of using mosquito repellents as citronella oil are its low toxicity, high tolerance and pleasant smell, which positions it even as a main ingredient used in essences, with the same purpose as environmental flavoring incense, candles, or oils. As a repellent for personal use is appropriate for young children and pregnant women, but has the disadvantage of:
a) A limited efficiency;
b) No action remain for long;
c) Both previous statements are correct.

Answer c. Read more in the monograph Repellents, update 2009 (only available in Spanish).