Benzene derivative which is topically used with creams and solutions (2-4%) as a bleaching agent for several skin disorders associated to hyper-pigmentation. In industry it is used as photographic developer. TLV or threshold limit value which means maximum exposure limit for workers is 2 mg / m3 (Flickinger 1976). At latest update relevant published data were not found on excretion into breast milk. It is well absorbed through the skin, both when used as a therapeutic agent (Bucks 1998, Wester 1998, Westerhof 2005, Andersen 2010, Bozzo 2011) or industrial use (Barber 1995, McGregor 2007), however, a significant excretion into breastmilk is not likely for their lack of fat solubility. There is controversy and doubt about a possible mutagenic and carcinogenic effect (Kooyers 2004, FDA 2006, Levitt 2007, Andersen 2010), so it does not seem wise a chronic or continued use while breastfeeding. Do not apply it on the breast to prevent ingestion by the infant; otherwise, do it just after a meal and clean the nipple thoroughly with water before the next feed.Do not apply it over large areas or on long-term treatments to avoid an excessive systemic absorption.