Serpone et al also described the deleterious effects of micronized TiO2 on DNA. They purported to have tested for the formation of hydroxyl radicals produced on irradiation of TiO2 extracted from sunscreen in both in vitro and in vivo studies. The authors verified TiO2 as an initiator of harmful reactions including DNA strand breaks through generation of free radicals. However, the methodology of the study was not described, and thus the results could not be reproduced or analyzed.