Para-phenylenediamines and their oxidative derivatives in infant formulas in China: Occurrence and health implications

Para- phenylenediamines (PPDs) and their quinone derivatives (PPD-Qs) are ubiquitous in the environment, while data on their occurrence in foods are scarce. In this study, twelve PPDs and PPD-Qs were measured in infant formula, and their daily intakes and health risks for infants were assessed. In the tested 141 samples, the median levels of ∑PPDs and ∑PPD-Qs were 2538 and 80.34 pg/g (powder), respectively. N-(1,3-Dimethylbutyl)- N ′-phenyl- p -phenylenediamine (6PPD) was detected in most samples, with a median level of 2125 pg/g. However, most other PPDs and all PPD-Qs presented low detection frequencies of <40%, with mean levels of <80 pg/g. Formulas for infants of 0–6 months had significantly higher levels of 6PPD than those for older infants. Estimated daily intakes (EDIs) of ∑PPDs and ∑PPD-Qs via formula feeding were < 200 and < 10 ng/kg bw/day, respectively, for infants, and formula feeding may represent an important dietary exposure pathway for infants.