Determination of Selected Harmful Substances in Baby Diapers Available on the South African Market.

Baby diaper rash is a common problem, especially allergic contact dermatitis, which could be due to heavy metals, pH, formaldehyde, or allergens in the diapers. This study reports on the determination of formaldehyde, heavy metals (Pb, As, Co, Cr, Ni, Cu, Zn, Mn, Sr, Fe, and Cd), and pH in diapers purchased from low-, medium-, and high-end stores. Inductively coupled plasma was used to determine the concentrations of heavy metals after extraction using artificial urine and artificial sweat. All heavy metals were found in all diapers except Sr, which was not found in sample M7. All samples had concentrations of heavy metals within the Oeko-Tex limits, except samples H2 and L2, whose Ni concentrations were above permissible limits. Fifty percent of diapers had a formaldehyde concentration above the Oeko-Tex recommended limits. The highest formaldehyde concentration of 17.62 mg/kg was found in diaper M2 and the lowest (ca. 10.4 mg/kg) in H1. All samples had pH values in the alkaline region, with only five samples having pH values within the recommended limits. The research concluded that the diaper rash experienced by some babies, among other factors, could be due to high alkaline skin pH and formaldehyde levels, which are higher than the Oeko-Tex recommended limits.