Plastic products for children often have an intense odor. The substances that cause such off-odors are not always well-known and, therefore, cannot be comprehensively determined in routine analyzes. The question arises as to whether these odorous substances pose a health risk to children or whether a conspicuous odor is an indication of contamination with substances of concern. In addition, children are much more sensitive to some odors than adults.
Christoph Wiedmer and Andrea Büttner, Fraunhofer Institute for Process Engineering and Packaging (IVV), Freising, Germany, use a combination of instrumental analytics and the human nose to determine the structures of various odorants.
In general, odors have only two properties in common: they are volatile enough to reach the human odor receptors via the air they breathe, and they can activate these receptors. Odors may contain various functional groups. Therefore, odor analysis methods must be able to detect a wide variety of substance classes, which are often only in the trace or ultratrace range.
The researchers have found toxic, potentially carcinogenic, and possibly mutagenic substances in several toys, including naphthalene, isophorone, and phenol. In some unpleasant-smelling products, odorless pollutants were also present in increased concentrations. In water wings, water balls, and similar products, the researchers found, for example, solvent residues, especially cyclohexanone, isophorone, and phenol. The smell of these individual substances is very similar to the overall smell of water toys. In addition, various polyunsaturated carbonyl compounds with fatty and cardboard box-like odors were detected.
To estimate the actual risk posed by the products, in addition to the toxicological properties of the substances, the concentrations in which they are present in the products are needed.