**4. Conclusions**

The present study proposes a methodological approach for the evaluation of short-term inhalation exposure for end users handling three different personal care polymeric items, i.e., electric heating bags. A near-to-real exposure scenario was simulated for each investigated item, taking into account the actual conditions of use ('heating mode') during the first period of life-cycle (first use events). Test emission chamber experiments were performed according to the relevant ISO standards, allowing us to derive 72-hour chamber concentrations and emission rates (ERs) for the main identified VOCs. Collected chamber emission data revealed that, under controlled environmental conditions, the item 'polyester-brand A' was characterized by the highest VOC emission (expressed as the sum of VOC concentrations) equal to 437 μg/m3, one order of magnitude higher than those of the other two bags, labeled as 'PVC-brand B' and 'PVC-brand C' (21.1 and 19.6 μg/m3, respectively). A remarkable result was the naphthalene emission from 'polyester-brand A', with a chamber concentration equal to 360.5 μg/m<sup>3</sup> and an emission rate of about 9 μg/h. This investigation level, although conventionally applied for the evaluation of short-term exposure for materials and products, was not exhaustive for the estimation of VOC inhalation exposure levels determined by each investigated item on 'heating mode' in a real setting. For this purpose, the effect of the temperature on emission characteristics was evaluated through dynamic head-space experiments and, as a result, VOC emission rates for the 'heating mode' were estimated. Indoor concentrations inside a 30 m3 reference room, representative of short-term exposure related to the item use in a realistic setting, were estimated as well. The simulation of the exposure scenario allowed us to highlight that the use of the 'polyester-brand A' heating bag in

the first period of its life-cycle could determine a concentration inside a 30 m3 room equal to 42 μg/m3, eight times higher than the reference value for health effects (LCI value equal to 10 μg/m3) reported in EU evaluation schemes. The inhalation exposure to naphthalene emission from 'polyester-brand A' could represent, therefore, a risk for end users and room occupants. Also of concern is the release of benzene, recognized as a carcinogen in humans, for which no safe level of inhalation exposure can be recommended.

**Author Contributions:** Conceptualization: J.P., G.d.G., M.T.; methodology: J.P., G.d.G., M.T.; investigation: J.P., E.C.; data curation: J.P., E.C., A.D.G.; supervision: G.d.G.; writing—original draft preparation: J.P., A.D.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors acknowledge the Operational Section 'Pronto Impiego' of Italian Finance Police placed in the City of Monopoli (Italy) and coordinated by the Company Commander, Luigi Mario Paone. The established collaboration was fruitful and fundamental for the development of the present study.

**Conflicts of Interest:** The authors declare no conflict of interest.
