*2.3. Experimental Design Description*

The first investigation level involved 72-hour emission testing inside a small-scale emission chamber under standardized environmental conditions, according to the relevant ISO standards. As a result, emission rates (ERs) for the main detected VOCs were derived, useful for the estimation of indoor concentrations potentially determined by the item in a real setting at ambient temperature (i.e., 'not-heating' mode) and representative of a short-term exposure. This investigation level, although conventionally applied to materials and products for providing data on emission characteristics under simulated indoor conditions, was not exhaustive for the estimation of VOC inhalation exposure levels determined by the item in a real room under the actual conditions of use. In order to derive ERs under heating, non-time-consuming and cost-effective dynamic head-space experiments were performed, placing the investigated items inside customized Nalophan bags. The effect of temperature on VOC emissions from the items was evaluated, and its extent was expressed in terms of the ratio of chromatographic peak areas obtained by GC/MS analysis of the samples collected both at laboratory ambient temperature (approximately 23 ◦C) and under heating. This second level of investigation allowed us to estimate ERs under heating (starting from ERs derived from 72-hours data inside the chamber) and, as a result, indoor concentrations inside the reference room representative of a realistic short-term exposure scenario for end users.
