## 2 Results and Discussion
### VOCs of Cling-Films for Retail Use
Moreover, 2-EH can be used in the production of 2-ethylhexanoic acid (2-EHA) and its calcium and zinc salts are used as heat-stabilizers during manufacturing of PVC films [26]. To date, the use of 2-EHA is not forbidden for manufacturing of food-contact material despite some concerns raised about its potential genotoxicity [27]. Among isolated VOCs, PE 200 sample did not release 2-EA and the triacetate ester of glycerol (triacetin, CAS 102-76-1). To our knowledge, no data are available in the literature concerning the presence of 2-EHA in cheese. An ester of adipic acid and 2-EH (di-(2-ethylhexyl) adipate, DEHA) is used as a plasticizer during manufacturing of PVC-based films. This compound could represent a degradation product arising from PVC manufacturing and, therefore, it can be considered as a NIAS [25]. Tri-, di- and monoacetin were present only in PVC-based films (812 and 818) as previously found in films for in-home use (data not shown). Triacetin was used for manufacturing food-contact plastics until 2009, as stated by Italian Regulation (Direttiva del Ministero Salute 23/4/2009) [28]. Triacetin possesses antifungal properties and it is used as a food additive (E 1518) for the solubilisation of humectant flavours in perfumery and cosmetics. To date, data concerning release of triacetin from food-contact plastics are not available even if, based on the available literature, this substance does not represent a hazard to human health [29; 30]. Indeed, triacetin was generally recognized as safe (GRAS) by the Food and Drug Administration (FDA) [30]. For these reasons, its exclusion from the positive lists provided by European directives and regulations cannot be easily explained. Probably, due to its antifungal properties, triacetin could be regarded as an \"active substance\" and, therefore, it should meet the requirements provided by EU Reg. 450/2009 for active and intelligent packaging [31; 32]. The PE 200 film released 2,4-bis(1,1-dimethylethyl)phenol (2,4-DTBP, CAS 96-76-4), an antioxidant added to plastics to inhibit or slow oxidative processes, while being itself oxidized. This antioxidant is also used as an intermediate for the preparation of UV stabilizers [33]. This compound is not included in any of the positive lists provided by European regulations and directives [34]. Different terpen as well as aromatic hydrocarbons were present among VOCs extracted from cling-films (Table 1). In particular, the presence of limonene, linalool and citronello is likely to be associated either with the storage conditions of films or migration from food packaging materials manufactured from waste or recycled food packaging like the internal (mandrino) or external cardboard part of a film roll (supplementary material) [35]. It is worth noting that no European regulations or directives exist for the use of recycled materials for food packaging. To date, mandrino and boxes must be manufactured using only virgin cellulose [35]. Only article 2 of directive 89/109/EEC requires that the consumer's health must not be endangered by food-contact material. The aromatic hydrocarbons styrene (ST, CAS 100-42-5) and xylenes (CAS \(p\)-XY, CAS 106-42-3; \(o\)-XY, CAS 65-47-6; \(m\)-XY, CAS 108-38-3) were also found in cling films. Several contaminants (aldehydes, alkanes, hydrocarbons, and ketones and trace elements) have also been detected arising from paper board materials made of recycled fibres [35,36]. Although not intended, these compounds may be found in the final recycled material, it is very difficult to remove them efficiently, and no specific requirements and limitations are provided by the European Union [35]. On these bases, the cling-films studied were sampled at different depths of the roll (Figure 3). Amounts of some VOC classes observed in the different sections are shown in Figure 4. In particular, the internal cling-film portion (close to the mandrino) was richer in aldehydes, esters and terpenes probably as a consequence of migration phenomena from the board.