## 3 Volatile Organic Compounds Emitted from WBPs
### Terpenes and Terpenoids
\begin{table}
\begin{tabular}{c l l} \hline \hline
**Wood** & **Volatile Terpenes Emitted * ** & **References** \\ \hline \multirow{4}{*}{\begin{tabular}{c} Pine \\ (_Pinus sylvestris, Pinus spp.) \\ \end{tabular} } & \(\alpha\)-pinene, \(\beta\)-pinene, limonene, & \\  & \(\Delta\)3-carene, \(\alpha\)-terpineol, camphene, & \\  & \(\beta\)-phellandrene, terpinolene, verbenol, & [50; 51; 61; 62; 63; 64; 65; 66] \\  & \(p\)-cymene, \(\beta\)-myrcene, and & \\  & \(\gamma\)-terpinene & \\ \hline \multirow{4}{*}{\begin{tabular}{c} Spruce \\ (_Pica abies_) \\ \end{tabular} } & \(\alpha\)-pinene, \(\beta\)-pinene, limonene, & \\  & \(\Delta\)3-carene, \(\beta\)-phellandrene, \(\beta\)-myrcene & [61; 63; 64; 66] \\  & and camphene & \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Larch \\ (_Larix decidlua, Larix sibirica, Larix gmelini_) \\ \end{tabular} } & \(\alpha\)-pinene, \(\beta\)-pinene, limonene, & \\  & \(\Delta\)3-carene, \(\beta\)-phellandrene, camphene, & \\  & terpinolene, sabinene, tricyclene, & \\  & \(\alpha\)-phellandrene, linalool, \(\tau\)-elemene, & \\  & \(\alpha\)-farnesene, \(\beta\)-caryophyllene, & [64; 67; 68; 69] \\  & longifolene, \(\beta\)-cubinene, \(\alpha\)/\(\tau\)-cadinene, & \\  & \(\alpha\)-caryophyllene, \(\beta\)-bourbone and & \\  & isolongifolene & \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Fir \\ (_Abies alba_) \\ \end{tabular} } & \(\alpha\)-pinene, \(\beta\)-pinene, limonene, & \\  & \(\Delta\)3-carene, camphene, \(\beta\)-phellandrene & [70] \\  & and myrcene & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Volatile terpen found in the most used wood types. In a study from [PERSON] et al. (1999) [74], 57 PB and MDF samples produced with southern pine, other pine, Douglas fir (_Pseudotsuga menziesii_) (PB only) and hardwood were analyzed to determine their terpene composition [74]. \(\alpha\)-pinene and \(\beta\)-pinene were quantified in all PB samples, showing higher results for both pine groups. PB produced from hardwood only showed emissions of \(\alpha\)-pinene, \(\beta\)-pinene and \(\Delta\)3-carene, which were significantly lower than in any other PB samples. Furthermore, MDF samples were mostly absent of terpene emissions. As mentioned before, hardwoods have significantly lower VOC emissions than softwoods as they mainly contain non-volatile higher terpen [45; 59] and only a few tropical hardwoods have been reported to emit monoterpenes, such as camphor from _Cinnamomum campora_[45]. A list of volatile terpen reported in particleboards and MDFs produced with different wood types can be seen in Table 5.  
Nowadays, with the increasing number of possible emission sources, the possibility of continuous VOCs exposure represents an important health concern. Exposure to VOCs and their consequences to human health has been increasingly documented, with reports targeting each class of compounds discussed in this insight. Terpenes are mostly associated with symptoms of irritation affecting the eyes, mouth, respiratory system, and skin [78]. According to [PERSON] et al. (1991) [79], A3-carene may  
\begin{table}
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cause irritation of the skin and mucous membranes while prolonged exposure may lead to allergic contact dermatitis or chronic impairment of lung function.