## 5 Results and Discussion  
The application of the proposed methodology to classify the materials under study in terms of hazard regarding the acceptance of solid waste at landfills and ecotoxicological potential allowed obtaining the results that are presented in Table 6. NA are considered VRM, which were previously classified as inert raw materials with no evidence of ecotoxicity (NOE) (Table 6 and [21]); this result can be supported by the study of [PERSON] et al. [42]. According to the European regulation for Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) [43], Portland cement is considered a well-defined mixture (Table 1); it is in the RBPRM group of raw materials. The existence of a safety data sheet (SDS) for Portland cement shows that this mixture meets the criteria for the classification of hazardous substances set out in the CLP regulation [44]. According to the information provided in the SDS, this material could be classified as non-dangerous for the aquatic environment [44]. Thus, it was not considered necessary to perform the CC and EC of cement, and it may be classified as NOE raw material (Table 6). This result is consistent with reports of [PERSON] et al. [17] and [PERSON] and [PERSON] [19]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{3}{*}{**Materials**} & \multicolumn{3}{c}{**Chemical Characterization**} & \multicolumn{3}{c}{**Ecotoxicological Characterization**} \\ \cline{2-7}  & \multicolumn{3}{c}{**Directive 1999/31/EC [23]**} & \multirow{3}{*}{**CEMWE [25]**} & \multirow{3}{*}{**TCS (Persoone**} \\  & & **EC Decision 2003/33/EC [24]** & & & **et al. [41]** \\ \cline{3-7}  & & **Class** & **Parameter** & & & \\ \hline \multirow{3}{*}{Raw materials} & NA & Inert & - & NOE & n/a & n/a \\  & Cement & - & - & NOE & n/a & n/a \\ \cline{1-1}  & RA & Non-dangerous & TDS & NOE & n/a & Class III \\ \cline{1-1}  & FA & Hazardous & Se, Cr, Mo & NOE & n/a & Class III \\ \hline \multirow{3}{*}{Construction materials} & A1 & Non-dangerous & TDS & NOE & n/a & Class III \\ \cline{1-1}  & A2 & Non-dangerous & TDS, Cr, Mo & Ecotoxic & \(D\). _magna_ & Class IV \\ \cline{1-1} \cline{2-7}  & A3 & Non-dangerous & TDS, Cr, Mo & Ecotoxic & \(D\). _magna_ & Class IV \\ \hline \hline \end{tabular} Legend: NA = Natural aggregates; RA = Recycled aggregates; FA = Hy ash; A1 = Aggregates recycled from NAC; A2 = Aggregates recycled from C40 FA60 NA100; A3 = Aggregates recycled from C40 FA60 RA100; TDS = Total dissolved solids; NOE = No evidence of ecotoxicity; n/a = Not applicable; \(D\). _magna = Daphnia mgnu_; Class III = Acute Toxicity; Class IV = High Acute Toxicity.  
\end{table} 
Table 6: Classification of the raw materials and of the concrete mixes according to the EC Decision 2003/33/EC (pursuant to Directive 1999/31/CE), the document of the CEMWE French proposal and the TCS system. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Classes** & **I** & **II** & **III** & **IV** & **V** \\ \hline \multirow{2}{*}{Toxicity level} & No acute toxicity & Low acute toxicity & Acute toxicity & High acute toxicity & Very high acute toxicity \\  & \(\leq\)0.4 & 0.4 \(<\) TU \(\leq\) 1.0 & 1.0 \(<\) TU \(\leq\) 10 & 10 \(<\) TU \(<\) 100 & TU \(\geq\) 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Ecotoxicity classes defined according to the TCS system [41]. RA prepared from source concrete also belong to the group of RBPRM. In this study, the CC and EC of eluate sample obtained from RA were performed (results described in Sections 5.1 and 5.2, respectively). The original RA constituents were the following raw materials: water, NA and cement (CEM II/AL 42.5R), which already have been classified [2].