# Comprehensive Analysis of the Acute Toxicity of Ionic Liquids Using Microtax(r) Bioassays
## 3 Results and Discussion
 \\ \hline C\({}_{2}\)C\({}_{1}\)Im TFSI & 97.11 (37.29; 156.94) & 43.33 (7.85; 78.81) & 22.82 (0.00; 48.22) \\ C\({}_{4}\)C\({}_{1}\)Im TFSI & 19.51 (1.67; 37.35) & 13.45 (1.05; 25.86) & 10.50 (0.00; 22.63) \\ C\({}_{4}\)C\({}_{1}\)C\({}_{1}\)Im TFSI [12] & 46.34 (5.74; 86.95) & 39.09 (20.78; 57.40) & 36.45 (26.05; 46.85) \\ C\({}_{6}\)C\({}_{1}\)Im TFSI & 12.60 (10.59; 14.60) & 12.43 (10.69; 14.17) & 17.15 (15.22; 19.08) \\ C\({}_{8}\)C\({}_{1}\)Im TFSI & 1.49 (1.37; 1.60) & 1.77 (1.48; 2.06) & 2.50 (1.68; 3.33) \\ AC\({}_{1}\)Im TFSI & 110.00 (46.34; 173.66) & 68.95 (27.41; 110.49) & 61.21 (25.35; 97.07) \\ AC\({}_{1}\)Im Cl & 376.21 (0.00; 797.78) & 310.13 (106.25; 514.02) & 268.03 (108.68; 427.38) \\ AC\({}_{1}\)Im DCA & 436.58 (262.10; 611.06) & 309.55 (225.00; 394.10) & 291.63 (217.70; 365.56) \\ C\({}_{4}\)C\({}_{1}\)Im FAP & 24.57 (12.19; 36.94) & 21.24 (13.01; 29.47) & 19.05 (11.28; 28.62) \\ C\({}_{1}\)C\({}_{1}\)Im DMP & 917.35 (839.85; 994.63) & 970.14 (914.78; 1026.19) & 997.02 (945.86; 1050.47) \\ C\({}_{2}\)Py TFSI & 54.17 (9.12; 99.22) & 26.67 (0.00; 54.39) & 12.37 (0.00; 34.03) \\ C\({}_{4}\)Py TFSI & 64.42 (52.13; 76.71) & 45.45 (35.55; 55.35) & 39.90 (28.93; 50.87) \\ C\({}_{6}\)Py TFSI & 21.69 (18.49; 24.88) & 20.00 (16.57; 23.44) & 24.66 (21.03; 28.29) \\ C\({}_{3}\)C\({}_{1}\)Piryr TFSI & 66.74 (36.70; 96.77) & 46.42 (26.57; 66.26) & 40.91 (19.42; 62.41) \\ C\({}_{4}\)C\({}_{1}\)Pip TFSI & 67.57 (59.56; 75.58) & 57.01 (49.72; 64.29) & 55.22 (49.76; 60.69) \\ C\({}_{4}\)C\({}_{1}\)Pyrr TFSI [12] & 684.04 (441.90; 926.09) & 416.73 (286.18; 545.93) & 289.18 (192.91; 386.85) \\ C\({}_{6}\)C\({}_{1}\)Pyrr TFSI & 39.71 (32.17; 47.25) & 33.50 (27.14; 39.87) & 41.44 (32.94;49.95) \\ C\({}_{8}\)C\({}_{1}\)Pyrr TFSI & 6.84 (4.87; 8.81) & 7.51 (5.22; 9.80) & 13.36 (7.02; 19.70) \\ C\({}_{4}\)C\({}_{1}\)Pyrr FAP & 428.33 (201.78; 654.88) & 385.65 (252.92; 518.38) & 337.60 (256.32; 418.89) \\ C\({}_{1}\)OC\({}_{2}\)C\({}_{1}\)Pyrr FAP & 20.47 (2.84; 38.10) & 13.00 (4.67; 21.33) & 11.36 (5.71; 17.01) \\ C\({}_{4}\)C\({}_{1}\)Pyrr\({}_{4}\)FAP & 49.88 (28.06; 71.70) & 28.72 (8.44; 49.09) & 21.95 (127.47; 26.63) \\ C\({}_{4}\)C\({}_{1}\)Pyrr\({}_{6}\)FAP & \multicolumn{2}{c}{\(\multicolumn{2}{c}{\multicolumn{2}{c}{\multicolumn{2}{c}{\multicolumn{2}{c}{\multicolumn{2}{c}\multicolumn{2}{2c}{\multicolumn{2}{2c}{\multicolumn{2}{2c}\multicolumn{2}{2c}{\multicolumn{2}{2c}\multicolumn{2}{2c}{\multicolumn{22}  
Another important observation is related to the fact that EC values of C\({}_{1}\)OC\({}_{2}\)C\({}_{1}\)Pyrr FAP are more than ten times lower than that the corresponding to C\({}_{4}\)C\({}_{1}\)Pyrr FAP, which means that the presence of an oxygen atom in the cation seems to induce higher toxicity to the IL. This statement was previously reported by [PERSON] et al. [36], who attributed this effect to an increase in the number of polar functional groups. It is also important to note that phosphorous-based moieties show the highest values of EC\({}_{50}\) in Figure 4a (ILs with the common anion FAP) and 4f (ILs with the common cation family imidazolium), which makes them especially interesting for developing greener and safer industrial applications, for example, fuel desulfurization, novel electrolytes, and lubrication [37; 38]. Among the scarce literature on the toxicity of FAP-based ILs is the work of [PERSON] et al. [13], who proposed the interesting evidence named \"reverse side-chain effect\", wherein an increase in the cation hydrophobicity chain results in decreased toxicity of FAP-based ILs. Similar conclusions to those of these authors can be obtained by the comparison between the EC\({}_{50}\) (15 min) for C\({}_{4}\)C\({}_{1}\)Im FAP (77.43 mg/L), here analyzed, and the corresponding C\({}_{2}\)C\({}_{1}\)Im FAP, reported by [PERSON] et al. [34] (12.7 mg/L). A possible explanation of this observation, reported by [PERSON] et al.