Partition coefficients between n-octanol and water (Kow) indicate bioaccumulation potential when Log Kow > 4. \*The Groundwater Ubiquity Score (GUS) is calculated using soil half-life (DT50) and organic-carbon sorption constant (Koc) as follows: GUS = log(DT50) x (4-log Koc). A compound is likely to leach if GUS > 2.8 and unlikely to leach when GUS < 1.8; other values in between indicate that leaching potential is marginal.


**Chemical Group Vapour Pressure**

368 Insecticides - Development of Safer and More Effective Technologies

**(mPa, 25oC)**

thiodicarb C 5.7 22.2 1.62 -0.24 low thiofanox C 22.6 5200 2.16 1.67 low triazamate C 0.13 433 2.59 -0.9 low cartap D 1.0 x 10-10 200000 -0.95 - high halofenozide IGR <0.013 12.3 3.34 **3.75** high

novaluron IGR 0.016 0.003 **4.3** 0.03 low teflubenzuron IGR 0.000013 0.01 **4.3** -0.82 low acetamiprid N 0.000173 2950 0.8 0.94 low clothianidin N 2.8 x 10-8 340 0.905 **4.91** high dinotefuran N 0.0017 39830 -0.549 **4.95** high imidacloprid N 0.0000004 610 0.57 **3.76** high nitenpyram N 0.0011 590000 -0.66 2.01 moderate thiacloprid N 0.0000003 184 1.26 1.44 unlikely to leach

thiamethoxam N 0.0000066 4100 -0.13 **3.82** high acephate OP 0.226 790000 -0.85 1.14 low demeton-S-methyl OP 40 22000 1.32 0.88 low dicrotophos OP 9.3 1000000 -0.5 **3.08** high dimethoate OP 0.25 39800 0.704 1.06 low disulfoton OP 7.2 25 3.95 1.29 low fenamiphos OP 0.12 345 3.3 -0.11 low fosthiazate OP 0.56 9000 1.68 2.48 moderate heptenophos OP 65 2200 2.32 0.26 low methamidophos OP 2.3 200000 -0.79 2.18 moderate mevinphos OP 17 600000 0.127 0.19 low monocrotophos OP 0.29 818000 -0.22 2.3 moderate omethoate OP 3.3 10000 -0.74 2.73 moderate oxydemeton-methyl OP 2.0 1200000 -0.74 0.0 low phorate OP 112 50 3.86 1.4 low phosphamidon OP 2.93 1000000 0.79 2.39 moderate thiometon OP 39.9 200 3.15 0.37 low vamidothion OP 1.0 x 10-10 4000000 -4.21 0.55 low fipronil PP 0.002 3.78 3.75 2.45 moderate

**Table 1.** Physicochemical properties of systemic insecticides. C = carbamates; D = dithiol; IGR = Insect growth
