158 
6.2.3 Endosulfan I and II 
Figure 26: Structures of endosulfan I or a (A) and endosulfan II or ß (B). 
Endosulfan (trade names: e. g. Cyclodan and Endosol) is used as a contact insecticide 
for a wide variety of insects and mites. Endosulfan is a sulphite ester of a chlorinated 
cyclodienediol (Figure 26). The technical mixture contains two parts of endosulfan I- 
and one part of endosulfan II isomer. It is used mainly in temperate, subtropic, and 
tropic climatic zones. In Europe, it has been registered since 1956 (Schadstoffberatung 
Tübingen, 2001). World-wide production in 1992 was about 5000 to 10000 t. One of the 
major manufacturers is Bayer CropScience. 469 t of the compound was used in Europe 
in 1999, mainly in southern Europe (OSPAR Background Document on Endosulfan, 
2002; BCMAF, 1999). 
Table 57: Physico-chemical properties of endosulfan. 
Endosulfan I 
Endosulfan II 
Technical mixture 
(2:1) 
CAS number 
959-98-8 
33213-65-9 
115-29-7 
Log Kow 
4.74 (22°C; pH 5) a 
4.79 (22°C; pH 5) a 
3.8 b 
Log K oc [L/kg] 
3.48-5.30 a 
See endosulfan I a 
- 
Solubility in water [mg/L] 
0.41 a , 0.15 (22°C) 
0.23 a , 0.06 (22°C) 
0.33 (20°C) 
Biodegradation 
- 
- 
> month b 
Vapour pressure [Pa] 
1.9xlO" 3 (25°C) a 
9.2xlO" 3 (25°C) a 
3.6x10-5 b 
Atmospheric half-life [d] 
- 
- 
1.3 b 
Data from: a (Background Document on Endosulfan, 2002), b (Lerche et ah, 2002). 
The German Gefahrstoffverordnung classifies endosulfan I and II as „toxic“ (LD 5 o 
value: 80 mg/kg bodyweight rat (Römpp, 1995)). Endosulfan has a very high acute