1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylindeno[5,6-c]pyran

Endpoint summary

Additional information

Toxicity tests were carried out with earthworms, springtails and plants.In the test with earthworms and plants the test materials at appropriate concentrations were dissolved in equal amounts of acetone, mixed with the quartz sand and allowed to slowly evaporate and mixed with the standard soil containing 10% Sphagnum peat, 20% kaolinite clay, approximately 70% fine quartz-sand (grain size 0.1-) and 0.5% calcium carbonate to adjust to pH 6.0±0.5. After preparation of the test concentrations and an equilibrium period of one week, the test organisms were added to the soil. The test medium was not refreshed during the test period.

In the test with wheat HHCB was directly applied to the soil in petridishes. These dishes were sealed to prevent volatilisation. The exposure time is not indicated but seed emergence of wheat is expected within 7 days.

Test species	Guideline	Results (nominal concentrations)	Remarks
Earthworm Eisenia foetida	ISO 11268 (OECD 207)	8wk-NOEC = 45 mg/kg, LOEC^2= 105 mg/kg, reproduction and food consumption 4wk-NOECgrowth= 105 mg/kg, LOEC = 250 mg/kg 4wk-NOECsurvival ≥ 250 mg/kg	Key study, Rel. 2 Gossmann 1997 inital weight adults 0.34- test range 8-250 mg/kg solvent: acetone artificial soil pH 6.1, 10% sphagnum DIN^1 temp. 17-23°C
Springtail Folsomia candida	ISO /CD 11267	4wk-NOEC = 45 mg/kg, LOEC^2= 105 mg/kg, mortality and reproduction	Key study, Rel. 2 Klepka 1997 10-12 d old juveniles test range 1-105 mg/kg solvent: acetone temperature 17-25°C artificial soil, 10% sphagnum DIN^1
WheatTriticum aestivum	short term exposure circa 7 days	NOEC 55.7 mg/kg	Key study, Reliability 2Field samplepH 6.23Organic matter: 3.86%CEC: 19:88 cmol/kgClay: 48.9%Silt: 36.2%Sand: 14.9%

¹ Sphagnum DIN standard: organic material minimum 90%, organic carbon 52%

² Dunnet’s test (p=0.05)

The earthworm Eisenia foetida was tested under GLP according to ISO 11268 (Gossman 1997).Adult worms were exposed to nominal concentrations in soil of 8, 19, 45, 105 and 250 mg/kg. The worms were fed weekly with finely ground cattle manure. Adult worms were removed after 4 weeks of exposure, counted and weighed. The remaining offspring remained in the test containers for another four weeks. Mortality of the adults was not affected after 4 weeks in concentrations up to 250 mg/kg. In the range finding test mortality was 100% after 14 days exposure to 1000 mg/kg. Growth was significantly inhibited (15%) in the highest concentration of 250 mg/kg. Reproduction was not significantly affected up to concentrations of 45 mg/kg (7% inhibition, NOEC). At the level of the LOEC (105 mg/kg), the reproduction was 57% of the control, whereas in the highest concentration reproduction was inhibited completely.

The springtail Folsomia candida was tested according to the draft ISO/CD 11267 (Klepka 1997). The test was started with juvenile springtails 10 to 12 days of age and survival and reproduction after 28 days were determined. Nominal test concentrations were 1, 3, 8, 19, 45 and 105 mg/kg soil. The animals were fed with granulated dry yeast. No significant mortality was observed in soils containing up to 45 mg/kg, but mortality was 72% in 105 mg/kg. Reproduction was inhibited by 23% in 45 mg/kg. However, this inhibition was not statistically significantly different from the control. The reproduction in 105 mg/kg was 16% of the control. Thus, the NOEC for HHCB is 45 mg/kg based on survival.

The chemical analyses in the sediment tests showed a reduction in the concentration to 54 to 80% of the initial concentration at day 0. Also in this test the concentration may have been reduced to a level > 50% of the nominal concentration. Therefore Rel. 2. In the terrestrial plant test the LC10 for seed germination, root elongation and shoot elongation were scored. The EC10 of root elongation was the most sensitive resulting in 55.7 mg/kg soil. This value is considered to be based on wet soil (though not presented).