α,α,6,6-tetramethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde

Toxicity to soil macroorganisms except arthropods

Description of key information

Pinyl Isobutyraldehyde is tested for its effects on Reproduction and Growth of Earthworms Eisenia andrei in Artificial Soil according to OECD TG 222. Adult worms were exposed to a control and the concentrations 3.2, 10, 40, 120 and 380 mg Pinyl Isobutyraldehyde/kg dw soil for 56 days. Four replicates were used for the test concentrations and 8 for the control. Every replicate contained 10 earthworms. Mortality, behavioural effects, such as feeding activity and biomass development was assessed after 28 days exposure in treated artificial soil. Reproduction rate (number of offspring) was assessed after additional 28 days (assessed 56 days after application). 

At experimental start nobehavioural abnormalitieswere observed up to the concentration of 40 mg test item/kg soil. The feeding activity was comparable to the control up to and including the test concentration of 120 mg test item/kg dw soil and was reduced at 380 mg test item/kg soil.

At 120 mg test item/kg dw soil in two replicates one earthworm did not burrow into the soil and at 380 mg test item/kg dw soil several earthworms were laying on the surface approximately 0.5 to 1 hour after introduction. Nomortalitywas observed up to and including the test concentration of 40 mg test item/kg soil. The mortality of 7.5% at 120 mg test item/kg was not statistically significantly different compared to the control. At 380 mg test item/kg soil all worms were dead after 28 days, the LC50 is therefore between 120 and 380 mg/kg dw soil. Thebody weight changesof the earthworms after 4 weeks exposure to Pinyl Isobutyraldehyde were not statistically significantly different compared to the control up to and including the test concentration of 40 mg test item/kg dw soil. At 120 mg test item/kg soil the weight increases were statistically significantly lower compared to the control. Thereproduction rateswere not statistically significantly different compared to the control up to and including the test concentration of 40 mg test item/kg soil. At 120 mg test item/kg dw soil and above reproduction was statistically significantly reduced compared to the control.

In this earthworm reproduction and growth study with Pinyl Isobutyraldehyde the LC50 was determined to be 156.7 mg test item/kg dw soil. The EC10 was determined to be 97.8 mg test item/kg dw soil (95% confidence limits of 93.1 to 102.7 mg test item/kg dw soil) and the NOEC was determined to be 40 mg test item/kg dw soil.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

97.8 mg/kg soil dw