1,6,7,8,9,14,15,16,17,17,18,18-dodecachloropentacyclo[12.2.1.16,9.02,13.05,10]octadeca-7,15-diene

Endpoint summary

Description of key information

Zhang et al. published in 2014 their findings on a study, they have performed similar to OECD207 guideline on acute toxicity to earthworms (eisenia fetida), in which nominal DP concentrations of 0, 0.1, 1, 10 and 50 mg/kg soil dw were applied for 14 days.

During the exposure period, no significant treatment-related changes in death rate and body weight were found (p > 0.05). Acute toxicity of DP was therefore very low. Even for the highest exposure concentration (50 mg/kg), the mortality rate was still lower than 10%. Thus, the LC10 and LC50 both were > 50 mg/kg soil dw.

In a subchronic toxicity studies with birds (quails) no toxicity or growth effects on organs were seen following 90 days exposure up to 100 mg/kg bw DP/d via gavage. No NOEL was derived by the authors but based on reported information, the highest dose applied in this study can be seen as No-Observed-Adverse-Effect-Level, as no sign of toxicity were seen. Enzyme activity was altered but not dose dependent and the meaning of this remained unclear. In summary, no toxic effects to quails were seen despite the high exposure (100 mg/kg bw/d). However, as the study was not following guidelines and only mortality, body weight and liver weight were assessed, besides liver enzyme activity and some other parameters, the study is considered to be of limited validity.

No further terrestrial study is proposed by the registrant based on the knowledge that the substance is highly insoluble in water, and that the substance did not show signs of toxicity to earthworm in a study recently published or in birds. Also, in multiple studies published on findings of Dechlorane Plus in the environment no effects in biota were reported in any of these publications.