Registration Dossier

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity to aquatic invertebrates:

A study with Dibenzylbenzene, ar-methyl derivative, hydrogenated was performed according to the OECD 202 2004 guideline under the conditions of GLP. The test substance was insoluble in water therefore preparation of loading rates was performed by direct addition and an extended mixing period according to OECD Guidance Document 23. The 24-hour EL50 and 48-hour EL50 of dibenzylbenzene, ar-methyl derivative, hydrogenated to Daphnia magna were both >100mg/l and the 48-hour NOEL was 100mg/l. These were all determined through direct observation of the data, since no Daphnia were immobilised. The Daphnia were examined at 24 hours and 48 hours for abnormal behaviour during the determination of immobility. Three types of abnormality were observed in all twenty Daphnia at 48 hours at 100mg/l. This included debris attached to Daphnia, slower movement and mobile Daphnia trapped in the meniscus . None (0%) of the twenty control Daphnia maintained in dilution water were immobilised and none were trapped in the meniscus during the study. Analytical measurements of the freshly prepared exposure solutions and of the 48 hour aged exposure solutions were made, the test substance could not be detected in the samples. This was expected due to the lack of water-solubility of dibenzylbenzene, ar-methyl derivative, hydrogenated. In conclusion, dibenzylbenzene, ar-methyl derivative, hydrogenated was not toxic to daphnia in the range of water solubility under the conditions of this study.

Toxicity to aquatic algae:

A studcy with Dibenzylbenzene, ar-methyl derivative, hydrogenated was performed according to the OECD 201 (2011) guideline and in compliance with GLP. The test substance was insoluble in water therefore preparation of loading rates was performed by direct addition and an extended mixing period according to OECD Guidance Document 23. The growth curves demonstrated that the algae in the control and at 100mg/l dibenzylbenzene, ar-methyl derivative, hydrogenated were in logarithmic growth for the duration of the study. The algal cells were examined microscopically during the determination of cell concentration. All cells within the control and test loading rate of 100mg/l appeared normal, no abnormalities were observed. The test substance, dibenzylbenzene, ar-methyl derivative, hydrogenated, was not detected by HPLC-UV analysis in the freshly prepared exposure solutions, or in samples taken after 72-hours exposure (no peaks were seen at the 100mg/l loading rate). All concentrations of the test substance therefore are reported as nominal as received, expressed as loading rates from direct addition. The 72-hour ErL50 and EyL50 of dibenzylbenzene, ar-methyl derivative, hydrogenated to Raphidocelis subcapitata were both >100mg/l (determined by Linear Interpolation). The 72-hour NOEL(r) was determined to be 100mg/l and the 0-72 hour LOEL was >100 mg/l.

Additional information