p,p',p''-tris(dimethylamino)trityl alcohol

Endpoint summary

Description of key information

Short term toxicity to aquatic invertebrates:

On the basis of EPI suite, ECOSAR version 1.11, the LC 50 value for short term toxicity to aquatic invertebrates was predicted to be 0.576mg/l for the test material in 48 hrs. Based on this value it can be concluded that the substance is considered to be toxic to aquatic environment and can be classified in aquatic acute / chronic 1 category as per the criteria mentioned in CLP regulation.

Toxicity to aquatic algae and cyanobacteria:

A freshwater algal growth inhibition test was conducted for 72 hrs for assessing the effect of test chemical on green algae Pseudokirchneriella subcapitata. The test was performed in accordance to OECD guideline No. 201 – Alga growth inhibition test under static condition. Initial cell density of the culture was kept at 10000 cells/ml. OECD medium composed of macronutrients, micronutrients, alkaline EDTA solution and iron solution was used as a growth medium. The test solution was prepared by dissolving 1000 mg of test chemical in 1000 ml of OECD media, and allowed for stirring for 96 hours, which was then filtered and the final stock solution obtained was 1000 mg/L, verified analytically by UV-Vis Spectrophotometer. The final solubility value obtained after analytical detection is 13.71 mg/L. To have a better growth and visibility of cells, the initial cell count of the culture was kept 10,000 cells/mL. Further, exposure concentrations of 0, 0.2, 0.54, 1.46, 3.94 and 10.64 mg/L (factor of 2.7), respectively was from the stock test concentrations. Test vessel were placed in orbital shaking incubator for 72 hrs at a temperature of 21 to 24 ± 2°C and with a continuous uniform illumination of 6000 -10000 lux light intensity, respectively. The speed of the orbital shaking incubator was set at a 120 revolutions per minute throughout the study period. The cultures were counted and observed daily with the help of a microscope. Potassium dichromate (K2Cr2O7) was used as a reference substance. The 72 hr EC50 value of the reference substance was determined to be 0.868 mg/l. The biomass in the control vessel have increased exponentially by a factor of 16, the coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 7% (i.e., reported to be 1.31%) and the mean coefficient of variation of specific growth rate was not exceeded 35% (i.e., reported to be 4.44%), respectively thus fulfilling the validity criterion. As the concentration of the test chemical being tested has not been satisfactorily maintained within ± 20 % of the nominal concentration throughout the test. Therefore, the analysis of the results was based on measured concentration. On the basis of growth rate of the test organism, the 72 hr median effect concentration (ErC50) value was determined to be 0.52 mg/l (nominal conc.) and 0.47 mg/l (measured conc.), respectively. Thus, test chemical was considered as toxic to aquatic algae at environmental relevant concentrations and hence, considered to be classified in 'aquatic acute/chronic category 1' as per the CLP classification criteria.

Additional information

Short term toxicity to aquatic invertebrates:

Based on the predicted and experimental data of structurally similar read across chemicals, toxicity of test chemical was determined on the basis of immobility rate of aquatic invertebrates. The studies are summarized below:

First study was based on the prediction done by EPI suite, ECOSAR version 1.11, on the basis of similarity of structure to chemicals for which the aquatic toxicity has been previously measured by structure-activity relationships (SARs) program, the LC 50 value for short term toxicity to aquatic invertebrates was predicted.

On the basis of this program, the LC50 value for short term toxicity to aquatic invertebrates was predicted to be 0.576mg/l for the test chemical in 48 hrs. Therefore, based on this value it can be concluded that the substance is considered to be toxic to aquatic environment and can be classified in aquatic acute / chronic 1 category as per the criteria mentioned in CLP regulation.

 

Second and third study was performed from primary source to support the first study for determining the toxicity of test chemical.

Aim of the second study was to assess the short term toxicity of test chemical to aquatic invertebrates daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilization Test) in a static system for the total exposure period of 48 hrs.

The stock solution 20.0mg/L was prepared by dissolving dark violet liquid in reconstituted water. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted water.

Various concentrations used were 0.06mg/L, 0.12mg/L, 0.24mg/L, 0.50mg/L, 1.00mg/L.

Effects on immobilization were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance, on Daphnia magna was determined to be 0.61mg/L on the basis of mobility inhibition effects in a 48 hour study. Thus, based on the EC50 value, substance is likely to be hazardous to aquatic invertebrate and can be classified as aquatic acute / chronic 1 category as per the CLP classification criteria.

 

Further the aim of third study was to assess the short term toxicity of test chemical to aquatic invertebrates daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilization Test) in a static system for the total exposure period of 48 hrs.

The stock solution 20.0 mg/l was prepared by dissolving yellow powder in reconstituted water. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. Various concentrations used were 0.006mg/L, 0.012mg/L, 0.025mg/L, 0.050mg/l, 0.100mg/L.Effects on immobilization were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 0.037 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, substance is likely to be hazardous to aquatic invertebrate and can be classified as aquatic acute / chronic 1 category as per the CLP classification criteria.

Thus, based on the above values, it can be concluded that the chemical is toxic and can be classified under aquatic acute / chronic 1 category.

Toxicity to aquatic algae and cyanobacteria:

A freshwater algal growth inhibition test was conducted for 72 hrs for assessing the effect of test chemical on green algae Pseudokirchneriella subcapitata. The test was performed in accordance to OECD guideline No. 201 – Alga growth inhibition test under static condition. Initial cell density of the culture was kept at 10000 cells/ml. OECD medium composed of macronutrients, micronutrients, alkaline EDTA solution and iron solution was used as a growth medium. The test solution was prepared by dissolving 1000 mg of test chemical in 1000 ml of OECD media, and allowed for stirring for 96 hours, which was then filtered and the final stock solution obtained was 1000 mg/L, verified analytically by UV-Vis Spectrophotometer. The final solubility value obtained after analytical detection is 13.71 mg/L. To have a better growth and visibility of cells, the initial cell count of the culture was kept 10,000 cells/mL. Further, exposure concentrations of 0, 0.2, 0.54, 1.46, 3.94 and 10.64 mg/L (factor of 2.7), respectively was from the stock test concentrations. Test vessel were placed in orbital shaking incubator for 72 hrs at a temperature of 21 to 24 ± 2°C and with a continuous uniform illumination of 6000 -10000 lux light intensity, respectively. The speed of the orbital shaking incubator was set at a 120 revolutions per minute throughout the study period. The cultures were counted and observed daily with the help of a microscope. Potassium dichromate (K2Cr2O7) was used as a reference substance. The 72 hr EC50 value of the reference substance was determined to be 0.868 mg/l. The biomass in the control vessel have increased exponentially by a factor of 16, the coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 7% (i.e., reported to be 1.31%) and the mean coefficient of variation of specific growth rate was not exceeded 35% (i.e., reported to be 4.44%), respectively thus fulfilling the validity criterion. As the concentration of the test chemical being tested has not been satisfactorily maintained within ± 20 % of the nominal concentration throughout the test. Therefore, the analysis of the results was based on measured concentration. On the basis of growth rate of the test organism, the 72 hr median effect concentration (ErC50) value was determined to be 0.52 mg/l (nominal conc.) and 0.47 mg/l (measured conc.), respectively. Thus, test chemical was considered as toxic to aquatic algae at environmental relevant concentrations and hence, considered to be classified in 'aquatic acute/chronic category 1' as per the CLP classification criteria.