9-(2-carboxyphenyl)-3,6-bis(diethylamino)xanthylium acetate

Endpoint summary

Description of key information

Short term toxicity to aquatic invertebrates:

The median effective concentration (EC50) for the test substance in Daphnia magna was determined to be 10.0 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 chronic 2 as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical for 72h the EC50 was determine to be 45.7 mg/l.

Additional information

Short term toxicity to aquatic invertebrates:

Based on the experimental data for the target as well as read-across analogues which were functionally and structurally similar to the target chemical, toxicity of test chemical was determined on the basis ofimmobilization of aquatic invertebrates.The studies are summarized as below:

Aim of this 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 100 mg/L was prepared by dissolving red -violet liquid in reconstituted water. Test solutions of required concentrations were prepared by mixing the stock solution of the test substance in reconstituted water. 0, 1, 2, 4, 8 and 16 mg/L concentrations were used in the study. Effects on immobilisation 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 10.0 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 chronic 2 as per the CLP classification criteria.

First study was further supported by second and third study as follows.

Aim of the second study was to assess the short term toxicity of test material to aquatic invertebrates daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) in a static system for the total exposure period of 48 hrs. The stock solution (100 mg/L) was prepared by dissolving pinkish red powder in reconstituted water. Concentrations used in the study were 0, 0.5, 1, 2, 3, 4 and 8 mg/L. Effects on immobilisation were observed for 48 hours. The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 3.4 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 chronic 2 category as per the CLP classification criteria.

Again, a 24h study was conducted for determining the toxicity of test chemical on aquatic invertebrates, Thamnocephalus platyurus. Lethal concentration LC50 for 24h calculation was done with use of two methods – probit and graphical ones. LC50 for 24h (in mg/l) for T. platyurus was determined to be 8.06 mg/l

 

Hence, from the above maximum values the test chemical is likely to be hazardous to aquatic invertebrate and can be classified as aquatic chronic 2 category as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

Based on the experimental data for the target as well as read-across analogues which were functionally and structurally similar to the target chemical, toxicity of test chemical was determined on the basis of growth inhibition of aquatic algae. The studies are summarized as below:

Aim of this study was to evaluate the nature of test chemical when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). The stock solution 100mg/L was prepared by dissolving red -violet liquid in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various concentration (0, 5, 10, 20, 40 and 80 mg/L) were used.

 Along 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. Effect on the growth of algae was determined after an exposure period of 72 hrs.

 The median effective concentration (EC50) for the test substance in algae was determined to be 45.7 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the EC50 value, which indicates that the substance is likely to be hazardous to aquatic algae and thus can be classified as aquatic chronic 3 category as per the CLP classification criteria.

 

Further the first study was supported by second and third study as follows.

 

Aim of the second study was to evaluate the nature of chemical test chemical when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The stock solution (100 mg/L) was prepared by dissolving pinkish red powder in OECD growth medium. Various concentration used were 0, 2.5, 5, 10, 20 and 40 mg/L.

After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determined after an exposure period of 72 hrs. The median effective concentration (EC50) for the test substance, in algae was determined to be 13.4 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the EC50 value, which indicates that the substance is likely to be hazardous to aquatic algae and can be classified as aquatic acute/ chronic 3 category as per the CLP classification criteria.

Another study was conducted to determine the toxicity of test chemical on freshwater algae,Scenedesmus subspicatus for 72h. The test was conducted by following the similar guidelines as mentioned in OECD 201. Overall, cell growth in controls was found to be increased up to16 folds. After 72h of exposure the EC50 valuewas determined to be 11mg/L. Whereas, EC10 and EC90 were also determined with values 3mg/L and 42mg/L respectively.

Thus, based on the EC50 value, the test chemical is classified under the category aquatic chronic 3.

Hence, from the above values the test chemical is likely to be hazardous to aquatic algae and can be classified as aquatic chronic 3 category as per the CLP classification criteria.