1,4-dibromobutane

Endpoint summary

Description of key information

Short-term toxicity to aquatic invertebrates:

Experimental key study and supporting predicted data for the test chemical and supporting studies for its structurally similar read across substance were reviewed for the short-term toxicity to aquatic invertebrates which are summarized as below:

Aim of this study was to determine the toxicity of test chemical on the aquatic invertebrates, daphnia magna by performing the test according to the OECD guideline 202. Test was conducted under the static system for the total exposure period of 48 hrs.

The stock solution 100 g/L was prepared by dissolving colourless liquid in acetone. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 0, 5, 10, 20, 40, 80 mg/l nominal concentrations were used. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. The median effective concentration (EC50) for the test substance, on Daphnia magna was determined to be 28.9 mg/L on the basis of immobility after 48 hours. Based on the EC50 value, indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP classification criteria.

Further, Estimation Programs Interface Suite (EPI suite) was run to predict the toxicity of the test compound to daphnia magna. The LC50 value of the test chemical, for 48 hours, on daphnia magna was estimated to be 14.167mg/L.

Based on the immobilization of test animal daphnia magna for 48 hrs of exposure, the chemical was considered to be toxic and can be classified as aquatic chronic 3 as per the CLP classification criteria.

Study was conducted according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), to determine the effect of test chemical on Daphnia magna. The test substance was soluble in Adams media. Therefore, the test solution was prepared by dissolving 100 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 3.125 mg/L,6.25 mg/L,12.5 mg/L,25 mg/L, and 50 mg/L, respectively, the test Daphnia magna were exposed to these concentration for 48 hours. The experimental median effective Concentrations [EC-50 (48 h)] for test chemical on daphnia was observed to be 50 mg/l. Thus, based on the immobilization of test animal daphnia magna after 48 hrs of exposure, chemical was considered to be toxic and was classified as aquatic chronic 3 as per the CLP classification criteria.

Thus, based on the above observation, the test chemical was considered to be toxic and can be classified as aquatic chronic 3 as per the CLP classification criteria.

Short-term toxicity to aquatic algae:

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

The Study was conducted to determine the effect of test chemical on fresh water algae, D. subspicatus, (86.81 SAG). All the parameters were followed as mentioned in the OECD guidelines 201. Initial stock solution was prepared by dissolving 200g/L in acetone.Further test solution of 200 mg/L was prepared by dissolving stock solution in OECD medium, and kept it in ultrasonic bath for 20 min to obtain homogenous solution. Algae were exposed to 200 mg/L concentration for the period of 72 hours. Simultaneously, to increase reliability of experiment, another study was conducted on algae using K2Cr2O7 (reference compound) under same conditions.Algal growth rate was counted at every regular interval of 24 hours, till the end of exposure period. On the basis of growth rate, median effective concentration (EC50) of test chemical was >200 mg/L. By considering EC50 value it can be concluded that test chemical is non toxic to aquatic algae, and cannot be classified as per CLP regulation.

 Again, the study was conducted following OECD guideline 201- (Alga, growth inhibition test), for determininig the toxicty of test chemical on green algae. The test chemical was prepared by adding 50 mg of test chemical in 250 ml of BBM to get the final concentration of 200 mg/L. This stock solution was kept for stirring for 2 hours to obtain a homogenous solution for the experiment. The test concentration chosen for the study were 6.25 mg/L, 12.5 mg/L, 25 mg/L,50 mg/L,100 mg/L, 200 mg/L. The test chemical concentrations were prepared using stock solution of the test chemical using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test chemical. The median effective concentration (EC50) of test chemical was 129.652 mg/L. Thus based on this value, it can be concluded that the substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP classification criteria.

Further, the third study was conducted to assess the toxic effects of the test compound on the green alga Chlorella vulgaris, in compliance with the OECD guideline 201 (Alga, Growth Inhibition Test). The test substance was prepared by adding 50 mg of test substance in 100 ml of BBM to get the final concentration of 500 mg/L. The test concentration chosen for the study were 3.125 mg/l, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, which were prepared using stock solution of the test substance using de-ionized water. The test was conducted in replicates. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. After 72 hours of exposure to test chemical to various nominal test concentrations, EC50 was determine to be 204.70 mg/l. Based on the EC50, it can be concluded that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.

Thus, based on the above EC50 values, it can be concluded that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.

Additional information

Short-term toxicity to aquatic invertebrates:

Experimental key study and supporting predicted data for the test chemical and supporting studies for its structurally similar read across substance were reviewed for the short-term toxicity to aquatic invertebrates which are summarized as below:

Aim of this study was to determine the toxicity of test chemical on the aquatic invertebrates, daphnia magna by performing the test according to the OECD guideline 202. Test was conducted under the static system for the total exposure period of 48 hrs.

The stock solution 100 g/L was prepared by dissolving colourless liquid in acetone. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 0, 5, 10, 20, 40, 80 mg/l nominal concentrations were used. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. The median effective concentration (EC50) for the test substance, on Daphnia magna was determined to be 28.9 mg/L on the basis of immobility after 48 hours. Based on the EC50 value, indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP classification criteria.

 Further, Estimation Programs Interface Suite (EPI suite) was run to predict the toxicity of the test compound to daphnia magna. The LC50 value of the test chemical, for 48 hours, on daphnia magna was estimated to be 14.167mg/L.

Based on the immobilization of test animal daphnia magna for 48 hrs of exposure, the chemical was considered to be toxic and can be classified as aquatic chronic 3 as per the CLP classification criteria.

Study was conducted according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), to determine the effect of test chemical on Daphnia magna. The test substance was soluble in Adams media. Therefore, the test solution was prepared by dissolving 100 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 3.125 mg/L,6.25 mg/L,12.5 mg/L,25 mg/L, and 50 mg/L, respectively, the test Daphnia magna were exposed to these concentration for 48 hours. The experimental median effective Concentrations [EC-50 (48 h)] for test chemical on daphnia was observed to be 50 mg/l. Thus, based on the immobilization of test animal daphnia magna after 48 hrs of exposure, chemical was considered to be toxic and was classified as aquatic chronic 3 as per the CLP classification criteria.

Thus, based on the above observation, the test chemical was considered to be toxic and can be classified as aquatic chronic 3 as per the CLP classification criteria.

Short-term toxicity to aquatic algae:

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

The Study was conducted to determine the effect of test chemical on fresh water algae, D. subspicatus, (86.81 SAG). All the parameters were followed as mentioned in the OECD guidelines 201. Initial stock solution was prepared by dissolving 200g/L in acetone.Further test solution of 200 mg/L was prepared by dissolving stock solution in OECD medium, and kept it in ultrasonic bath for 20 min to obtain homogenous solution. Algae were exposed to 200 mg/L concentration for the period of 72 hours. Simultaneously, to increase reliability of experiment, another study was conducted on algae using K2Cr2O7 (reference compound) under same conditions.Algal growth rate was counted at every regular interval of 24 hours, till the end of exposure period. On the basis of growth rate, median effective concentration (EC50) of test chemical was >200 mg/L. By considering EC50 value it can be concluded that test chemical is non toxic to aquatic algae, and cannot be classified as per CLP regulation.

Again, the study was conducted following OECD guideline 201- (Alga, growth inhibition test), for determininig the toxicty of test chemical on green algae. The test chemical was prepared by adding 50 mg of test chemical in 250 ml of BBM to get the final concentration of 200 mg/L. This stock solution was kept for stirring for 2 hours to obtain a homogenous solution for the experiment. The test concentration chosen for the study were 6.25 mg/L, 12.5 mg/L, 25 mg/L,50 mg/L,100 mg/L, 200 mg/L. The test chemical concentrations were prepared using stock solution of the test chemical using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test chemical. The median effective concentration (EC50) of test chemical was 129.652 mg/L. Thus based on this value, it can be concluded that the substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP classification criteria.

Further, the third study was conducted to assess the toxic effects of the test compound on the green alga Chlorella vulgaris, in compliance with the OECD guideline 201 (Alga, Growth Inhibition Test). The test substance was prepared by adding 50 mg of test substance in 100 ml of BBM to get the final concentration of 500 mg/L. The test concentration chosen for the study were 3.125 mg/l, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, which were prepared using stock solution of the test substance using de-ionized water. The test was conducted in replicates. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. After 72 hours of exposure to test chemical to various nominal test concentrations, EC50 was determine to be 204.70 mg/l. Based on the EC50, it can be concluded that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.

Thus, based on the above EC50 values, it can be concluded that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.