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Short term toxicity to aquatic invertebrates:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on Daphnia magna was predicted for 6-Methoxy-2-naphthaldehyde (3453-33-6). The EC50 value was estimated to be 110.4696 mg/l when 6-Methoxy-2-naphthaldehyde exposed to Daphnia magna for 48hrs.

 

Toxicity to aquatic algae and cyanobacteria:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the eight closest read across substances, the toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Target substance6-Methoxy-2-naphthaldehyde (3453-33-6).EC50 value was estimated to be 192.060 mg/l for Species Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72 hrs duration when exposed to6-Methoxy-2-naphthaldehyde. Based on this value it can be concluded that the substance6-Methoxy-2-naphthaldehydeis considered as nontoxic to aquatic environment as per the criteria mentioned in CLP regulation.

Additional information

Summarized result of toxicity of 6-Methoxy-2-naphthaldehyde (3453-33-6) on the growth and other activity of aquatic invertebrates, algae and cyanobacteria by considering the data for target as well as RA chemical which was selected on the basis of structure similarity are as follows:

Short term toxicity to aquatic invertebrates:

Based on the various experimental data and prediction data for the target chemical, study have been reviewed to determine the toxic nature of 6-Methoxy-2-naphthaldehyde (3453-33-6) on the growth of aquatic invertebrates. The studies are as mentioned below

 

In the first weight of evidence study for 6-Methoxy-2-naphthaldehyde (3453-33-6), 2017, Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on Daphnia magna was predicted for 6-Methoxy-2-naphthaldehyde (3453-33-6). The EC50 value was estimated to be 110.4696 mg/l when 6-Methoxy-2-naphthaldehyde exposed to Daphnia magna for 48hrs.

 

Similarly in another weight of evidence study for RA chemical vanillin (121-33-5) Short term toxicity of vanillin on the growth and mobility of daphnia magna was checked for 24hrs. Daphnia magna was expose with chemical and measured the effect concentration at which the 50% inhibition was occurred. Based on the immobilization of daphnia magna due to the vanillin for 24hrs, the EC50 was 180mg/l. Based on the EC50 value vanillin was nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Similarly in another weight of evidence study for RA chemical Phenyltrichlorosilane (98-13-5) Short term toxicity study of the chemical Phenyltrichlorosilane on the growth of daphnia magna. Test was performed according to the standard OECD guidelines. Toxicity was measured at the different concentrations 2.0, 4.3, 9.4, 20.7, 45.5 and 100 mg/L. solvent and one control was also run simultaneously. A 100 mg test item/L stock solution was prepared prior to test initiation by adding 352 μL of the dosing stock solution to 1600 mL dilution water using a Hamilton syringe. Prior to addition of the dosing stock solution, the glass beaker containing the dilution water was placed on a magnetic stirrer. The spiked solution was stirred continuously overnight. The pH of the solution was then adjusted to 7.01 with 1 N hydrochloric acid (HCl) and 1 N sodium hydroxide (NaOH). Thereafter, the stock solution was further diluted to a final volume of 2000 mL with dilution water, resulting in a solvent (THF) concentration of 0.10 mL/L. Nominal concentrations of 2.0, 4.3, 9.4, 20.7, 45.5 and 100 mg/L were prepared by dilution of the stock solution. And addition of THF to a final concentration of 0.1 mL/L. After the exposure of < 24 hours old daphnia’s to the Phenyltrichlorosilane, the NOEC was 9.4mg/l and EC50 was >100mg/l. based on the EC50 value the chemical was toxic and can be consider to be not classified as toxic as per the CLP classification criteria.

 

 In the fourth weight of evidence study for another RA chemical Hydroxy-2-naphthalenecarboxylic acid (92-70-6) Short term toxicity study of 3-Hydroxy-2-naphthalenecarboxylic acid on the growth of daphnia magna was observed. 98 % pure chemical was tested on the growth of daphnia magna. Based on the immobility of daphnia magna due to the exposure with 3-hydroxy-2-naphthoic acid, the EC50 was 137.03 mg/l.

 

Based on the data obtain from various sources for target and RA chemicals, it can be concluded that the substance 6-Methoxy-2-naphthaldehyde (3453-33-6) is considered to be not toxic to aquatic environment and cannot be classified toxic as per the criteria mentioned in CLP regulation.

 

Toxicity to aquatic algae and cyanobacteria:

Based on the various experimental data and prediction data for the target chemical, study have been reviewed to determine the toxic nature of 6-Methoxy-2-naphthaldehyde (3453-33-6) on the growth of aquatic algae. The studies are as mentioned below

 

In the first weight of evidence study for 6-Methoxy-2-naphthaldehyde (3453-33-6), 2017 Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the eight closest read across substances, the toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for Target substance6-Methoxy-2-naphthaldehyde (3453-33-6).EC50 value was estimated to be 192.060 mg/l for Species Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) for 72 hrs duration when exposed to6-Methoxy-2-naphthaldehyde. Based on this value it can be concluded that the substance6-Methoxy-2-naphthaldehydeis considered as nontoxic to aquatic environment as per the criteria mentioned in CLP regulation.

 

 

Similarly in another weight of evidence study for RA chemical p-Anisaldehyde (123-11-5) Evaluation of toxic nature of the chemical p-Anisaldehyde on the growth of green algae for 96hrs. Based on the growth inhibition of green algae due to the exposure of analdehyde for 96hrs, the EC50 was 110.07 mg/l. thus based on the EC50 value it was concluded that the chemical was nontoxic to the green algae and thus can be consider to be not classified as toxic as per the CLP classification criteria.

 

Similarly in second weight of evidence study for RA chemical Phenyltrichlorosilane (98-13-5), from SIDS report, Short term toxicity study of the chemical Phenyltrichlorosilane on the growth of green algae was observed by the exposure of chemical for 72hrs. Test was performed by static method in Erlenmeyer flasks with different concentrations 0,6.25, 12.5, 25.0, 50.0 and 100 mg/L.

 

A 100 mg test item/L stock solution was prepared prior to test initiation by adding 176 μL of the dosing stock solution to 800 mL algal medium using a Hamilton syringe. Thereafter, the stock solution was further diluted to a final volume of 1000 mL with algal medium, resulting in a solvent (THF) concentration of 0.10 mL/L. initial cells density was394 x 104 cells/mL. Cell concentration and all other parameters was checked and maintained. The growth rate and biomass was observed in the interval of 24hrs. After the 72hrs of exposure the NOEC was ≥ 100 mg/l and the EC50 was > 100 mg/l on the basis of biomass and growth rate. Thus based on the EC50, the chemical was nontoxic and can be consider to be not classified as toxic as per the CLP classification criteria.

 

Based on the data obtain from various sources for target and RA chemicals, it can be concluded that the substance 6-Methoxy-2-naphthaldehyde (3453-33-6) is considered to be not toxic to aquatic environment and cannot be classified toxic as per the criteria mentioned in CLP regulation.

Based on the data obtain for the toxicity to invertebrates and algae from various sources for target and RA chemicals, it can be concluded that the substance 6-Methoxy-2-naphthaldehyde (3453-33-6) is considered to be not toxic to aquatic environment and cannot be classified toxic as per the criteria mentioned in CLP regulation.