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Description of key information

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 closest read across substances, the toxicity on aquatic invertebrate predicted for 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0). Effect concentration i.e EC50 value estimated to be 188.753 mg/l for Daphnia magna for 48 hrs duration. It can be concluded that the 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0) is likely to be not toxic to aquatic invertebrate, hence it can be considered to benot classifiedas per the CLP classification criteria for aquatic environment.

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 closest read across substances, the toxicity on aquatic algae predicted for 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0). Effect concentration i.e EC50 value estimated to be 139.118 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It can be concluded that the 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0) is likely to be not toxic to aquatic algae, hence it can be considered to be“not classified”as per the CLP classification criteria for aquatic environment.

Additional information

Short-term toxicity to aquatic invertebrates

Following studies include the predicted data and experimental study for the target chemical and structurally similar read across to conclude the toxicity extent of7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0)towards invertebrate is summarized as follows:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity on aquatic invertebrate predicted for 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0). Effect concentration i.e EC50 value estimated to be 188.753 mg/l for Daphnia magna for 48 hrs duration. It can be concluded that the 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0) is likely to be not toxic to aquatic invertebrate, hence it can be considered to benot classifiedas per the CLP classification criteria for aquatic environment.

The predicted data of the target chemical is suported by the is supported by the experimental study for the target chemical 4-methoxyphenylacetic acid (CAS:104-01-8) from the ABITEC Lab report suggests that theDetermination of the inhibition of the mobility of Daphnids was carried out with the substance4-methoxyphenylacetic acidaccording to OECD Guideline 202.

The stock solution 150.0 mg/L was prepared by dissolving white powder in reconstituted water. The solution was kept in ultrasonic bath for 20 min. The test solutions of required concentrations were prpared by mixing the stock solution of the test sample in reconstituted water.The test substance was tested at the concentrations 0, 30.0, 45.0, 67.5, 100.0 and 150.0 mg/L.The test was performed under static conditions in a fresh water system at a temperature of 20 °C± 1 °C. EC50 was calculated using non linear regression by the software Prism 4.0.

The median effective concentration (EC50) for the test substance,4-methoxyphenylacetic acid, in Daphnia magna was determined to be 100.8 mg/L for immobilisation effects with 95% CI of 94.7 to 107.4 mg/L. Thus, based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance,4-methoxyphenylacetic aciddoes not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna).

Further it is supported by another experimental study of structurally similar read across p-anisic acid (CAS: 100-09-4) Chemosphere 2005, also suggests that the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) test was carried out for p-anisic acid to study the effects on aquatic invertebrate.

Neonates (<24 h old) from 2–3-week-old mothers were placed in a 50 ml glass beaker containing 40 ml of a test solution. All experiments for exposure and controls without chemicals were made in four replicates and performed at 21 ± 0.3[1]C under 16 h light: 8 h dark photoperiod. After 24 and 48 h, the number of immobile daphnids was recorded to determine the concentration able to achieve 50% immobilization and it was indicated as EC50.

The Effective concentration EC50 to 50% of Daphnia magna for p-anisic acid in 48 hr is 943 mg/L. Immobilization was measured during the test. It can be concluded from the value that the p-anisic acid (CAS: 100-09-4) is not toxic to the aquatic environment and can be considered as “not classified” as per the classification criteria for aquatic environment.

Thus based on the effect concentrations which is in the range 100.8 mg/L to 943 mg/l give the conclusion that test substance 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0) was likely to be not toxic to aquatic invertebrate at environmentally relevant concentrations and applying weight of evidence it can be considered to benot classifiedas per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

Following studies include the predicted data and experimental study for the target chemical and structurally similar read across to conclude the toxicity extent of 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0)towards algae is summarized as follows:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the closest read across substances, the toxicity on aquatic algae predicted for 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0). Effect concentration i.e EC50 value estimated to be 139.118 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It can be concluded that the 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0) is likely to be not toxic to aquatic algae, hence it can be considered to be“not classified”as per the CLP classification criteria for aquatic environment.

The predicted data of the target chemical is suported by the is supported by the experimental study for the target chemical 4-methoxyphenylacetic acid (CAS:104-01-8) from the ABITEC Lab report 2017, suggests that the freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance4-methoxyphenylacetic acid(CAS No.- 104 -01 -8) according to OECD Guideline 201

The stock solution 150.0 mg/L was prepared by dissolving white powder 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 and tested at the concentrations 0, 0, 30.0, 45.0, 67.5, 100.0 and 150.0 mg/L.Effects on the growth rate of the organism were studied. The test was performed under static conditions in a static fresh water system at a temperature of 23± 2°C. Initial cell density of test organism used was 5x10(3) cells/ml. Determination of cell counting involve the use of microscope with counting chamber Cyrus I or electronic particle counter. ErC50 was calculated using non-linear regression by the software Prism 4.0.

The median effective concentration (ErC50) for the test substance,4-methoxyphenylacetic acid, in a freshwater algae Desmodesmus subspicatus was determined to be 106.9 mg/L on the basis of effects on growth rate in a 72 hour study with 95% Cl of 83.2 - 137.3 mg/L. Thus, based on this ErC50 value and according to CLP Criteria for aquatic classification of the substance, it is concluded that4-methoxyphenylacetic acid(CAS No.- 104 -01 -8) does not exhibits toxicity to aquatic algae (Desmodesmus subspicatus).

Further it is supported by another experimental study of structurally similar read across p-anisic acid (CAS: 100-09-4) UERL 2017, also suggests that the effect of test item 4-methoxyphenylacetic acid, CAS No. 104-01-8 was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 0.9 mg/L,2.7 mg/L,8.1 mg/L,24.3 mg/L,72.9 mg/L,218.7 mg/L. The test concentrations were prepared using stock solution of the test item 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 item. EC50 calculated graphically through probit analysis was observed to be >200 mg/L.

Thus, based on this EC50 value and according to CLP Criteria for aquatic classification of the substance, it is concluded that 4-methoxyphenylacetic acid (CAS No.- 104 -01 -8) does not exhibits toxicity to aquatic algae (Chlorella vulgaris).

Thus based on the effect concentrations which is in the range 106.9 mg/L to >200 mg/l give the conclusion that test substance 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-one (CAS: 4133-34-0) was likely to be not toxic to aquatic algae at environmentally relevant concentrations and applying weight of evidence it can be considered to benot classifiedas per the CLP classification criteria.