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Short-term toxicity to fish

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 to fish was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). LC50 mortality value was estimated to be 463.2022 mg/l for Danio rerio for 96 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to fish.

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 to aquatic invertebrate was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). EC50 Intoxication value was estimated to be 233.8082 mg/l for Daphnia magnafor 48 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to aquatic invertebrate.

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 to aquatic algae was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). EC50 growth rate value was estimated to be 203.376 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to aquatic algae.

Toxicity to microorganisms

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 to micro-organisms was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). IGC50 growth value was estimated to be 209.582 mg/l for Tetrahymena pyriformis for 48 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to micro-organisms.

Additional information

Short-term toxicity to fish

Following studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) towards fish 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 to fish was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). LC50 mortality value was estimated to be 463.2022 mg/l for Danio rerio for 96 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to fish.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across 4-methoxyphenylacetic acid (CAS No. 104-01-8) from the UERL Lab report 2017, suggests that theFish Acute Toxicity test according to OECD Guideline 203 was conducted for 4-methoxyphenylacetic acid. The nominal concentration selected for the experiment were 100mg/L and test fish were exposed to these concentration for 96 hours. The median lethal concentration (LC50) for 4-methoxyphenylacetic acid on Danio rerio in a 96 hours study on the basis of mortality effect was found to be >100 mg/L. Thus, on the basis of this LC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance, 4-methoxyphenylacetic acid (CAS No. 104-01-8) does not exhibit short term toxicity to fish.

LC0 (96 hours) (highest loading at which no mortality was observed) = 100 mg/L

LC50 (96 hours) Experimental = >100 mg/L

Another supporting experimental study for the structurally similar read across Cyclohexanol (CAS: 108-93-0) from the handbook Acute Toxicities of Organic Chemicals to Fathead Minnows (Pimephales promelas), Vol. 1. 1984, also suggests that To study the effects of cyclohexanol on fish test was carried out for 96 hr under static condition. Mortality was measured during the test. Lethal concentration LC50 to 50% of Pimephales promelas when exposed to Cyclohexanol for 96 hr is 704 mg/L. It can be concluded from the value that the Cyclohexanol (CAS: 108-93-0)  is not toxic to the fishcan 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 mg/L to704 mg/lgive the conclusion that test substance 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) is likely to be not toxic to fish at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “not classified” as per the CLP classification criteria.

Short-term toxicity to aquatic invertebrates

Following studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) towards aquatic 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 to aquatic invertebrate was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). EC50 Intoxication value was estimated to be 233.8082 mg/l for Daphnia magnafor 48 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to aquatic invertebrate.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across 4-methoxyphenylacetic acid (CAS No. 104-01-8) from the ABITEC Lab report 2017, 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).

Another supporting experimental study for the structurally similar read across 4-Methoxybenzoic (p-anisic) acid from the Chemosphere 2005, also suggests that the acute immobilization toxicity of 4-Methoxybenzoic acid (p-Anisic acid) on the aromatic ring was determined for the freshwater crustacean Daphnia magna under neutralized condition. Test was performed in static system at different concentration ranges from 2-12 mmol/l. Neonates obtain from National Institute for Environmental Studies (NIES), Tsukuba, Japan. Daphnia feeds once daily on green alga Selenastrum capricornutum NIES-35. After the exposure of 24hrs no effect was observed. But after 48hrs with 4-Methoxybenzoic (p-anisic) acid the, EC50 was 943 mg/l with 95 % confidence interval of 8.55-1019.39 mg/l. (5.60-6.70 mmol/l). Thus based on the immobilization of daphnia magna due to 4-Methoxybenzoic (p-anisic) acid for 48hrs, EC50 was 943.318 mg/l.

Thus based on the effect concentrations which is in the range 100.8 mg/L to943.318 mg/lgive the conclusion that test substance 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) is likely to be not toxic to aquatic invertebrate at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “not classified” as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

Following studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) towards aquatic 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 to aquatic algae was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). EC50 growth rate value was estimated to be 203.376 mg/l for Pseudokirchneriella subcapitata for 72 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to aquatic algae.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across 4-methoxyphenylacetic acid (CAS No. 104-01-8) from the ABITEC Lab report 2017, suggests that thefreshwater 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).

Another supporting experimental study for the structurally similar read across 3-methoxyacetophenone (CAS: 586-37-8) from the ABITEC Lab report 2016, also suggests that theFreshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance 3-methoxyacetophenone according to OECD Guideline 201.

The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 2.2, 11, 25, 55 and 120 mg/L. Effects on the growth rate of the organism were studied.

The median effective concentration (ErC50) for the test substance, 3-methoxyacetophenone, in Desmodesmus subspicatus was determined to be 129.3 mg/L. Based on this ErC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance3-methoxyaceto phenonedoes not exhibittoxicity to aquatic algae (Desmodesmus subspicatus).

Thus based on the effect concentrations which is in the range 106.9 mg/L to203.376 mg/lgive the conclusion that test substance 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) is likely to be not toxic to aquatic algae at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “not classified” as per the CLP classification criteria.

Toxicity to microorganisms

Following studies of target chemical and structurally similar read across includes predicted data and experimental data to conclude the toxicity extent of 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) towards micro-organisms 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 to micro-organisms was predicted 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9). IGC50 growth value was estimated to be 209.582 mg/l for Tetrahymena pyriformis for 48 hrs duration. It was concluded that 1-(4-methoxyphenyl)propan-2-one (CAS: 122-84-9) was likely to be not toxic to micro-organisms.

The above predicted data of target chemical is supported by the experimental study of structurally similar read across 2 -octanone (CAS No. 111-13-7) from the publication Toxicology Methods 1997, suggests that theToxicity to micro-organisms study was conducted onTetrahymena pyriformisstrain GL for 72 hrs.

The assay was conducted in a buffered medium under static conditions.

 Stock solutions of test chemical was prepared either in solvent DMSO or in distilled water.The solvent DMSO has low toxicity toTetrahymena,low volatility, and high ability to dissolve organic chemicals. Concentration not greater than 0.75% DMSO (350 µL per 50 mL of medium) are used. This conc. was shown to have no effect onTetrahymenapopulation growth. Standard stocks are prepared on a milligram per liter basis.

 When using distilled water for prepare stock solutions, extra care must be taken to maintain sterility.

Tests were conducted in a 250 mL Erlenmeyer flask containing 50 mL of sterile, semidefined proteose – peptone – based medium and five different conc. of test substance. Then the flasks were inoculated with log-growth-phase culture ofTetrahymena pyriformisof initial cell density of approx. 2500 cells/ml and incubated for about 40 hrs at27 ± 1ᵒC with pH 7.4. After incubation, growth inhibition was measured spectrophotometrically or by electronic particle counting and 50% effect levels are determined at 72 hrs.

 The nutritional requirement of test organism was met by a solution of proteaose-peptone, yeast extract, glucose, and Fe-EDTA. For test bacterial strain, the optimum temp. for growth was in between 27ᵒC and 35ᵒC and pH range is 5.0 – 8.6, with the optimum pH being 7.5, respectively.

Control test vessel contains the test medium inoculated with the test organism with no addition of test chemical and blank was also prepared for the study.

The 50% inhibitory growth concentration in mg/l (IGC50) and the 95% fiducial interval are determined for each test compound. The IGC50 was calculated with the probit procedure.

Thus, based on growth inhibition of test organism, for 2 -octanonethe IGC50 value was found to be 181.1 and 90.7 mg/l, respectively.