4-methoxyphenylacetic acid

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29.03.2017 - 31.03.2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result using OECD guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

Determination of the inhibition of the mobility of Daphnids was carried out with the substance 4-methoxyphenylacetic acid according to OECD Guideline 202.

GLP compliance:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No. of test material: No data
- Expiration date of the lot/batch: No data
- Purity test date: No data

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: No data
- Specific activity: No data
- Locations of the label: No data
- Expiration date of radiochemical substance: No data

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: No data
- Stability under test conditions: No data
- Solubility and stability of the test substance in the solvent/vehicle: No data
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No data

Analytical monitoring:

no

Details on sampling:

No data

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
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.

- Controls: Reconstituted water as specified in OECD 202, used as a control and for sample dilution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age: Young daphnids, aged less than 24 hours used at the start of the test and they should not be first brood progeny.
- Feeding during test : Without feeding

ACCLIMATION
- Acclimation period: No data
- Acclimation conditions (same as test or not): No data
- Type and amount of food: No data
- Feeding frequency: No data
- Health during acclimation (any mortality observed): No data

QUARANTINE (wild caught)
- Duration: No data
- Health/mortality: No data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 h

Post exposure observation period:

No data

Hardness:

No data

Test temperature:

20 °C ± 1 °C

pH:

Sample at concentration 150 mg/L: pH = 7.3 changed to pH = 7.2 during the test,
Control: pH = 7.8 changed to pH = 7.6 during the test.

Dissolved oxygen:

Higher than 8.1 mg/L both in the control and the sample.

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

0, 30.0, 45.0, 67.5, 100.0 and 150.0 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- Material, size, headspace, fill volume: 25 ml
- Aeration: no data
- No. of organisms per vessel: 5 pieces
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): No data
- No. of vessels per vehicle control (replicates): No data
- Biomass loading rate: No data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Natural water (surface or ground water), reconstituted water or dechlorinated tap water are acceptable as culturing and dilution water if D. magna survives in it for the duration of the culturing, acclimation and testing without showing signs of stress. Waters in the range pH 6 to pH 9, with hardness between 140 mg/l and 275 mg/l (as CaCO3) are recommended.As an example, the preparation of dilution water meeting the requirements is described below.Dissolve known quantities of reagents in water. The dilution water prepared shall have a pH of 7.8 ± 0.5, a hardness of (225 ± 50) mg/l (expressed as CaCO3), a molar Ca + Mg ratio close to 4 + 1 and a dissolved oxygen concentration above 7 mg/l.

Prepare the solutions specified below:
- Calcium chloride solution: Dissolve 117.6 g of calcium chloride dihydrate (CaCl2.2H2O) in water (4.2) and make up to 1 l with water (4.2).
- Magnesium sulfate solution: Dissolve 49.3 g of magnesium sulfate heptahydrate (MgSO4.7H2O) in water (4.2) and make up to 1 l with water (4.2).
- Sodium bicarbonate solution: Dissolve 25.9 g of sodium bicarbonate (NaHCO3) in water (4.2) and make up to 1 l with water (4.2).
- Potassium chloride solution: Dissolve 2.3 g of potassium chloride (KCI) in water (4.2) and make up to 1 l with water (4.2).

Mixing
Mix 2.5 ml of each of the four solutions and make up to 1 l with water.
The dilution water shall be aerated until the dissolved oxygen concentration has reached saturation and the pH has stabilized. If necessary, adjust the pH to 7.8 ± 0.5 by adding sodium hydroxide (NaOH) solution or hydrochloric acid (HCI). The dilution water prepared in this way shall not be further aerated before use.

- Sodium hydroxide solution, e.g. [NaOH] : 1 mol/l.
- Hydrochloric acid, e.g. [HCl] : 1 mol/l.

OTHER TEST CONDITIONS
- Adjustment of pH: Without adjustment
- Photoperiod: No - Darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 was calculated using non linear regression by the software Prism 4.0.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

100.8 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI = 94.7 - 107.4 mg/L

Details on results:

No data

Results with reference substance (positive control):

- Results with reference substance valid
- 24h EC50 = 0.73 mg/L K2Cr2O7

Reported statistics and error estimates:

No data

Control solution: Reconstituted water without the sample, 0 % of the daphnids were immobilized at the end of test.

Validity criteria fulfilled:

yes

Conclusions:

The median effective concentration (EC50) for the test substance, 4-methoxyphenylacetic acid, in Daphnia magna was determined to be 100.8 mg/L on the basis of mobility inhibition effects in a 48 hours of study.

Executive summary:

Determination of the inhibition of the mobility of Daphnids was carried out with the substance 4-methoxyphenylacetic acid according 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 acid does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna).

Description of key information

Determination 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).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100.8 mg/L

Additional information

Various studies including experimental data following OECD guideline and predicted results from validated model for toxicity to aquatic invertebrates with the target substance 4-methoxyphenylacetic acid (CAS No. 104-01-8) and the relevant read across substances 4-Hydroxy-3-methoxybenzoic (vanillic) acid (121 -34 -6) and 4-Methoxybenzoic acid (100-09-4) by considering its structure-activity relationships,were summarized as follows:

Determination of the inhibition of the mobility of Daphnids was carried out with the substance 4-methoxyphenylacetic acid according 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 immobilisa tion effects with 95% CI of 94.7 to 107.4 mg/L.

 

Also, based on the Ecological Structure Activity Relationships (ECOSAR) Predictive Model version 1.11 (2017), the median lethal concentration (LC50) for the test substance, 4-methoxyphenylacetic acid, in daphnia magna was estimated to be 2043.6 mg/L on the basis of mortality effect in a 48 hour study.

 

In another study for the read across substance conducted by Yasushi Kamaya et al.(Chemosphere 59 (2005) 255–261). The short term toxicity to aquatic invertebrates was performed in Daphnia magna for 48 hrs. The young daphnids were obtained from continuous cultures in 1 liter glass beakers at 21 ± 0.3 degree C, in dechlorinated and conditioned tap water, the medium was renewed in three weeks and daphnids were fed daily with the green alga Selenastrum capricornutum. The pH of test solution was adjusted to 7.45 ± 0.05 with HCL and NaOH. The concentrations of the resultant solutions were checked before and after (48 h) exposure using a UV–visible spectrophotometer. At the start of the experiment neonate were placed in 50 ml of beaker with 40 ml of test solution. All experiment was made in four replicates and performed at 21 ± 0.3 degree C under 16 h light: 8 h dark photoperiod. Immobility was observed after 24 and 48 hrs and EC 50 value was calculated. The EC 50 value of 4-Hydroxy-3-methoxybenzoic (vanillic) acid (121 -34 -6) for Daphnia magna was determined to be 908 mg/l in 48 hrs.

Moreover, short-term toxicity to aquatic invertebrates was conducted by Yasushi Kamaya et al.( Chemosphere 59 (2005) 255–261), in Daphnia magna for 48 hrs. The young daphnids were obtained from continuous cultures in 1 liter glass beakers at 21 ± 0.3 degree C, in dechlorinated and conditioned tap water, the medium was renewed in three weeks and daphnids were fed daily with the green alga Selenastrum capricornutum. The pH of test solution was adjusted to 7.45 ± 0.05 with HCL and NaOH. The concentrations of the resultant solutions were checked before and after (48 h) exposure using a UV–visible spectrophotometer. At the start of the experimentneonate were placed in 50 ml of beaker with 40 ml of test solution. All experiment was made in four replicates and performed at 21 ± 0.3 degree C under 16 h light: 8 h dark photoperiod. Immobility was observed after 24 and 48 hrs and EC 50 value was calculated. After the experiment the EC 50 value of 4-Methoxybenzoic acid (100-09-4) for Daphnia magna was determined to be 943 mg/l in 48 hrs of exposure.

 

So, based on the above experimental studies for target substance 4-methoxyphenylacetic acid (CAS No. 104-01-8) and the relevant read across substances 4-Hydroxy-3-methoxybenzoic (vanillic) acid (121 -34 -6) and 4-Methoxybenzoic acid (100-09-4), the median effective concentration (EC50) was found to be in the range of 100.8 – 943 mg/L and the lethal concentration (LC50) to be 2043.6 mg/L on the basis of various effects (mobility and mortality) in a 48 hours of exposure. 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 acid does not exhibit short term toxicity to aquatic invertebrate (Daphnia Magna).