p-anisic 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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Specific details on test material used for the study:

Chemical was used from Wako Pure Chemical Industries, Osaka, Japan

Analytical monitoring:

yes

Details on sampling:

- Concentrations: concentrations of the resultant solutions were checked
- Sampling method: sampling at test start and test end (48 h)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: highest test item concentration (stock solution) was establihed by dissolving appropriate test compound in the aerated test medium; following dilution series was performed by dilution of this stock solution
- Controls: yes, medium

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Daphnia magna
- Source: National Institute for Environmental Studies (NIES), Tsukuba, Japan
- Age of parental stock: 2–3-week-old mothers
- Feeding during test: no

ACCLIMATION
- Acclimation period: at 21 ± 0.3 °C, in dechlorinated and conditioned tap water (total hardness ca.100 mg/L as CaCO3; pH 7.5 ± 0.1), photoperiod: 16 h light: 8 h dark; density: below 20 per beaker; medium was renewed three times a weak
- Acclimation conditions: same as test
- Food type: Selenastrum capricornutum NIES-35
- Amount: 3.0 – 3.5 x 10E+08 cells/L
- Frequency: daily

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Neonates (<24 h old)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

ca.100 mg CaCO3 /L

Test temperature:

21 ± 0.3 °C

pH:

7.45 ± 0.05

Nominal and measured concentrations:

304.3 to 1825.8 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
Test vessel:
- Type: open
- Material, size, headspace, fill volume: 50 mL glass beaker; 40 mL test solution; 10 mL headspace
- Age of test organisms: Neonates (<24 h old)
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Test medium used was ‘‘moderately hard water’’ prepared from deionized and distilled water (total hardness, ca.100 mg CaCO3/L; USEPA, 1993)

OTHER TEST CONDITIONS
- Adjustment of pH: yes, where necessary with 1 mol /L NaOH solution to pH 7.45 ± 0.05
- Photoperiod: 16 h light . 8 h dark

EFFECT PARAMETERS MEASURED: Immobility (showing no movement within 15 s after gentle stirring were defined to be immobile) was recorded after 24 h and 48 h.

RANGE-FINDING STUDY: no range-finding test was performed

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

943 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Reported statistics and error estimates:

Using Probit amalyses (USEPA, 1993); The relationship between the toxicity and the physicochemical and/or structural descriptors was analyzed by least-square regression using JMP 5.0 J software (SAS Institute Inc., USA). Log (EC50, in mol/L) was taken as the dependent variable, while the structural and/or physicochemical descriptors were used as the independent variables. The following descriptive information was provided: n (number of observations used in analysis), r2 (square of the correlation coefficient adjusted for degrees of freedom), s (the root of the mean square for error), F (the Fisher statistic), p (the significance level).

Analytical Results:

No significant spectral changes in most test solutions were observed, indicating the stability of these compounds under the test conditions.

Validity criteria fulfilled:

not applicable

Description of key information

EC50 (48 h) = 943 mg/L (publication, Daphnia magna, nominal)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

943 mg/L

Additional information

The acute toxicity of the test item to aquatic invertebrates was investigated in a study by Kamaya et al. (2005). Daphnia magna was exposed for 48 hours to the test material at nominal concentrations of 2 mmol/L (304.3 mg/L) to 12 mmol/L (1825.8 mg/L). Samples from all concentrations and the control was checked before and after (48 h) exposure experiments by the UV spectra (400–200 nm). The EC50 (48 h) was determined at 943 mg/L.