Methacrylic acid, monoester with propane-1,2-diol

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report):Methacrylic acid, monoester with propane 1,2diol; HPMA
- Physical state: liquid
- Analytical purity: 99.1%
- Lot/batch No.: 0347403
- Storage condition of test material: room temperature in the dark

Analytical monitoring:

yes

Details on sampling:

For three renewal sets during the exposure, a portion, 0.75 mL, of the test solution was taken from one vessel per concentration group and equal amount of acetonitrile was added to perform HPLC analysis. The concentration of test substance in test solutions was determined by comparing the peak area with that of standard solution.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The stock solution was prepared and diluted with dilution water. The stock solution was prepared every 5 - 8 days, and kept under refrigeration and darkness (stable for 8 days under this condition).
- Controls: dilution water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The appearances of all test solutions were colorless and transparent at the preparation.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Justification for species other than prescribed by test guideline:
- Source: National Institute for Environmental Studies, Japan
- Age of parental stock (mean and range, SD): female juvenile (less than 24 hours)
- Feeding during test: yes
- Food type: Chlorella vulgaris
- Amount: 0.15 mg C (organic carbon) per daphnid per day
- Frequency: daily

ACCLIMATION
- Acclimation period: 2 weeks
- Acclimation conditions (same as test or not): same
- Type and amount of food: 0.2 mg C (organic carbon) per daphnid per day
- Feeding frequency: daily
- Health during acclimation (any mortality observed): 0%


METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: The produced offsprings were counted and removed daily after the first brood production.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

232 to 240 mg/L

Test temperature:

19.8 to 20.2 °C

pH:

7.1 to 8.8

Dissolved oxygen:

7.1 to 8.8 mg/l

Nominal and measured concentrations:

0, 5.00, 10.5, 22.0, 47.0 and 100 mg/L- nominal
(100mg/L is ceiling)

0, 4.56, 9.93, 20.1, 45.2, 96.5 mg/L- time-weighted mean measured

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beaker (the vessel was covered with plate and surface was covered with teflon sheet)
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): periodically 3 times / week
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10 vessels /concentration
- No. of vessels per control (replicates): 10 vessels /concentration
- Biomass loading rate:
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (Elendt M4) recommended by OECD Guideline for Testing of Chemicals No. 211 "Daphnia magna Reproduction Test" was used for dilution water.
- Culture medium different from test medium: same
Feeding: Chlorella vulgaris

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light /8 hours dark
- Light intensity: 800 lux or less

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Parent daphnids: The presence of dead individuals and any abnormal swimming and appearance were recorded. Dead animals were removed. Offspring daphnids: The produced offsprings were counted and removed daily after the first brood. The presence of dead offspring, aborted eggs and ephippia were recorded. The date of the first brood was recorded.

RANGE-FINDING STUDY: Definitive test concentrations based on the acute toxicity testing results of the same test substance which resulted in a 48-hour EC50 value of >143 mg/L.

Reference substance (positive control):

yes

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

45.2 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

In the control, the mortality of parent daphnid was 0% at the end of the exposure. Thus, this result fulfilled the validity of the test (mortality The date of first brood for the control was 8 days after the start of the exposure. This results fell witin the proper range. The day of the first brood for the 4.56, 9.93, 20.1, 45.2, 96.5 mg/L test concentration group was 8, 8, 8, 8, and 9 days after start of the exposure, respectively.
The mean number of offspring per parent for the control during the 21 day exposure was 113. This result fulfilled the validity of the test (>/= 60 offspring). The mean number of offspring per parent for the 4.56, 9.93, 20.1, 45.2, 96.5 mg/L test concentration group was 107, 114, 112, 116, and 93.
There was no aborted eggs observed in all test concentration groups throughout the exposure.

Results with reference substance (positive control):

Acute immobilization test of a reference substance (K2Cr2O7, guaranteed reagent) has been conducted every six months since June 1998. The 48 hour median effect concentration (EC50) was as follows: average +/- standard deviation = 0.76 +/- 0.16 mg/L, n=13, minimum value -maximum value = 0.57 - 1.02 mg/L.

Reported statistics and error estimates:

Multiple comparison test (two groups or more other than control).
Bartlett's homogeneity of variances: If variances are equal, a one-way analysis of variance (ANOVA); Parametric multiple comparison test, Dunnett, Williams or Scheffe are performed. If variances are not equal, a Kruskal-Wallis test; Nonparametric multiple comparison test, Dunnett, Williams or Scheffe are performed. Analysis conducted using Yukms Statlight #4 software (Yukms Corp, Tokyo).

Validity criteria fulfilled:

yes

Conclusions:

In accordance with OECD test guideline 211, the 21-day NOEC was determined to be 45.2 mg/L in Daphnia magna.

Executive summary:

A 21 -day chronic toxicity study with methacrylic acid, monoester with propane-1,2-diol to daphnids (Daphnia magna) was conducted under semi-static conditions with 10 replicates of 1 daphnid per test concentration exposed to a nominal limit test concentrations of 0 (control), 5.00, 10.5, 22.0, 47.0 and 100 mg/L. Water samples were measured for analytical verification of test concentrations during the exposure from three renewal sets and the resulting time-weighted mean measured concentrations were 0 (control), 4.56, 9.93, 20.1, 45.2, and 96.5 mg/L. The most sensitive endpoint was reproduction and the resulting 21-day NOEC for reproduction was 45.2 mg/L.

Description of key information

A long-term toxicity test with Daphnia magna exposed to 2 methacrylic acid, monoester with propane-1,2-diol and conducted under GLPs, semi-static conditions, and following standard test guidelines (OECD 211), resulted in a NOEC for reproduction of 45.2 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

45.2 mg/L

Additional information

One long-term freshwater aquatic invertebrate study was available for methacrylic acid, monoester with propane-1,2-diol and considered reliable for assessment of this endpoint. The study was conducted with Daphnia magna and found to be of good quality and assigned a Klimisch score of one. The study was conducted for 21-days, under semi-static conditions, following OECD Test Guideline 211, and under GLP. The study concluded the 21-day NOEC for reproduction was 45.2 mg/L and was considered the key parameter for this endpoint.