Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

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:
other: see 'Remark'
Remarks:
According to OECD-guideline no. 202, part II five concentrations (14, 30, 53, 110 and 230 mg/l; measured) were tested. Due to the steep dose/response curve in both acute and chronic daphnia toxicity study, the missing result of the 30 mg/l concentration group is without relevance because this concentration was less than the established NOEC (53 mg/l).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 211 (Daphnia magna Reproduction Test)
Version / remarks:
Cited as OECD Guide-line 202, part 2 (Daphnia sp., Reproduction Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Glacial methacrylic acid; purity: 97.11 %. Clear liquid.
Lot number 0034D002 received from Rohm and Haas, stored at room temperature in the dark.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Both replicates of each treatment level and control were analyzed for MAA concentration twice prior to the start of the definitive exposure. Each
replicate solution was sampled and analyzed for MAA concentration on day 0 and weekly thereafter (day 7, 14 and 21)

Test solutions

Vehicle:
no
Details on test solutions:
Nominal concentrations were maintained by introducing approximately 6.0 aquarium volumes per day of newly prepared test solution via an intermittent proportional flow through dilution apparatus.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Organisms were obtained from laboratory cultures maintained at Springborn. Culture water was prepared by fortifying well water and filtering. Two weeks prior to study intiation the water had total hardness and total alkalinity ranges of as CaCO3 of 160-180 and 110-120 mg/L, respectively, a pH range of 7.4 to 8.5, a specific conductance range of 500-600 umhos/cm and a dissolved oxygen concentration >60%. Light intensity ranged from 70-90 footcandles. The culture solution temperature was maintained at 20 +/-2C. Daphnia were fed once daily.

Study design

Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d

Test conditions

Hardness:
160-180 mg CaCO3/L.
Test temperature:
20 - 21°C
pH:
5.6 - 8.1 (at 14 - 110 mg/l)
4.2 - 5.7 (at 230 mg/l)
Dissolved oxygen:
8.6 - 9.2 mg/l
Nominal and measured concentrations:
Nominal 13, 25, 50, 100 and 200 mg a.i./L.
Based on results of weekly analysis, mean measured concentrations of MAA averaged 110% of nominal concentrations and defined the exposure
concentrations as 14, 30, 53, 110 and 320 mg a.i./L.
Details on test conditions:
40 organisms (20 per replictae concentration) were exposed to each of five concentrations of MAA and a dilution water control for 21 days. Biological observations as well as observations of physical characteristics of the exposure solutions were madeand recorded on days 1, 2, 4, 7, 8, 9, 11, 14, 16, 18 and 21.
Illumination of 16 hours light: 8 hours dark at 30 to 60 footcandles.
The exposure system consisted of an intermittent flow proportional diluter and a set of 12 exposure vessels.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
53 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
70 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
immobilisation
Remarks on result:
other: 95% CI of 53-110 mg/L
Duration:
21 d
Dose descriptor:
other: EC100
Effect conc.:
110 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 53 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
reproduction
Details on results:
Exposure solutions were clear, colorless and contained no visible signs of undissolved material throughout the test. Total alkinlinity and pH of the solutions decreased with increasing concentration of MAA.
Following 21 days of exposure survival of control Daphnids was 95%. No organism survived the 21 day exposure to the two highest dose levels (110 and 230 mg a.i./L). Survival of 85 and 90% was observed among the organisms exposed to 14 and 53 mg a.i./L, respectively, and was not significantly different from controls.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In a valid guideline study the LOEC was 110 mg a.i./L; the NOEC was 53 mg a.i./L and based on these data the Maximum Acceptable Toxicant
Concentration of MAA to Daphnia magna was <110 mg a.i./L and > 53 mg a.i./L.
Executive summary:

In a valid guideline study the LOEC was 110 mg a.i./L; the NOEC was 53 mg a.i./L and based on these data the Maximum Acceptable Toxicant Concentration of MAA to Daphnia magna was <110 mg a.i./L and > 53 mg a.i./L.