Alcohols, C9-11, branched and linear, ethoxylated

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

Study period:

20 Aug - 24 Nov 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

adopted October 2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all concentrations
- Sampling method: Analytical samples taken at respective time points during the study course (exposure start, day 1 (aged), day 10 (fresh), day 11 (aged), day 20 (fresh), day 21 (aged))
- Sample storage conditions before analysis: The samples were mixed with 10 mL acetonitrile and stored deep-frozen (≤ - 18 °C) until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution with a nominal concentration of 50 mg/L was prepared by adding the necessary amount of test item to a volumetric flask. Test medium was added and the solution was homogenised by shaking. The solution was observed to be clear and transparent and some foam was observed. Test item concentrations were prepared by dilution with test medium. Test solutions were observed to be clear and transparent.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Clone V
- Age at study initiation (mean and range, SD): < 24 h
- Method of breeding: Daphnia magna was bred as single culture (1 daphnid per 100 mL) in Elendt M4 medium. pH-value: 6.0 – 9.0, dissolved oxygen: > 60 % saturation, total hardness 140 - 250 mg/L (as CaCO3), fed with single cell green algae (Desmodesmus subspicatus, formerly Scenedesmus subspicatus) at least three times a week.
- Source: bred at testing faciltiy, originally obtained from the Federal Environment Agency in Berlin/Germany.
- Feeding during test
- Food type: unicellular green algae (D. subspicatus) and additional nutrients (Tetra Min Baby®)
- Amount:
0.1 mg carbon / daphnia / day from day 0 to 7
0.15 mg carbon / daphnia / day from day 8 to 14
0.2 mg carbon / daphnia / day from day 15 to 20
- Frequency: daily

ACCLIMATION
- Acclimation period: none

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

214 - 250 mg/L as CaCO

Test temperature:

19.2 – 20.4 °C

pH:

7.31 – 8.02

Dissolved oxygen:

≥ 6.56 mg/L

Nominal and measured concentrations:

Nominal test substance concentrations: 1.00, 0.500, 0.250, 0.125 and 0.0625 mg/L
Time weighted mean concentrations: 0.382, 0.170, 0.107, 0.0428, 0.0218 mg/L (based on 3 representative constituents)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers (nominal: 100 mL)
- Type (delete if not applicable): covered by glass plate
- Volume of solution: ≥ 50 mL
- Aeration: none
- Renewal rate of test solution (frequency): every 24 h
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Biomass loading rate: ≥ 50 mL / animal

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4 medium
- Culture medium different from test medium: no
- Intervals of water quality measurement: Temperature, pH-value, oxygen concentration and total hardness was measured at test start and end and each weekday in all test item concentrations and control from fresh and aged solutions.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light and 8 hours darkness
- Light intensity: 1099 lux (mean)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Dead animals were counted and removed daily. Observations (e.g. presence of eggs in the brood pouch, males or winter eggs, condition and size of parental generation) were recorded. Offsprings were counted and removed daily after appearance of first brood.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0.001, 0.0100, 0.100, and 1.00 mg/L
- Results used to determine the conditions for the definitive study: Mean number of alive offspring per alive adult at test end 100% inhibtion at 1 mg/L

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.107 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

other: based on three representative constituents

Remarks:

C10EO2, C10EO3, C10EO6

Basis for effect:

mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

0.212 mg/L

95% CI:

>= 0.082 - <= 0.55

Nominal / measured:

meas. (TWA)

Conc. based on:

other: based on three representative constituents

Remarks:

C10EO2, C10EO3, C10EO6

Basis for effect:

mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.315 mg/L

95% CI:

>= 0.196 - <= 0.506

Nominal / measured:

meas. (TWA)

Conc. based on:

other: based on three representative constituents

Remarks:

C10EO2, C10EO3, C10EO6

Basis for effect:

mortality: Number of living offspring produced per surviving parental animal {for Daphnia magna, TG 211}

Details on results:

- Observations on body length and weight: No statistically significant inhibitory effects were determined
- Mortality of control: no
- Other adverse effects control: no

Reported statistics and error estimates:

The NOEC and LOEC were determined by using a multiple comparison method (Fisher’s exact binomial test with Bonferroni correction for mortality of adult daphnia, step-down Jonckheere-Terpstra test for alive offspring per adult from test start, multiple sequentially-rejective median (2x2-table) test after Bonferroni-Holm for alive offspring per adult from test end and body length). The EC10, 20, 50 - values for alive offspring per alive adult from test start and alive offspring per alive adult from test end was determined with non-linear regression using a 3 parametric normal cumulative distribution function. The LC10, 20, 50 for mortality of adult daphnia and EC10, 20, 50 – values for body length was not determined statistically.

Table 1: Validity criteria for OECD 211

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality of the parent animals in the control (female Daphnia) does not exceed 20% at the end of the test.	0 %	yes
The mean number of living offspring produced per parent animalsurvivingat the end of the test is ≥ 60 in the control.	152.7	yes

Table 2:   Sum of alive offspring at test end per adult from test start

Nominal conc.	Mean number of alive offspring per adult from test start	Inhibition to Control [%]
Control	152.7	-
0.0625 mg/L	138.5	9.3
0.125 mg/L	132.3	13.4
0.250 mg/L	157.9	-3.4
0.500 mg/	137.5*	10.0
1.00 mg/L	32.0*	79.0

- not calculated

* statistically significant different from control

Table 3:      Sum of alive offspring per surviving adult at the end of the test

Nominal conc.	Mean number of alive offspring per alive adult at test end	Inhibition to Control [%]
Control	152.7	-
0.0625 mg/L	138.5	9.3
0.125 mg/L	132.3	13.4
0.250 mg/L	175.4	-14.9
0.500 mg/L	144.7*	5.2
1.00 mg/L	40.0*	73.8

- not calculated

* statistically significant different from control

 

Validity criteria fulfilled:

yes

Remarks:

Please see table 1 at "any other information on results incl. tables"

Description of key information

NOEC (21 d): 0.107 mg/L (TWA)

Additional information

The chronic toxicity of Alcohols, C9-11, branched and linear, ethoxylated to aquatic invertebrates was investigated in a GLP guideline study following OECD 211. The study was conducted under semi-static conditions with a daily renewal of test solutions. During the test period of 21 days the mortality of test organisms (Daphnia magna), time of first production of offspring and the number of offspring were assessed. The test organisms were exposed to nominal test item concentrations of 0.0625, 0.125, 0.250, 0.500 and 1.00 mg/L. The test concentrations were analytically monitored by HPLC-MS/MS. The time weighted mean measured concentrations, based on three representative constituents of the UVCB substance, were 0.382, 0.170, 0.107, 0.0428 and 0.0218 mg/L. Based on the number of living offspring produced per surviving parental animal a NOEC (21 d) of 0.107 mg/L (TWA) was observed.