4,4',4''-(ethan-1,1,1-triyl)triphenol

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

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline No. 202, Part 2 (Daphnia sp., Acute Immobilisation Test and Reproduction Test)

Deviations:

no

Remarks:

Study conducted according to guideline in effect at time of study conduct

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations Sampled: control, 0.2, 0.63, 2.0, 6.3, and 20 mg/L
- Sampling Times: Days 0 (fresh media), 2, 5, 7, 9, 12, 14, 16, 19, and 21 (expired media).
- Sample storage conditions before analysis: not reported; samples were analyzed at the HRC Department of Analytical Chemistry within one hour of receipt.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Fresh stock solutions (20 mg/L) were prepared using agitation with a magnetic stirrer for 24 hours at 30°C. Before use, the solution was cooled to test temperature, 21°C.
- Controls: Dechlorinated and aged laboratory tap water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): not reported

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Source: Laboratory culture originating from a strain supplied by IRChA, France
- Age of parental stock (mean and range, SD): <24 hours; mean and range not reported
- Feeding during test
- Food type: Mixed unicellular algal culture supplemented with fry fish food
- Amount: 5 ml per vessel; at a level to maintain a green tinge in the test solutions
- Frequency: daily

ACCLIMATION
- Acclimation period: not reported

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

350 mg/L CaCO3

Test temperature:

21 ± 1°C

pH:

8.1-8.4

Dissolved oxygen:

8.0-8.5 mg/L

Salinity:

not reported

Nominal and measured concentrations:

Nominal: 0, 0.20, 0.63, 2.0, 6.3, and 20 mg/L
Measured: 0, 0.16, 0.52, 1.7, 5.5, and 18 mg/L

Details on test conditions:

OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 16 h light: 8 h dark
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Number of live and dead Daphnia of the "parental" generation and general condition and size of the Daphnia as compared with controls were recorded daily. Number of live and dead "filial" Daphnia plus number of "parental" Daphnia with eggs or young in the brood pouch and number of discarded unhatched eggs were recorded at each test media renewal.

VEHICLE CONTROL PERFORMED: no

TEST SYSTEM
- Test vessel: Glass flasks
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: Glass, 400 mL fill volume
- Aeration: none
- Renewal rate of test solution (frequency): Renewal on Days 2, 5, 7, 9, 12, 14, 16, and 19
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated (with sodium thiosulphate) and aged laboratory tap water. Mean values for water parameters during the period from January 1, 1990 to December 31, 1990 are given below.
- Total organic carbon: 4.1 mg/L
- Particulate matter: 0.35 FTU
- Metals: Mg, 8.8 mg/L; Al, 5.7 µg/L; Fe, 46 µg/L; Mn, 7.4 µg/L; Cu, 57 µg/L; Zn, 14 µg/L; Cr, 1 µg/L; Ni, 3 µg/L; and Pb, <4.6 µg/L. Ag, Cd, Hg, Sb, and Se were below the limit of detection
- Pesticides: 0.22 µg/L
- Chlorine: 0.29 mg/L
- Alkalinity: 240 mg/L
- Ca/mg ratio: 14.8/1
- Conductivity: 950 µS/cm
- Salinity: not reported

- Intervals of water quality measurement: not reported

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.91 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Approximate 95% confidence limits of 0.58-1.5 mg/L

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.16 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: NOEC is based on the statistical analysis of the total number of live young produced (Williams' test).

Reported statistics and error estimates:

EC50 values for immobilisation of the parental Daphnia were calculated according to the method of Thompson and Weil. EC50 values for the effects on reproduction were determined by fitting logistic response curves to the data. Williams' test was used for comparison of treatment means with the control mean.

Validity criteria fulfilled:

yes

Conclusions:

Although exposure of Daphnia magna to the test substance resulted in delayed, progressive mortality of the parental (P1) generation, impairment of reproduction at 0.52 mg/L and above was immediately apparent after sexual maturation. The 21-day "NOEC" has been determined as 0.16 mg/L.

Executive summary:

The report assesses the effects of the test material on reproduction of Daphnia magna according to OECD Guideline No. 202, part 2.  Daphnia were exposed to measured concentrations of 0. 0.16, 0.52, 1.7, 5.5, or 18 mg/L for 21 days. The 48-hour EC₅₀value was >18 mg/L. The “no effect’ level (immobilization ≤10%) at 21 days was 0.16 mg/L. the 21-day EC₅₀(reproduction) value for the test substance has been estimated to be 0.91 mg/L with approximate 95% confidence limits of 0.58-1.5 mg/L. The lowest concentration exhibiting significant adverse effects is 0.52 mg/L. The “no observed effect concentration” is estimated to be 0.16 mg/L. This value is based on the statistical analysis of the total number of live young produced (Williams’ test). All calculations and estimations are based on mean measured concentrations.

Description of key information

21-day NOEC: 0.16 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.16 mg/L