2,2,6,6-tetramethylpiperidin-4-ol

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:

other: GLP-guideline study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Measured by gas chromatography 2 - 3 times a week (before and after the replacement of the test water.)

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Supplied by NIES (National Institute of Environmental Studies) of Japan.
- Age at study initiation: Juveniles within 24 h old.
- Control group: Yes.

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

21 d

Hardness:

228 - 236 mg/L as CaCO3

Test temperature:

19.2 - 20.7 °C

pH:

pH = 7.1-9.5

Dissolved oxygen:

DO = 8.0 - 8.6 mg/L

Nominal and measured concentrations:

0, 3.7, 6.7, 12.0, 21.6, 38.9, 70.0 mg/L

Details on test conditions:

Test conditions
- Stock solutions preparation and stability: No solvent used. Test chemical was diluted to 0.3 wt.% with dilution water (Elendt M4) and it was diluted with the dilution water for testing.
- Exposure vessel type: A 80 ml test solution in a 100 ml glass beaker; 10 beakers per treatment.
- Dilution water source: Dechlorinated tap water
- Lighting: < 1,200 lux, 16 h : 8 h light-dark cycle
- Water chemistry in test: ;
- Feeding: Chlorella vulgaris, 0.1 - 0.2 mgC/day/individual
- Element (unit) basis: Mean cumulative numbers of juveniles produced per adult (reproduction)
- Number of replicate, individuals per replicate: Ten replicates, One daphnia per replicate concentrations: 0, 3.7, 6.7, 12.0, 21.6, 38.9 and 70.0 mg/L, because 48 h-EiC50 for parent Daphnia (Acute immobilisation test) was 100.0 mg/L.
- Method of calculating mean measured concentrations: Geometric mean.
- Exposure period: 21 day
- Analytical monitoring: By GC analysis. A 88.9 - 105.4 % of the nominal concentration at preparation; 84.7 - 118.9 % just before the renewal of the test water (after 2 days exposure).

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

3.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

6.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Results of analytical monitoring by GC analysis: A 88.9 - 105.4 % of the nominal concentration at preparation; 84.7 - 118.9 % just before the renewal of the test water (after 2 days exposure).

- LC50 for parental Daphnia (21 d) : > 70.0 mg/L

- EC50 (21 d, reproduction) : 46.2 mg/L

Validity criteria fulfilled:

yes

Conclusions:

LC50 and EC50 values after 21 days exposure were more than 70 mg/L and 46.2 mg/L (38.6 - 57.5 mg/L) based on the nominal concentration. The NOEC and LOEC for reproduction rate were evaluated to be 3.7 mg/L and 6.7 mg/L, respectively. Experimental designs and results were well documented and prescribed conditions in the guideline were well satisfied.

Description of key information

The NOEC (21 d) regarding the reproduction is 3.7 mg/L. The No Observed Effect Concentration is based on nominal concentration as the measured concentration was within 80-120% of the analytical measured concentration.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

3.7 mg/L