3,5-di-tert-butyl-4-hydroxybenzyl alcohol

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 Jun - 15 Jul 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2008

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: OECD Series on Testing and Assessment, No. 23, Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures

Version / remarks:

2000

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: SANCO/3029/99 rev. 4 11/07/00: Residues: Guidance for generating and reporting methods of analysis in support of pre-registration data requirements for Annex II (part A; Section 4) and Annex III (part A; Section 5) of directive 91/414

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium für Umwelt, Klimaschutz, Landwirtschaft und Verbraucherschutz, Germany

Test material

Test material information

Constituent 1

Reference substance name:

3,5-di-tert-butyl-4-hydroxybenzyl alcohol

EC Number:

201-815-6

EC Name:

3,5-di-tert-butyl-4-hydroxybenzyl alcohol

Cas Number:

88-26-6

Molecular formula:

C15H24O2

IUPAC Name:

2,6-Di-tert-butyl-4-(hydroxymethyl)phenol

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations and method: duplicate samples from the freshly prepared test media filtrates of all concentrations and from the control were taken at the start of the test.
Duplicate samples from the test media filtrates of all test concentrations and the control were taken also at the end of the test after pooling the replicates. Additional samples of the control blank and the dilution solvent acetonitrile were taken at test start and test end without any sample treatment.
- Sample storage conditions before analysis: all samples were diluted by a factor of 2 with acetonitrile and stored at ≤ - 20 °C, protected from light

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: a stock solution was prepared with a concentration of the test substance as close as possible to the saturation level by dissolving 107.8 mg test item in 1078 mL test water. Solution was mixed 47 h. Then, non-dissolved fractions of the test item were separated from the test medium by membrane filtration (0.45 μm cellulose acetate filter). Then dilutions of the stock solution were prepared to obtain the remaining concentrations.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Clone: clone 5
- Source: laboratory culture
- Age of parental stock: 1.25 to 17.75 h old

BREEDING
- Breeding conditions: similar temperature and light conditions as used in the test. Medium was the same as in the test (Elendt M4 medium)
- Type and amount of food: Daphnia in the stock culture were fed at least on all working days with green algae (Desmodesmus subspicatus) freshly grown in the laboratory

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

2.5 mmol/L as CaCO3

Test temperature:

20 - 21 °C

pH:

7.9 - 8.1

Dissolved oxygen:

6.7 - 8.9 mg/L

Nominal and measured concentrations:

Nominal test concentrations: 0 (control), 6.25, 12.5, 25, 50 and 100 mg/L
Mean measured concentrations: 0 (control), 2.5, 2.5, 6.53, 14.9 and 29.9 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers (covered with a lid)
- Fill volume: 60 mL
- No. of organisms per vessel: 5 animals per replicate
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium, according to guideline
- Alkalinity: 0.9 mmol/L
- Intervals of water quality measurement: temperature, pH and dissolved oxygen concentrations were determined at test start and test end in each treatment group

OTHER TEST CONDITIONS
- Photoperiod: 16 h light - 8 h dark
- Light intensity: 760 to 1000 lux

EFFECT PARAMETERS MEASURED : mobility of the Daphnids was determined by visual observation after 24 and 48 h

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

20.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI: 18.0 - 23.2 mg/L

Details on results:

- Mortality of control: no, no signs of disease or stress

Results with reference substance (positive control):

- Results with reference substance valid: yes
- Relevant effect levels: EC50 (24 h) = 1.58 mg/L (95% CI: 1.32 - 1.92 mg/L), indicates that the sensitivity of the Daphnia was consistent with the level proposed by the OECD 202 guideline (EC50-24 h between 0.6 and 2.1 mg potassium dichromate/L).

Reported statistics and error estimates:

48 h EC50, EC20 and EC10 values and their 95%-confidence limits were calculated by logit analysis.
ToxRat Professional, Version 3.2.1, was used to perform the statistical analysis.

Any other information on results incl. tables

Table 1: Further biological results.

	Effect Concentration in mg/L	95 % CI in mg/L
EC20	16.2	14.0 - 18.2
EC10	14.2	11.9 - 16.1
NOEC	14.9	-
LOEC	29.9	-

Table 2: % of immobilization of Daphnids after 48 h.

Mean Measured Concentration [mg test item/L]	% of immobilised Daphnia after 48 h
Control	0
2.50* (1.47)	0
2.50* (3.45)	0
6.53	0
14.9	0
29.9	100
Test concentration was <LOQ, therefore ½ LOQ (corresponding to 2.5 mg test item/L) was used for further calculations. Values in parentheses represent the measured values

At the start of the test 28% of the nominal test concentrations were found (mean value of the nominal concentrations of 100, 50, and 25 mg/L).

After 48 h, 29% of the nominal value was determined (mean value of the nominal concentrations of 100, 50, and 25 mg/L).

During the test the daphnids were exposed to a mean of 29% of nominal.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes