Di-tert-butyl 1,1,4,4-tetramethyltetramethylene diperoxide

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:

From 2008-10-07 to 2010-04-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well-conducted and documented study done according to established guidelines under GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

2008-11-12

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Melting point: no data
- Boiling point: no data
- Vapour pressure: no data
- Water solubility (under test conditions): 7 µg/L

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 1.00, 1.10, 4.50, 4.95, 20.0, 21.6, and 22.0 µg/L
- Sampling method: Treatment samples and control samples were shaken manually to obtain homogeneous sample solutions. 100 mL of the treatment samples and control samples were extracted with 40 mL of ethyl acetate. Thus, the samples were concentrated by a factor of 0.4. The application solutions were diluted with ethyl acetate. Aliquots of the final solutions were analyzed by GC-MS.
- Sample storage conditions before analysis: no data

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Prior to the start of the test and prior to each test medium renewal, the test media and the controls were prepared as follows:
The application solution for the dosage of the highest test concentration was prepared by completely dissolving 20 mg (effective weights in the range of 20.0 to 20.2 mg) of the test item in 100 mL of DMF by intense mixing for 5 minutes. Further dilutions of this application solution with DMF were performed to obtain the application solutions for the dosage of the lower test concentrations. The application solutions were prepared once a week (three preparations during the test period) and were used for all test media preparations during this week. Between the test medium renewal periods, the application solutions were stored in a refrigerator. The stability of the application solutions during their use was examined in a pre-experiment (non-GLP). For the preparation of the test media, adequate volumes of the application solutions were added to the test water (100 μL per liter of test water) during intense stirring to obtain the test concentrations as stated above. The concentration of DMF was the same in all test media and in the solvent control (100 μL DMF per liter of test water).
- Eluate: ethyl acetate
- Differential loading: cf. Table 1 in "Any other information on material and methods incl. tables"
- Controls: For the control, test water without addition of test item or solvent was used.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): ethyl acetate.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnids
- Strain/clone: clone 5
- Source: supplied by the University of Sheffield/UK in 1992.
- Age of parental stock (mean and range, SD): at least 14 days old, and not older than 28 days old. They were not first brood progeny. At the start of the test, the test animal were less than 24 hours old.
- Feeding during test
- Food type: Green algae, Scenedesmus subspicatus; and with a fish suspension.
- Amount: no data
- Frequency: 3 times a week.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

no data

Hardness:

no data

Test temperature:

20°C

pH:

7.6-8.0

Dissolved oxygen:

3 mg/L

Salinity:

not applicable

Nominal and measured concentrations:

- nominal concentrations: 0.93, 2.0, 4.3, 9.3, and 20 µg/L
- measured concentrations: 6.5 µg/L (time weighted mean of the highest test concentration)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 80 mL of culture medium
- Aeration: no data
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate): culture medium was changed twice a week.
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- No. of vessels per vehicle control (replicates): not applicable

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted freshwater (Elendt M7 medium)

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16:8
- Light intensity: 500-630 lux

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 20 µg/L

Nominal / measured:

nominal

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 20 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

no data

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

no data

Table 2: Results after 21 days of exposure of the test animals.

	Control	Solvent control	Peroxide, 1,1'-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1-dimethylethyl)] (nominal concentration µg/L)
			0.93	2.0	4.3	9.3	20
Mortality (%) after 21 days of exposure	0	0	10	0	0	0	0
Mean reproduction rate (living offspring per surviving adult)	151.4	142.1	141.2	141.1	138.4	140.8	141.8
Mean reproduction rate in % of solvent control	107	100	99	99	97	99	100

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1 -dimethylethyl)] on the survival and reproduction of Daphnia magna was tested in a semi-static test over 21 days following the OECD Guidelines for Testing of Chemicals, 211. The test item had no toxic effects on survival and reproduction of Daphnia magna after the exposure period of 21 days up to the solubility limit of the test item in test water (approximately 7 μg/L) . Thus, the 21-day NOEC of the test item was determined to be at least 6.5 μg/L (nominal 20 μg/L). The 21-day LOEC was above the highest test concentration of 6.5 μg/L (nominal 20 μg/L). The 21-day EC50 for the inhibition of the reproduction rate of the daphnids was higher than 6.5 μg/L (nominal 20 μg/L).

Executive summary:

The effect of the test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1 -dimethylethyl)] (CAS# 78-63-7) on the survival and reproduction of Daphnia magna was tested in a semi-static test over 21 days following the OECD Guidelines for Testing of Chemicals, No. 211 (1998): “Daphnia magna Reproduction Test”.

The nominal concentrations tested were 0.93, 2.0, 4.3, 9.3 and 20 μg/L. Additionally, a control and a solvent control were tested in parallel. The test method is based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000). The measured test item concentrations in the samples from the freshly prepared test media of nominal 20 μg/L (NOEC) varied in the range of 44 to 121% of the nominal values. In the stability control samples without food particles and daphnids, the mean test item concentrations were in the range of 3-25% of the nominal values. In the stability control samples including food particles the mean test item concentrations had further decreased to 1-5% of the nominal values. The biological results were based on mean measured concentrations calculated as time-weighted means of the test item concentrations measured at the start of the test medium renewals and the concentrations measured in the stability control samples without food at the end of the renewal periods. The mean measured concentration of nominal 20 μg/l calculated as time-weighted mean was 6.5 μg/L.

The test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1-dimethylethyl)] (CAS# 78-63-7) had no toxic effects on survival and reproduction of Daphnia magna after the exposure period of 21 days up to the solubility limit of the test item in test water (approximately 7 μg/L) . Thus, the 21-day NOEC of the test item was determined to be at least 6.5 μg/L (nominal 20 μg/L). The 21-day LOEC was above the highest test concentration of 6.5 μg/L (nominal 20 μg/L). The 21-day EC50 for the inhibition of the reproduction rate of the daphnids was higher than 6.5 μg/L (nominal 20 μg/L).

Description of key information

Höger, (2010), tested the effect of the test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1 -dimethylethyl)] (CAS# 78-63-7) on the survival and reproduction of Daphnia magna in a semi-static test over 21 days following the OECD Guidelines for Testing of Chemicals, No. 211 (1998): “Daphnia magna Reproduction Test”.The test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1-dimethylethyl)] (CAS# 78-63-7) had no toxic effects on survival and reproduction of Daphnia magna after the exposure period of 21 days up to the solubility limit of the test item in daphnid test medium (approximately 7 μg/L) . Thus, the 21-day NOEC of the test item was determined to be at least 6.5μg/L (nominal 20 μg/L). The 21-day LOEC was above the highest test concentration of 6.5 μg/L (nominal 20μg/L). The 21-day EC50 for the inhibition of the reproduction rate of the daphnids was higher than 6.5 μg/L (nominal 20μg/L). No toxicity was observed up to the maximum testable concentration in the study.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

6.5 µg/L

Additional information

Höger (2010), tested the effect of the test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1 -dimethylethyl)] (CAS# 78-63-7) on the survival and reproduction of Daphnia magna in a semi-static test over 21 days following the OECD Guidelines for Testing of Chemicals, No. 211 (1998): “Daphnia magna Reproduction Test”.

The nominal concentrations tested were 0.93, 2.0, 4.3, 9.3 and 20μg/L. Additionally, a control and a solvent control were tested in parallel. The test method is based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (2000). The measured test item concentrations in the samples from the freshly prepared test media of nominal 20μg/L (NOEC) varied in the range of 44 to 121% of the nominal values (greater than the solubility of the test substance). In the stability control samples without food particles and daphnids, the mean test item concentrations were in the range of 3-25% of the nominal values. In the stability control samples including food particles the mean test item concentrations had further decreased to 1-5% of the nominal values. The biological results were based on mean measured concentrations calculated as time-weighted means of the test item concentrations measured at the start of the test medium renewals and the concentrations measured in the stability control samples without food at the end of the renewal periods. The mean measured concentration of nominal 20 μg/l calculated as time-weighted mean was 6.5μg/L, the maximum testable concentration of the test substance under the conditions of the study.

The test item Peroxide, 1,1’-(1,1,4,4-tetramethyl-1,4-butanediyl)bis[2-(1,1-dimethylethyl)] (CAS# 78-63-7) had no toxic effects on survival and reproduction of Daphnia magna after the exposure period of 21 days up to the solubility limit of the test item in test water (approximately 7 μg/L). Thus, the 21-day NOEC of the test item was determined to be at least 6.5μg/L (nominal 20 μg/L). The 21-day LOEC was above the highest test concentration of 6.5 μg/L (nominal 20μg/L). The 21-day EC50 for the inhibition of the reproduction rate of the daphnids was also higher than 6.5 μg/L (nominal 20μg/L).