1,1,3,3-tetramethylbutyl hydroperoxide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

March 2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: QSAR estimation with publicly available software; additionally, a fish embryo toxicity test has been conducted in support of this endpoint to ensure that the effects to fish have not been underestimated.

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Qualifier:

according to guideline

Guideline:

other: ECHA TGD, Ch. R.6 - QSARs and grouping of chemicals (Chapter R.6)

GLP compliance:

not specified

Test organisms (species):

Pimephales promelas

Total exposure duration:

96 h

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

18.679 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: QSAR calculation used for qualitative analysis

Validity criteria fulfilled:

not applicable

Conclusions:

The estimated 96hr LC50 to fish is 18.679 mg/L, which is higher than the estimated Daphnid 48hr LC50 of 11.525 mg/L and the Green Algae 96hr EC50 of 12.105 mg/L. The QSAR estimation of this substance is provided as additional supporting qualitative (trend) evidence that fish is the least sensitive species for this class of volatile liquid organic hydroperoxide. Additionally, a fish embryo toxicity test has been conducted in support of this endpoint to ensure that the effects to fish have not been underestimated.

Executive summary:

The estimated 96hr LC50 to fish is 18.679 mg/L, which is higher than the estimated Daphnid 48hr LC50 of 11.525 mg/L and the Green Algae 96hr EC50 of 12.105 mg/L. The QSAR estimation of this substance is provided as additional supporting qualitative (trend) evidence that fish is the least sensitive species for this class of volatile liquid organic hydroperoxide. Additionally, a fish embryo toxicity test has been conducted in support of this endpoint to ensure that the effects to fish have not been underestimated.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study was conducted to OECD 236 guideline. Study is non GLP and is considered reliable for use as a weight of evidence with supporting studies.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD 236

Deviations:

yes

Remarks:

Static setup, No chemical analysis, More embryos, Less test concentrations

GLP compliance:

no

Remarks:

Conducted in a GLP facility under non GLP

Analytical monitoring:

no

Details on sampling:

N/A

Vehicle:

no

Details on test solutions:

Preparation of the stock solution:
A stock solution in the standard manner was made at 100 mg/L. The test material (0.01979g) was weighed out in a 200 mL beaker. 200 mL of test
medium was then added using a 200 mL volumetric flask. The test substance was then agitated with a Teflon™ coated magnetic stirrer. A homogeneous solution resulted with a pH of 7.9. The stock was not pH adjusted as no pH shift from the control was observed.

Test concentrations and controls:
The test concentrations 1 and 10 mg/L were made by addition of the appropriate volume of the 100 mg/L stock solution and subsequent dilution with test medium. A positive control of 3, 4-dichloro aniline at a concentration of 4 mg/L was prepared as indicated by the test guideline. Due to the positive control being prepared with acetone, a solvent control was also required according to the test guideline. A solvent control of 100μl/L was therefore also prepared in test medium as well as the standard control containing test medium only.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Fertilized zebra fish wild type embryos were sourced at Wageningen UR Animal sciences group 6708 WG Wageningen the Netherlands. Fertilized embryos were between 2-3 hours old when added to the test solutions. This was confirmed by microscopic observation.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

The test medium Dutch Standard Water (DSW) was used for testing. DSW has a pH of 8.2, conductivity of 550-650µs/cm, and contains: 200 mg of CaCl2·2H2O, 180 mg of MgSO4·7H2O, 100 mg of NaHCO3 and 20 mg of KHCO3 per liter. The water was made by an automatic dosing system and was continually aerated before being used in the test.

Test temperature:

26ºC +/- 2ºC

pH:

8.2

Dissolved oxygen:

All media saturated before use

Nominal and measured concentrations:

1, 10 and 100 mg/L including a control in test medium were prepared. In addition a positive control of 3,4-dichloro aniline at a concentration of 4 mg/L was prepared as indicated by the test guideline. Due to the positive control being prepared with acetone, a solvent control was also required according to the test guideline. A solvent control of 100 µl/L was therefore also prepared. Test concentrations were not measured.

Details on test conditions:

The stock solution was checked for pH and adjusted with HCL or NaOH as required if pH deviated from that of the test medium. The received embryos were placed directly in beakers containing the appropriate test solution to maximize exposure prior to being added to the well plates. The well plates were then prepared. Each well was rinsed with the appropriate test solution and then discarded to reduce any adsorption effect that may take place. Each well was then filled for the second time with the appropriate test solution by transfer of 2-3 ml of the test solution using a pipette. 5 embryos per well were initially added using a glass pipette to the test plates. A total of 25 embryos were tested per test concentration. The test plate contained 15 embryos in control medium as an internal plate control. In addition a negative control plate containing 25 embryos and a positive control plate
containing 25 embryos was also tested. A solvent control replicate (solvent was used to prepare positive control) of 25 embryos was also included.
The control plate also contained and internal plate control of 15 embryos.

Observations were made at 0, 24 48, 72 and 96 hours. Coagulation of fertilized eggs, lack of somite formation, lack of detachment of the tail-bud from the yolk sac, and a lack of a heartbeat were scored were scored as primary indications of lethality. Any other clearly visible effects were also recorded.

Reference substance (positive control):

yes

Remarks:

3,4 Dichloroanaline

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

11.3 mg/L

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Nominal test concentration corrected for measured recovery of 47%

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

24 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Additional Secondary endpoint (other biological effects)
Reduce size observed in embryos at 10 mg/L. This is however not a guideline
endpoint and lethality only has been used for endpoint determination.

In this study the control had 80% survival and solvent control 100% survival after 96 hours. The positive control embryos were scored as 70% affected (mortality) according to the guideline criteria after 96 hours. The validity criteria can therefore be considered to have been met.
Due to no chemical analysis having been conducted, measured values form GLP study (in the parallels without algae) were used as a stability correction to avoid an underestimation of the measured toxicity.
The OECD 236 guideline was validated using wide range of chemicals for which, quality adult fish data was available and is therefore considered an acceptable alternative to the OECD 203 guideline.

Results with reference substance (positive control):

Exposure to the positive control (3,4 Dichloroanaline) resulted in a minimum of 30% mortality at the end of the test as required by the test guideline.

Reported statistics and error estimates:

Trimmed spearman-karber test was chosen to determine the LC50.

Sublethal observations / clinical signs:

Validity Criteria

The following validity criteria for the test were met:

 

·        The fertilization rate of the embryos in the batch tested was > 70%

·        The temperature was maintained at 26ºC +/- 2 ºC during the test

·        Exposure to the positive control met the guideline requirements

·        Hatching rate in the negative control was > 80% at the end of the test

·        Internal control success was >80%

 

 

The following validity criterion was not met:

 ·        The oxygen concentration in the control at the end of the test was not measured. Requirements and hence detrimental shortage of oxygen could not have occurred. In addition the test medium was continually aerated before use and the test solutions were replaced daily. This is therefore not expected to have negatively influenced the study. 

 

Validity criteria fulfilled:

yes

Conclusions:

The study can be considered a reliable indication of the toxicity of the test substance to fish embryos. The guideline was followed and critical quality
criteria were met and study design adapted for the test substance properties. Due to the study not being GLP it is reliable as a supporting evidence
only.

Executive summary:

A non GLP fish embryo study to the OECD236 guideline was conducted.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

Sept 21-29, 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP accredited and study guideline followed but no measured concentrations. Solution refreshment did however take place.

Justification for type of information:

See attached document in section 13.2 "Read Across justification - Acute fish endpoint"

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

no measured concentrations

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Principles of method if other than guideline:

- No measurement of concentrations

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Miscible with water

Analytical monitoring:

no

Details on sampling:

Not applicable.

Vehicle:

no

Test organisms (species):

Poecilia reticulata

Details on test organisms:

The test organism was Poecilia reticulata (guppy). In contravention to the study plan they were obtained from the IOB (Instituut voor Onderzoek van Bestrijdingsmiddelen), Wageningen, The Nether.ands. The fish were held in stock for 10 days in the Akzo Research Laboratories Arnhem, dept. CRL, in conformity with Standard Operating Procedures SOP CRL T9 and T42 to determine the acceptability of the batch. The size of the fish was approximately 2 cm.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

13 dH

Test temperature:

22 - 24 °C

pH:

Measured at 0, 48 and 96h (8.2 - 8.3 when freshly prepared and 7.9 - 8.2 48h old solutions).

Dissolved oxygen:

Measured at 48 and 96h (7.4 - 8.2 mg/L).

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: Control, 9, 16.7, 29.8, 54.2 and 97.2 mg/L.

Details on test conditions:

The temperature was kept between 22°C and 24°C and the light regime was 12 hours of ambient light per day. The duration of the test was 96 hours. As test vessels were used 2-L covered glass aquaria which contained 1 L of test medium. The loading of the test vessels was approximately 0.6 g biomass/L.
The surviving fish were counted daily and dead fish removed immediately upon observation. Measurements of the oxygen concentration were carried out on days 2 and 4, pH-measurements on days 0, 2 and 4. If a high mortality was observed on the other days, the oxygen concentration and pH were measured then also.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

56.9 mg/L

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL were 45.4 and 71.3 mg/L

Details on results:

No other effects such as deviations in the behaviour or appearance of the fish were observed.

Validity criteria fulfilled:

no

Remarks:

No evidence of concentrations stability during test

Conclusions:

The 96hr LC50 was calculated to be 56.9 mg/L

Executive summary:

The 96hr LC50 was calculated to be 56.9 mg/L

Description of key information

The 96h-LC50 for fish is 11.3 mg/L. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

11.3 mg/L

Additional information

An OECD 236 non-GLP screening study is available. The 96h-LC50 for zebrafish embryos is 24 mg/L (nom.). From the algae study it is known that the substance is not stable over time, therefore a correction to 47% (mean measured conc. in the 72h algae study) of the nominal concentration is made. The corrected 96h-LC50 for fish is then 11.3 mg/L.

This result is considered worst case and is supported by an acute fish result of an analogous substance (tert-butyl hydroperoxide, CAS 75 -91 -2) This substance has a 96h-LC50 for fish of 56.9 mg/L which is in the same order of magnitude as 1,1,3,3-Tetramethylbutyl hydroperoxide. Furthermore, QSAR estimates have been provided for both 5809-08-5 and 75-91-2 for qualitative supporting evidence.