Reaction mass of 1-methyl-4-(4-methylpentyl)cyclohex-3-ene-1-carbaldehyde and 1-methyl-3-(4-methylpentyl)-3-cyclohexene-1-carboxaldehyde

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

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)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult items and mixtures, OECD series on testing and assessment number 23, December 14, 2000.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1-methyl-4-(4-methylpentyl)cyclohex-3-ene-1-carbaldehyde

EC Number:

266-314-7

EC Name:

1-methyl-4-(4-methylpentyl)cyclohex-3-ene-1-carbaldehyde

Cas Number:

66327-54-6

Molecular formula:

C14H24O

IUPAC Name:

1-methyl-4-(4-methylpentyl)cyclohex-3-ene-1-carbaldehyde

Constituent 2

Reference substance name:

1-methyl-3-(4-methylpentyl)-3-Cyclohexene-1-carboxaldehyde

Cas Number:

693252-50-5

Molecular formula:

C14H24O

IUPAC Name:

1-methyl-3-(4-methylpentyl)-3-Cyclohexene-1-carboxaldehyde

impurity 1

Reference substance name:

Cyclohexanecarboxaldehyde, 1-methyl-4-(4-methylpentyl)-, trans-

Cas Number:

76169-46-5

Molecular formula:

C14H26O

IUPAC Name:

Cyclohexanecarboxaldehyde, 1-methyl-4-(4-methylpentyl)-, trans-

impurity 2

Reference substance name:

Cyclohexanecarboxaldehyde, 1-methyl-4-(4-methylpentyl)-, cis-

Cas Number:

76169-45-4

Molecular formula:

C14H26O

IUPAC Name:

Cyclohexanecarboxaldehyde, 1-methyl-4-(4-methylpentyl)-, cis-

impurity 3

Reference substance name:

1-methyl-4-(4-methylpentylidene)cyclohexanecarbaldehyde

Molecular formula:

C14H24O

IUPAC Name:

1-methyl-4-(4-methylpentylidene)cyclohexanecarbaldehyde

impurity 4

Reference substance name:

1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

EC Number:

257-942-2

EC Name:

1-methyl-4-(4-methyl-3-pentenyl)cyclohex-3-ene-1-carbaldehyde

Cas Number:

52475-86-2

Molecular formula:

C14H22O

IUPAC Name:

1-Methyl-4-(4-methylpent-3-en-1-yl)cyclohex-3-ene-1-carbaldehyde

impurity 5

Reference substance name:

1-methyl-3-(4-methylpentylidene)cyclohexanecarbaldehyde

Molecular formula:

C12H24O

IUPAC Name:

1-methyl-3-(4-methylpentylidene)cyclohexanecarbaldehyde

Specific details on test material used for the study:

Test item: 205237/B
Identification: VERNALDEHYDE
Appearance: Clear colourless liquid (determined at Charles River Den Bosch)
Batch: SC00016844
Test item storage: In refrigerator (2-8°C) protected from light
Stable under storage conditions: until 26 November 2016 (expiry date)

Sampling and analysis

Details on sampling:

Samples for possible analysis were taken from all test concentrations and the control according to the schedule below.

Frequency: At the start and the end of both 24-hour renewal periods
Volume: 15 mL from the approximate centre of the test vessels
Storage: Samples were stored in a freezer until analysis.

At the end of both refreshment periods, samples were taken from one of the replicates of each
concentration.

Additionally, reserve samples of 15 mL were taken for possible analysis. If not used, these samples were stored in a freezer for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Test solutions

Vehicle:

not specified

Details on test solutions:

VERNALDEHYDE 4.6, 10, 22, 46 and 100% of a SS at 1 mg/L
Control Test medium without test item or other additives

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions.
Source: In-house laboratory culture with a known history.
Reason for selection: This system has been selected as an internationally accepted invertebrate species.
Validity of batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
Characteristics: For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old.

Breeding
Start of each batch: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
Temperature of medium: 18-22°C
Feeding: Daily, a suspension of fresh water algae.
Medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

Continuously in a temperature control vessel, beginning at the start of the test. The temperature continuously measured in a temperature control vessel was 20°C during the
test, and complied with the requirements as laid down in the study plan (18-22°C, constant within 2°C)

pH:

Measured at the start and the end of both renewal periods, for all concentrations and the control. pH: 6.0-8.5

Dissolved oxygen:

Measured at the start and the end of both renewal periods, for all concentrations and the control.

Nominal and measured concentrations:

Nominal concentrations: 4.6, 10, 22, 46 and 100% of a SS at 1 mg/L
Final Test 1 measured concentrations: Analysis of the samples taken at the start of the first renewal period showed measured concentrations of 0.0066, 0.0089, 0.017, 0.032 and 0.064 mg/L in 4.6, 10, 22, 46 and 100% of a SS at 1 mg/L, respectively.These concentrations remained stable during the 24-hour renewal period (91-101% of initial at the end of the renewal period), except for the 0.017 mg/L concentration that slightly decreased to 78% of initial. Analysis of the samples taken at the start of the second renewal period showed measured concentrations of 0.022, 0.047, 0.13, 0.20 and 0.46 mg/L in 4.6, 10, 22, 46 and 100% of a SS at 1 mg/L, respectively. These concentrations were a factor of 3-8 higher than the initial concentrations of the first renewal period and were more in line with the concentrations measured during the combined limit/range-finding test. The concentrations generally decreased during the 24-hour renewal period (52-82% of initial at the end of the renewal period). Given the discrepancy between the initial measured concentrations for the two renewal periods and the small responses observed in the control samples, it was decided to repeat the final test.

Final Test 2 measured concentrations:Analysis of the samples taken at the start of the first renewal period showed measured concentrations of 0.024, 0.055, 0.12, 0.26 and 0.63 mg/L in 4.6, 10, 22, 46 and 100% of a SS at 1 mg/L, respectively. These concentrations decreased to 32-75% of initial during the 24- hour renewal period. Analysis of the samples taken at the start of the second renewal period showed measured concentrations of 0.033, 0.073, 0.15, 0.33 and 0.76 mg/L in 4.6, 10, 22, 46 and 100% of a SS at 1 mg/L, respectively. These concentrations decreased to 64-86% of initial at the end of the renewal period. Given this result, the EC50 values were expressed in terms of the average exposure concentrations.

Details on test conditions:

Test procedure and conditions
Test duration: 48 hours
Test type: Semi-static with renewal of test solutions after 24 hours
Test vessels: 60 mL, all-glass. Since the test item was treated as volatile the study was performed in air-tight vessels.
Medium: Adjusted ISO medium
Number of daphnids: 20 per concentration
Loading: 5 per vessel containing 60 ml of test solution
Light: No light
Feeding: No feeding
Aeration: No aeration of the test solutions
Introduction of daphnids: Within 40 minutes after preparation of the test solutions.

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.17 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The 48h-EC50 was 0.17 mg/L based on average exposure concentrations (95% confidence interval between 0.099 and 0.25 mg/L).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 was 0.17 mg/L based on average exposure concentrations (95% confidence interval between 0.099 and 0.25 mg/L).