Reaction products from Nerolidol by dehydration

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:

September - November 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Although a GLP compliant study conducted to OECD guidelines, the higher loading WAFs appeared turbid indicating that phase separation may have not been complete prior to drawing off the WAF. Hence the study is considered reliable with restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(3Z,6Z)-3,7,11-trimethyldodeca-1,3,6,10-tetraene

Cas Number:

28973-99-1

Molecular formula:

C15H24

IUPAC Name:

(3Z,6Z)-3,7,11-trimethyldodeca-1,3,6,10-tetraene

Constituent 2

Reference substance name:

(E)-1-methyl-4-(6-methylhepta-2,5-dien-2-yl)cyclohex-1-ene

Cas Number:

25532-79-0

Molecular formula:

C15H24

IUPAC Name:

(E)-1-methyl-4-(6-methylhepta-2,5-dien-2-yl)cyclohex-1-ene

Constituent 3

Reference substance name:

(Z)-1-methyl-4-(6-methylhepta-2,5-dien-2-yl)

Cas Number:

29837-07-8

Molecular formula:

C15H24

IUPAC Name:

(Z)-1-methyl-4-(6-methylhepta-2,5-dien-2-yl)

Constituent 4

Reference substance name:

(E)-7,11-dimethyl-3-methylenedodeca-1,6,10-triene

EC Number:

242-582-0

EC Name:

(E)-7,11-dimethyl-3-methylenedodeca-1,6,10-triene

Cas Number:

18794-84-8

Molecular formula:

C15H24

IUPAC Name:

7,11-dimethyl-3-methylenedodeca-1,6,10-triene

Constituent 5

Reference substance name:

(E)-1-methyl-4-(6-methylhept-5-en-2-ylidene)

Cas Number:

53585-13-0

Molecular formula:

C15H24

IUPAC Name:

(E)-1-methyl-4-(6-methylhept-5-en-2-ylidene)

Constituent 6

Reference substance name:

(Z)-1-methyl-4-(6-methylhept-5-en-2-ylidene)

Cas Number:

13062-00-5

Molecular formula:

C15H24

IUPAC Name:

(Z)-1-methyl-4-(6-methylhept-5-en-2-ylidene)

Constituent 7

Reference substance name:

1-methyl-4-(6-methylhepta-1,5-dien-2-yl)

Cas Number:

869843-05-0

Molecular formula:

C15H24

IUPAC Name:

1-methyl-4-(6-methylhepta-1,5-dien-2-yl)

Constituent 8

Reference substance name:

(3Z,6E)-3,7,11-trimethyldodeca-1,3,6,10-tetraene

Cas Number:

26560-14-5

Molecular formula:

C15H24

IUPAC Name:

(3Z,6E)-3,7,11-trimethyldodeca-1,3,6,10-tetraene

Constituent 9

Reference substance name:

(Z)-7,11-dimethyl-3-methylenedodeca-1,6,10-triene

Cas Number:

28973-97-9

Molecular formula:

C15H24

IUPAC Name:

(Z)-7,11-dimethyl-3-methylenedodeca-1,6,10-triene

Constituent 10

Reference substance name:

1-methyl-4-(6-methylhept-5-en-2-yl)cyclohexa-1,4-diene

Cas Number:

72345-84-7

Molecular formula:

C15H24

IUPAC Name:

1-methyl-4-(6-methylhept-5-en-2-yl)cyclohexa-1,4-diene

Constituent 11

Reference substance name:

2,6,10-trimethyldodeca-2,6,9,11-tetraene

EC Number:

207-948-6

EC Name:

2,6,10-trimethyldodeca-2,6,9,11-tetraene

Cas Number:

502-61-4

Molecular formula:

C15H24

IUPAC Name:

3,7,11-trimethyldodeca-1,3,6,10-tetraene

Constituent 12

Reference substance name:

Likely sesquiterpene hydrocarbons

Cas Number:

n/a

Molecular formula:

C15H24

IUPAC Name:

Likely sesquiterpene hydrocarbons

Test material form:

liquid

Details on test material:

UVCB substance

Specific details on test material used for the study:

Batch number VE00446520
Expiry date 2017-12-27
Recommended storage Dry, well-ventilated, preferably full, hermetically sealed, ambient temperature, protected against light

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The test item was prepared as a water accomodated fraction (WAF).
The test vessels were filled up to the top with the test solutions. The daphnids were inserted with a small amount of dilution water (start of the exposure) or test solution (water renewal) by pipette. Thereafter, the test vessels were closed immediately with screw caps. There was no headspace in the test vessels.

Test solutions

Details on test solutions:

In view of the difficulties associated with the evaluation of aquatic toxicity of poorly water soluble and multi-component test items, a modification of the standard method for the preparation of aqueous media was performed. An approach endorsed by several important regulatory authorities in the EU and elsewhere (ECETOC 1996 and OECD 2000), is to expose the organisms to a Water Accommodated Fraction (WAF) of the test item in cases where the test item is a complex mixture (UVCB) and is poorly soluble in water and in the permitted solvents.
Five Water Accommodated Fractions (WAF) of the test item were prepared at loading levels of 0.111 - 0.333 - 1.00 - 3.00 - 9.00 mg/L in a geometric series with a separation factor of 3.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Less than 24 hours old daphnids from a healthy stock were used for the study. 20 daphnids, divided into 4 replicates, each with 5 daphnids, were used per WAF and control.
Acclimatization of the daphnids was not necessary, because the dilution water was equivalent to the culture medium.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

18 - 22 °C, constant within ± 1 °C

pH:

6-9

Nominal and measured concentrations:

Two non-GLP preliminary range finding tests were performed. The first one with three water accommodated fractions (WAF) with nominal loading levels of 1, 10 and 100 mg/L and the second one with three water accommodated fractions (WAF) with nominal loading levels of 0.01, 0.1 and 1 mg/L.
Based on the findings of the two range finding tests, the definitive test was conducted with five WAFs prepared at nominal loading levels of 0.111, 0.333, 1.00, 3.00 and 9.00 mg/L.

Details on test conditions:

Due to the volatility of the test item, the study was performed in a closed system without headspace, to reduce contact with air and losses of the test item by evaporation.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

4.08 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on nominal loading levels

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EL10

Effect conc.:

2.79 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on nominal loading levels

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EL10

Effect conc.:

1.78 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on nominal loading levels

Effect concentrations 4

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on nominal loading levels

Effect concentrations 5

Duration:

24 h

Dose descriptor:

EL100

Effect conc.:

> 9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on nominal loading levels

Effect concentrations 6

Duration:

48 h

Dose descriptor:

EL100

Effect conc.:

> 9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Based on nominal loading levels

Details on results:

The measured concentrations of the test item in fresh media at the start of the exposure (0 hours) were 0.0557, 0.174, 0.518, 2.61 and 7.79mg/L and at renewal (24 hours) were 0.0907, 0.270, 0.831, 2.72 and 8.41mg/L. The expected trend of increasing concentration with loading rates was observed. Furthermore, the measured concentrations in the fresh media (0 and 24 hours) were similar for a given loading level indicating consistent preparation of each WAF. The measured concentrations of the test item in fresh media at the start of the exposure and at renewal (0 and 24 hours) were in the range of 0.0557 to 8.41 mg/L. The measured concentrations in old media at renewal and at the end of the test (24 and 48 hours) were in the range of 30 to 83% of the initially measured concentrations. However, given that all efforts were made to minimise loss (sealed system) and maximise exposure (semi-static design) and given that WAFs were used because of the low aqueous solubility and complex nature of the test item, it is considered appropriate to express the effects based on loading levels.

At preparation, the WAFs were checked via laser beam (Tyndall effect) for undissolved test item (formation of emulsion). All WAFs showed a positive Tyndall effect. The 0.111 to 1.00 mg/L WAFs were visually clear throughout the exposure period. The 3.00 and 9.00 mg/L WAFs were turbid throughout the exposure period.

No immobility nor any adverse effects were observed at the loading levels of 0.111 to 0.333 mg/L. The % immobilization was 5, 30 and 90% at the loading levels of 1.00, 3.00 and 9.00 mg/L.

Results with reference substance (positive control):

The health of the daphnia culture and the overall quality of the test organism is monitored regularly by using the reference toxicant, potassium dichromate. Reference test performed from 2017-09-12 to 2017-09-13 under static conditions with a test duration of 24 hours gave an EC50 of 1.76 mg/L. The result was within the valid range for this reference item; 0.6 - 2.1mg/L (OECD202).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on the nominal loadings of the test item, the 48 hour-EL50 for Daphnia magna was 4.08 mg/L (95% confidence limits: 3.56 – 4.80 mg/L).

Executive summary:

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item BISABOLENE (batch number: VE00446520) were determined at the test facility according to OECD 202 (2004) from 2017-09-18 to 2017-09-21, with the definitive exposure phase from 2017-09-19 to 2017-09-21.

The study was conducted in a closed system (sealed glass flasks) without headspace, due to the volatility of the test item, to reduce contact with air and losses of the test item by evaporation. Due to the low aqueous solubility and complex nature of the test item for the purposes of the test, the test item was prepared as a water accommodated fraction (WAF). The study was performed under semi-static conditions over a period of 48 hours as a worst case exposure with five Water Accommodated Fractions (WAF) of the test item prepared individually at loading levels in the range of 0.111 to 9.00 mg/L in a geometric series with a separation factor of 3.

The 0.111 to 1.00 mg/L WAFs were visually clear throughout the exposure period. The 3.00 and 9.00 mg/L WAFs were turbid throughout the exposure period.

Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each WAF and the control.

The concentrations of the test item were analytically verified via GC-FID in fresh media at the start of the exposure and at renewal (0 and 24 hours) and in old media at renewal and at the end of the test (24 and 48 hours) in all loading levels and the control. Details of the analytical method are presented in section 14.

The measured concentrations of the test item in fresh media at the start of the exposure and at renewal (0 and 24 hours) were in the range of 0.0557 to 8.41 mg/L. The measured concentrations in old media at renewal and at the end of the test (24 and 48 hours) were in the range of 30 to 83% of the initially measured concentrations. The geometric mean measured concentrations are: 0.0513 – 0.162 – 0.560 – 2.17 – 5.24 mg/L. The analytical results are presented in Table 9.

Per definition of the WAF, all terms related to concentration levels have to be given as loading levels because partly dissolved compounds and mixtures cannot be related to concentrations. Therefore, the EL10 / 50 / 100-values given in Table 1 were based on the nominal loading levels.

The validity criteria of the test guideline were fulfilled.

Table 1: EL10-, EL50- (with 95% Confidence Limits) and EL100-Values

(based on the nominal loadings of the test item)

Effect levels	Test duration (hours)	Nominal loading of the test item (mg/L)
EL10 with 95% confidence limits	24	2.79 (CI: 0.44 - 7.98)
EL10 with 95% confidence limits	48	1.78 (CI: 1.29 - 2.29)
EL50 with 95% confidence limits	24	> 9.00 (CI: not applicable)
EL50 with 95% confidence limits	48	4.08 (CI: 3.56 - 4.80)
EL100	24	> 9.00
EL 100	48	> 9.00