2,6-dimethyloct-7-en-2-ol

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP using linalool, a close chemical analogue of the test item with similar physico-chemical properties

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

mean fish length was 63 mm (57-72 mm).

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples of each test concentrations (approximately 150ml) were taken from the center of the test vessel before and after the 96 hour exposure period. Samples were kept at -18 degrees C to -22 degrees C until analysis.

Vehicle:

yes

Details on test solutions:

5g of test substance was mixed with 5g of dimethylformamide to produce the stock solution. Amounts of the stock solution were then added to the test water (dechlorinated tap water) to produce the desired concentration.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow Trout
- Source: P. Hohler / CH-4314 Zeiningen
- Length at study initiation: 63 mm based on 10 fishes ( range: 57-72 mm)
- Weight at study initiation: 2.12 g based on 10 fishes (range: 1.51-2.75 g)
- Feeding during test: none

ACCLIMATION
- Acclimation period: 34 days

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

180 mg CaCO3/l

Test temperature:

13 - 17 +/- 1 degrees C

pH:

At 0 h: 7.6 - 7.8
At 96 h: 8.3 - 8.4

Dissolved oxygen:

At 0 h: 104 - 110%
At 96h: 86 - 97%

Nominal and measured concentrations:

Nominal concentrations: 10, 18, 32, 58 and 100 mg/l
Measured concentrations: 3.5, 6.4, 10.3, 19.9 and 38.8 mg/l (arithmetic means of 0h and 96h measurements)

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 litre glass aquaria
- Material, size, headspace, fill volume: Aquaria filled with 15 litres
- Aeration: Gentle aeration during exposure
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 0.71 g/l

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water (carbon filtered)

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: Fluorescent light

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

27.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 22.9 - 33.7 mg/l

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

38.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

19.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

< 3.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

behaviour

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

27.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 22.9 - 33.7 mg/l

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

27.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 22.9 - 33.7 mg/l

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

27.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 22.9 - 33.7 mg/l

Details on results:

Behavioural observations: At the 2 lowest concentrations (3.5 and 6.4 mg/l) swimming was affected at 72 hours, in addition to this, doses of 10.3 mg/l at 48 hours and 19.9 at 24 hours also affected swimming behaviour. At 10.3 mg/l at 48 hours and 19.9 mg/l at 24 hours, there was loss of equilibrium. Respiratory function and pigmentation were observed at 19.9 mg/l at 24 hours.

All fish exposed at 38.8 mg/l were dead at the 24 hour observation time.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this study, the 96 hour LC50 of the read-across substance linalool is 27.8 mg/l.

Executive summary:

In a 96-h acute toxicity study, {Rainbow Trout,Oncorrhynchus mykiss} were exposed to linalool at measured concentrations of 3.5, 6.4, 10.3, 19.9 and 38.8 mg/l.  The 96-h LC₅₀was 27.8 mg/l. Sublethal effects were observed at the 2 lowest concentrations (3.5 and 6.4 mg/l): swimming was affected at 72 hours. In addition to this, exposure to 10.3 mg/l at 48 hours and 19.9 at 24 hours also affected swimming. At 10.3 mg/l at 48 hours and 19.9 mg/l at 24 hours, there was loss of equilibrium. Respiratory function and pigmentation were observed at 19.9 mg/l at 24 hours. 

All fish exposed at 38.8 mg/l died within 24 hours.

Results Synopsis

 

96h LC₅₀:  27.8 mg/l    

96h NOEL: < 3.5 mg/l                         

96h LC0: 19.9 mg/l

96h LC100: 38.8 mg/l

Description of key information

No reliable experimental data for the test item acute toxicity to fish are available. However acute toxicity to fish of the close chemical analogue linalool has been investigated: the results of this study are considered suitable for use in the assessment of the test item acute toxicity to fish. 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

27.8 mg/L

Additional information

Linalool is a close chemical analogue of the test item, with similar physico-chemical properties. Results of its testing for acute toxicity to fish are therefore deemed suitable to assess the acute toxicity of the test item to fish. The linalool acute toxicity test using rainbow trout gave a 96 hour LC50 value of 27.8 mg/l: it is reasonable to assume that the test item would produce a similar response in freshwater fish.