Oct-2-ene

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, available as unpublished report, acceptable with restrictions

Justification for type of information:

Read-across between the target substance Oct-2-ene (EC 203-894-2 / CAS 111-67-1) and source substance 1-Decene (EC 212-819-2/ CAS 872-05-9) is based upon the similarity of the chemical structures and their respective physico-chemical properties. The ECHA Read-Across Assessment Framework (RAAF) states that substances with qualitatively similar properties can form the basis of read-across in circumstances where the source and target substances share such similar characteristics.
Target substance Oct-2-ene and source substance 1-Decene are each mono-constituent linear olefins. Structurally, the differences between source and target substances include: 1) the length of the carbon chain (eight for the target substance, and ten for the source substance); and 2) the location of the carbon-carbon double bond (uniformly at the C2 position for the target substance, but uniformly at the C1 terminal position for the source substance).
The target and source substances both fit within the boundaries of chemical category of higher olefins. Studies conducted by the HOPA consortium on a large range of higher olefin category members (including 1-Decene) demonstrated sufficiently similar physico-chemical, environmental fate and toxicological properties to substantiate the basis for read-across; category members in the C6-C10 range may be moderately toxic to highly toxic to aquatic organisms and environmental toxicity is expected to be manifested as non-polar narcosis. Therefore Oct-2-ene (which falls within the C6-C10 range) is expected to behave similarly. Justification for inclusion of Oct-2-ene within the boundaries of the higher olefins category, and the relevance of each category member as an analogue substance to Oct-2-ene, is provided in Section 13 (Document name: “HOPA Higher Olefins CJD with Category Matrix Report [rev 1 Sept 2016]”; Document name: "ACC Product Stewardship Summary for Higher Olefins Category (2008-12-03)”).

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Test concentrations were renewed daily, and analysis made at on and off. Samples will be taken from midway between top, bottom and sides of the test vessel.

Vehicle:

yes

Details on test solutions:

A concentrated 10 mg/ml stock solution of dec-1-ene was made by adding 100mg in 10 ml DMF.

The required amount of the stock solution was then added to dechlorinated water and stirred for 48 hours in airtight sealed vessels with the minimum headspace to give a nominal loading of 0.064, 0.14, 0.31, 0.68 and 1.5 mg/l test substance. DWC and solvent control test solutions were also be stirred for 48 hours.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Fish were held on site for at least 12 days before use and were not used if treated within 7 days of test start or if more than 3% mortality with 48 hours of test start. Not fed for 24 hours prior to or during the test.

Test type:

other: daily renewal

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentration of 0.064, 0.14, 0.31, 0.68 and 1.5 mg/l test substance. Mean measured concentrations 0.0213, 0.05, 0.1049, 0.191, 0.2523mg/l. Measured concentrations fluctuated outside acceptable limits so results are reported based on nominal loading rates.

Details on test conditions:

Test conducted in glass vessels of at least 20 litres working volume to achieve a loading capacity of no more than 1 g of fish per litre of test solution. The test vessels will be sealed to limit any potential losses of the test substance. A photoperiod of 16 hours of light, followed by 8 hours of dark, with dawn and dusk transition periods.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

no mortality seen in blank or solvent control. One mortality in highest exposure group

Validity criteria fulfilled:

yes

Conclusions:

The 96 hour LC50 is >1.5mg/l..

Executive summary:

The toxicity of dec-1 -ene to fish was investigated in an OECD 203 test with Oncorhynchus mykiss (Brixham Environmental Laboratories, 2010). Due to the low solubility of the test substance the test used a solvent carrier. The test substance was mixed with the solvent before being added to the dilution water. It was then stirred for 48 hours under sealed conditions to maximise the exposure concentrations. The test was carried out with sealed test vessels and the solutions were renewed daily to minimise the loss of the test substance. Measured concentrations did not remain above the solubility (0.31mg/l) throughout the exposure period in any of the test concentrations, so results are reported based on nominal loading rates. After 96 hours there were no mortalities in the blank control or solvent control. A single mortality was seen in the highest exposure concentration. These results are interpreted as demonstrating that the 96 hour LC50 of dec-1 -ene is >1.5mg/l nominal.

Reference 2

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:

24.07.1995-14.06.1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP, guideline, available as an unpublished report, limitations in design but otherwise adequate for assessment

Justification for type of information:

Read-across between the target substance Oct-2-ene (EC 203-894-2 / CAS 111-67-1) and source substance Alkenes, C7-9-branched, C8-rich (EC 307-300-3 / CAS 97593-00-5) is based upon the similarity of the chemical structures and their respective physico-chemical properties. The ECHA Read-Across Assessment Framework (RAAF) states that substances with qualitatively similar properties can form the basis of read-across in circumstances where the source and target substances share such similar characteristics.
Target substance Oct-2-ene and source substance Alkenes, C7-9-branched, C8-rich are mono-constituent and UVCB olefins, respectively. Structurally, the differences between source and target substances include: 1) the length of the carbon chain (uniformly eight for the target substance, but variably seven to nine for the source substance); 2) the position of the carbon-carbon double bond (uniformly at the C2 position for the target substance, but variable for the source substance); and 3) the degree of branching (the target substance is a linear, non-branched structure, whereas branching in the source substance is variable).
The target and source substances both fit within the boundaries of chemical category of higher olefins. Studies conducted by the HOPA consortium on a large range of higher olefin category members (including Alkenes, C7-9-branched, C8-rich) demonstrated sufficiently similar physico-chemical, environmental fate and toxicological properties to substantiate the basis for read-across; category members in the C6-C10 range may be moderately toxic to highly toxic to aquatic organisms and environmental toxicity is expected to be manifested as non-polar narcosis. Therefore Oct-2-ene (which falls within the C6-C10 range) is expected to behave similarly. Justification for inclusion of Oct-2-ene within the boundaries of the higher olefins category, and the relevance of each category member as an analogue substance to Oct-2-ene, is provided in Section 13 (Document name: “HOPA Higher Olefins CJD with Category Matrix Report [rev 1 Sept 2016]”; Document name: "ACC Product Stewardship Summary for Higher Olefins Category (2008-12-03)”).

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Remarks:

no certificate

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No data reported

Analytical monitoring:

yes

Details on sampling:

Samples of WAFs taken on Day 0, 1, 2, and 3 and from old WAFs on Day 1 and at termination. Observations of fish performed on all replicate chambers at 3, 24, 48 72 and 96hr. pH, dissolved oxygen and temperature measured on new WAF on Days 0, 1, 2 and 3. Temperature, dissolved oxygen and pH measured on the old WAF on Days 1, 2 and 3 and at termination.

Vehicle:

no

Details on test solutions:

WAFs prepared by addition of the appropriate amount of TS to 19.5L of laboratory dilution water in a 20L size glass carboy. WAFs siphoned from the bottom of the vessel. Vessels sealed. Renewal treatment and control mixtures prepared daily. New WAF siphoned into the bottom of the bottle.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Obtained from Thomas Fish Company, Anderson, CA. Held in dilution water for at least 12 days prior to test and at 14±1°C for at least 7 days prior to testing. Fish were fed Salmon Starter, Salmon Crumble and/or Tetramin flake fish food. 72 fish. Age: 6 weeks at test initiation. Mean weigt - 0.272g, mean total length - 3.5cm. (smaller than the length specified in the protocol in order to maintain sufficient dissolved oxygen levels).

Test type:

other: semi-static, renewal, no headspace

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

174-178 CaCO3 mg/l

Test temperature:

mean test temperature = 15°C

pH:

7.0-8.7

Dissolved oxygen:

6.8-10.2 mg/l

Salinity:

not applicable

Nominal and measured concentrations:

Loading rates: 2.6mg/l, 4.3mg/l, 7.2mg/l, 12mg/l and 20mg/l. A control of lab dilution water also tested. Mean measured concentrations were 0.19, 0.36, 0.70, 1.2 and 2.5mg/l. Practical Quantitation Limit was 0.03mg/l.

Details on test conditions:

test chambers were 4L glass aspirator bottles. 4 fish per chamber. 3 replicate chambers per treatment. 16h light 8h dark. 578-580 Lux during full daylight periods for the study. Not fed for at least 24hrs prior to study start or during the study.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.87 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 0.79-0.96

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.36 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

based on the mean of the measured concentrations of the 'new' and 'old' WAFs for each treatment

Results with reference substance (positive control):

No data reported

Reported statistics and error estimates:

the 24, 48, 72 and 96h LC50 and LL50 values calculated using the Spearman-Karber Method.

Validity criteria fulfilled:

yes

Remarks:

Validity criteria met

Conclusions:

The reported 96h LC50 was 0.87mg/l.

Executive summary:

The reported 96h LC50 was 0.87mg/l. This study is GLP compliant and follows a standard guideline, with only minor deviations. It is considered reliable and suitable for use for this endpoint.

Description of key information

Two key studies were selected based on analog substances. Both key studies were semistatic acute fish toxicity tests on the effects of the analog substances on the freshwater rainbow trout (Oncorhynchus mykiss) following OECD Guideline 203. In the first key study, (Davi RA, 1996), the 96-h NOEC was reported as 0.36 mg/L and the 96-h LC50 was reported as 0.87 mg/L based on measured concentrations. In the second key study, (Brixham Environmental Laboratories, 2010), the 96-h LC50 was reported as > 1.5 mg/L based on nominal concentrations. The key value (96-h LC50 = 0.87 mg/L) was based upon the lower of the two values from the two key studies.                                                                                                                                                                                                           

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.87 mg/L