2-Oxepanone, polymer with 1,6-hexanediol

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Remarks:

The study on a similar substance serves as data source for the endpoint study record "TARGET - Short-term toxicity to aquatic invertebrates-Capa 2043" and the justification for read-across is provided there.

Adequacy of study:

key study

Study period:

05/2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

This study was carried out in accordance with OECD guideline no. 202. This study was also carried out in accordance with GLP standards with the exception of the analytical measurement of test concentrations, which was carried out at a non-GLP facility.

Justification for type of information:

Study serves as data source; read-across justification is found in Target record.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Test solution concentrations were only measured at the highest and lowest nominal concentrations, but these were shown to be within 20% of the nominal concentrations so this should be deemed acceptable.

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples of the lowest and highest test concentrations were taken at test initiation (0 hours) and test termination (48 hours) and were stored in darkness until analysis.

Vehicle:

no

Details on test solutions:

Test solutions were prepared on the day of test initiation by adding 400 mg of the test substance to 400 ml of aerated M7-media and stirring for 10 minutes. The solution was then membrane filtered (0.45 µm) and used as stock solution. The nominal concentration of the stock solution was 580 mg/L of test substance. Test concentrations were made by dilution of the stock solution with aerated M7-media.

Test organisms (species):

Daphnia magna

Details on test organisms:

Newly hatched Daphnia magna between 6 and 24 hours old were used in this test. Test organisms were taken from Toxicon's continuous culture of Daphnia magna. Cultures were fed with the green algae Pseudokirchneriella subcapitata.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

No information provided

Hardness:

250 ± 25 mg/L CaCO3

Test temperature:

21.5± 1°C

pH:

7.8 ± 0.2

Dissolved oxygen:

97-105% saturation

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations: 25, 50, 100, 200 and 400 mg/L.
Measured concentrations were within ± 20% of the nominal concentrations.

Details on test conditions:

See methods below

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

290 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The 48-hour EC50 was found to be 290 mg/L for 2-Oxepanone, polymer with 1,4-butanediol. The 48-hour NOEC was observed to be 100 mg/L.

Results with reference substance (positive control):

No information provided

Reported statistics and error estimates:

No information provided

Table 1: Nominal NOEC and EC50 values (mg/L) determined after 24 and 48 hours exposure to the test item 2-Oxepanone, polymer with 1,4-butanediol

24 h NOEC (mg/L)	48 h NOEC (mg/L)	24 h EC50 (mg/L)	48 h EC50 (mg/L)
100	100	330	290

Table 2: Results of TOC determination of saturated 2-Oxepanone, polymer with 1,4-butanediol solutions and the measured concentrations in test solutions.

Nominal test concentration	TOC (mg/L)	Capa 2043 concentration (mg/L)	Nominal value ± 20%
25 mg/L (0 h)	15	24.6	20-30
25 mg/L (48 h)	16	26.2	20-30
400 mg/L (0 h)	230	377	320-480
400 mg/L (48 h)	240	393	320-480

Validity criteria fulfilled:

yes

Conclusions:

With a 48-hour EC50 of 290 mg/L and a 48-hour NOEC of 100 mg/L, 2-Oxepanone, polymer with 1,4-butanediol can be regarded as non-toxic to Daphnia magna according to 67/548/EEC (KIFS 2005:7) and EC no 1272/2008 (CLP).

Executive summary:

A 48-hour toxicity test was carried out to determine the acute toxicity of 2-Oxepanone, polymer with 1,4-butanediol to Daphnia magna. The study was carried out according to OECD guideline no. 202. Test solutions were created by diluting a stock solution of the test substance in M7 media. Test organisms were incubated in glass petri dishes with 25 ml solution at 21.5 ± 1°C. Four replicates were used for both test and control solutions, with five test organisms in each.

The pH and oxygen saturation were measured at test initiation and test termination. Observations for immobilisation were made at 24 and 48 hours. Analytical measurements were not made at a GLP compliant facility and were only made at the lowest and highest concentrations. Although this can be considered a limitation in this study, it is not considered to have adversely affected the results as indications from the analysis were that test concentrations had remained within 20% of the nominal concentrations.

The results showed that the 48-hour EC50 was 290 mg/L, while the 48-hour NOEC was found to be 100 mg/L. An EC50 of greater than 100 mg/L indicates that 2-Oxepanone, polymer with 1,4-butanediol can be regarded as non-toxic to Daphnia magna according to 67/548/EEC (KIFS 2005:7) and EC no 1272/2008 (CLP).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Study period:

05/2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

This study was carried out in accordance with OECD guideline no. 202. This study was also carried out in accordance with GLP standards with the exception of the analytical measurement of test concentrations, which was carried out at a non-GLP facility.

Justification for type of information:

It is considered appropriate to address the short-term toxicity to aquatic invertebrates' data requirement for 2-oxepanone, polymer with 1,6-hexanediol by applying read-across from available experimental study data on 2-oxepanone, polymer with 1,4-butanediol. The source and target substances are low molecular weight polyester diols terminated by primary hydroxyl groups and are structurally similar in that they both contain 6-hydroxyhexanoic acid repeating units. The linking unit is 1,4-butanediol in 2-oxepanone, polymer with 1,4-butanediol and 1,6-hexanediol in 2-oxepanone, polymer with 1,6-hexanediol. The diols differ by two carbons in the aliphatic chain and are therefore sufficiently structurally similar to support a read-across approach. The source and target substances share similar physico-chemical properties in that both are liquids at room temperature and have similar water solubility and log Pow values. The substances are therefore sufficiently similar in terms of basic physico-chemical properties to support a read-across approach. A read-across justification document is attached in section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

290 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The 48-hour EC50 was found to be 290 mg/L for 2-Oxepanone, polymer with 1,4-butanediol. The 48-hour NOEC was observed to be 100 mg/L.

Results with reference substance (positive control):

No information provided

Reported statistics and error estimates:

No information provided

Table 1: Nominal NOEC and EC50 values (mg/L) determined after 24 and 48 hours exposure to the test item 2-Oxepanone, polymer with 1,4-butanediol

24 h NOEC (mg/L)	48 h NOEC (mg/L)	24 h EC50 (mg/L)	48 h EC50 (mg/L)
100	100	330	290

Table 2: Results of TOC determination of saturated 2-Oxepanone, polymer with 1,4-butanediol solutions and the measured concentrations in test solutions.

Nominal test concentration	TOC (mg/L)	Capa 2043 concentration (mg/L)	Nominal value ± 20%
25 mg/L (0 h)	15	24.6	20-30
25 mg/L (48 h)	16	26.2	20-30
400 mg/L (0 h)	230	377	320-480
400 mg/L (48 h)	240	393	320-480

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the target substance 2-oxepanone, polymer with 1,6-hexanediol to Daphnia magna is estimated to be a 48 h EC50 = 290 mg/L, based on read-across from a reliable study testing 2-oxepanone, polymer with 1,4-butanediol.

Executive summary:

A 48-hour toxicity test was carried out to determine the acute toxicity of 2-Oxepanone, polymer with 1,4-butanediol to Daphnia magna. The study was carried out according to OECD guideline no. 202. Test solutions were created by diluting a stock solution of the test substance in M7 media. Test organisms were incubated in glass petri dishes with 25 ml solution at 21.5 ± 1°C. Four replicates were used for both test and control solutions, with five test organisms in each. The pH and oxygen saturation were measured at test initiation and test termination. Observations for immobilisation were made at 24 and 48 hours. Analytical measurements were not made at a GLP compliant facility and were only made at the lowest and highest concentrations. Although this can be considered a limitation in this study, it is not considered to have adversely affected the results as indications from the analysis were that test concentrations had remained within 20% of the nominal concentrations. The results showed that the 48-hour EC50 was 290 mg/L, while the 48-hour NOEC was found to be 100 mg/L. An EC50 of greater than 100 mg/L indicates that 2-Oxepanone, polymer with 1,4-butanediol can be regarded as non-toxic to Daphnia magna according to 67/548/EEC (KIFS 2005:7) and EC no 1272/2008 (CLP).

The basic physico-chemical properties and chemical structural of the source substance 2-oxepanone, polymer with 1,4-butanediol and the target substance 2-oxepanone, polymer with 1,6-hexanediol are considered to be sufficiently similar to support a read-across approach. Therefore, the target substance 2-oxepanone, polymer with 1,6-hexanediol is also concluded to have a 48-h EC50 value of 290 mg/L.      

Description of key information

The acute toxicity of the target substance 2-oxepanone, polymer with 1,6-hexanediol to Daphnia magna is estimated to be a 48 h EC50 = 290 mg/L, based on read-across from a reliable study testing 2-oxepanone, polymer with 1,4-butanediol.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

290 mg/L

Additional information

A 48-hour toxicity test was carried out to determine the acute toxicity of the read-across substance 2-Oxepanone, polymer with 1,4-butanediol to Daphnia magna. The study was carried out according to OECD guideline no. 202. Test solutions were created by diluting a stock solution of the test substance in M7 media. Test organisms were incubated in glass petri dishes with 25 ml solution at 21.5 ± 1 °C. Four replicates were used for both test and control solutions, with five test organisms in each. The pH and oxygen saturation were measured at test initiation and test termination. Observations for immobilisation were made at 24 and 48 hours. Analytical measurements were not made at a GLP compliant facility and were only made at the lowest and highest concentrations. Although this can be considered a limitation in this study, it is not considered to have adversely affected the results as indications from the analysis were that test concentrations had remained within 20% of the nominal concentrations. The results showed that the 48-hour EC50 was 290 mg/L, while the 48-hour NOEC was found to be 100 mg/L. An EC50 of greater than 100 mg/L indicates that 2-Oxepanone, polymer with 1,4-butanediol can be regarded as non-toxic to Daphnia magna according to 67/548/EEC (KIFS 2005:7) and EC no 1272/2008 (CLP).

The basic physico-chemical properties and chemical structural of the source substance 2-oxepanone, polymer with 1,4-butanediol and the target substance 2-oxepanone, polymer with 1,6-hexanediol are considered to be sufficiently similar to support a read-across approach. Therefore, the target substance 2-oxepanone, polymer with 1,6-hexanediol is also concluded to have a 48-h EC50 value of 290 mg/L.