2-Octen-1-ylsuccinic anhydride, mixture of cis and trans

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

key study

Study period:

December 20 to 24, 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

GLP Range finding test with no analytical monitoring. Study design followed Internal T.R. Wilbury Lab Protocol 1093-LU based on procedures of OECD Guidelines (1984) and the U.S. EPA (1993).

Justification for type of information:

A category approach will be used for the hazard assessment of several endpoints. The hypothesis for the category of C8-12 Alkenyl Succinic Anhydrides is that data can be read-across among members of the category because their properties and behaviours are similar, based on common functional groups and similar breakdown products, and based on a constant pattern in changing of the potency of properties of the various carbon chain lengths. These features are in accordance with Annex XI, Section 1.5, of Regulation EC No. 1907/2006.  Common functional groups are: a dihydro-2,5-Furandione (cyclic anhydride) ring, carbon chain of length 8 to 12 carbons, with or without branching alkyl groups, and a single carbon-carbon double bond in the carbon chain, location unspecified. There are no additional functional groups which would contribute incremental or different toxicity.
 
For each category member, the breakdown product is the dioic acid of the corresponding anhydride; these dioic acids also have common functional groups. A constant pattern may also be displayed in acute toxicity, dermal irritancy and biodegradation, with the lowest carbon chain length (C8) displaying the highest activity. Irritation, toxicity and degradation potential diminish with increasing carbon chain length. Read-across among the category members is substantiated by the common behaviour in physico-chemical and toxicity behaviours, as provided in the Chemical Category Report Format (CCRF) attached to the IUCLID file. It is adequate to fulfil the information requirements of Annex IX, to be the basis for classification and labelling decisions, and for risk assessment. 

Reason / purpose for cross-reference:

read-across source

Principles of method if other than guideline:

Internal T.R. Wilbury Test Lab Protocol 1093-LU based on procedures of OECD Guidelines (1984) and the U.S. EPA (1993).

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

Algae used for the test (Selenastrum capricornutum, UTEX 1648) were from a culture originally procured from the Culture Collection of algae at the Universityof Texas at Austin and delivered to T.R. Wilbury Laboratories on June 25, 1996. The culture was transferred to sterile enriched media identical to media used for this test and maintained at test conditions for at least 14 days before the definitive test. The subsample of algae used to inoculate media at the start of the definitive test came from an eight-day –old culture. Identification of the culture organisms was verified using an appropriate taxonomic key.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

Test temp. : 24 ± 1 °C; Temperatures measured during the conduct of the test ranged from 23.5 °C to 23.6 °C.

pH:

The pH was measured at the start (0 h) and end (96 h) of the test. The pH range of the control was 7.4 (initial pH) to 10.7 (final pH). The pH range of the treatment tests was 3.8 (initial pH in the 3,300 mg/L treatment) to 10.6 (final pH in the 0.3 mg/L , 3.3 mg/L and 33 mg/L treatments).

Nominal and measured concentrations:

Nominal concentrations of test substance were 0 (control), 0.3 mg/L, 3.3 mg/L, 33 mg/L, 330 mg/L and 3,300 mg/L.

Details on test conditions:

Each of the five Water Accommodated Fractions (WAFs) were prepared by combining the appropriate amount of test substance and dilution water in a mixing vessel equipped with a magnetic stirrer (the vortex extended from the surface approximately 25% of the way to the bottom of the mixing vessel) and stirring
these mixtures for approximately 20 hours, settling the mixtures for approximately four hours, and siphoning the water phase containing the WAF.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

110 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

calculated using cells/ml

Remarks on result:

other: 95% CI 33 to 330 mg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

160 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

calculated using average specific growth rate

Remarks on result:

other: 95% CI 33 to 330 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

33 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

using both cells/ml and average specific growth rate

Details on results:

Insoluble material was observed throughout the test in vessels containing 3,300 mg/L test media (test solution at this concentration was turbid). The algal population grew well, resulting in an average of 1,159,000 cells/ml in the control after 96 h. Water quality throughout the test was within acceptable limts. The range of the incubator temperatures was 23.5 to 23.6 °C. The two highest concentrations of test substance significantly lowered the pH of test media at the beginning of the test. At test initiation, the pH of the 330 mg/L test solution was 5.8, and the pH of the 3,300 mg/L test solution was 3.8.
No effects (sizes, differences, unusual cell shapes, colors, flocculations, adherence of cells to test containers, or aggregation of cells) were noted during the test. Exposure of freshwater alga to OS#18230U resulted in a 96 h median effective concentration (EC50) of 110 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using cells/ml, and 160 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using average specific growth rate. The 96 h no observed effect concentration (NOEC) was determined to be 33 mg/L using both the cells/ml and average specific growth rate.

Reported statistics and error estimates:

Statistical Methods: The average specific growth rate was calculated as the natural log of the number of cells/ml at 72 and 96 h of exposure, minus the natural log of the number of cells/ml at 0 h, divided by the hour of exposure. Results of the toxicity test were interpreted by standard statistical techniques. All calculations were performed using nominal concentrations of OS# 18230U with the number of cells/ml, then with the average specific growth rates.
The binomial/nonlinear interpolation method (Stephan, 1983) was used to calculate the 72 and 96 h EC50 values. The no observed effect concentration (NOEC) is the highest concentration of test substance that allowed at least 90% of control growth. This definition of the NOEC differs slightly from the TSCA test guidelines.

Exposure of the algae to the test substance resulted in the following growth after 96 hours:

Concentration (mg/L)	Average Cells/ml	Percent of Control
0 (control)	1,159,000	--
0.3	1,200,000	104
3.3	1,188,000	103
33	1,173,000	101
330	27,000	2
3,300	<10,000	<1

The determination of whether toxic effects were algistatic or algicidal was performed at the conclusion of the test. A 0.5 ml aliquot of test media from each 3,300 mg/L OS#18230U vessel was transferred to a flask containing 100 ml of fresh media and incubated under test conditions for seven days. Algae increased from <10,000 cell/ml to 230, 000 cells/ml, indicating that the effect of OS#18230U at the highest tested concentration was algistatic rather than algicidal.

Validity criteria fulfilled:

yes

Remarks:

Range of incubator temperatures within acceptable limits (23.5 to 23.6 °C) and test limit is 24 ± 1 °C , no abnormalities in algal culture noted.

Conclusions:

Exposure of freshwater alga to OS#18230U (CAS RN 26544-38-7) resulted in a 96 h median effective concentration (EC50) of 110 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using cells/ml, and 160 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using average specific growth rate. The 96 h no observed effect concentration (NOEC) was determined to be 33 mg/L using both the cells/ml and average specific growth rate. An additional algal toxicity test indicated that the effect of the test substance at the highest test concentration of 3,300 mg/L was algistatic rather than algicidal. Data can be read-across among members of the C8-12 Alkenyl Succinic Anhydrides Category, based on common functional groups, similar break-down products and potency patterns among carbon-chain length. This is adequate to fulfil the information requirements, to be the basis for classification and labelling decisions, and for risk assessment.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 20 to 24, 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

GLP Range finding test with no analytical monitoring. Study design followed Internal T.R. Wilbury Lab Protocol 1093-LU based on procedures of OECD Guidelines (1984) and the U.S. EPA (1993).

Principles of method if other than guideline:

Internal T.R. Wilbury Test Lab Protocol 1093-LU based on procedures of OECD Guidelines (1984) and the U.S. EPA (1993).

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

Algae used for the test (Selenastrum capricornutum, UTEX 1648) were from a culture originally procured from the Culture Collection of algae at the Universityof Texas at Austin and delivered to T.R. Wilbury Laboratories on June 25, 1996. The culture was transferred to sterile enriched media identical to media used for this test and maintained at test conditions for at least 14 days before the definitive test. The subsample of algae used to inoculate media at the start of the definitive test came from an eight-day –old culture. Identification of the culture organisms was verified using an appropriate taxonomic key.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

Test temp. : 24 ± 1 °C; Temperatures measured during the conduct of the test ranged from 23.5 °C to 23.6 °C.

pH:

The pH was measured at the start (0 h) and end (96 h) of the test. The pH range of the control was 7.4 (initial pH) to 10.7 (final pH). The pH range of the treatment tests was 3.8 (initial pH in the 3,300 mg/L treatment) to 10.6 (final pH in the 0.3 mg/L , 3.3 mg/L and 33 mg/L treatments).

Nominal and measured concentrations:

Nominal concentrations of test substance were 0 (control), 0.3 mg/L, 3.3 mg/L, 33 mg/L, 330 mg/L and 3,300 mg/L.

Details on test conditions:

Each of the five Water Accommodated Fractions (WAFs) were prepared by combining the appropriate amount of test substance and dilution water in a mixing vessel equipped with a magnetic stirrer (the vortex extended from the surface approximately 25% of the way to the bottom of the mixing vessel) and stirring
these mixtures for approximately 20 hours, settling the mixtures for approximately four hours, and siphoning the water phase containing the WAF.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

110 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

calculated using cells/ml

Remarks on result:

other: 95% CI 33 to 330 mg/L

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

160 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

calculated using average specific growth rate

Remarks on result:

other: 95% CI 33 to 330 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

33 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

using both cells/ml and average specific growth rate

Details on results:

Insoluble material was observed throughout the test in vessels containing 3,300 mg/L test media (test solution at this concentration was turbid). The algal population grew well, resulting in an average of 1,159,000 cells/ml in the control after 96 h. Water quality throughout the test was within acceptable limts. The range of the incubator temperatures was 23.5 to 23.6 °C. The two highest concentrations of test substance significantly lowered the pH of test media at the beginning of the test. At test initiation, the pH of the 330 mg/L test solution was 5.8, and the pH of the 3,300 mg/L test solution was 3.8.
No effects (sizes, differences, unusual cell shapes, colors, flocculations, adherence of cells to test containers, or aggregation of cells) were noted during the test. Exposure of freshwater alga to OS#18230U resulted in a 96 h median effective concentration (EC50) of 110 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using cells/ml, and 160 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using average specific growth rate. The 96 h no observed effect concentration (NOEC) was determined to be 33 mg/L using both the cells/ml and average specific growth rate.

Reported statistics and error estimates:

Statistical Methods: The average specific growth rate was calculated as the natural log of the number of cells/ml at 72 and 96 h of exposure, minus the natural log of the number of cells/ml at 0 h, divided by the hour of exposure. Results of the toxicity test were interpreted by standard statistical techniques. All calculations were performed using nominal concentrations of OS# 18230U with the number of cells/ml, then with the average specific growth rates.
The binomial/nonlinear interpolation method (Stephan, 1983) was used to calculate the 72 and 96 h EC50 values. The no observed effect concentration (NOEC) is the highest concentration of test substance that allowed at least 90% of control growth. This definition of the NOEC differs slightly from the TSCA test guidelines.

Exposure of the algae to the test substance resulted in the following growth after 96 hours:

Concentration (mg/L)	Average Cells/ml	Percent of Control
0 (control)	1,159,000	--
0.3	1,200,000	104
3.3	1,188,000	103
33	1,173,000	101
330	27,000	2
3,300	<10,000	<1

The determination of whether toxic effects were algistatic or algicidal was performed at the conclusion of the test. A 0.5 ml aliquot of test media from each 3,300 mg/L OS#18230U vessel was transferred to a flask containing 100 ml of fresh media and incubated under test conditions for seven days. Algae increased from <10,000 cell/ml to 230, 000 cells/ml, indicating that the effect of OS#18230U at the highest tested concentration was algistatic rather than algicidal.

Validity criteria fulfilled:

yes

Remarks:

Range of incubator temperatures within acceptable limits (23.5 to 23.6 °C) and test limit is 24 ± 1 °C , no abnormalities in algal culture noted.

Conclusions:

Exposure of freshwater alga to OS#18230U (CAS RN 26544-38-7) resulted in a 96 h median effective concentration (EC50) of 110 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using cells/ml, and 160 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using average specific growth rate. The 96 h no observed effect concentration (NOEC) was determined to be 33 mg/L using both the cells/ml and average specific growth rate. An additional algal toxicity test indicated that the effect of the test substance at the highest test concentration of 3,300 mg/L was algistatic rather than algicidal. Data can be read-across among members of the C8-12 Alkenyl Succinic Anhydrides Category, based on common functional groups, similar break-down products and potency patterns among carbon-chain length. This is adequate to fulfil the information requirements, to be the basis for classification and labelling decisions, and for risk assessment.

Description of key information

The toxicity of the water-accommodated fraction of tetrapropenyl succinic anhydride to the green alga Selenastrum capricornutum (now called Pseudokirchneriella subcapitata) was determined in a GLP-compliant study based on OECD and U.S. EPA guidelines, by read-across based on a grouping of substances (category approach).

Key value for chemical safety assessment

EC50 for freshwater algae:

110 mg/L

EC10 or NOEC for freshwater algae:

33 mg/L

Additional information

The study entitled “Acute Toxicity of the Water Accommodated Fraction (WAF) of OS# 18230U to the Freshwater Alga,Selenastrum capricornutum–Range Finding Test“ (Ward et al., T.R. Wilbury Laboratory, 1997), exposure of freshwater alga to tetrapropenyl succinic anhydride was identified as the key study, by read-across based on a grouping of substances (category approach). The study reported a 96 h median effective concentration (EC₅₀) of 110 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using cells/ml, and an EC₅₀ of 160 mg/L (95% confidence interval = 33 to 330 mg/L) when calculated using average specific growth rate. The 96 h NOEC was determined to be 33 mg/L using both the cells/ml and average specific growth rate. An additional algal toxicity test indicated that the effect of the substance at the highest test concentration of 3,300 mg/L tested was algistatic rather than algicidal.

A category approach is used for the hazard assessment of several endpoints. The hypothesis for the category of C8-12 Alkenyl Succinic Anhydrides is that data can be read-across among members of the category, because the properties and behaviours of category members are similar, based on common functional groups, similar breakdown products, and demonstration of a constant pattern associating the potency of properties with the various carbon chain lengths. Functional groups include a dihydro-2,5-furandione cyclic anhydride ring, a carbon chain of length 8 -12 carbons, and a single carbon-carbon double-bond within the carbon chain. The primary functional group associated with toxicity is the succinic anhydride moiety, which is quickly hydrolysed to form a butanedioic acid. A constant pattern may also be displayed in acute toxicity, dermal irritancy and biodegradation, with the lowest carbon chain length (C8) displaying the highest activity. Irritation, toxicity and degradation potential diminish with increasing carbon chain length. Read-across among the category members is substantiated by the common behaviour in physico-chemical and toxicity behaviours, as provided in the Chemical Category Report Format (CCRF) attached to the IUCLID file. It is adequate to fulfil the information requirements of Annex IX, to be the basis for classification and labelling decisions, and for risk assessment.