[No public or meaningful name is available]

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:

02 June 1994 - 01 April 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Water accomodated fractions of SBP 80:95 LNH were produced by stirring water (25 h) appropriate to the test organisms and SBP 80:95 LNH, leaving the contents of the vessel to stand for at least 1hour and running off the aqueous phase for use as the test medium. This method of media preparation is appropriate to test materials that are mixtures containing poorly soluble components.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Source (laboratory, culture collection): derived from semi-axenic laboratory culture of the American Type Culture Collection, Maryland, Ohio, USA.
- Method of cultivation: maintained on agar plates (plates prepared by adding 1.5% mass/volume agar to liquid medium prior to autoclaving), used to inoculate liquid cultures which, while in exponential phase growth, are in turn used to inoculate test solutions. Maintenance: continuous illumination at nominally 18-22°C. Cultures are renewed aprrox. every two weeks. Cultures in liquid medium are initiated with cells transferred on a sterile loop from an agar plate. The culture are grown as 100 mL batch cultures in 250 mL Erlenmeyer flasks for up to 4 days. Cultures are maintained at 21-25°C under constant illumination.

Inoculation of test cultures: The culture inoculum volume introduced at the start of the test is sufficient to give an initial concentration of 5000 cells/mL in the vessels. The cell concentration of an exponentially growing starter culture is measured using a Coulter Counter or Coulter Multisizer and the and the required inoculum volume calculated. All flasks used for a particular test are inoculated from the same starter culture.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24 - 26°C

pH:

7.3 - 8.4 at test initiation and 8.8 - 9.4 at test termination

Nominal and measured concentrations:

1.0, 3.0, 10, 30, 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: 300 mL conical flasks that were completely filled with test solution.
- Initial cells density: 5000 cells/mL
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 7

OTHER TEST CONDITIONS
- Photoperiod: continuous
- Light intensity and quality: at ~3000 lux

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

>= 30 - <= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL0

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EL0

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Details on results:

see "remarks on results"

Reported statistics and error estimates:

EL50 values estimated by visual inspection of data without using interpolative statistical techniques. This is most appropriate for test substances that are complex mixtures. Williams test used to determine NOELs.

Tab.: Growth of Raphidocelis cultures exposed to WAFs of SBP 80:95 LNH:

Loading rate used to produce WAF mg/L	Cell concentration (million cells/mL)				Mean cell concentration (million cells/mL)				Calculated mean area (A) under the growth curve (A/1 million)			Mean reduction in A relative to controls (%)			Mean calculated average specific growth rate (µ)			Mean reduction in µ relative to controls (%)
	0h	24h	48h	72h	0h	24h	48h	72h	0-24h	0-48h	0-72h	0-24h	0-48h	0-72h	0-24h	0-48h	0-72h	0-24h	0-48h	0-72h
Controls	0.005	0.0092	0.057	0.15	0.005	0.01	0.054	0.13	0.069	0.73	2.9	-	-	-	0.033	0.051	0.046	-	-	-
	0.005	0.0095	0.054	0.12
	0.005	0.011	0.065	0.14
	0.005	0.012	0.049	0.13
	0.004	0.011	0.054	0.11
	0.005	0.01	0.057	0.14
1	0.004	0.0089	0.054	0.1	0.0043	0.001	0.053	0.11	0.066	0.71	2.6	5.0	2.8	9.1	0.034	0.052	0.045	-2.2	-1.9	2.3
	0.004	0.011	0.062	0.13
	0.004	0.0093	0.043	0.11
3	0.005	0.01	0.048	0.15	0.0044	0.001	0.047	0.14	0.063	0.64	2.8	9.5	13	3.6	0.033	0.050	0.048	2.2	3	-3
	0.005	0.0091	0.05	0.14
	0.004	0.0096	0.044	0.12
10	0.005	0.0088	0.051	0.14	0.0045	0.0083	0.038	0.095	0.045	0.49	2.0	35	33	31	0.025	0.043	0.040	26	15	14
	0.004	0.0096	0.04	0.11
	0.005	0.0067	0.023	0.034
30	0.004	0.0057	0.025	0.049	0.0043	0.0057	0.025	0.052	0.016	0.28	1.1	76	62	62	0.012	0.036	0.035	65	29	26
	0.005	0.0053	0.024	0.055
	0.004	0.006	0.024	0.051
100	0.005	0.006	0.0082	0.025	0.0045	0.0061	0.013	0.024	0.019	0.14	0.47	72	81	84	0.013	0.021	0.023	62	59	51
	0.005	0.0064	0.015	0.024
	0.004	0.0059	0.016	0.022

There was a change in pH greater than the target for change. This was aresult of the growth of the cultures and could not be avoided. The temperature was slightly higher than the target range of 21-25 Deg C. These deviations were not sufficient to invalidate the study.

Validity criteria fulfilled:

yes

Conclusions:

The toxicity, as measured by biomass and growth rate to green alga (Pseudokirchneriella subcapitata formerly Raphidocelis subcapitata) was evaluated in freshwater. Under the conditions of this study, the test substance, hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane, produced a significant effect on biomass at 10 to 30 mg/L, and on growth rate ate 30 to 100 mg/L, based on nominal loading of the test substance in water. NOELs for growth and biomass were determined to be 3 mg/L.

Executive summary:

The toxicity, as measured by biomass and growth rate to green alga (Pseudokirchneriella subcapitata formerly Raphidocelis subcapitata) was evaluated in freshwater. Under the conditions of this study, the test substance, hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% hexane, produced a significant effect on biomass at 10 to 30 mg/L, and on growth rate ate 30 to 100 mg/L, based on nominal loading of the test substance in water. NOELs for growth and biomass were determined to be 3 mg/L.

Reference 2

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:

25 January - 2 August 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

The justification for read across is provided as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Water accomodated fractions (WAFs) were prepared. The test substance was added to test medium and stirred for 52 hrs. Vessels had minimal headspace to prevent volitilization. Contents of the vessels were then allowed to settle for 1-2 hrs. Aqueous phase was used for the test. Controls were subject to the same regime

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: ATCC 22662
- Source (laboratory, culture collection): American Type Culture Collection, Maryland, Ohio, U.S.A.
- Method of cultivation: Axenic stock cultures are maintained on agar plates. These are used to inoculate liquid cultures which, while in exponential phase growth, are in turn used to inoculate test media.Cells are cultured in as 100 mL batches in 240 mL Erlenmeyer flasks for up to 4 days. They are maintained at nominally 21-25°C in an orbital incubator under constant illumination. Algal cultures are streaked onto agara plates and maintained under continuous illumination in a vertical incubator. Cultures are renewed approximately every fortnight.


ACCLIMATION
- Culturing media and conditions (same as test or not): yes

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23.7 - 24.2°C

pH:

8.3 - 9.1

Nominal and measured concentrations:

0, 1, 3, 10, 30, 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: Erlenmeyer flasks, 287 mL, no headspace
- Initial cells density: 5000 cells/mL (in 3 test flasks and 6 control flasks)
- Control end cells density: 0.095 million cells/mL
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 7


GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Nutrient medium was prepared by dissolving Analar grade salts in reverse osmosis filtered water
- Total organic carbon: 2.5 mg/L
- Chlorine: 0.02 mg/L Cl2
- Alkalinity: 257 mg/L CaCO3
- Ca/mg ratio: 48:1
- Conductivity: 496 µs/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: 6 months


OTHER TEST CONDITIONS
- Photoperiod: constant illumination
- Light intensity and quality: approx. 5200 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : growth rate
- Determination of cell concentrations: electronic particle counter

TEST CONCENTRATIONS
- Range finding study
- Results used to determine the conditions for the definitive study: 72h EL50: 1 -10 mg/L

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: time: 0-24 h

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: time: 0-24 h

Duration:

24 h

Dose descriptor:

NOELR

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: time: 0-24 h

Duration:

24 h

Dose descriptor:

NOELR

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: time: 0-24 h

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: time: 0-48 h

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: time: 0-48 h

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: time: 0-48 h

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: time: 0-48 h

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: time: 0-24 h

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

>= 10 - <= 30 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: time: 0-24 h

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: time: 0-24 h

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: time: 0-72 h

Reported statistics and error estimates:

Loading rates used to produce WAF that cause a 50% effect (LL50) were estimated by visual inspection of the data. This was considered more appropriate than an interpolative statistical analysis when considering toxicity data based on WAF of test substances that are mixtures containing components of low solubility.

Table: Growth of Raphidocelis subcapitata cultures exposed to WAF of SBP 100/140

Loading rate used to produce WAF	Cell concentration (million cells/mL)				Mean cell concentration (million cells/mL)				Calculated mean area (A) under growth curve (+ 1 million)			Mean reduction in A relative to controls (%)			Mean calculated average specific growth rate (u)			Mean reduction in u relative to controls (%)
	0h	24h	48h	72h	0h	24h	48h	72h	0-24h	0-48h	0-72h	0-24h	0-48h	0-72h	0-24h	0-48h	0-72h	0-24h	0-48h	0-72h
Control	0.0049	0.011	0.04	0.087	0.0054	0.013	0.043	0.095	0.086	0.62	2.1				0.035	0.043	0.04
	0.0058	0.011	0.042	0.092
	0.0049	0.013	0.042	0.095
	0.0056	0.014	0.043	0.1
	0.0055	0.014	0.045	0.097
	0.0057	0.013	0.044	0.097
1	0.0047	0.01	0.036	0.061	0.0048	0.011	0.043	0.078	0.07	0.6	1.9	18	2.9	9.8	0.033	0.045	0.038	5.5	-5.6	3.7
	0.0048	0.011	0.047	0.086
	0.005	0.011	0.046	0.086
3	0.0048	0.012	0.042	0.083	0.0049	0.012	0.042	0.09	0.09	0.62	2.1	-4.6	-0.73	2.6	0.039	0.045	0.04	-10	-3.8	-1.3
	0.0048	0.013	0.041	0.085
	0.0051	0.012	0.043	0.1
10	0.005	0.0094	0.038	0.11	0.0051	0.0098	0.039	0.12	0.056	0.52	2.3	34	16	-8.4	0.027	0.042	0.044	22	2.2	-10
	0.005	0.01	0.034	0.13
	0.0053	0.01	0.044	0.13
30	0.0052	0.0065	0.009	0.0092	0.0049	0.0058	0.009	0.009	0.011	0.071	0.17	87	89	92	0.007	0.013	0.0084	80	71	79
	0.0044	0.0053	0.0099	0.0099
	0.0053	0.0057	0.0082	0.008
100	0.0051	0.0057	0.0081	0.011	0.0051	0.0054	0.006	0.0077	0.0037	0.018	0.059	96	97	97	0.0025	0.0025	0.0048	93	94	88
	0.0053	0.0052	0.0054	0.0073
	0.0049	0.0053	0.0044	0.0046

Validity criteria fulfilled:

yes

Conclusions:

This study examined the toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to algae. The algae Raphidocelis subcapitata was exposed to loading rates of 0, 1, 3, 10, 30, or 100 mg/L of test substance for 72 hrs. The test solution was not renewed and cell counts were taken at 0, 24, 48, and 72 hrs after start of exposure. No analytical monitoring was done as studies of closely related products has shown that the solubility of the test substance is likely to be less than the determination limit of the analytical equipment. The 72-hr EbL50 for algae was 10 -30 mg/L (WAF), and the 72-hr ErL50 was 10-30 mg/L (WAF). The 72-hr NOEL value for biomass and growth rate was 10 mg/L.

Executive summary:

This study examined the toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to algae. The algae Raphidocelis subcapitata was exposed to loading rates of 0, 1, 3, 10, 30, or 100 mg/L of test substance for 72 hrs. The test solution was not renewed and cell counts were taken at 0, 24, 48, and 72 hrs after start of exposure. No analytical monitoring was done as studies of closely related products has shown that the solubility of the test substance is likely to be less than the determination limit of the analytical equipment. The 72-hr EbL50 for algae was 10 -30 mg/L (WAF), and the 72-hr ErL50 was 10-30 mg/L (WAF). The 72-hr NOEL value for biomass and growth rate was 10 mg/L.

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of 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: Adopted according to OECD SIDS (public available peer reviewed source) and respective study summary. The original source is not available and has not been reviewed.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

GLP compliance:

yes

Analytical monitoring:

yes

Details on test solutions:

Individual treatment concentrations were prepared as water accommodated fractions (WAF). Control and dilution water were laboratory prepared algal nutrient medium. Test substance was mixed with dilution water in covered vessels for ~22 hours, and the mixtures were allowed to settle for ~21 hours prior to drawing off the aqueous phase for testing.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Source (laboratory, culture collection): Algal cells obtained from testing laboratory cultures. Original algal cultures obtained from University of Texas, Austin, Texas

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

23 - 26°C

pH:

7.7-8.1 at test initiation
8.1-10.1 at 72 hours
8.0-10.7 at test termination

Nominal and measured concentrations:

0, 3.1, 6.3, 13, 25, 50, and 100 mg/L (nominal)
Measured concentrations of the 0 and 96 hour samples ranged from 0.50 to 11% of nominal.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: 300 mL bottles that were completely filled with test solution
- Initial cells density: 5000 cells/mL
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): 6

OTHER TEST CONDITIONS
- Photoperiod: 24 h
- Light intensity and quality: 4010-4730 lux

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

12 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Remarks on result:

other: 95% Cl 9.8 to 16

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

29 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Remarks on result:

other: 95% Cl 18 to 35

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

6.3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

6.3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

EL50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

other: cell density

Remarks on result:

other: 95% Cl 11 to 14

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

6.3 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accomodated Fraction (WAF)

Basis for effect:

other: cell density

Reported statistics and error estimates:

Linear interpolation (ICp) for EL50s. ANOVA and Dunnett’s test for NOELs.

The pH increased by more than one unit after 72 hours as a result of good algal growth in the cultures. This increase was not sufficient to invalidate the study.

Tab: Inhbition in %

Nominal concentration (mg/L)	% inhibition (72 h)	% inhibition (96 h)
0	-	-
3.1	22	2.4
6.3	6.3	7.7
13	54	53
25	86	89
50	100	100
100	94	90

Tab.: Cell density in cells/mL

Nominal concentration (mg/L)	concentration (72 h) (cells/mL)	concentration (96 h) (cells/mL)
0	43.4 x E4	9.2 x E5
3.1	34.0 x E4	9.0 x E5
6.3	40.6 x E4	8.5 x E5
13	20.0 x E4	4.3 x E5
25	6.13 x E4	1.1 x E5
50	0	0
100	27.4 x E3	8.8 x E5

Validity criteria fulfilled:

not specified

Conclusions:

The toxicity, as measured by biomass and growth rate to the green alga (Pseudokirchneriella subcapitata formerly Raphidocelis subcapitata) was evaluated in freshwater. Under the conditions of this study, the test substance, hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics, produced a significant effect on biomass at 13 mg/L, based on nominal loading of the test substance in water.

Executive summary:

The toxicity, as measured by biomass and growth rate to the green alga (Pseudokirchneriella subcapitata formerly Raphidocelis subcapitata) was evaluated in freshwater. Under the conditions of this study, the test substance, hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics, produced a significant effect on biomass at 13 mg/L, based on nominal loading of the test substance in water.

Description of key information

There is no data available for this substance. However, key and supporting data is available for structural analogues Hydrocarbons C7-C9, n-alkanes, isoalkanes, cyclics; Hydrocarbons C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane. The data is read across to this substance based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13. Key information is summarised below:

In one study. the test substance, hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics, produced a significant effect on green algae biomass at 13 mg/L, based on nominal loading of the test substance in water.

In a second study, the test substance hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics exhibited a 72-hr EbL50 for algae of 10 -30 mg/L (WAF), and the 72-hr ErL50 of 10-30 mg/L (WAF). The 72-hr NOEL value for algal biomass and growth rate was 10 mg/L.

The test substance, hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane, produced a significant effect on algal biomass at 10 to 30 mg/L, and on growth rate at 30 to 100 mg/L, based on nominal loading of the test substance in water. NOELs for growth and biomass were determined to be 3 mg/L.

Additional information

The substances are poorly soluble in water, most of the studies are performed using Water accommodated fractions (WAFs) and all the results are based on nominal loadings. Thus, the values indicated below as NOECs are actually NOELRs (No observed effect loading rates). No study could lead to the calculation of EL₅₀.

The study from Shell (2000) measured the toxicity of , hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics, to the green alga (Pseudokirchneriella subcapitata formerly Raphidocelis subcapitata) based on biomass and growth rate. Under the conditions of this study, the test substance, hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics, produced a significant effect on biomass at 13 mg/L, based on nominal loading of the test substance in water.

 

The study from Shell (1995a) examined the toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to algae. The algae Raphidocelis subcapitata was exposed to loading rates of 0, 1, 3, 10, 30, or 100 mg/L of test substance for 72 hrs. The test solution was not renewed and cell counts were taken at 0, 24, 48, and 72 hrs after start of exposure. No analytical monitoring was done as studies of closely related products has shown that the solubility of the test substance is likely to be less than the determination limit of the analytical equipment. The 72-hr EbL50 for algae was 10 -30 mg/L (WAF), and the 72-hr ErL50 was 10-30 mg/L (WAF). The 72-hr NOEL value for biomass and growth rate was 10 mg/L.

 

The study from Shell (1995b) examined the toxicity of hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% hexane, to green alga (Pseudokirchneriella subcapitata formerly Raphidocelis subcapitata) based on effects to biomass and growth rate. Under the conditions of this study, the test substance, , produced a significant effect on biomass at 10 to 30 mg/L, and on growth rate ate 30 to 100 mg/L, based on nominal loading of the test substance in water. NOELs for growth and biomass were determined to be 3 mg/L.