Linseed oil, oxidized

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:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

September 28, 1992 - October 10, 1992

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: GLP study performed according to OECD 201 (1984) and EC method C.3, with the single deviation of no analytical measurements. Considered not reliable as effects are observed at levels exceeding the Sw. Exposure solutions were opaque and inhomogenous

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

Also performed according to EEC method C.3.

Deviations:

yes

Remarks:

No analytical confirmation of concentrations of test compound in test solutions.

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock suspension of 1.054 g/L was prepared by dispersing the test substance in deionised water of 70°C with an ultrasonic processor for 10 min. Finally the solution was mixed for another 15 minutes at 70°C. The test solutions were prepared by adding a known volume of stock solution to mineral test medium.
- Eluate: not relevant
- Differential loading: not relevant
- Controls: controls were untreated
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): not relevant
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)):not relevant
- Evidence of undissolved material (e.g. precipitate, surface film, etc): No observations on the appearance of the stock and test solutions were reported. The mean extinction values at 0 h, where all flasks contained the same number of algae (10000 cells) were 0.003, 0.014, 0.034, 0.115, 0.234 and 0.680 at 0, 1, 3, 9, 27 and 81 mg/L, indicating that the test solutions were opaque due to the presence of the test substance, which is an oil.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Selenastrum capricornutum
- Strain: ATCC 22662
- Source (laboratory, culture collection): American Type Culture Collection, Rockville, Maryland, USA
- Age of inoculum (at test initiation): The strain was maintained at the test laboratory for about two years prior to use in the test.
- Method of cultivation: The strain was maintained on sloped agar tubes with mineral salt medium at 4°C. The stock culture was regularly transferred to fresh mineral medium to act as inoculums. The stock culture from the test was inoculated with algae from a sloped agar tube and an exponentially growing culture was obtained, of which the cell density was determined. A dilution of this exponentially growing culture was prepared from which the test flasks were inoculated with 10000 cells.

ACCLIMATION
- Acclimation period: no data
- Culturing media and conditions (same as test or not): no
- Any deformed or abnormal cells observed: no data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

no data

Test temperature:

Overall range during the test about 23-24°C

pH:

Overall range during the test 8.2-9.5

Dissolved oxygen:

Not measured (not relevant)

Salinity:

Not relevant

Nominal and measured concentrations:

Nominal concentrations were 0, 1, 3, 9, 27 and 81 mg/L.
The nominal concentrations were not verified by chemical analysis.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL Erlenmeyer flask
- Type (delete if not applicable): closed with cotton-wool stoppers
- Material, size, headspace, fill volume: fill volume 40 mL
- Aeration: no
- Initial cells density: 10000 cells/mL
- Control end cells density: 1775585 cells/mL after 72 hours
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes, except the NaHCO3 concentration was 150 mg/L instead of 50 mg/L.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: the deionised water used for the mineral standard medium was produced from tap water in a water purification system.
- Total organic carbon: the deionised water used for the mineral standard medium had TOC <2 mg/L
- Particulate matter: no data
- Metals: the deionised water used for the mineral standard medium had copper content <0.01 mg/L
- Pesticides: no data
- Chlorine: no data
- Alkalinity: no data
- Ca/mg ratio: no data
- Conductivity: the deionised water used for the mineral standard medium had conductivity <5 µS/cm
- Culture medium different from test medium: yes
- Intervals of water quality measurement: pH was measured at 0 and 96 hours (test end). Temperature was recorded every two hours.

OTHER TEST CONDITIONS
- Sterile test conditions: no data
- Adjustment of pH: no
- Photoperiod: continuous light
- Light intensity and quality: continuous light in the range 400-700 nm by 30W fluorescent lamps of the type warm white. The measured light intensity during the test was about 9500 Lux.
Other: the flasks were shaken continuously on an orbital shaker at 100 rpm.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometer; A calibration curve of extinction versus cell number was made by measuring four dilutions from an exponentially growing culture at 436 nm. The cell density of the same samples was determined using a microscope and counting chamber.
- Chlorophyll measurement: no
- Other:

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3
- Justification for using less concentrations than requested by guideline: not relevant
- Range finding study: yes
- Test concentrations: 0, 0.1, 1, 10 and 100 mg/L.
- Results used to determine the conditions for the definitive study: inhibition was observed at 10 and 100 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

96 h

Dose descriptor:

other: EbC50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI 11-14 mg/L. Based on inhomogeneous test solutions, no chemical analysis of test substance concentrations.

Duration:

96 h

Dose descriptor:

other: ErC50

Effect conc.:

20 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI 16-24 mg/L. Based on inhomogeneous test solutions, no chemical analysis of test substance concentrations.

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

7.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: calculated by author of summary (see above). Based on inhomogeneous test solutions, no chemical analysis of test substance concentrations.

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: calculated by author of summary (see above). Based on inhomogeneous test solutions, no chemical analysis of test substance concentrations.

Duration:

72 h

Dose descriptor:

other: EyC50

Effect conc.:

6.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield according to OECD 201 (2006)

Remarks on result:

other: calculated by author of summary (see above). Based on inhomogeneous test solutions, no chemical analysis of test substance concentrations.

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Based on approximate solubility limit of test substance in test medium.

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Based on approximate solubility limit of test substance in test medium.

Duration:

72 h

Dose descriptor:

other: EyC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: Based on approximate solubility limit of test substance in test medium.

Details on results:

Exponential growth in the control (for algal test): yes (factor of 170 within 72 hours)
- Observation of abnormalities (for algal test): no data
- Unusual cell shape:no data
- Colour differences:no data
- Flocculation:no data
- Adherence to test vessels:no data
- Aggregation of algal cells:no data
- Any stimulation of growth found in any treatment: no.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No observations on the appearance of the stock and test solutions were reported. The mean extinction values at 0 h, where all flasks contained the same number of algae (10000 cells) were 0.003, 0.014, 0.034, 0.115, 0.234 and 0.680 at 0, 1, 3, 9, 27 and 81 mg/L, indicating that the test solutions were opaque due to the presence of the test substance, which is an oil. Inhomogeneity is expected under such conditions.
- Effect concentrations exceeding solubility of substance in test medium: yes (see below)

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50: EbC50 0.48 mg/L, ErC50 1.2 mg/L.
- Other:

Reported statistics and error estimates:

The reported 96-h EC50 values were computed from the least squares method through the points given by probit anlaysis of the percentage inhibition and the logarithm of the concentration of the test substance. The reported 96-h NOEC values were determined by comparison of the growth at each concentraion and the control using thershold values from the Williams test.

The results for the 72-h percentage inhibition values are summarized in the table below.

 

Table 1. 72-h percentage inhibition values calculated by the author of this summary.

Nominal conc.	Vessel	Area (A)	Growth rate (µ)	Yield
(mg/L)	number	inhibition %	Growth rate reduction (%)	inhibition %
1.0	1	18	3	14
1.0	2	-1	1	3
1.0	3	7	2	8
	mean	8	2	8
3.0	1	15	4	20
3.0	2	16	4	18
3.0	3	14	2	10
	mean	15	3	16
9.0	1	66	26	74
9.0	2	66	25	73
9.0	3	71	29	79
	mean	68	27	75
27.0	1	87	57	95
27.0	2	87	54	94
27.0	3	85	54	94
	mean	86	55	95
81.0	1	96	74	98
81.0	2	94	75	99
81.0	3	89	70	98
	mean	93	73	98

 

 

Evaluation.

The reported and re-calculated EC50 values are based on nominal concentrations, not verified by chemical analysis. Observations on the appearance of the test solutions were not reported. Considering the limit of solubility of the test material in water (<1 mg/L), and the fact that at t=0 h the extinction strongly increased with increasing test substance concentration, it is reasonable to assume that the test solutions were inhomogeneous. Due to the fact that the test solutions were inhomogeneous and far in excess of the solubility limit, the concentrations of which were not analytically determined, there is no information about the actual concentrations to which the algae were exposed during the study. Due to the method of their preparation, it is reasonable to assume that the stock solution was homogeneous and that the solubility limit of the test substance in the stock solution was achieved. The test solutions were prepared by spiking mineral test medium with an aliquot of known volume of stock solution. It is not certain that the solubility limit of the test substance in the test solutions was achieved immediately after preparation. However, the test solutions were rapidly shaken at 100 rpm at 25°C throughout the test, and it is therefore certain that within a short time after the start of the test the solubility limit of the test substance in the test water was achieved in all test solutions. Since at 1 mg/L there were no biologically relevant adverse effects on algal growth (effects all <10%), the conclusion of the study is that all EC50 values are in excess of the solubility limit. The actual EC50 values may be an order of magnitude higher, based on the results of the present test. The effects at 3 mg/L and above may be due to physical effects of the test material (an oil), e.g. clotting of the algal cells.

 

 

Validity criteria fulfilled:

yes

Remarks:

72-h growth factor in control was 178, hence >>16.

Conclusions:

Study according to OECD 201 (1984) with Selenastrum capricornutum: static test, 72-hour EbC50, ErC50 and EyC50 are all in excess of the solubility limit (hence in excess of about 1 mg/L), determined with inhomogeneous test solutions, concentrations not confirmed by chemical analysis. 72-hour EbC50, ErC50 and EyC50 values for exposure to inhomogeneous test solutions are 7.4, 25 and 6.4 mg/L, respectively. Study considered not reliable as effects are observed at levels exceeding the Sw. Exposure solutions were opaque and inhomogenous

Executive summary:

Study according to OECD 201 (1984) with Selenastrum capricornutum: static test, 72-hour EbC50, ErC50 and EyC50 are all in excess of the solubility limit (hence in excess of about 1 mg/L), determined with inhomogeneous test solutions, concentrations not confirmed by chemical analysis. 72-hour EbC50, ErC50 and EyC50 values for exposure to inhomogeneous test solutions are 7.4, 25 and 6.4 mg/L, respectively. Study considered not reliable as effects are observed at levels exceeding the Sw. Exposure solutions were opaque and inhomogenous

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22/10/2013 - 25/10/2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to international guideline (OECD guideline 201) under GLP. Validity criteria met, deviations from protocol did not adversely affect study integrity.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not relevant

Analytical monitoring:

yes

Details on sampling:

- Concentrations: nominal WAFs of 10, 18, 32, 56 and 100 mg/l.
- Sampling method: 40 ml samples for analysis were taken from extra vessels containing test solutions incubated without algae after 0 and 72 hours. Additionally, reserve samples of 40 ml were taken from all test solutions for possible analysis. If not already used, these samples were stored in a refrigerator for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.
- Sample storage conditions before analysis: Samples were stored in a refrigerator until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The standard test procedures required generation of test solutions, which contained completely dissolved test substance concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that would disturb the test system was prevented as much as possible (e.g. film of the test substance on the water surface). No correction was made for the purity/composition of the test substance. The batch of Blown Linseed Oil tested was a hazy yellow to brown viscous liquid and an UVCB substance. The test substance was not completely soluble in test medium at the loading rates prepared.
Preparation started with individual loading rates ranging from 1.0 to 100 mg/l. A 2-day period of magnetic stirring was applied to accelerate the dissolving of the test substance in the test medium. The obtained mixtures were left for a period of 1 hour to stabilise. Subsequently, the aqueous Water Accommodated Fractions (WAFs) were siphoned off and used as test solutions. After preparation, volumes of 50 ml were added to each replicate of the respective test concentration.
- Controls: Yes, controls and blanks withut algae
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The highest WAF in the final test was slightly hazy, whereas the remaining test solutions were all clear and colourless.

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: NIVA CHL 1
- Source (laboratory, culture collection): In-house laboratory culture
- Method of cultivation: Algae stock cultures were started by inoculating growth medium with algal cells from a pure culture on agar. The suspensions were continuously aerated and exposed to light in a climate room at a temperature of 21-24°C. 3 days before the start of the test, cells from the algal stock culture were inoculated in culture medium at a cell density of 1 x 10^4 cells/ml. The pre-culture was maintained under the same conditions as used in the test. The cell density was measured immediately before use.

ACCLIMATION
- Acclimation period: 3 days
- Culturing media and conditions (same as test or not): same

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

Not relevant

Hardness:

24 mg/L CaCO3

Test temperature:

22.5 - 23.3ºC

pH:

7.4 - 8.1

Dissolved oxygen:

No data

Salinity:

Not relevant

Nominal and measured concentrations:

Nominal: 10, 18, 32, 56 and 100 mg/L WAF
Measured (t=0h, TOC, corrected for control): 0.5508, 1.2109, 2.7069, 4.0589 and 6.3469 mg/L
Measured (t=72h, TOC, corrected for control): 0.5281, 1.1415, 2.4805, 2.4995 and 5.9645 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Vessel
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: Glass, 100 mL filled with 50 mL of test medium
- Aeration: None
- Initial cells density: 1.0 x 10^4 cells/mL
- Control end cells density: 53.6 x 10^4 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per control (no algae): 2

GROWTH MEDIUM
- Standard medium used: yes, Elendt M1/M2 medium
- Detailed composition if non-standard medium was used:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Milli-RO water
NH4Cl 15 mg/l
MgCl2.6H2O 12 mg/l
CaCl2.2H2O 18 mg/l
MgSO4.7H2O 15 mg/l
KH2PO4 1.6 mg/l
FeCl3.6H2O 64 μg/l
Na2EDTA.2H2O 100 μg/l
H3BO3 185 μg/l
MnCl2.4H2O 415 μg/l
ZnCl2 3 μg/l
CoCl2.6H2O 1.5 μg/l
CuCl2.2H2O 0.01 μg/l
Na2MoO4.2H2O 7 μg/l
NaHCO3 50 mg/l
Hardness (Ca+Mg): 0.24 mmol/l
- Culture medium different from test medium: No
- Intervals of water quality measurement: pH at the beginning and end of the test, temperature was recorded continuously in a temperature control vessel

OTHER TEST CONDITIONS
- Photoperiod: Continuous
- Light intensity and quality: TLD-lamps with a light intensity within the range of 91 to 97 uE/m2^/s.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: At the beginning of the test, cells were counted using a microscope and a counting chamber. Thereafter cell densities were determined by spectrophotometric measurement of samples at 720 nm using a spectrophotometer with immersion probe (pathlength =20 mm). Algal medium was used as blank and the extra replicates as background for the treated solutions.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study
- Test concentrations: 1, 10 amd 100 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

61 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95%CL: 56 - 64 mg/L

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

41 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95%CL: 37 - 44 mg/L

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95%CL: 72 - 78 mg/L

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities: Microscopic observations at the end of the test revealed a normal and healthy appearance of the
exposed cells when compared to the control.
- Any stimulation of growth found in any treatment: Yes, in the 10, 18 and 32 mg/L treatments
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The highest WAF in the final test was slightly hazy, whereas the remaining test solutions were all clear and colourless.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50: 1.3 mg/L

Reported statistics and error estimates:

For determination of the NOEL and the EL50 the approaches recommended in the OECD guideline 201 were used. An effect was considered to be significant if statistical analysis of the data obtained for the test concentrations compared with those obtained in the negative control revealed significant inhibition of growth rate or inhibition of yield (Williams Multiple Sequential t-test Procedure, α=0.05, one-sided, smaller). Additionally, the EL10 and EL20 were determined to meet the recommendations as put down in "A Review of Statistical Data Analysis and Experimental Design in OECD Aquatic Toxicology Test Guidelines" by S. Pack, August 1993. Calculation of the ELX values was based on probit analysis using linear max. likelihood regression with the percentages of growth rate inhibition and the percentages of yield inhibition versus the logarithms of the corresponding loading rate initially applied. The calculations were performed with ToxRat Professional v. 2.10.05 (ToxRat Solutions® GmbH, Germany).

Individual cell densities

		Individual cell densities (x 10^4 cells/mL)
			WAF (mg/L)
Time	Replicate	Control	10	18	32	56	100
0h	1	1	1	1	1	1	1
	2	1	1	1	1	1	1
	3	1	1	1	1	1	1
	4	1
	5	1
	6	1
n:		6	3	3	3	3	3
Mean:		1	1	1	1	1	1
St. Dev.:		0	0	0	0	0	0
CV:		0	0	0	0	0	0
24h	1	4.151	4.260	3.766	3.696	3.333	2.388
	2	4.083	3.445	3.749	3.575	3.083	2.351
	3	4.039	3.575	3.948	3.661	3.124	2.004
	4	4.208
	5	4.168
	6	4.377
n:		6	3	3	3	3	3
Mean:		4.2	3.8	3.8	3.6	3.2	2.2
St. Dev.:		0.1	0.4	0.1	0.1	0.1	0.2
CV:		2.8	11.6	2.9	1.7	4.2	9.4
48h	1	13.541	17.622	13.761	16.622	9.688	5.601
	2	12.700	14.183	14.275	15.189	10.544	5.754
	3	12.632	15.508	17.171	17.360	9.019	5.361
	4	14.506
	5	13.915
	6	14.616
n:		6	3	3	3	3	3
Mean:		13.7	15.8	15.1	16.4	9.8	5.6
St. Dev.:		0.9	1.7	1.8	1.1	0.8	0.2
CV:		6.3	11	12.2	6.7	7.8	3.6
72h	1	55.207	77.040	55.616	69.421	38.076	14.146
	2	45.952	60.703	54.419	61.237	42.250	17.598
	3	51.912	65.086	71.855	67.536	34.898	15.414
	4	56.225
	5	54.715
	6	57.483
n:		6	3	3	3	3	3
Mean:		53.6	67.8	60.6	66.1	38.4	15.7
St. Dev.:		4.2	8.8	9.7	4.3	3.7	1.7
CV:		7.8	13	16.1	6.5	9.6	11.1

Individual growth rates (day^-1)

			WAF (mg/L)
Time	Replicate	Control	10	18	32	56	100
24h	1	1.423	1.449	1.326	1.307	1.204	0.87
	2	1.407	1.237	1.321	1.274	1.126	0.855
	3	1.396	1.274	1.373	1.298	1.139	0.695
	4	1.437
	5	1.427
	6	1.476
n:		6	3	3	3	3	3
Mean:		1.428	1.320	1.340	1.293	1.156	0.807
St. Dev.:		0.028	0.113	0.029	0.017	0.042	0.097
CV:		2.000	8.600	2.100	1.200	3.600	12.000
48h	1	1.303	1.435	1.311	1.405	1.135	0.861
	2	1.271	1.326	1.329	1.360	1.178	0.875
	3	1.268	1.371	1.422	1.427	1.100	0.84
	4	1.337
	5	1.316
	6	1.341
n:		6	3	3	3	3	3
Mean:		1.306	1.377	1.354	1.398	1.138	0.859
St. Dev.:		0.032	0.055	0.059	0.034	0.039	0.018
CV:		2.400	4.000	4.400	2.400	3.400	2.100
72h	1	1.337	1.451	1.339	1.413	1.213	0.833
	2	1.276	1.369	1.332	1.372	1.248	0.956
	3	1.317	1.392	1.425	1.404	1.184	0.912
	4	1.343
	5	1.334
	6	1.350
n:		6	3	3	3	3	3
Mean:		1.326	1.404	1.366	1.396	1.215	0.917
St. Dev.:		0.027	0.043	0.052	0.022	0.032	0.037
CV:		2.000	3.000	3.800	1.600	2.600	4.000

Section-by-section growth rate

			WAF (mg/L)
Time	Replicate	Control	10	18	32	56	100
0 - 24h	1	1.400	1.400	1.300	1.300	1.200	0.9
	2	1.400	1.200	1.300	1.300	1.100	0.9
	3	1.400	1.300	1.400	1.300	1.100	0.7
	4	1.400
	5	1.400
	6	1.500
n:		6	3	3	3	3	3
Mean:		1.400	1.300	1.300	1.300	1.200	0.800
St. Dev.:		0.030	0.110	0.030	0.020	0.040	0.100
CV:		2.000	8.600	2.100	1.300	3.600	12.000
24 - 48h	1	1.200	1.400	1.300	1.500	1.100	0.900
	2	1.100	1.400	1.300	1.400	1.200	0.900
	3	1.100	1.500	1.500	1.600	1.100	1.000
	4	1.200
	5	1.200
	6	1.200
n:		6	3	3	3	3	3
Mean:		1.200	1.400	1.400	1.500	1.100	0.900
St. Dev.:		0.040	0.030	0.090	0.050	0.100	0.070
CV:		3.400	2.000	6.700	3.700	8.600	7.400
48 - 72h	1	1.400	1.500	1.400	1.400	1.400	0.900
	2	1.300	1.500	1.300	1.400	1.400	1.100
	3	1.400	1.400	1.400	1.400	1.400	1.100
	4	1.400
	5	1.400
	6	1.400
n:		6	3	3	3	3	3
Mean:		1.400	1.500	1.400	1.400	1.400	1.000
St. Dev.:		0.050	0.030	0.050	0.040	0.020	0.100
CV:		3.300	1.700	3.400	2.500	1.300	9.500

Individual yields

			WAF (mg/L)
Time	Replicate	Control	10	18	32	56	100
24h	1	3.151	3.260	2.766	2.696	2.333	1.388
	2	3.083	2.445	2.749	2.575	2.083	1.351
	3	3.039	2.575	2.948	2.661	2.124	1.004
	4	3.208
	5	3.168
	6	3.377
n:		6	3	3	3	3	3
Mean:		3.171	2.760	2.821	2.644	2.180	1.248
St. Dev.:		0.118	0.438	0.11	0.062	0.134	0.212
CV:		3.700	15.900	3.900	2.400	6.200	17.000
48h	1	12.541	16.622	12.761	15.622	8.688	4.601
	2	11.700	13.183	13.275	14.189	9.544	4.754
	3	11.632	14.508	16.171	16.360	8.019	4.361
	4	13.506
	5	12.915
	6	13.616
n:		6	3	3	3	3	3
Mean:		12.652	14.771	14.069	15.390	8.750	4.572
St. Dev.:		0.859	1.735	1.838	1.104	0.764	0.198
CV:		6.800	11.700	13.100	7.200	8.700	4.300
72h	1	54.207	76.740	54.616	68.421	37.076	13.146
	2	44.952	59.703	53.419	60.237	41.250	16.598
	3	50.912	64.086	70.855	66.536	33.898	14.414
	4	55.225
	5	53.715
	6	56.483
n:		6	3	3	3	3	3
Mean:		52.582	66.843	59.630	65.065	37.408	14.719
St. Dev.:		4.175	8.847	9.740	4.286	3.687	1.746
CV:		7.900	13.200	16.300	6.600	9.900	11.900

Validity criteria fulfilled:

yes

Remarks:

> 16-fold increase in controls, coefficients of variation for section-by-section specific growth rates and average specific growth rates were 9.8 and 2.0% respectively

Conclusions:

The acute toxicity (72h-ELr50) of Blown linseed oil towards Pseudokirchneriella subcapitata is > 100 mg/L.

Executive summary:

The acute toxicity of Blown linseed oil towards Pseudokirchnerialla subcapitata was investigated according to OECD guideline 201 under GLP. Algal cells were exposed to nominal WAFs of 10, 18, 32, 56 and 100 mg/L and were observed for 72 hours. Based on nominal loading rates the 72h-ErL10, 72h-EbL10, 72h-ErL50 and 72h-EbL50 were found to be 61, 41, >100 and 75 mg/L respectively.

Description of key information

In a WAF study with Linseed oil, oxidized according to the guideline 201, the EL50 based on the growth rate was observed to be >100 mg/L, whereas the EL10 (growth rate) was 61 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

61 mg/L

Additional information

Two studies are available for the toxicity towards algae with Blown linseed oil. The study of Kroon (1992) is disregarded because effects are observed at levels exceeding the solubility limit of the substance and exposure solutions were opaque and inhomogenous. Undissolved material has disturbed the measurements of algal cell density.

The WAF study of Tobor-Kaplon (2013) is conducted according to the guideline 201 and fulfills all validity criteria. The EL50 based on the growth rate was >100 mg/L, whereas the EL10 (growth rate) was 61 mg/L.