4-amino-5-(ethylsulphonyl)-o-anisic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 February 2015 - 24 February 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: SANCO/3029/99 rev.4 11/07/00: Residues: Guidance for generating and reporting methods of analysis in support of preregistration data requirements for Annex II (part A; Section 4) and Annex III (part A; Section 5) of directive 91/414

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Name of test material (as cited in study report): Acilian (4-Amino-5-ethylsulfonyl-2-methoxybenzoic acid)
- batch No.of test material:GS00012
- Expiration date of the lot/batch:February 28, 2015
- Purity test date:March 13, 2014
- Purity: 98.0 – 101.5% (nominal)
100.9% (analytical), according to certificate of analysis

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:At room temperature (20 ± 5 °C), in the dark
- Stability under test conditions: yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Nominal concentrations of test item : Nominal:100, 32, 10, 3.2 and 1.0 mg test item/L and a 0 for control
Mean measured concentrations: 98.0, 28.8, 8.3, 2.59 and 0.87 mg test item/L and 0 (control).
- Sampling method:
Analysis of the Test Item Concentrations
Duplicate samples from the freshly prepared test media (containing algae) of all test concentrations and from the control were taken at the start of the test. For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the test media of all test concentrations and the control (containing algae) were taken at the end of the test (after the 72 hours test period) by pouring together the contents of the test beakers of each treatment. All samples were diluted by a factor of 2 with acetonitrile.One additional sample of the blank control and the dilution solvent were taken at test start and test end without any sample treatment.
- Analyses:The concentrations of the test item were analysed in the duplicate test media samples from all test concentrations and in the duplicate control samples each from both sampling times (0 and 72 hours). All samples were centrifuged before analysis, in order to remove the algae.

- Fortified Samples:Two stock solutions were prepared. Approximately 50 mg of the test item were dissolved (1 minute ultrasonification, 30 minutes stirring) in 50 mL test water to obtain a stock solution of approximately 1 g test item/L. Appropriate amounts of these stock solutions were diluted with test water to obtain fortified samples at a level of 0.6, 15 and 140 mg test item/L.
- Sample storage conditions before analysis:All samples were stored in a freezer (≤ - 10 °C), protected from light until analysis was performed.

Standard Solutions used for the Quantification:
- Stock Solution:The test item was used to prepare a stock solution. 50.20 mg of the test item were dissolved in 50 mL acetonitrile to obtain a stock solution of approximately 1 g test item/L.
- Standard Solutions:Appropriate amounts of the stock solution were diluted with acetonitrile / test water (1/1, v/v) to obtain standard solutions in the range from 0.1 to 20 mg test item/L.

Analysis of Treatment Samples and Control Samples:
- Sample Preparation:The samples were shaken and where appropriate treated with ultrasound for 1 minute after thawing to obtain homogenous samples. The samples were diluted with acetonitrile by factor 2 (see chapter 6.10). The samples were further diluted with acetonitrile / test water (1/1, v/v) to match the calibration range, if necessary. The samples were centrifuged (13000 rpm, 10 minutes) before analysis.

- Sample storage conditions before analysis: All samples were stored in a freezer (≤ - 10 °C), protected from light until analysis was performed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution of 100mg test item / L was prepared by dissolving 100.8 mg test item was dissolved into 1008 mL test water by intense stirring for 30 minutes and ultrasonic treatment for 2 minutes.The pH of the stock solution was adjusted from 6.3 to 8.1 with 1 M NaOH.Adequate volumes of this stock solution were diluted with test water to prepare the test media of the desired test concentrations. The test media were prepared just before introduction of the algae (= start of the test).
- Controls: test water was used without addition of the test item
- Evidence of undissolved material (e.g. precipitate, surface film, etc.):No

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata,
- Strain: 61.81 SAG
- Source (laboratory, culture collection):The algae were supplied by the Sammlung von Algenkulturen, Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Universität Göttingen", 37073 Göttingen, Germany.
- Method of cultivation:The algae were cultivated in the laboratories of ibacon under standardised conditions according to the test guidelines.

ACCLIMATION
- Acclimation period:4 days
- Any deformed or abnormal cells observed: NO

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

0.24 mmol/L (= 24 mg/L) as CaCO3.

Test temperature:

21 to 22 °C

pH:

8.1 to 8.2 at test start and
9.3 to 9.5 at test end

Nominal and measured concentrations:

Nominal:100, 32, 10, 3.2 and 1.0 mg test item/L and a control
Mean measured concentrations: 98.0, 28.8, 8.3, 2.59 and 0.87 mg test item/L and 0 (control).

Details on test conditions:

TEST SYSTEM
- Test vessel:Erlenmeyer flasks of 50 mL volume with 50 mL of test medium.
- Type (delete if not applicable): closed.
- Aeration: continuously stirred with magnetic stirrers.
- Initial cells density: 5000 cells per mL test medium.
- Control end cells density: was determined by spectrophotometrical measurement : (See EFFECT PARAMETERS MEASURED)
- No. of vessels per concentration (replicates):3
- No. of vessels per control (replicates):6

GROWTH MEDIUM
- Standard medium used: yes - OECD medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted Water, according the OECD TG 201
- Culture medium different from test medium: NO

OTHER TEST CONDITIONS
- Adjustment of pH:The pH was adjusted with 1 M NaOH to pH 8.1.
- Photoperiod: Continuous illumination
- Light intensity and quality:Mean light intensity: 5655 lux (range: 5420 to 6180 lux). Measured once during the test at 6 posotions distributed over the experimental area at the surface of the test media.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter]:Spectrophotometer: Defined volumes of the algal suspensions from all replicates and from the blanks were sampled after 24, 48 and 72 hours of exposure, and were not replaced. The algal cell densities were calculated by subtracting the absorption of the blanks, from each of the measured absorption of the test media (with algae).
- Other : EC50,EC20,EC10, NOEC, LOEC for Yield and growth rate

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.13
- Range finding study: Pre-experiments were performed to determine a suitable concentration range and to establish suitable methods to prepare the test solutions. The pre-experiments were not performed in compliance with the GLP-Regulations and are excluded from the Statement of Compliance in the final report.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 28.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

ca. 98 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): no
- Observation of abnormalities (for algal test): NO
- Unusual cell shape:NO
- Colour differences: YES-After 24 hours until the end of the test, the test item caused colouration of the test medium in the concentrations of nominal 32 and 100 mg test item/L. Only after 48 hours the test item caused colouration of the test medium in the concentration of nominal 10 mg test item/L (see Table 11).
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: NO

Results with reference substance (positive control):

- Results with reference substance valid : YES

Parameter: (0-72 h): EC50
Yield [mg test item/L]: 0.454
Growth rate [mg test item/L]: 1.05
Biomass [mg test item/L]: 0.492
95 % conf. Interval for : Yield= 0.439 - 0.471, Growth rate =1.02 - 1.08, Biomass = 0.475-0.510

Parameter: (0-72 h): EC20
Yield [mg test item/L]: 0.265
Growth rate [mg test item/L]: 0.520,
Biomass [mg test item/L]: 0.290
95 % conf. Interval for : Yield= 0.250 - 0.279, Growth rate =0.493 - 0.546, Biomass = 0.274 - 0.305

Parameter: (0-72 h): EC10
Yield [mg test item/L]: 0.200
Growth rate [mg test item/L]: 0.361,
Biomass [mg test item/L]: 0.220
95 % conf. Interval for : Yield= 0.185 - 0.214, Growth rate =0.335 - 0.385, Biomass = 0.204 - 0.235

Parameter: (0-72 h): NOEC
Yield [mg test item/L]: 0.094
Growth rate [mg test item/L]: 0.094,
Biomass [mg test item/L]: 0.094

Parameter: (0-72 h): LOEC
Yield [mg test item/L]: 0.210
Growth rate [mg test item/L]: 0.210
Biomass [mg test item/L]: 0.210

Values refer to nominal test concentrations

Reported statistics and error estimates:

Calculations were made with the probit method, whereas analyses were conducted with Professional, Version 2.10.05, ToxRat Solutions GmbH., and the Williams t-test Procedure.

Table No.1: Algal Cell Densities during the Test Period of 72 Hours

Measured concentration  [mg test item/L]	Flask	Density of algal cells [10000/mL] after
	No.	24 hours	48 hours	72 hours
Control	1	3.316	19.098	121.001
	2	3.650	23.033	129.657
	3	3.650	22.246	124.149
	4	3.316	21.852	132.805
	5	2.983	22.639	132.411
	6	3.316	22.639	126.903
	m	3.372	21.918	127.821
	s	0.251	1.438	4.693
0.870	1	3.650	22.246	132.018
	2	3.650	24.606	131.624
	3	3.650	21.852	127.690
	m	3.650	22.902	130.444
	s	0.000	1.490	2.393
2.59	1	3.316	21.459	120.608
	2	3.650	22.639	124.936
	3	3.650	23.033	125.329
	m	3.539	22.377	123.624
	s	0.193	0.819	2.620
8.30	1	3.983	24.213	135.165
	2	3.983	26.574	139.985
	3	3.650	23.426	123.362
	m	3.872	24.738	131.755
	s	0.193	1.638	7.531
28.8	1	3.650	25.787	137.919
	2	4.317	23.820	133.985
	3	3.316	22.246	123.362
	m	3.761	23.951	131.755
	s	0.509	1.774	7.531
98.0	1	2.983	19.492	109.951
	2	3.316	17.131	103.296
	3	3.316	19.098	117.067
	m	3.205	18.574	109.985
	s	0.193	1.265	6.894

m: mean value; s: standard deviation

Table No.2: Yield during the Test Period of 72 Hours

Measured concentration  [mg test item/L]	Flask	Yield y [10000 cells/mL] after
	No.	24 hours	48 hours	72 hours
Control	1	2.816	18.598	120.501
	2	3.150	22.533	129.157
	3	3.150	21.746	123.649
	4	2.816	21.352	132.305
	5	2.483	22.139	131.911
	6	2.816	22.139	126.403
	m	2.872	21.418	127.321
	s	0.251	1.438	4.693
0.870	1	3.150	21.746	131.518
	2	3.150	24.106	131.124
	3	3.150	21.352	127.190
	m	3.150	22.402	129.944
	s	0.000	1.490	2.393
2.59	1	2.816	20.959	120.108
	2	3.150	22.139	124.436
	3	3.150	22.533	124.829
	m	3.039	21.877	123.124
	s	0.193	0.819	2.620
8.30	1	3.483	23.713	134.665
	2	3.483	26.074	138.993
	3	3.150	22.926	129.944
	m	3.372	24.238	134.534
	s	0.193	1.638	4.526
28.8	1	3.150	25.287	137.419
	2	3.817	23.320	133.485
	3	2.816	21.746	122.862
	m	3.261	23.451	131.255
	s	0.509	1.774	7.531
98.0	1	2.483	18.992	109.091
	2	2.816	16.631	102.796
	3	2.816	18.598	116.567
	m	2.705	18.074	109.485
	s	0.193	1.265	6.894

m: mean value; s: standard deviation

Cell density of 5000 algal cells/mL at test start are subtracted from the yield values

Table NO.3: Growth rate during the Test Period of 72 Hours

Measured concentration  [mg test item/L]	Flask	Growth ratesμ[1/day] after
	No.	0 - 24 hours	0 - 48 hours	0 - 72 hours
Control	1	1.892	1.821	1.830
	2	1.988	1.915	1.853
	3	1.988	1.898	1.838
	4	1.892	1.889	1.861
	5	1.786	1.906	1.860
	6	1.892	1.906	1.846
	m	1.906	1.889	1.848
	s	0.075	0.034	0.012
0.870	1	1.988	1.898	1.859
	2	1.988	1.948	1.858
	3	1.988	1.889	1.848
	m	1.988	1.911	1.855
	s	0.00	0.032	0.006
2.59	1	1.892	1.880	1.829
	2	1.988	1.906	1.840
	3	1.988	1.915	1.841
	m	1.956	1.900	1.837
	s	0.055	0.018	0.007
8.30	1	2.075	1.940	1.867
	2	2.075	1.987	1.877
	3	1.988	1.923	1.855
	m	2.046	1.950	1.866
	s	0.050	0.033	0.011
28.8	1	1.988	1.972	1.873
	2	2.156	1.932	1.864
	3	1.892	1.898	1.836
	m	2.012	1.934	1.858
	s	0.133	0.037	0.019
98.0	1	1.786	1.832	1.797
	2	1.892	1767	1.777
	3	1.892	1.821	1.819
	m	1.857	1.807	1.797
	s	0.061	0.035	0.021

m: mean value; s: standard deviation

Table No.4: Yield y and Percentage Inhibition of y during the Test Period

Measured concentration  [mg test item/L]	Yields y [10000 cells/mL] and % inhibition of y
	24 hours		48 hours		72 hours
	y	%	y	%	y	%
Control	2.872	-	21.418	-	127.321	-
0.870	3.150	-9.7	22.402	-4.6	129.944	-2.1
2.59	3.039	-5.8	21.877	-2.1	123.124	3.3
8.30	3.372	-17.4	24.238	-13.2	134.534	-5.7
28.8	3.261	-13.5	23.451	-9.5	131.255	-3.1
98.0	2.705	5.8	18.074	15.6*	109.485-	14.0*

negative values in ‘% inhibition’ indicate an increase in growth relative to that of the control

* mean value significantly different from the control (tested with Williams t-test, α = 0.05, one-sided)

Table No.5: Growth Rates μ and Percentage Inhibition of μ during the Test Period

Measured concentration  [mg test item/L]	Growth ratesμ[1/day] and % inhibition ofμ
	24 hours		48 hours		72 hours
	μ	%	μ	%	μ	%
Control	1.906	-	1.889	-	1.848	-
0.870	1.988	-4.3	1.911	-1.2	1.855	-0.4
2.59	1.956	-2.6	1.900	-0.6	1.837	0.6
8.30	2.046	-7.3	1.950	-3.2	1.866	-1.0
28.8	2.012	-5.5	1.934	-2.3	1.858	-0.5
98.0	1.857	2.6	1.807	4.4*	1.797	2.7*

negative values in ‘% inhibition’ indicate an increase in growth relative to that of the control

* mean value significantly different from the control (tested with Williams t-test, α = 0.05, one-sided)

Temperature in the test media (water) during the test period:

0hours= 21ºC

24 hours =22ºC

48 hours =21ºC

72 hours=22ºC

Table No. 6 pH-Values in the Test Media at the Start and End of the Test

Measured concentration[mg test item/L]	pH at 0hours	pH at 72Hours
Control	8.2	9.3
0.870	8.1	9.5
2.59	8.1	9.5
8.30	8.1	9.5
28.8	8.1	9.4
98.0	8.1	9.3

Table No.7: Appearance of the Test Item in the Test Media

Measured concentration[mg test item/L]	Appearance at 0hours	Appearance at 24 Hours	Appearance at 48 hours	Appearance at 72 hours
0.870	0	0	0	0
2.59	0	0	0	0
8.30	0	0	1	0
28.8	0	1	1	1
98.0	0	1+	1+	1+

Abbreviations:

0: No remarkable observations, clear test medium

1: Colouration caused by the test item

2: Turbidity caused by the test item

3: Inhomogeneous dispersion of the test item

4: Precipitation of the test item

5: Test item at the surface

6: Test item lying at the bottom of the test vessel

+: Effects were strongly pronounced

Effects in parenthesis were only slightly pronounced

Table No.8 Results for the Determination of the Test Item in the Test Samples

mple Description [mg test item/L]	AGE		Concentration found [mg test item/L]^1	D.F.	Concentration calculated [mg test item/L]^1	Concentration nominal [mg test item/L]^2	% of Nominal^3	Geometric mean concentration [mg test item/L]^5
	day	h
Control	0	0	<LOD	2	n.a.	0.000	n.a.	0.870
Control	0	0	<LOD	2	n.a.	0.000	n.a.
Control	3	72	<LOD	2	n.a.	0.000	n.a.
Control	3	72	<LOD	2	n.a.	0.000	n.a.
1	0	0	0.554	2	1.109	1.000	111
1	0	0	0.551	2	1.102	1.000	110
1	3	72	0.339	2	0.678	1.000	68
1	3	72	0.337	2	0.675	1.000	67
						4geometric mean value (n=2):	87
3.2	0	0	1.684	2	3.368	3.200	105	2.59
3.2	0	0	1.713	2	3.427	3.200	107
3.2	3	72	0.989	2	1.979	3.200	62
3.2	3	72	0.986	2	1.971	3.200	62
						4geometric mean value (n=2):	81
10	0	0	5.173	2	10.347	10.000	103	8.30
10	0	0	5.216	2	10.431	10.000	104
10	3	72	3.294	2	6.588	10.000	66
10	3	72	3.308	2	6.616	10.000	66
						4geometric mean value (n=2):	83
32	0	0	16.453	2	32.905	32.000	103	28.8
32	0	0	16.492	2	32.985	32.000	103
32	3	72	12.287	2	24.573	32.000	77
32	3	72	12.416	2	24.833	32.000	78
						4geometric mean value (n=2):	90
100	0	0	5.267	20	105.346	100.000	105	98.0
100	0	0	5.216	20	104.327	100.000	104
100	3	72	4.5969	20	91.382	100.000	91
100	3	72	4.550	20	90.991	100.000	91
						4geometric mean value (n=2):	98

1 The tabulated results represent rounded results calculated on the exact raw data

2 Nominal values given by the study director

3 The results represent rounded values

4 geometric mean values are calculated with the mean values of the fresh and aged samples

5 geometric mean concentrations are calculated with the geometric mean values of the recovery rates in percent

and the nominal test item concentrations

LOD: Limit of Detection = 0.09 mg test item/L

n.a.: not applicable

RSD: Relative Standard Deviation

D.F.: Dilution factor

Table No.9. Results for the Determination of the Test Item in the Fortified Samples

ple Description [mg test item/L]		Concentration found [mg test item/L]^1		D.F.	Concentration calculated [mg test item/L]^1		Concentration nominal [mg test item/L]^2	% of Nominal^3
Analytical Blank Control	0	<LOD	2		n.a.	0.000			n.a.
Analytical Blank Control	0	<LOD	2		n.a.	0.000			n.a.
Fortified Sample	0.6	0.337	2		0.674	0.599			112
Fortified Sample	0.6	0.335	2		0.670	0.599			112
Fortified Sample	0.6	0.334	2		0.668	0.596			112
Fortified Sample	0.6	0.336	2		0.672	0.596			113
Fortified Sample	0.6	0.336	2		0.672	0.596			113
						mean value (n=5):			112
						RSD (n=5):			0
Fortified Sample	15	7.449	2		17.898	14.982			99
Fortified Sample	15	7.463	2		14.925	14.982			100
Fortified Sample	15	7.435	2		14.870	14.907			100
Fortified Sample	15	7.246	2		14.493	14.907			97
Fortified Sample	15	7.361	2		14.721	14.907			99
						mean value (n=5):			99
						RSD (n=5):			1
Fortified Sample	140	7.213	20		144.258	139.832			103
Fortified Sample	140	7.179	20		143.577	139.832			103
Fortified Sample	140	7.078	20		141.568	139.132			102
Fortified Sample	140	7.091	20		141.824	139.132			102
Fortified Sample	140	7.007	20		140.134	139.132			101
						mean value (n=5):			102
						RSD (n=5):			101

mean value (n=15): 105

RSD (n=15) : 6

1 The tabulated results represent rounded results calculated on the exact raw data

2 The results represent rounded values

LOD: Limit of Detection = 0.09 mg test item/L

n.a.: not applicable

RSD: Relative Standard Deviation

D.F.: Dilution factor

Results:

The EuC50, EuC20 and EuC10 (72 h) value were > 98.0 mg test item/L.

The EyC50 and EyC20 (72 h) value was > 98.0 mg test item/L.

The EyC10 (72 h) value was 79.6 mg test item/L.

The LOEC (72 h) for growth rate was 98.0 mg test item/L.

The NOEC (72 h) for growth rate was 28.8 mg test item/L.

The LOEC (72 h) for yield was 98.0 mg test item/L.

The NOEC (72 h) for yield was 28.8 mg test item/L.

Validity criteria fulfilled:

yes

Remarks:

Control increased by a factor of 256 (> 16-fold growth), Coefficient of Variation of Sectional (Daily) Growth Rates in Control Cultures: 5.8% (<35%). Coefficient of Variation of Average Growth between Control Replicates:0.7% (<7%)

Conclusions:

The EC50 (based on growth inhibition rate and geometric mean measured concentrations) of the test item in green algae was > 98.0 mg test item /L after 72 hours of exposure. The EC10 (growth) > 98.0, EC10 (yield) egual to 79.6 mg test item/L, and NOEC 28.8 mg test item /L respectively. The yield inhibition and growth inhibition are observed in the concentration > 98 mg test item/L.

Executive summary:

The green algae growth inhibition test was performed according to OECD Guideline 201 (GLP study). The purpose was to determine the inhibitory effect of the test item Acilian on the growth of the freshwater green algae Pseudokirchneriella subcapitata. The initial density(1 x 105 cells/mL) of Pseudokirchneriella subcapitata were exposed to geometric mean measured concentrations of 0 (control, 6 replicates), 0.87 mg test item /L, 2.59 mg test item /L, 8.30 mg test item /L, 28.8 mg test item /L, and 98.0 mg test item /L (3 replicates) for 72 hours under static conditions.The number of algal cells was determined by spectrophotometric measurement after 24, 48, and 72 hours of the exposure. Based on these measurements the growth rate and yield were calculated. After 24 hours until the end of the test, the test item caused colouration of the test medium in the nominal concentrations 32 and 100 mg test item/L. After 48 hours the test item caused colouration of the test medium in the nominal concentration 10 mg test item/L. The endpoints values based on the geometric mean measured test item concentrations : In 72 hours, measured EC50 value was > 98.0 mg test item /L, NOEC value 28.8 mg test item /L and LOEC egual to 98.0 mg test item /L for the growth and yield rate. EC10 (growth) > 98 mg test item/L and EC10 (yield) egual to 79.6 mg test item/L.

Description of key information

Key study: OECD guideline 201, GLP study. In 72 hours, measured EC50 value was >  98.0 mg test item /L, NOEC value 28.8 mg test item /L and LOEC egual to 98.0 mg test item /L for the growth and yield rate. EC10 (growth) > 98 mg test item/L and EC10 (yield) egual to 79.6 mg test item/L. The yield inhibition and growth inhibition are observed in the concentration > 98 mg test item/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

98 mg/L

EC10 or NOEC for freshwater algae:

28.8 mg/L

Additional information

Key study: OECD GUIDELINE 201, GLP study: The green algae growth inhibition test was performed according to OECD Guideline 201 (GLP study). The initial density of 1 x 105 cells/mL Pseudokirchneriella subcapitata were exposed to geometric mean measured concentrations for 72 hours under static conditions. The algal cells was determinated by spectrophotometric measurement after 24, 48, and 72 hours of the exposure. Based on these measurements the growth rate and yield were calculated. After 24 hours until finish, the test item caused colouration of the test medium in the nominal concentrations 32 and 100 mg test item/L, after 48 hours in the nominal concentration 10 mg test item/L. The endpoints values based on the geometric mean measured test item concentrations: During 72 hours, measured EC50 value was >  98.0 mg test item /L for the growth and yield rate, EC10 (growth) > 98 mg test item/L and EC10 (yield) egual to 79.6 mg test item/L. The NOEC value was 28.8 mg test item /L and LOEC egual to 98.0 mg test item /L for both of growth and yield rate.