Propanoic acid, 2-hydroxy-, ammonium salt (1:1), (2S)-

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:

supporting study

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 750 mg/L

Nominal / measured:

nominal

Conc. based on:

other: nitrogen content in NH3

Basis for effect:

other: cell density

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

ca. 500 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

ammonium-N

Basis for effect:

growth rate

The growth properties of Chlorella vulgaris under different nitrogen concentrations.

NH3-N conc. [mg L^-1]	Specific growth rate [day^-1]	R^2	Maximum count [x10^6cells mL^-1]	Final count [x10^6cells mL^-1]
0	0.054	0.87	3.16 (day 14)	2.64
10	0.204	0.90	22.59 (day 21)	22.59
20	0.228	0.89	54.48 (day 18)	53.46
40	0.214	0.97	49.55 (day 17)	44.70
50	0.212	0.98	50.69 (day 18)	50.18
60	0.211	0.96	46.85 (day 18)	32.50
80	0.219	0.97	49.30 (day 17)	44.70
125	0.213	0.95	50.30 (day 21)	50.30
250	0.236	0.99	50.39 (day 21)	50.39
500	0.221	0.97	37.75 (day 21)	37.75
750	0.204	0.99	44.89 (day 21)	44.89
1000	0.199	0.99	38.30 (day 18)	29.18
Bristol medium	0.229	0.96	67.85 (day 17)	13.19

Validity criteria fulfilled:

not applicable

Remarks:

Non-guideline study, but scientifically robust result published in peer-reviewed article.

Conclusions:

Although algal growth was inhibited for all tested concentrations of ammmonia nitrogen, compared to the ideal Bristol medium, in the range of 10 to 500 mg N/L the added ammonia had no significant effect on algal growth. A negative effect on algal growth could be observed starting at 500 mg N/L.

Executive summary:

A 21-d study was performed to determine the effects of ammonium on the unicellular green alga Clorella vulgaris. Growth occurred in all ammonia concentrations examined (10–1000 mg N/L) although less growth was found in cultures containing either very low (0, 10 mg N/L) or very high (750 and 1000 mg N/L) ammonia concentrations, expressed as NH3-N. At high nitrogen concentrations between 20 and 250 mg N/L, there were no significant differences in specific growth rates and maximal cell densities attained. The study revealed that within the tested ammonia concentration range no EC₅₀ value could be determined because the effect was not strong enough. 1000 mg N/L inhibited growth by less than 50 %, expressed as growth rate.

Results synopsis

Test organism: Chlorella vulgaris

Test type: static

21 d NOEC:  500 mg N/L 

21 d LOEC: > 750 mg N/L                 

Endpoint(s) effected: Cell density, growth

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

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

Justification for type of information:

For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

pH:

Buffered solutions

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 533 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.9 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3.5 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 2.8 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

By visual comparison of the measured and the calculated growth curves of algal suspensions exposed to the test substance with those of the algal controls, the no-observed-effect-concentration (NOEC) of the 80 % aqueous solution of L(+) lactic acid was estimated to be 1.9 g/L.
Microscopic examination of the cells at the start and end of the incubation period revealed no abnormalities, however many bacteria were found in the cultures exposed to test substance concentrations of 1.0,1.9 and 2.8 g/L.
The pH of the algal medium containing different test substance concentrations was adjusted to the range pH 7.5-8.0 at the start of the test. It was found to remain constant (pH 8.0-8.1) during the test. In the presence of algae the pH was found to increase a little with algal cell density (pH 8.2-8.7).

The toxicity of a solution of about 80 % L(+) lactic acid to the freshwater green alga Selenastrum capricornutum was determined in a growth inhibition test according to the OECD Guideline no. 201 and the OECD principles of Good Laboratory Practice. The test included chemical determinations of the test substance concentrations during the test.

The nominal concentrations of neutralized 80 % L(+)lactic acid tested were 0, 0.10, 0.33, 0.56, 1.0, 1.9 and 2.8 g/L . The algal growth was determined by electronic particle counting. The effect values were calculated using a parametric model assuming an error proportional to the number of cells.

The EC50 with respect to inoculum viability followed by exponential growth (EeC50) was found to be 3.5 g/L, with a 95 % confidence interval of 2.8-4.4 g/L. The corresponding EeC10 and EeC90 values were 2.3 g/L and 5.4 g/L respectively. The EC50 with respect to the area under the growth curve (EbC50) was found to be > 2.8g/L. The corresponding EbC10 and EbC90 values were 2.4 g/L (in the range 1.9-2.8 g/L) and > 2.8 g/L respectively.

The no-observed-effect-concentration (NOEC) with respect to the effects referred to above was estimated to be 1.9 g/L.

An effect on the inoculum viability, as found in this test, may be expected when a substance loses its toxicity during the test, in this case probably due to biodegradation.

The concentrations quoted in the report are the nominal concentrations of the test substance (a solution of about 80 % L(+) lactic acid) as supplied by sponsor. At the start of the test 65-82% of the nominal test substance concentrations were found by chemical analysis. At the end of the test the concentrations were considerably lower: ca. 15, 57 and 73 % at the three concentrations analysed.

Validity criteria fulfilled:

yes

Conclusions:

NOEC of lactic acid to green algae is above 533 mg/L actual concentration of active substance (TWM).

Executive summary:

In a 72 hour acute toxicity study, the cultures ofSelenastrum capricornutum (ATCC 22662) were exposed to L(+) lactic acid (80 % a.i.) at nominal concentrations of 0, 0.10, 0.33, 0.56, 1.0, 1.9 and 2.8 g/L under static conditions in accordance with the OECD 201 guideline. The NOEC and EC₅₀values based on growth rate were 1.9 g/L and 3.5 g/L, respectively. 

There were no compound related phytotoxic effects.

This toxicity study is classified as acceptable and satisfies the guideline requirements for alga growth inhibition study with S. capricornutum.

 

Results Synopsis

 

Test Organism: Selenastrum capricornutum

Test Type (Flowthrough, Static, Static Renewal): static

 

72 hr EC₅₀:  3.5 g/L (2.8 g a.i./L)                95% C.I.:  2.8 to 4.4 g/L; 2.24 to 3,52 g a.i./L; nominal concentration > invalid

72hr NOEC:  1.9 g/L (1.52 g a.i./L); nominal concentration > invalid

72hr NOEC > 533 mg a.i./L; time weighted mean from the measured concentration of the a.i.

Endpoint(s) Effected:  mortality, abnormalities of the cells

 

An effect on the inoculum viability, as found in this test, may be expected when a substance loses its toxicity during the test, in this case probably due to biodegradation. The concentrations quoted in this report are the nominal concentrations of the test substance (a solution of about 80 % L(+) lactic acid) as supplied by sponsor. At the start of the test 65-82 % of the nominal test substance concentrations were found by chemical analysis. At the end of the test the concentrations were considerably lower: 15, 57 and 73 % at the three concentrations analysed. The actual (active substance) tested at the start of the test were < 0.005, 0.020-0.065, 0.44-0.62, 1.45-1.74 g/L. According to the calculated time-weighted mean (see formula below from the OECD guideline 211: TWM = (conc0 – conc1)/(LN(conc0) – (LN(conc1))) the concentrations which should be used for effect calculations are 31 mg a.i./L, 533 mg a.i./L and 1620 mg a.i./L. The EC50 and the NOEC from the test report have to be regarded as not valid, as they were calculated on the basis of nominal values. Concerning the NOEC of 1.9 g/L, the replicates with the test concentration of 1.9 g/L have not been assessed analytically. Hence no conclusion on the actual concentration can be drawn. Though the next lower concentration was assessed analytically, revealing that the NOEC is above 533 mg/L (time-weighted mean of the measured a.i.).

TWM= (conc0 -conc1)/(ln (conc0)- ln(conc1)
	conc 0 (mean of 2 replicates)	conc 1 (mean of 2 replicates)		TWM			nominal, a.i.	nominal test item
mg/L	65	12		31,37059			80	100
	620	455		533,2522			800	1000
	1595	1645		1619,871			2240	2800

This information is used in a read-across approach in the assessment of the target substance.

For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Water media type:

freshwater

Remarks:

Bowerbird Billabong (latitude –12°46'15'', longitude 133°02'20'')

Duration:

72 h

Dose descriptor:

IC10

Remarks:

Chlorella sp.

Effect conc.:

ca. 66.03 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

other: IC20

Remarks:

Chlorella sp.

Effect conc.:

ca. 108.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

IC50

Remarks:

Chlorella sp.

Effect conc.:

ca. 226.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

IC10

Remarks:

Lemna aequinoctialis

Effect conc.:

ca. 22.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

other: LC20

Remarks:

Lemna aequinoctialis

Effect conc.:

ca. 26.05 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

IC50

Remarks:

Lemna aequinoctialis

Effect conc.:

ca. 36.06 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

IC10

Remarks:

Hydra viridissima

Effect conc.:

ca. 1.82 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: population growth

Duration:

96 h

Dose descriptor:

other: IC20

Remarks:

Hydra viridissima

Effect conc.:

ca. 3.21 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: population growth

Duration:

96 h

Dose descriptor:

IC50

Remarks:

Hydra viridissima

Effect conc.:

ca. 8.41 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: population growth

Duration:

144 h

Dose descriptor:

IC10

Remarks:

Moinodaphnia macleayi

Effect conc.:

ca. 26.92 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: reproduction

Duration:

144 h

Dose descriptor:

other: LC20

Effect conc.:

ca. 34.38 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: reproduction

Duration:

144 h

Dose descriptor:

IC50

Remarks:

Moinodaphnia macleayi

Effect conc.:

ca. 55.24 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: reproduction

Duration:

14 d

Dose descriptor:

IC10

Remarks:

Amerianna cumingi

Effect conc.:

ca. 16.73 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: reproduction (egg numbers)

Duration:

14 d

Dose descriptor:

other: LC20

Remarks:

Amerianna cumingi

Effect conc.:

ca. 26.29 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: reproduction (egg numbers)

Duration:

14 d

Dose descriptor:

IC50

Remarks:

Amerianna cumingi

Effect conc.:

ca. 63.23 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

other: reproduction (egg numbers)

Duration:

7 d

Dose descriptor:

IC10

Remarks:

Mogurnda mogurnda

Effect conc.:

ca. 5.39 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

other: LC20

Remarks:

Mogurnda mogurnda

Effect conc.:

ca. 8.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Duration:

7 d

Dose descriptor:

IC50

Remarks:

Mogurnda mogurnda

Effect conc.:

ca. 18.54 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total ammonia nitrogen (mg/L)

Basis for effect:

growth rate

Details on results:

please refer to Table 2

Table 2 - Summary of the ammonia toxicity estimates for Chlorella sp. in Magela Creek Water

Species	pH	Temperature (°C)	IC10 total ammonia nitrogen (mg/L)	IC20 total ammonia nitrogen (mg/L)	IC50 total ammonia nitrogen (mg/L)	IC10* total ammonia nitrogen (mg/L), pH 7, 20°C	IC20* total ammonia nitrogen (mg/L), pH 7, 20°C	IC50* total ammonia nitrogen (mg/L), pH 7, 20°C	Ammonia NH3 (mg/L) IC10
Chlorella sp.	6.1	29.3	66.03	108.50	226.7	16.12	26.50	57.51	0.077

 

 *Toxicity values were adjusted to pH7 and 20°C using the equations of Emerson et al. (1975) "Aqueous ammonia equilibirum calculations: Effect of pH and temperature".

Conclusions:

Low-effect chronic inhibition concentration for Chlorella sp. = 66 mg/L total ammonia nitrogen.

Executive summary:

The present study assessed the toxicity of ammonia to 6 tropical freshwater species in low-ionic-strength waters. Because ammonia toxicity varies depending on the pH and temperature, test water pH concentrations were maintained at approximately pH 6.0-0.3 at temperatures between 27.5 and 30°C.

Low-effect chronic inhibition concentrations are reported here for Chlorella sp. only, as the other species do not represent algae or cyanobacteria. Chlorella sp.: IC10 = 66 mg/L total ammonia nitrogen.

(corresponding to 505 mg/L ammonium-S-lactate);

This toxicity study made use of appropriate controls that were valid and it can be assumed that results are reliable.

The information on ammonia is used in a read-across approach in the assessment of the target substance ammonium-S-lactate. For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reference 4

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

GLP compliance:

no

Reference substance (positive control):

no

Duration:

10 d

Dose descriptor:

NOEC

Remarks:

Navicula sp.

Effect conc.:

ca. 26.8 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

10 d

Dose descriptor:

LOEC

Remarks:

Navicula sp.

Effect conc.:

ca. 53.5 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

10 d

Dose descriptor:

EC50

Remarks:

Navicula sp.

Effect conc.:

ca. 90.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Ammonia concentrations higher than 0.5 mg-at N/L inhibited growth of the cultures. The rate of photosynthesis of diatoms from the field and from cultures was also inhibited by 0.5 mg-at N/L of ammonia under certain conditions. Inhibition of photosynthesis by ammonia was strongly enhanced by high irradiance and high pH.

According to OECD SIDS (2003), the following results were found:
NOEC (10d) = 26.8 mg/L based on growth rate
LOEC (10d) = 53.5 mg/L based on growth rate
EC50 (10d) = 90.4 mg/L

- Ammonium chloride concentration vs Relative growth (as % chlorophyll a) : 5.35mg/L - 86%, 26.8mg/L - 100%, 53.5% - 75%, 134mg/L - 21%, 268mg/L - 0-5%

- Remarks:
1) For the other five species (Nitzschiac.f.dissipata, Nitzschia dubiformis, Nitzschia closterium, Amphiprora c.f.paludosa and Stauroneis constricta) NOECs were observed to be 26.8mg/L
2) Nominal concentration were calculated on measured concentrations, because measured concentrations were within plus or minus 20 % of nominal concentrations. However, concentrations were considerably reduced by algal growth. This may explain the fact that occasionally growth at the lowest concentration was sub-optimal.

Relative growth (as % chlorophyll a) of 10 diatom species in 4 concentration of ammonia)

Species	5.35 mg/L	26.8 mg/L	53.5 mg/L	134 mg/L	268 mg/L
Navicula arenaria	86	100	75	21	0-5
Nitzschia c.f. dissipata	89	100	38	0-5	0-5
Nitzschia dubiformis	100	97	27	0-5	0-5
Nitzschia closterium	82	90	80	100	23
Amphiprora c.f. paludosa	70	100	54	0-5	0-5
Stauroneis constricta	65	100	67	53	57
Navicula cryptocephala	68	100	86	37	9
Navicula salinarum	58	100	82	71	66
Gyrosigma spencerii	100	100	34	0-5	0-5
Nitzschia sigma	71	100	34	0-5	0-5

Validity criteria fulfilled:

not applicable

Conclusions:

According to OECD SIDS (2003), the NOEC (growth rate; 0-10 d), the LOEC (growth rate; 0-10 d) and the EC50 (growth rate; 0-10 d) for ammonium chloride for Navicula sp. were 26.8 mg/L, 53.5 mg/L and 90.4 mg/L, respectively.

Executive summary:

Ten species of benthic diatoms from the Eems-Dollard estuary (Navicula arenaria, Nitzschia c.f. dissipata, Nitzschia dubiformis, Nitzschia closterium, Amphiprora c.f. paludosa, Stauroneis constricta, Navicula cryptocephala, Navicula salinarum, Gyrosigma spencerii, Nitzschia sigma) were cultured unialgally in synthetic media with various concentrations of ammonia (NH4+ + NH3), nitrite ion, nitrate ion and orthophosphate. Most of the species grew well in media with very high concentrations of nitrite ion (1 to 10 mg-at N/L), nitrate ion (about 16.9 mg-at N/L) and orthophosphate (at least 0.9 mg-at P/L). Ammonia concentrations higher than 0.5 mg-at N/L inhibited growth of the cultures. The rate of photosynthesis of diatoms from the field and from cultures was also inhibited by 0.5 mg-at N/L of ammonia under certain conditions. Inhibition of photosynthesis by ammonia was strongly enhanced by high irradiance and high pH.

According to OECD SIDS (2003), the NOEC (growth rate; 0-10 d), the LOEC (growth rate; 0-10 d) and the EC₅₀ (growth rate; 0-10 d) for ammonium chloride for Navicula sp. were 26.8 mg/L, 53.5 mg/L and 90.4 mg/L, respectively. Those values correspond to 53.66 mg/L (NOEC), 107.12 mg/L (LOEC) and 90.4 mg/L (10d EC₅₀) ammonium-S-lactate.

In the OECD SIDS (2003), the study was evaluated with a Klimisch of 2. It is therefore assumed that approriate methods were applied and that results can be regarded as reliable in this study.

The information on ammonia is used in a read-across approach in the assessment of the target substance ammonium-S-lactate. For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Description of key information

Neither ammonium nor lactate, of which ammonium-(S)-lactate is composed, exhibit any growth inhibition in algae up to the maximum concentration tested (ca. 500 mg/L, respectively). Therefore, the target substance ammonium-(S)-lactate is not considered to be toxic to aquatic plants. Classification as hazardous to aquatic life according to the EU CLP Regulation is not warranted based on algal data.

Key value for chemical safety assessment

EC50 for freshwater algae:

533 mg/L

EC10 or NOEC for freshwater algae:

533 mg/L

Additional information

ECx values for the read-across partners lactic acid and ammonium chloride were experimentally determined in the algaeSelenastrum capricornutumandChlorella vulgaris:

S. capricornutum:

NOEC (72 h) > 533 mg lactate/L (measured TWA)

Experiments were performed in buffered solutions, i.e., the adjusted pH of the algal medium containing different test substance concentrations (pH 7.5–8.0 at the start of the test) remained largely constant (pH 8.0–8.1, pH 8.2–8.7 in the presence of algae) during the tests.

C. vulgaris:

NOEC (21 d) = ca. 500 mg N/L (Tam 1996, NH4Cl)

Neither ammonium nor lactate, of which ammonium-(S)-lactate is composed, exhibit any growth inhibition in algae up to the maximum concentration tested (ca. 500 mg/L, respectively). Therefore, the target substance ammonium-(S)-lactate is not considered to be toxic to aquatic plants. Classification as hazardous to aquatic life according to the EU CLP Regulation is not warranted based on algal data.

Additionally, the effect of ammonia and ammonium chloride on freshwater and marine algae, respectively, is described in two publications (Mooney et al., 2019 and Admiraal, W., 1977). The effect of ammonia nitrogen onChlorella sp. was calculated as IC₁₀= 66 mg/L (14 d) (Mooney et al., 2019), which corresponds to 505 mg/L ammonium-S-lactate and supports the results of the key study.

In a study on marine diatoms (Navicula sp.) using ammonium chloride, Admiraal, W., 1977 observed an EC50 value = 90.4 mg/L, which corresponds to 181.0 mg/L ammonium-S-lactate. This study was conducted at higher pH (pH = 8) than the other studies, which increases the fraction of unionized and more toxic ammonia (NH3) of total ammonia present in the test media. Consequently, the observed threshold concentrations for toxicity are lower in this study compared to the other studies (Hanstveit, 1992, Tam 1996, Mooney, 2019) and generally support the EC₁₀value of 533 mg/L carried forth as key value for the chemical safety assessment.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.