Cuprate(4-), [μ-[[3,3'-[azobis[(2-hydroxy-4,1-phenylene)azo]]bis[4-hydroxy-6-[(3-sulfophenyl)amino]-2-naphthalenesulfonato]](8-)]]di-, ammonium sodium

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:

2015-05-04~2015-05-07

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test organisms (species):

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

Water media type:

freshwater

Total exposure duration:

3 d

Key result

Duration:

3 d

Dose descriptor:

EC50

Effect conc.:

59.21 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Table 2 : Preliminary test for average growth rate

Group	0~3 Day	0~3 Day
	Average growth rate	Growth inhibition rate
Control	1.03	0.00
Test group (mg/L)
100	0.46	56.82
50	0.54	49.39
25	0.90	12.77
12.5	0.94	8.59
6.25	0.98	4.89

Table 3 : pH value variation of Alga Growth Inhibition experiment

Group	0 Day	3 Day	△pH values
Control	8.99 ± 0.02	8.38 ± 0.04	-0.61
Test group (mg/L)
100	8.10 ± 0.05	7.95 ± 0.02	-0.15
50	8.16 ± 0.04	7.84 ± 0.03	-0.32
25	8.21 ± 0.07	7.80 ± 0.01	-0.41
12.5	8.48 ± 0.01	8.02 ± 0.06	-0.46
6.25	8.87 ± 0.03	8.30 ± 0.04	-0.57

Table 5 : Average growth rate of Algo Growth Inhibition experiment

Group	Average growth rate
	Day 0~1	Day 1~2	Day 2~3	Day 0~3
Control	0.69	1.43	1.18	1.10
Test group (mg/L)
100	0.00	0.85	0.62	0.49
50	0.00	0.85	0.89	0.58
25	0.69	0.85	1.00	0.85
12.5	0.69	0.98	1.16	0.94
6.25	0.69	1.15	1.17	1.00

Table 6 : Growth inhibition rates of test substances

Test group (mg/L)	Specific growth inhibition rates (%)				EC50 (mg/L)
	Day 0~1	Day 1~2	Day 2~3	Day 0~3
100	69.31	57.98	55.65	60.98	59.21
50	69.31	57.98	28.83	52.04
25	0.00	57.98	17.70	25.23
12.5	0.00	44.63	1.63	15.42
6.25	0.00	27.44	0.91	9.45

Validity criteria fulfilled:

yes

Conclusions:

The data in this test were valid and EC50 of the test substance was 59.21 mg/L.

Executive summary:

According to OECD Guideline 201 (Alga, Growth Inhibition Test), EC₅₀ of the test substance was 59.21 mg/L.

Description of key information

EC50 of the test substance was 59.21 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

59.21 mg/L

Additional information

In Preliminary test, the test substance has been tested in 100 mg/L and the result of test was 56.82% growth inhibition to Pseudokirchneriella subcapitata. The value was less than 75%, so that the highest does of test substance was 100 mg/L. The △pH values at 100, 50, 25, 12.5 and 6.25 mg/L were less than ± 1.5. The specific growth rate of control group in this test came up to quality requirements, so that the data in this test were valid. According to OECD Guideline 201 (Alga, Growth Inhibition Test), EC₅₀of the test substance was 59.21 mg/L.