Tetrasodium 7,7'-[[6-(morpholin-4-yl)-1,3,5-triazine-2,4-diyl]diimino]bis[4-hydroxy-3-[(4-methoxy-2-sulphonatophenyl)azo]naphthalene-2-sulphonate]

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-04-09~2015-05-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

>= 0 - <= 29 d

Initial conc.:

> 10 - < 20 mg/L

Based on:

test mat.

Parameter:

% degradation (CO2 evolution)

Value:

> 60

Sampling time:

10 d

Table 1 : The amount of CO₂ produced in the Ready Biodegradability Test

Time (day)	CO2 produced (mg)
	Test article			Blank			Positive control	Toxicity control
	Flask1	Flask2	Mean	Flask3	Flask4	Mean	Flask5	Flask6
0	0.55	0.44	0.50	0.33	0.44	0.38	0.33	0.44
3	22.88	21.78	22.33	10.34	9.46	9.90	27.39	26.84
6	19.91	20.68	20.30	7.48	6.60	7.04	25.52	21.45
9	7.37	7.04	7.21	4.18	3.52	3.85	10.89	7.59
12	1.76	1.32	1.54	1.10	1.98	1.54	2.64	1.98
16	2.64	2.86	2.75	1.65	2.64	2.15	2.97	2.97
20	1.21	1.87	1.54	1.43	0.88	1.16	2.42	1.98
24	2.09	1.76	1.93	2.42	1.87	2.15	2.64	2.31
29	1.54	1.76	1.65	1.54	0.77	1.16	1.43	1.87

Table 2 : The percent of degradability in the Ready Biodegradability Test

Time (day)	(The accumulated of CO2produced– The average amount of CO2produced in control group) / The test substance ( mg )		% ThCO2
	Test article	Positive control	Test article	Positive control
0	0.00	0.00	0.24	-0.09
3	0.42	0.58	26.89	27.16
6	0.86	1.20	55.31	55.94
9	0.97	1.43	62.50	66.91
12	0.97	1.47	62.50	68.62
16	0.99	1.50	63.80	69.91
20	1.00	1.54	64.62	71.88
24	1.00	1.55	64.15	72.65
29	1.01	1.56	65.21	73.08

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test groups cultured in the activated sludge for 10 days and the %ThCO2 of the test article was greater than 60%. Therefore, this test article in the activated sludge belonged to the easy biodegradable substance.

Executive summary:

According to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test), this test article was readily biodegradable.

Description of key information

This test article should be the readily biodegradable substance.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The final concentration of the test article and control article in this test was 15 mg/L, and the final concentration of activated sludge was 20 mg/L. The ThCO2 of the test article is 1.55 and that of article of the positive (Sodium benzoate) is 2.14. The result in this test came up to quality requirements, so that the data is valid. The test article in the activated sludge for 10 days, %ThCO2 of the test article was greater than 60%. According to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test), this test article was readily biodegradable.