5-({4-chloro-6-[(2-methylphenyl)amino]-1,3,5-triazin-2-yl}amino)-4-hydroxy-3-[(2-sulfophenyl)diazenyl]naphthalene-2,7-disulfonic acid, lithium sodium salts

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:

From April 27, 2016 to November 08, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The structure of the read-across substance, EC:300-504-3, is the same as the test substance. Therefore, the human toxicity and environmental toxicity is the same. The only difference is the test substance containing lithium. However, the low level of lithium will not change the classification.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Specific details on test material used for the study:

Evercion SR61, Reactive red 3-1, EC: 300-504-3

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, adapted

Details on inoculum:

- Source of inoculum/activated sludge: Dihua sewage treatment plant, Taiwan.

Duration of test (contact time):

29 d

Initial conc.:

1 g/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance:

acetic acid, sodium salt

Remarks:

Sodium acetate

Parameter:

% degradation (CO2 evolution)

Remarks on result:

other: The percentage biodegradation of Evercion SR61 was not be exceed 10 % and percentage biodegradation was not achieve 60 % with following 10 days. Therefore, Evercion SR61 was not the readily biodegradable article.

Results with reference substance:

At Day 14 during the study, the biodegradation was 69.33 %.

At the end of the test, the CO2 production of blank control groups were 38.09 mg/L.

 

Table 1. The percentage biodegradation of the test groups

Day	Percentage of biodegradation (% ThCO2)^a
	Test group
	Flask 1	Flask 2	Mean	Difference of replicate^b
2	0.86	1.43	1.14	-0.57
5	1.14	1.14	1.14	0.00
7	1.90	2.47	2.19	-0.57
9	3.42	2.09	2.76	1.33
14	4.18	2.28	3.23	1.90
19	5.61	2.38	3.99	3.23
23	6.75	2.76	4.75	3.99
27	7.99	2.85	5.42	5.13
29	9.41	3.33	6.37	6.09

^a Percentage of biodegradation (% ThCO₂) = (cumulative CO₂of test group (mg) -cumulative CO₂of blank control group (mg)) / (added TOC (mg) × 3.67) ×100%

^b Difference of replicate = Flask 1- Flash 2

 

Table 2. The percentage biodegradation of the reference and toxicity control group

Day	Percentage of biodegradation (% ThCO2)^a
	Referencecontrol group	Toxicity control group
	Flask 5	Flask 6
2	21.44	11.31
5	47.79	23.33
7	60.59	29.66
9	66.77	31.67
14	69.33	32.48
19	71.15	33.43
23	73.49	33.63
27	75.09	34.39
29	75.20	34.54

^a Percentage of biodegradation (% ThCO₂) = (cumulative CO₂of reference control group or toxicity control (mg) - cumulative CO₂of toxicity control group (mg)) / (added TOC (mg) × 3.67) ×100%

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

According to OECD 301B test method, Evercion SR61 was not be considered readily biodegradable.

Executive summary:

This test using the procedures outlined in the SuperLab Study Plan for M62-151100099001EN which is based on the SOP for the OECD 301B (SOPE-503) and OECD 301B (OECD, 1992). The results of this OECD 301B test for Evercion SR61 show that all validity criteria were met. Evercion SR61 was not readily biodegradable under the test conditions and the percentage biodegradation of Evercion SR61 in sludge was less than 60 %.

Description of key information

Not readily biodegradable (OECD TG 301B).

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

According to OECD 301B test method, CJ307 was not be considered readily biodegradable.