Reaction product of 1,3,5-Triazine-2,4,6-triamine, polymer with formaldehyde, methylated and C16-18 fatty alcohols

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:

2 May - 4 June 2018

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)

Version / remarks:

Adopted 17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesanstalt für Umwelt Baden-Württemberg, Karlsruhe, Germany

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum: activated sludge from municipal waste water treatment plant of Pforzheim (Germany), collected from the aeration tank
- Storage conditions: The activated sludge was kept under aerobic conditions in the period between sampling and inoculation.
- Concentration of sludge: 30 mg/L suspended solids

Duration of test (contact time):

28 d

Initial conc.:

15 mg/L

Based on:

other: mg carbon/L

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Test temperature: range of 21-25°C (mean: 23°C)
- pH: 7.51 - 7.53 on day 0; 7.76 - 7.84 on day 28
- pH adjusted: no
- suspended solids concentration: 30 mg/L
- Continuous darkness: not reported


TEST SYSTEM
- Preparation of test solution: A mineral salts medium concentrate was prepared and inoculated with activated sludge to a suspended solids concentration of 30 mg/L, and dispensed in 500 mL aliquots to all the test vessels. The volumes were then raised to the correct volume 1500 mL stocks by adding water.
- Number of culture flasks/concentration: 2 replicates
- Method used to create aerobic conditions: After preparation of the test solutions, the vessels were sealed and sparged overnight with a supply of CO2-free air to purge the medium of CO2 prior to the beginning of the study.
- Test performance: At the beginning of the study, test vessels were put into the test chamber, and were allowed to acclimatise for about one hour with slightly opened manometer and test vessel lids. Prior to the test start lids were closed tightly and simultaneously. The samples were permanently stirred during the test period.
- Details of trap for CO2 and carbon measurement: At intervals, the first trap in each train was disconnected and removed for titration with acid (0.05 M HCl) to determine the residual hydroxide concentration. The second and third traps were moved up one position and a new bottle containing a barium hydroxide Ba(OH)2 solution attached to the end of the train. Titrations were repeated at intervals not exceeding three days up to Day 10. Thereafter, titrations were performed at intervals not exceeding 5 days. On Day 28, the incubation vessels were opened and the pH measured. Each mixture was then acidified by adding 1 mL concentrated hydrochloric acid (HCl). The vessels were then re-sealed and the aeration continued overnight to purge any residual dissolved CO2 and carbonates before titrating the all the remaining trap bottles on Day 29.


SAMPLING
- Sampling frequency: samples for titration were taken on days 1, 4, 6, 8, 11, 15, 18, 22, 25, 28, and 29


CONTROL AND BLANK SYSTEM
- Inoculum control: yes, 2 replicates
- Toxicity control: yes, 1 replicate
- Reference substance: yes, 2 replicates

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

11

Sampling time:

28 d

Details on results:

In the toxicity control, biodegradation amounted to 34 % within 14 days. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms at the tested concentration due to a biodegradation > 25 %.

Results with reference substance:

The reference substance achieved 70% degradation after 28 days.

Table 1: % Degradation

Degradation^1[%]
Time [days]	Test Item		Reference Control		Toxicity Control
	Replicate 1	Replicate 2	Replicate 1	Replicate 2	-
1	1	0	32	33	11
4	6	1	50	50	19
6	6	3	59	58	29
8	8	6	62	60	30
11	4	8	64	60	31
15	5	8	67	62	34
18	6	8	70	64	35
22	8	10	71	65	36
25	8	10	72	66	36
28	10	10	72	67	37
29	5	4	69	63	33
29	11	4	70	64	35
29	9	3	69	64	33
Mean (28 days)	11		70		37

¹Corrected for the mean oxygen uptake of the inoculum controls

Table 2: Individual Daily Values for Cumulative Carbon Dioxide Production

	Test Item		Reference Control		Inoculum Control		Toxicity Control
Time	Replicate 1	Replicate 2	Replicate 1	Replicate 2	Replicate 1	Replicate 2	Replicate 1
[days]	[mg/L]
1	12.9	11.8	39.3	39.6	12.4	12.4	21.2
4	31.4	27.5	67.7	67.7	26.4	26.1	42.4
6	39.1	36.0	82.8	82.0	33.8	33.8	57.8
8	49.5	48.1	94.3	92.7	42.6	43.5	67.7
11	53.6	56.7	103.4	100.4	49.5	51.2	76.5
15	57.8	59.7	109.2	104.5	52.3	54.2	81.7
18	59.4	61.3	112.5	107.8	53.9	55.6	83.6
22	61.1	63.0	113.9	108.9	53.9	55.6	84.7
25	62.2	63.3	114.7	109.7	53.9	56.7	85.0
28	63.8	64.1	115.5	111.4	53.9	57.2	86.4
29	64.4	64.1	117.4	112.8	58.6	62.4	88.0
29	70.1	64.9	119.4	114.4	58.9	63.8	90.2
29	70.4	65.5	120.2	115.5	59.7	65.7	90.2

Table 3: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
Difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20%.	< 20 %	yes
Percentage degradation of the reference compound has reached the pass levels by day 14.	70% degradation after 14 d	yes
The toxicity control should degrade to at least 35% (based on DOC) or at least 25% (based on ThOD or ThCO2) within 14 d.	37% degradation (based on ThCO2) after 14 d	yes
The IC content of the test substance suspension in the mineral medium at the beginning of the test must be less than 5% of the TC.	not stated	cannot be determined
The total CO2 evolution in the inoculum blank at the end of the test should not normally exceed 70 mg/L medium.	59.7 – 65.7 mg/L	yes

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Interpretation of results:

not readily biodegradable

Description of key information

not readily biodegradable (11 % biodegradation after 28 days; OECD 301B)

Additional information

The substance achieved a biodegradation of 11% after 28 days in an OECD 301B study (CO2 evolution). The substance is therefore considered not readily biodegradable.