6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

The temperature reduction at day 29 occurred within the last hours of incubation and therefore is not considered to have an influence on the integrity of results at all.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione

EC Number:

249-682-3

EC Name:

6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione

Cas Number:

29529-99-5

Molecular formula:

C11H20N4S2

IUPAC Name:

6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione

Test material form:

solid: particulate/powder

Study design

Oxygen conditions:

not specified

Inoculum or test system:

sewage, predominantly domestic (adaptation not specified)

Details on inoculum:

Prior to use a sample of activated sludge from the sewage plant at Taunusstein-Bleidenstadt was washed twice with mineral nutrient solution of the CO2-Evolution-Test to eliminate organic components and carbonates from the sludge. After resolution with mineral nutrient medium the sludge was aerated by means of compressed air for about four hours. Before use as inoculum for the CO2-Evolution-Test the sludge was homogenised in a "Waring Blender" at low speed for 2 minutes and then filtered through a cotton filter previously carefully rinsed with deionised water. The filtrate was used as inoculum (1% of the final volume of the test solution) on the same day of preparation

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

ca. 10 other: mg C/L

Based on:

TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The test item and polyvalent inoculum (sewage microorganisms from a sewage plant working with predominantly domestic sewage, see below) were incubated at room temperature for 28 days. CO2 released from the test item was trapped as BaCO3 using a trap system described in the indicated guideline and the study plan. The degradation was followed by CO2 analysis. After reference to blank control, the total amount of CO2 produced by the test item was determined for the test period and calculated as a percentage of the total CO2 that the test item, based on its carbon content, could have theoreti¬cally produced (%TCO2).

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

9

St. dev.:

1.4

Sampling time:

28 d

Any other information on results incl. tables

Results of Testing Biodegradability according to OECD 301 B

- 1^stTest Solution with the Test Item -

 

 

Test Item:       6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione

 

                                                           Concentration: 73.0 mg / 3.5 L /»10 mg TOC¹⁾/L

                                                           ThCO₂²⁾:         1758.9 mg CO₂/g test item

 

                                                                                                         Theoretical amount of CO₂being generated if the test item is completely trans­formed to CO₂: 128.4 mg CO₂/ 3500 mL test solution

 

Inoculum:                                                      Activated sludge from the sewage plant of Taunusstein-Bleidenstadt dealing with predomi­nantly domestic sewage

 

Volume of the test solution:                          3500 mL

 

Functional control:                                        Sodium benzoate, 123.8 mg / 3.5 L test solution; equivalent to 263.1 mg CO₂, 86 % biode­gra­dation within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Total CO₂Evolution of the Blank:       83.9 mg CO₂/ 3.5 L within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Time [d]	Concentration:	73.0	mg / 3.5 L  ThCO2:	128.4	mg CO2/ 3.5 L
	mg CO2produced in the Test solution, cumulative			% TCO2 (= % Degradation)^3)
3		1.24		1
6		2.26		2
9		3.31		3
14		3.31		3
17		5.31		4
22		8.85		7
28		11.03		9		^4)
29		12.48		10		^5)

 

¹⁾TOC:                      Total Organic Carbon

²⁾ThCO₂:        Theoretical amount of CO₂that can be generated by the test item

³⁾% TCO₂:     Percentage of total CO₂the test item has generated in relation to the ThCO₂

⁴⁾                     The test solution was stopped by the addition of 1 mL conc. HCl;

⁵⁾                                The difference between this titration and that before is due to the liberation of CO₂after acidification of the test solution.

Table 2:        Results of Testing Biodegradability according to OECD 301 B

- 2^ndTest Solution with the Test Item -

 

 

Test Item:       6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione

 

Concentration: 73.0 mg / 3.5 L /»10 mg TOC¹⁾/L

                                                           ThCO₂²⁾:         1758.9 mg CO₂/g test item

 

                                                                                                         Theoretical amount of CO₂being generated if the test item is completely trans­formed to CO₂: 128.4 mg CO₂/ 3500 mL test solution

 

Inoculum:                                                      Activated sludge from the sewage plant of Taunusstein-Bleidenstadt dealing with predomi­nantly domestic sewage

 

Volume of the test solution:                          3500 mL

 

Functional control:                                        Sodium benzoate, 123.8 mg / 3.5 L test solution; equivalent to 263.1 mg CO₂, 86 % biode­gra­dation within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Total CO₂Evolution of the Blank:       83.9 mg CO₂/ 3.5 L within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Time [d]	Concentration:	73.0	mg / 3.5 L  ThCO2:	128.4	mg CO2/ 3.5 L
	mg CO2produced in the Test solution, cumulative			% TCO2 (= % Degradation)^3)
3		1.90		1
6		3.06		2
9		4.17		3
14		4.17		3
17		5.94		5
22		8.57		7
28		9.59		7		^4)
29		10.47		8		^5)

 

¹⁾TOC:                      Total Organic Carbon

²⁾ThCO₂:        Theoretical amount of CO₂that can be generated by the test item

³⁾% TCO₂:     Percentage of total CO₂the test item has generated in relation to the ThCO₂

⁴⁾                     The test solution was stopped by the addition of 1 mL conc. HCl;

⁵⁾                                The difference between this titration and that before is due to the liberation of CO₂after acidification of the test solution.

 

 

 

 

Table 3:         Results of Testing Biodegradability according to OECD 301 B

- 3^rdTest Solution, Sodium Benzoate-

 

Control Item:                                    Sodiumbenzoate

                                                           Concentration:123.8 mg/3.5 L /»21 mg TOC¹⁾/L

                                                           ThCO₂²⁾:         2125.1 mg CO₂/ g control item

           

                                                                      Theoretical amount of CO₂being generated if control item is completely trans­formed to CO₂: 263.1 mg CO₂/ 3500 mL test solution

 

Inoculum:                                                      Activated sludge from the sewage plant of Taunusstein-Bleidenstadt dealing with predomi­nantly domestic sewage

 

Volume of the test solution:                          3500 mL

 

Total CO₂Evolution of the Blank:       83.9 mg CO₂/ 3.5 L within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Time [d]	Concentration:	123.8	mg / 3.5 L ThCO2:	263.1	mg CO2/ 3.5 L
	mg CO2produced in the Test solution, cumulative			% TCO2 (= % Degradation)
3		81.58		31
6		162.49		62
9		187.52		71
14		200.31		76
17		209.92		80
22		217.64		83
28		222.33		85		^4)
29		226.87		86		^5)

 

¹⁾TOC:                      Total Organic Carbon

²⁾ThCO₂:        Theoretical amount of CO₂that can be generated by the control item

³⁾% TCO₂:     Percentage of total CO₂the control item has generated in relation to the ThCO₂

⁴⁾                     The test solution was stopped by the addition of 1 mL conc. HCl;

⁵⁾                                The difference between this titration and that before is due to the liberation of CO₂after acidification of the test solution.

 

 

Table 4:         Results of Testing Biodegradability according to OECD 301 B

- 4^thTest Solution, Toxicity Control -

 

Item:                         6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithioneand Sodium Benzoate,

 

                       Concentration of the test item:            73.0 mg / 3.5 L / ≈10 mg TOC¹⁾/L

                       Concentration of sodiumbenzoate:    124.2 mg / 3.5 L / ≈21 mg TOC¹⁾/L

           

                                                                      Theoretical amount of CO₂being generated if all the carbon material in the test solution is trans­formed to CO₂: 392.3 mg CO₂/ 3500 mL test solution

 

Inoculum:                                                      Activated sludge from the sewage plant of Taunusstein-Bleidenstadt dealing with predomi­nantly domestic sewage

 

Volume of the test solution:                          3500 mL

 

Sodiumbenzoate (separate

test solution):                                                123.8 mg/3.5 L test solution; equivalent to 263.1 mg CO₂, 86 % biode­gra­dation within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Test item (separate test solutions):    73.0 mg/3.5 L test solution; equivalent to 128.4 mg CO₂, 10 % biodegradation within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

                                                                      73.0 mg/3.5 L test solution; equivalent to 128.4 mg CO₂, 8% biodegradation within 28 d (+ 1 d of purging off the CO₂from the test solution)

 

Total CO₂Evolution of the Blank:       83.9 mg CO₂/ 3.5 L within 28 d (+ 1 d of purging off the CO₂from the test solution)

Time [d]	Concentration:	124.2	mg  Sodium Benzoate +			73.0	mg Test Item
		ThCO2:			392.3	mg CO2/ 3.5 L
	mg CO2produced in the Test solution, cumulative					% TCO2 (= % Degradation)
3		82.01				21
6		159.73				41
9		198.09				50
14		208.87				53
17		214.69				55
22		220.78				56
28		225.61				58		^4)
29		229.79				59		^5)

¹⁾TOC:                      Total Organic Carbon

²⁾ThCO₂:        Theoretical amount of CO₂that can be generated by the test item + control item

³⁾% TCO₂:     Percentage of total CO₂the test + control items have generated in relation to the ThCO₂

⁴⁾                     The test solution was stopped by the addition of 1 mL conc. HCl;

⁵⁾                                The difference between this titration and that before is due to the liberation of CO₂after acidification of the test solution.

 

From these degradation results it is assumed, that there is no toxicity towards the microorganisms (CO2-evolution is much higher than within the sodium benzoate control).

 

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Interpretation of results:

not readily biodegradable

Conclusions:

The test item 6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione must be regarded as “not readily biodegradable"

Executive summary:

6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithione was tested for biodegradability according to 'CO₂-Evolution-Test' (OECD Guideline 301B). Calculated from the organic carbon content of the test item and the measured CO₂generation, 10 % of the theoretical CO₂(ThCO₂) has been generated by the test item within 28d of test period in the first culture with 73.0 mg of test item. 8% of the theoretical CO₂(ThCO₂) has been generated by the test item within 28d in the second culture with 73.0 mg of test item. The calculated mean degradation value of the test item was 9%.Thus, the test item6-(dibutylamino)-1,3,5-triazine-2,4(1H,3H)-dithionemust be regarded as “not readily biodegra­dable". The control item sodium benzoate was degraded 86% and the conditions of the "10-days-window" were met within 6 days (62%). The total CO₂-evolution of the Blank was 83.9 mg CO₂/3.5L and thus being in the requested range of <40 mg/L as indicated in the OECD guideline 301B. Thus the test is regarded to be valid. The results obtained with the toxicity control indicate that there was no toxicity of the test item towards microorganisms at the concentration used within the test as a degradation value of >30% was achieved in total within that treatment (59%) within 28d (+1d).