N-cyclopropyl-1,3,5-triazine-2,4,6-triamine

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1983/06/08 to 1983/06/29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Justification for type of information:

Study was not performed under GLP conditions. The guidelines followed in this study are not stated. There are no deviations in the study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

N-cyclopropyl-1,3,5-triazine-2,4,6-triamine

EC Number:

266-257-8

EC Name:

N-cyclopropyl-1,3,5-triazine-2,4,6-triamine

Cas Number:

66215-27-8

Molecular formula:

C6H10N6

IUPAC Name:

N2-cyclopropyl-1,3,5-triazine-2,4,6-triamine

Test material form:

solid: particulate/powder

Remarks:

Colorless powder

Specific details on test material used for the study:

The test material is cyromazine.

Sampling and analysis

Analytical monitoring:

yes

Remarks:

Analytical determinations of test substance concentrations were made on sample collected on days 1, 7, 14 and 21.

Details on sampling:

Ten test organisms were assigned to each test beaker, totaling 40 test organisms per concentration and control. Live animals were recorded and dead animals removed daily, except on Days 3, and 6. The number of live animals was recorded daily (except on days 3, 4 and 6) and the dead animals removed. From day 10 onwards, live animals were counted and newly hatched neonates counted and removed. At the end of the 21-day exposure period the surviving adults in each test chamber were removed, preserved in alcohol and their length was determined.

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The Daphnia Magna used for this test are static cultures maintained on trout chow at 20-24 °C. About 7 days prior to testing, large adults were gently netted from stock cultures and placed in the test chambers (~20/chamber) under flow-through conditions. The daphnia were fed a mixture of the unicellular algae Chlamydomonas reinhardtii and a solution of 'Cerophyl', the food was supplied automatically as the test solution was refreshed.

Study design

Test type:

flow-through

Water media type:

other: dechlorinated, biologically aged tap water

Total exposure duration:

21 d

Test conditions

Test temperature:

20 ± 2°C

Nominal and measured concentrations:

Nominal concentrations (mg/L): 0.23, 0.46, 0.91, 1.82 and 3.64
Mean measured concentrations (mg/L): 0.31, 0.64, 0.96, 1.8, 3.7

Details on test conditions:

4 test vessels were used, each vessel containing 10 neonates at age <48 hours. The test chamber were 1500ml glass beaker with 330-micron nitex net collars. 200ml of fresh test solution (or control) was pumped through test system every 15 minutes during exposure period

The test chambers were cleaned twice weekly for the duration of the experiment when the chambers were being cleaned the Daphnia magna were gently pipetted into 100mL of test solution in a separate vessel. For the 21 days duration of the test, the test vessels were subjected to a 16 hour photoperiod and maintained in a water bath set at 20 ± 2°C.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

> 0.31 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

growth

Remarks:

adult daphnia body lengths

Effect concentrations 2

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

> 0.64 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

reproduction: production of clutches per surviving parent organism {for L. stagnalis, TG 243}

Details on results:

There was  no  statistically  significant  difference  in mortality (Scheffées multiple comparison) between the control treatments and the 0.31 and 0 64 mg/L test material treatments However, test material concentrations of 0.96 mg/L and above resulted in a statistically significant increase in mortality on day 21.

Reported statistics and error estimates:

There was no statistical difference in length of the surviving Daphnia magna in the 0.31 mg/L test material treatment. However, based on a one-tailed Dunnett's test, treatment with 0.64 mg/L test material resulted in a statistically significant reduction in length compared to the control treatment (3.94 mm compared to 4.43 mm). No young were produced in the 0.96, 1.8 and 3.7 mg/L test material treatments but in the 0.31 and 0.64 mg/L treatments young were released from day 10 onwards. An initial one-way analysis of variance detected no significant differences in reproduction however, a subsequent analysis using the one-tailed Dunnett's test showed a significant difference between the control and the 0 64 mg/L treatment.

Any other information on results incl. tables

Analytical findings

The measured concentration of test material in some of the test chambers was outside the 80-120% limit and therefore the measured concentration will be used The  mean measured concentrations (mg/L) are: 0.31, 0.64, 0.96, 1.8, 3.7 compared to the nominal concentrations (mg/L) of 0.23, 0.46, 0.91, 1.82 and 3.64.

 

Table 1

 

Measured cyromazine levels during the Daphnia magna chronic toxicity study

 

 

Nominal test substance con (mg/L)	Measured concentrations
	Day 1		Day 7		Day 14		Day 21		Mean
	mg/L	% of nominal	mg/L	% of nominal	mg/L	% of nominal	mg/L	% of nominal	mg/L	% of nominal
Control	<0.2 7	-	<0.27	-	<0.27	-	<0.27	-	<0.27	-
0 23	0.35	152.2	0.28	121.7	<0.27	-	0.31	134.8	0.31	134.8
0 46	0.75	163.0	0.56	121.7	0.63	137.0	0.63	137.0	0.64	139.1
0 91	0.88	96.7	0.81	89.0	1.2	131.9	nd	-	0.96	105.5
1 82	2.1	115.4	1.4	76.9	nd	-	nd	-	1.8	98.9
3 64	4.3	118.1	3.1	85.2	nd	-	nd	-	3.7	101.6

nd: not determined as all test organisms in those concentrations were dead Detection limit was 0.27 mg/L

 

Table 2

 

Survival of Daphnia magna, exposed under flow-through conditions, to cyromazine in a 21-day chronic study

 

Mean measured treatment concentrations Test material (mg/L)	Mean number of living Daphnia magna			Mean % living Daphnia magna (day 21)
	Day 7	Day 14	Day 21
Control	9.3	8.3	8	80.0
0.31	9.5	9.3	8.5	85.0
0.64	9	8	6.8	67.5
0.96	3.5	0.5	0	0 0*
1 8	0 5	0	0	0 0*
3 7	0	0	0	0 0*

• Significant difference from the control (Scheffés multiple comparison test, P= 0.05)

 

Table 3

 

Reproductive performance of Daphnia magna exposed under flow-through conditions, to test material in a 21-day chronic study

Mean measured conc. Test material (mg/L)	Mean no. Young/test chamber	No. 8reeding Adults	No. of Adult Reproduction Days	Young/Adult reproductive day (Mean )
Control	423 75	6-10	72-120	4.33
0.31	414 75	7-10	101-120	3.84
0.64	262	6-10	81-117	2.91*
0.96	0	-	-	-
1.8	0	-	-	-
3.7	0	-	-	-

• Significantly different from the control, one tailed Dunnett's test (P= 0.05)

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

In a 21-day chronic flow through study the NOEC for reproduction of Daphnia magna is > 0.64 mg/L cyromazine and for length of surviving adults the NOEC is > 0.31 mg/L cyromazine. In summary the NOEC using length and reproduction is 0.45 mg/L.

Executive summary:

The effect of cyromazine on the mortality, growth and reproductive success of Daphnia magna was investigated in a 21-day chronic, flow-through study The test substance was tested at 0.23, 0.46, 0.91, 1.82 and 3.64 mg/L. All treatments were made up in dechlorinated, biologically aged tap water. Since there were no guideline used in this study, there was no validity criteria that was met. 

 

In a 21-day chronic flow through study the NOEC for reproduction of Daphnia magna is > 0.64 mg/L cyromazine and for length of surviving adults the NOEC is > 0.31 mg/L cyromazine.