N,N'-[dithiobis[2-(2-hydroxyethyl)-1-methylvinylene]]bis[N-[(4-amino-2-methyl-5-pyrimidinyl)methyl]formamide

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

27 September 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

N,N'-[dithiobis[2-(2-hydroxyethyl)-1-methylvinylene]]bis[N-[(4-amino-2-methyl-5-pyrimidinyl)methyl]formamide

EC Number:

200-644-4

EC Name:

N,N'-[dithiobis[2-(2-hydroxyethyl)-1-methylvinylene]]bis[N-[(4-amino-2-methyl-5-pyrimidinyl)methyl]formamide

Cas Number:

67-16-3

Molecular formula:

C24H34N8O4S2

IUPAC Name:

N,N'-[dithiobis[2-(2-hydroxyethyl)-1-methylvinylene]]bis[N-[(4-amino-2-methyl-5-pyrimidinyl)methyl]formamide

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Purity of test material is not specified in the study report.

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

yes

Details on test solutions:

To prepare the stock solution, the test item was dissolved or dispersed directly in LC reconstituted water. The obtained preparation was agitated mechanically for up to 24 hours in an attempt to completely dissolve or disperse the test item and homogenize the solution. Water reconstituted (LC) was prepared using deionized water with a conductivity less than 10 PS/cm. The final solution after autoclaving has a pH of 7.5 ± 0.3.

Test organisms

Test organisms (species):

Scenedesmus sp.

Details on test organisms:

Strain No.: CCAP 276/20
Rapidly growing unicellular species commonly used in Europe for aquatic toxicity testing and recommended in OECD and EEC guidelines.

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Hardness:

Not specified

Test temperature:

between 23,2°C and 25,4°C

pH:

between 7,65 and 9,40

Dissolved oxygen:

Not specified

Salinity:

Not specified

Conductivity:

less than 10 PS/cm

Nominal and measured concentrations:

Nominal concentration : 0, 1, 10 & 100mg/L

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

The highest No Observed Effect Concentration on the growth rate (NOEC) at T72h was 100 mg/L, based on growth rate and biomass (p = 0.05).
The 0-72h EC50r and the 0-72h EC50b was > 100 mg/L.

Any other information on results incl. tables

Table 1: pH and temperature

Nominal charge rate (mg/L)	pH at hour TO	pH at hour T72
0 100	7,67 7,65	9,40 8,73

Temperature measured in water between T2 hours and TO time: 23.9°C

Temperature measured in a beaker of water dilution placed in the conditions of the study: minimum 23.20°C / maximum 25.40°C

Table 2: T72 hours - number of cells and calculation of the specific growth rate for each concentration

Nominal charge rate (mg/L)	Replicat	Total number of cells at T72 hours (104/mL)	Ln number of cells	Average Ln number of cellss	Specific growth rate	Inhibition of growth rate
0	1 2 3	139,0 121,0 130,0	14,14 14,08	14,08	0,07
1	1 2 3	188,0 156,0 177,0	14,45 14,26 14,39	14,36	0,07	-5,92
10	1 2 3	112,0 127,0 133,0	13,93 14,05 14,10	14,03	0,07	0,99
100	1 2 3	104,0 122,0 136,0	13,85 14,01 14,12	14,00	0,07	1,62

Ln number of cells to T 0 hours (10,000 cells) = 9,21

Table 3: T72 hours - number of cells (10⁴ cells x mL^{- l}) at each observation time and calculation of the area under the growth curve (biomass) at each concentration.

Area = cells x mL^-1 x hour

Nominal charge rate (mg/L)	Replicat	Total number of cells at T72 hours (104/mL)	Growth O à 72 hours	Average (0-72 hours)	Growth inhibition
	1 2 3	139,0 121,0 130,0	4968,0 4320,0 4644,0	4644,0
1	1 2 3	188,0 156,0 177,0	6732,0 5580,0 6336,0	6216,o	-33,85
10	1 2 3	112,0 127,0 133,0	3996,0 4536,0 4752,0	4428,0	4,65
100	1 2 3	104,0 122,0 136,0	3708,0 4356,0 4860,0	4308,0	7,24

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The highest No Observed Effect Concentration on the growth rate (NOEC) at T72h was 100 mg/L, based on growth rate and biomass (p = 0.05).
The 0-72h EC50r and the 0-72h EC50b was > 100 mg/L.