N,N-diethyl-2-propynylamine

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 Oct 1989 to 13 Oct 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: DIN 38412 L.9

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): Golpanol DEP

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

not specified

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21.4 °C

pH:

- pH at study initiation: 7.58 - 8.68
- pH at study termination: 7.60 - 8.02

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 2.5, 5.0, 10.0, 25.0, 50.0, 100.0 and 100.0 (pH neutralised) mg/L
- Measured concentrations: not determined.

Details on test conditions:

TEST SYSTEM
- Initial cells density: 1.2E+04 - 1.3E+04 cells/mL
- Control end cells density: 5.2E+05 cells/mL

EFFECT PARAMETERS MEASURED: cell density, chlorophyll fluorescence with and without CMU.
The cell density was determined at 0, 24, 48, 72 and 96 hours exposure in all treatments. At study termination, the chlorophyll fluorescence intensity was determined with and without chlorphenyl-dimethyl-urea (CMU).

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

27.536 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% C.I.: 19.681 - 38.527 mg/L)

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

3.17 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% C.I.: 1.934 - 5.196 mg/L)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

23.179 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% C.I.: 17.489 - 30.721 mg/L)

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

3.176 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% C.I.: 2.061 - 4.894 mg/L)

Details on results:

Inhibition of ≥ 10% based on growth rate was observed from 5 mg/L (14.6%), and increased in a dose dependent manner up ~72% in the two highest concentrations (71.6%, 74.1% and 70.4% in the 50 mg/L, 100 mg/L and pH-controlled 100 mg/L treatments) after 72 hours exposure. In 'Any other information on results incl. tables' the results are tabulated and additional effect values are presented.

Table: Evaluation after 72 hours

Concentration [mg/L]	Growth rate	Biomass inhibition [%]	Growth rate related inhibition [%]
Control	.94	-	-
2.500	.86	6.3	8.9
5.000	.80	16.9	14.6
10.000	.73	30.2	222
25.000	.49	58.5	47.6
50.000	.27	72.6	71.6
100.000	.24	77.0	74.1
100.000 (pH neutralised)	.28	74.8	70.4

 

Table: cell density throughout the study

Concentration [mg/L]	Cell density [N/mL] [*10^3]
	0 h	24 h	48 h	72 h	96 h
Control	---	33	72	202	520
2.500	12	34	73	170	415
5.000	13	34	66	145	359
10.000	13	33	58	108	237
25.000	12	31	38	57	89
50.000	13	26	30	29	29
100.000	13	26	25	27	24
100.000 (pH neutralised)	13	26	27	30	25

 

 Table: Measurements

Concentration [mg/L]	Chlorophyll fluorescence (photosynthesis measurement)			pH		T [°C]
	F (without CMU)	F (with CMU)	Cap. [%]	Start	End
Control	2354	3384	30	7.61	7.84	21.4
2.500	1976	2970	33	7.78	7.88	21.4
5.000	1620	2538	36	7.88	7.84	21.4
10.000	1042	1507	30	8.08	7.85	21.4
25.000	386	509	24	8.24	7.79	21.4
50.000	114	139	17	8.47	7.84	21.4
100.000	87	108	19	8.68	8.02	21.4
100.000 (pH neutralised)	95	123	22	7.58	7.60	21.4

CMU = chlorphenyl-dimethyl-urea
Cap [%] (photosynthetic capacity) = ( F (with CMU) - F (without CMU) ) / F(with CMU) * 100

ADDITIONAL EFFECT VALUES

- 96-h ErC50: 23.010 mg/L (95% C.I.: 16.577 - 31.940 mg/L)

- 96-h ErC10: 3.837 mg/L (95% C.I.: 2.401 - 6.132 mg/L)

- 96-h EbC50: 10.812 mg/L (95% C.I.: 8.165 - 14.317 mg/L)

- 96-h EbC10: 1.600 mg/L (95% C.I.: 0.922 - 2.777 mg/L)

Validity criteria fulfilled:

not specified

Description of key information

72-h ErC50 = 27.536 mg/L

72-h ErC10 = 3.170 mg/L

Additional information

The toxicity towards algae was determined in a study according to DIN 38412 L.9 (GLP not specified) (Dr. Noack Laboratorium, 1989). In this study, exponentially growing algae (species/strain not specified) were exposed to nominal test substance concentrations of 0 (control), 2.5, 5.0, 10.0, 25.0, 50.0, 100.0 and pH-controlled 100 mg/L for 96 hours under static conditions. As no analytical confirmation of the test concentrations was performed, the effect values were are expressed as nominal. At the start of the test and after 24, 48, 72 and 96 hours exposure duration, the cell density was determined. At study termination, the chlorophyl fluorescence intensity with and without chlorophenyl-dimethyl-urea (CMU) was measured. Inhibition of ≥ 10% based on growth rate (relative to control) was observed from 5 mg/L (14.6%), and increased in a dose dependent manner up ~72% in the two highest concentrations (71.6%, 74.1% and 70.4% in the 50 mg/L, 100 mg/L and pH-controlled 100 mg/L treatments) after 72 hours exposure. Based on these findings, the 72-h EC50 values for growth rate and biomass are determined at 27.536 mg/L and 23.179 mg/L, respectively. The 72-h EC10 values for growth rate and biomass are determined at 3.170 mg/L and 3.176 mg/L.