Nonane-1,9-diol

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:

2004-01-27 to 2004-01-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

June 1984

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

Updating 29 December 1992

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

Version / remarks:

Public Draft, April 1996

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: batch No. 42638, substance no. 03/0183-1

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: ambient, under N2
- Stability under test conditions: The stability of the test substance under storage conditions over the exposure period was confirmed by reanalysis

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Before weighting the test substance was melted in water quench at circa 60°C for circa 1.5 hours.

FORM AS APPLIED IN THE TEST (if different from that of starting material): liquid

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 1.56, 6.25, 25 and 100 mg/L, after 0 hours (start of exposure) and 72 h (end of exposure)
- Sampling method: Twenty milliliters (20 mL) samples were applied onto SPE-columns (solid phase extraction column, Chromabond easy). The columns were then eluted with five 5 mL acetonitrile each. Aliquots of the solutions were used for GC - analysis.
- Sample storage conditions before analysis: None (analyzed immediately after sample delivery)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 125.4 mg/L was freshly prepared. Before weighting the test substance was melted in water quench at circa 60°C for circa 1.5 hours. Circa 800 mL deion. water were put into 1000 mL flask .The water was stirred and heat to circa 60°C. The test substance (125 mg/L) was weighed on plastic pad and put into the flask. The flask was filled to 1000 mL with deion. water. The stock solution was stirred circa 0.5 hours.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): The stock solution was clear.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green algae
- Strain: CHODAT SAG 86.81
- Source (laboratory, culture collection): The test strain of Desmodesmus subspicatus CHODAT SAG 86.81 is obtained at regular intervals from SAG (Sammlung von Algenkulturen/Collection of algal cultures in Göttingen) and is kept in liquid culture in the Laboratory of Experimental Toxicology and Ecology.
- Age of inoculum (at test initiation): 3 days
- Method of cultivation:
seed-culture: A seed culture was incubated for 4 days at 23 ± 2°C final cell density: 78 x 10^4 ceIls/mL
pre-culture: Seed-culture was taken to inoculate a pre-culture (initial cell density: 1 x 10^4 cells/mL). The pre-culture was incubated for 3 days at 23 ± 2°C. Final celI density: 36 x 10^4 cells/mL.

ACCLIMATION
- Culturing media and conditions (same as test or not): same as test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23 ± 2°C

pH:

8 - 8.2
After 0 h and 72 h in an additional uninoculated replicate and after 72 h in the inoculated replicate No. 1 of each concentration.

Nominal and measured concentrations:

nominal: 0 (control), 0.391, 0.781, 1.56, 3.13, 6.25, 12.5, 25, 50, 100 mg/L
measured: The concentration control analyses were performed with test solutions of the following nominal concentrations of the test substance (mg/L):
0 (control) = < LOQ
1.56 = 1.46 (mean of measured concentration d0)
6.25 = 5.60 (mean of measured concentration d0)
25 = 22.60 (mean of measured Ohconcentration d0)
100 = 102.59 (mean of measured concentration d0)

The analytical recovery rates in the range of the EC-values were > 80%. Therefore no transformation of the nominal EC-values into the values of the concentration control analysis occurs.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks (nominal volume 250 mL)
- Type: closed, plugged with gas permeable siliconsponge caps
- Material, size, headspace, fill volume: Size: 250 mL, fill volume: 100 mL
- Initial cells density: 1 x 10^4 cells/mL
- Control end cells density: The cell multiplication factor in the untreated control was after 72 hours: 28-fold (counted).
- No. of vessels per concentration (replicates): 3 replicates
- No. of vessels per control (replicates): 3 replicates

GROWTH MEDIUM
- Standard medium used: yes (OECD medium)

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: no
- Photoperiod: permanent illumination
- Light intensity and quality: artificial light, type universal white (OSRAM L 25), about 60 - 120 µE/(m^2*s) at a wave length of 400 - 700 nm

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: After 72 h in a counting chamber (Neubauer improved)
- Chlorophyll measurement: in vivo chlorophyll-a-fluorescence (pulsed excitation with light flashes having a wavelength of 435 nm), after 0, 24, 48 and 72 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: yes (non-GLP)

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

24.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

72 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

53.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Observation of abnormalities (for algal test): no information available

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50 (72h): 0.42 mg/L

Table 1: Analytical recovery rates (%)

time (h)	inoculation	Test solution
		minimum	maximum
0	yes	89.6	102.6
72	yes	72.3	120.9

Table 2: pH values at the start (t = 0 h) and at the end (t = 72 h) of the test (pa = parallel)

Concentration (mg/L)	uninoculated (pa.5) 0 h	uninoculated (pa.6) 72 h	inoculated (pa.1) 72 h
0 (control)	8.0	8.0	8.1
100	8.0	8.1	8.1
50	8.0	8.1	8.1
25	8.0	8.1	8.2
12.5	8.0	8.1	8.1
6.25	8.0	8.1	8.1
3.13	8.0	8.1	8.1
1.56	8.1	8.1	8.1*
0.781	8.1	8.1	8.1
0.391	8.1	8.1	8.1

Remark: * inoculated parallel 4

Table 3 – Test Data: Measured fluorescence (relative units) after 0 h, 24 h, 48 h and 72 h

time (h)	flask No.	concentration (mg/L)
		0 (control)	100	50	25	12.5	6.25	3.13	1.56	0.781	0.391
0	1	38	39	38	38	35	38	38	37	38	37
	2	38	39	38	39	35	37	39	37	37	37
	3	37	38	40	39	35	37	38	37	37	38
	no	0	0	0	0	0	0	0	0	0	0
24	1	140	85	120	140	120	130	140	120	140	150
	2	130	86	120	140	120	120	130	130	140	140
	3	130	80	110	130	130	130	130	130	130	150
	no	0	0	0	0	0	0	0	0	0	0
48	1	600	140	500	540	530	670	570	570	620	530
	2	550	140	430	430	580	510	530	540	550	680
	3	530	140	440	500	510	520	490	540	540	550
	no	0	0	0	0	0	0	0	0	0	0
72	1	1240	230	1120	1040	1260	1940	1280	1620	1230	980
	2	1040	200	860	990	1980	920	1160	940	1090	1680
	3	970	220	820	930	1030	960	890	990	980	1000
	no	0	0	0	0	0	0	0	0	0	0

Table 4: Test Results: CeII density after 0 h, 24 h, 48 h and 72 h

The measured fluorescence was corrected by the fluorescence of the test substance and converted into celI densities (cells x 1 0000/mL) by the following correlation:

ceII density (cells x 10000/mL) = fluorescence (relative units) / slope (m); m = 22.779

The linear correlation was obtained from a calibration curve (cell density versus fluorescence).

time (h)	flask No.	concentration (mg/L)
		0 (control)	100	50	25	12.5	6.25	3.13	1.56	0.781	0.391
0	1	1.7	1.7	1.7	1.7	1.5	1.7	1.7	1.6	1.7	1.6
	2	1.7	1.7	1.7	1.7	1.5	1.6	1.7	1.6	1.6	1.6
	3	1.6	1.7	1.8	1.7	1.5	1.6	1.7	1.6	1.6	1.7
	mean	1.7	1.7	1.7	1.7	1.5	1.6	1.7	1.6	1.6	1.6
24	1	6.1	3.7	5.3	6.1	5.3	5.7	6.1	5.3	6.1	6.6
	2	5.7	3.8	5.3	6.1	5.3	5.3	5.7	5.7	6.1	6.1
	3	5.7	3.5	4.8	5.7	5.7	5.7	5.7	5.7	5.7	6.6
	mean	5.9	3.7	5.1	6.0	5.4	5.6	5.9	5.6	6.0	6.4
48	1	26.3	6.1	22.0	23.7	23.3	29.4	25.0	25.0	27.2	23.3
	2	24.1	6.1	18.9	18.9	25.5	22.4	23.3	23.7	24.1	29.9
	3	23.3	6.1	19.3	22.0	22.4	22.8	21.5	23.7	23.7	24.1
	mean	24.6	6.1	20.0	21.5	23.7	24.9	23.3	24.1	25.0	25.8
72	1	54.4	10.1	49.2	45.7	55.3	85.2	56.2	71.1	54.0	43.0
	2	45.7	8.8	37.8	43.5	86.9	40.4	50.9	41.3	47.9	73.8
	3	42.6	9.7	36.0	40.8	45.2	42.1	39.1	43.5	43.0	43.9
	mean	47.6	9.5	41.0	43.3	62.5	55.9	48.7	51.9	48.3	53.6

Table 5 - Test Results: Calculation of biomass and inhibition of biomass after 72 h

 

parameter	flask No.	concentration (mg/L)
		0 (control)	100	50	25	12.5	6.25	3.13	1.56	0.781	0.391
biomass [rel]	1	56	11	48	49	52	74	55	62	56	47
	2	49	10	39	42	70	44	50	46	50	69
	3	46	10	38	44	47	46	43	47	47	49
	mean	50	10	41	45	57	54	49	52	51	55
Inhibition [%]		0.0	79.4	17.3	10.3	-12.9	-8.4	1.6	-3.1	-2.0	-9.6

 

 

Table 6 - Test Results: Calculation of growth rate and inhibition of growth rate after 72 h

 

parameter	flask No.	concentration (mg/L)
		0 (control)	100	50	25	12.5	6.25	3.13	1.56	0.781	0.391
growth rate [rel]	1	0.0484	0.0246	0.0470	0.0460	0.0498	0.0546	0.0488	0.0525	0.0483	0.0455
	2	0.0460	0.0227	0.0433	0.0449	0.0560	0.0446	0.0471	0.0449	0.0470	0.0530
	3	0.0454	0.0244	0.0420	0.0441	0.0470	0.0452	0.0438	0.0456	0.0455	0.0454
	mean	0.0466	0.0239	0.0441	0.0450	0.0509	0.0482	0.0466	0.0477	0.0469	0.0480
Inhibition [%]		0.0	48.7	5.3	3.4	-9.3	-3.4	0.0	-2.4	-0.8	-3.0

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of Nonane-1,9-diol on Desmodesmus subspicatus was determined in a reliable GLP study according to OECD 201. The algae were exposed to 0.391, 0.781, 1.56, 3.13, 6.25, 12.5, 25, 50 and 100 mg/L of Nonane-1,9-diol for 72 hours. The concentrations were analytically verified via GC-FIS and recovery rates were > 80%. Therefore, results were given based on nominal concentrations. Inhibition of growth rate (ErC50) and biomass (EyC50) of the algae were observed at > 100 mg/L and 72 mg/L, respectively. The NOEC and LOEC of both, inhibition of growth rate and biomass, were 50 mg/L and 100 mg/L, respectively.

Description of key information

Effect on growth rate:

ErC10 (72 h) = 53.9 mg/L

ErC50 (72 h) > 100 mg/L

NOEC (72 h) = 50 mg/L

LOEC (72 h) = 100 mg/L

Effect on biomass:

EyC10 (72 h) = 24.8 mg/L

EyC50 (72 h) = 72.0 mg/L

NOEC (72 h) = 50 mg/L

LOEC (72 h) = 100 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

53.9 mg/L

Additional information

The toxicity of Nonane-1,9-diol on Desmodesmus subspicatus was determined in a reliable GLP study according to OECD 201. The algae were exposed to 0.391, 0.781, 1.56, 3.13, 6.25, 12.5, 25, 50 and 100 mg/L of Nonane-1,9-diol for 72 hours. The concentrations were analytically verified via GC-FIS and recovery rates were > 80%. Therefore, results were given based on nominal concentrations. Inhibition of growth rate (ErC50) and biomass (EyC50) of the algae were observed at > 100 mg/L and 72 mg/L, respectively. The NOEC and LOEC of both, inhibition of growth rate and biomass, were 50 mg/L and 100 mg/L, respectively.