Undec-10-enal

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard OECD test guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

The effect of test substance was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga growth inhibition test. The test concentration chosen for the study were 2.83 mg/l, 4.25 mg/l, 6.37 mg/l, 9.55 mg/l, 14.33 mg/l and 21.5 mg/l were prepared.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was prepared by adding 8.6 mg of test substance in 400 ml of BBM to get the final concentration of 21.5 mg/l. The sock solution was subjected to stirring for 30 minutes to obtain a homogenous solution for the experiment. The remaining test solutions were prepared by dilution from the above stock solution, under aseptic condition. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 10000 cells/ml. Care was taken to have a homogeneous solution for the experiment.

Test organisms (species):

Chlorella vulgaris

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Source (laboratory, culture collection): National Environmental Engineering Research Institute (NEERI), Nagpur
- Method of cultivation:Bold’s Basal Medium (BBM).

ACCLIMATION
- Culturing media and conditions (same as test or not):The medium to be used for the growth of algae was Bold’s Basal Medium (BBM). It is a medium composed of macronutrients, micronutrients, alkaline EDTA solution and Iron solution. Stock solution of each of these was prepared separately and then a complete medium was prepared and sterilized. De-ionized water was used to prepare the BBM.
- Any deformed or abnormal cells observed:The culture was examined under the microscope to confirm that it was unicellular, healthy and not contaminated.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

24, 48, 72 hrs

Hardness:

no data

Test temperature:

24 °C ±2°C

pH:

6.8 -7.1

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

The effect of the test substance on the green algae Chlorella vulgaris culture was observed at nominal test concentration of 2.83 mg/l, 4.25 mg/l, 6.37 mg/l, 9.55 mg/l, 14.33 mg/l and 21.5 mg/l. All the six concentration were in geometric series spaced by a factor of 1.5.

Details on test conditions:

TEST SYSTEM
- Test vessel: Conical flasks
- Material, size, headspace, fill volume: 100 ml conical flasks filled with 60 ml was used for the study.
- Initial cells density: 10000cells/ml
- No. of organisms per vessel: 10000cells/ml
- No. of vessels per concentration (replicates): Two replicates for each test concentration
- No. of vessels per control (replicates): Three replicates for Control

GROWTH MEDIUM
- Standard medium used: yes
- Detailed composition if non-standard medium was used: The medium to be used for the growth of algae was Bold’s Basal Medium (BBM). It is a medium composed of macronutrients, micronutrients, alkaline EDTA solution and Iron solution. Stock solution of each of these was prepared separately and then a complete medium was prepared and sterilized. De-ionized water was used to prepare the BBM.


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: Yes
- Photoperiod: 16 Hour Light Period : 8 Hour Dark Period
- Light intensity and quality: continuous, uniform fluorescent illumination(1500Lux)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Spectrophotometer - The absorbance values of each test vessel and control vessel was noted at 680nm.The BBM was taken as blank for both control and test vessels. The absorbance value of each vessel was in line with the average specific growth rate.
- Chlorophyll measurement: No data
- Other: The cultures were observed daily with the help of a microscope to verify a normal and healthy appearance of the algal culture and also to
observe any abnormal appearance of the algae (as may be caused by the exposure of the test item). Apart from this, the cell count of each test vessel was also noted with the help of a microscope and haemocytometer.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: All the six concentrations were in geometric series spaced by a factor of 2.
- Test concentrations: Six test concentration were: 2.83 mg/l, 4.25 mg/l, 6.37 mg/l, 9.55 mg/l, 14.33 mg/l and 21.5 mg/l (Nominal concentrations)
- Results used to determine the conditions for the definitive study: Mortality of test organisms


Other:
Incubation :
1. The temperature of the orbital shaking incubator was kept constant throughout the period of exposure of the experiment. The temperature was maintained at 24 ° C±2°C.
2. The test vessels were incubated with a continuous, uniform fluorescent illumination (1500Lux).
3. The pH of the control cultures needs to be noted during the study and the pH of the control medium should not increase by more than 1.5 units during the test.
4. The orbital shaking incubator was set at a speed of 120 revolutions per minute throughout the study period. This is to provide constant shaking to the algal cells to keep them in suspension and to ensure that they do not settle down on the bottom of the test vessel.
5. Study duration : The experimental phase of the study was lasted for a period of 72 hours.

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.23 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Other effect were not observed

Reported statistics and error estimates:

To obtain a quantitative concentration-response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined.

Table 1: Showing the average cell count using Haemocytometer of the experimental flasks at an equal interval of 24hrs, 48hrs and 72hrs

Experimental Flasks and test concentration	24 Hours	48 Hours	72 Hours
Control
Replicate 1	68.5 x 10^4	71.5 x 10^4	11.4 x 10^5
Replicate 2	72 x 10^4	75.5 x 10^4	11 x 10^5
Replicate 3	73 x 10^4	83.5 x 10^4	12.65 x 10^5
Test chemical
2.83 mg/l
Replicate 1	65.5 x 10^4	73 x 10^4	66.5 x 10^4
Replicate 2	61 x 10^4	76.5 x 10^4	68.5 x 10^4
4.25 mg/l
Replicate 1	67 x 10^4	72.5 x 10^4	62 x 10^4
Replicate 2	66 x 10^4	35.5 x 10^4	61 x 10^4
6.37 mg/l
Replicate 1	59 x 10^4	69 x 10^4	65 x 10^4
Replicate 2	61.5 x 10^4	67 x 10^4	64 x 10^4
9.55 mg/l
Replicate 1	58.5 x 10^4	70.5 x 10^4	56.5 x 10^4
Replicate 2	60.5 x 10^4	66.5 x 10^4	44.5 x 10^4
14.33 mg/l
Replicate 1	61 x 10^4	66.5 x 10^4	48.5 x 10^4
Replicate 2	53 x 10^4	63 x 10^4	54.5 x 10^4
21.5 mg/l
Replicate 1	60 x 10^4	63.5 x 10^4	53.5 x 10^4
Replicate 2	56.5 x 10^4	66 x 10^4	52.5 x 10^4

 

Table 2 : Showing the values of average specific growth rate and percentage inhibition after an interval of 72 hours

	CONTROL		2.83 mg/l		4.25 mg/l		6.37 mg/l		9.55 mg/l		14.33 mg/l		21.5 mg/l
Average Specific Growth rate (µ )	R1	1.578	R1	1.399	R1	1.375	R1	1.391	R1	1.344	R1	1.293	R1	1.326
	R2	1.566	R2	1.408	R2	1.370	R2	1.386	R2	1.332	R2	1.332	R2	1.320
	R3	1.613
Mean of Avg. Specific growth rate	1.586		1.404		1.373		1.388		1.338		1.313		1.323
Percentage Inhibition (%I)	_		11.493		13.447		12.446		15.607		17.211		16.573

 

 

Table 3 : Depicting pH values at test initiation (0 Hours) and test termination ( 72 Hours)

 

Experimental Flasks and test concentration	0 Hours	72 Hours
CONTROL
Replicate 1	7.2	7.1
Replicate 2	7.2	7.2
Replicate 3	7.1	7.1
Test chemical
2.83 mg/l
Replicate 1	7.1	6.9
Replicate 2	7.1	6.9
4.25 mg/l
Replicate 1	7.0	6.8
Replicate 2	7.1	6.8
6.37 mg/l
Replicate 1	7.1	6.8
Replicate 2	7.1	6.8
9.55 mg/l
Replicate 1	7.1	6.7
Replicate 2	7.1	6.8
14.33 mg/l
Replicate 1	7.0	6.8
Replicate 2	7.0	6.8
21.5 mg/l
Replicate 1	7.1	6.8
Replicate 2	7.1	6.8

Validity criteria fulfilled:

yes

Conclusions:

After 72 hours of exposure to test chemical to various nominal test concentration, EC10 calculated through probit analysis was determine to be 2.23 mg/L based on the effect observed on the growth of green algae Chlorella vulgaris.

Executive summary:

The effect of test substance was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga growth inhibition test. The test substance was prepared by adding 8.6 mg of test substance in 400 ml of BBM to get the final concentration of 21.5 mg/l. The sock solution was subjected to stirring for 30 minutes to obtain a homogenous solution for the experiment. The remaining test solutions were prepared by dilution from the above stock solution, under aseptic condition. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 10000 cells/ml. Care was taken to have a homogeneous solution for the experiment. The effect of the test substance on the green algae Chlorella vulgaris culture was observed at nominal test concentration of 2.83 mg/l, 4.25 mg/l, 6.37 mg/l, 9.55 mg/l, 14.33 mg/l and 21.5 mg/l. All the six concentration were in geometric series spaced by a factor of 1.5. For the assessment of algal growth, the test was conducted in replicates. The control flask was maintained in triplicates as recommended in the OECD guideline and the test concentration were selected in geometric series which were maintained in duplicates. To obtain a quantitative concentration-response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. After 72 hours of exposure to test chemical to various nominal test concentration, EC10 calculated through probit analysis was determine to be 2.23 mg/L based on the effect observed on the growth of green algae Chlorella vulgaris. As the EC10 was calculated which is 2.23 mg/l, thus on that basis chemical cannot be classified in any criteria and can be consider that the EC50 was > 2.23 mg/l.

Description of key information

The effect of test substance was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga growth inhibition test. The test substance was prepared by adding 8.6 mg of test substance in 400 ml of BBM to get the final concentration of 21.5 mg/l. The sock solution was subjected to stirring for 30 minutes to obtain a homogenous solution for the experiment. The remaining test solutions were prepared by dilution from the above stock solution, under aseptic condition. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 10000 cells/ml. Care was taken to have a homogeneous solution for the experiment. The effect of the test substance on the green algae Chlorella vulgaris culture was observed at nominal test concentration of 2.83 mg/l, 4.25 mg/l, 6.37 mg/l, 9.55 mg/l, 14.33 mg/l and 21.5 mg/l. All the six concentration were in geometric series spaced by a factor of 1.5. For the assessment of algal growth, the test was conducted in replicates. The control flask was maintained in triplicates as recommended in the OECD guideline and the test concentration were selected in geometric series which were maintained in duplicates. To obtain a quantitative concentration-response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. After 72 hours of exposure to test chemical to various nominal test concentration, EC10 calculated through probit analysis was determine to be 2.23 mg/L based on the effect observed on the growth of green algae Chlorella vulgaris. As the EC10 was calculated which is 2.23 mg/l, thus on that basis chemical cannot be classified in any criteria and can be consider that the EC50 was > 2.23 mg/l.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

2.23 mg/L

Additional information

The effect of test substance was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga growth inhibition test. The test substance was prepared by adding 8.6 mg of test substance in 400 ml of BBM to get the final concentration of 21.5 mg/l. The sock solution was subjected to stirring for 30 minutes to obtain a homogenous solution for the experiment. The remaining test solutions were prepared by dilution from the above stock solution, under aseptic condition. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 10000 cells/ml. Care was taken to have a homogeneous solution for the experiment. The effect of the test substance on the green algae Chlorella vulgaris culture was observed at nominal test concentration of 2.83 mg/l, 4.25 mg/l, 6.37 mg/l, 9.55 mg/l, 14.33 mg/l and 21.5 mg/l. All the six concentration were in geometric series spaced by a factor of 1.5. For the assessment of algal growth, the test was conducted in replicates. The control flask was maintained in triplicates as recommended in the OECD guideline and the test concentration were selected in geometric series which were maintained in duplicates. To obtain a quantitative concentration-response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. After 72 hours of exposure to test chemical to various nominal test concentration, EC10 calculated through probit analysis was determine to be 2.23 mg/L based on the effect observed on the growth of green algae Chlorella vulgaris. As the EC10 was calculated which is 2.23 mg/l, thus on that basis chemical cannot be classified in any criteria and can be consider that the EC50 was > 2.23 mg/l.