Oct-7-enal

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-07-18 to 2017-07-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all test concetrations and control
- Sampling method: Another solution sampled separately from the preparation container (at the preparation). The mixed solution taken out with equal volume from the middle layer of the test solution in test vessels in each test level (before the renewal and at the end of exposure).

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test sample (50.0 mg) and dilution water processing similar to the control (471 mL) were mixed and stirred to prepare the stock solution of 100 mg/L. Required volumes of the stock solution and dilution water processing similar to the control were mixed and stirred in a preparing container to prepare the test solution which was divided into each test vessel. This preparation was carried out at the start of exposure and renewal of test solution.
- Controls: Dilution water filtered with a membrane filter (GV, 0.22 µm pore size, Millipore) by suction.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Common water flea
- Strain/clone: Clone A
- Source: The University of Sheffield, UK
- Age of parental stock (mean and range, SD): 20 days
- Feeding during test: No

ACCLIMATION
- Acclimation period: Less than 24 hours.
- Acclimation conditions (same as test or not): Yes
- Type and amount of food: Chlorella vulgaris of 0.1 - 0.2 mg C (Organic carbon content)/day per Daphnia was fed.
- Feeding frequency: Once a day.
- Health during acclimation (any mortality observed): No.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

19.9 - 20.0°C

pH:

7.8 - 7.9

Dissolved oxygen:

7.0 - 8.3 mg/L

Nominal and measured concentrations:

Nominal: Control (0), 0.854, 1.88, 4.13, 9.09 and 20.0 mg/L
Measured:

Details on test conditions:

TEST SYSTEM
- Test vessel: Autoclaved 50 mL stoppered Erlenmeyer flask (closed vessel)
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 50 mL
- Aeration: No.
- Renewal rate of test solution (frequency/flow rate): Each 24 hours.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated tap water filtered with a membrane filter (GV, 0.22 µm pore size, Millipore) by suction.
- Total organic carbon: < 0.5 mg/L
- Alkalinity: 36 mg/L
- Ca/mg ratio: 32 mg/L
- Conductivity: 13 mS/m
- Culture medium different from test medium: No.

OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: Room light, 16-hour light/8-hour dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobility

RANGE-FINDING STUDY
- Test concentrations: 1 and 10 mg/L
- Results used to determine the conditions for the definitive study: Yes.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8.24 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

13.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: In the 4.13, 9.09 and 20.0 mg/L test level, immobility, lethargy and reduced activity was observed.
- Mortality of control: No.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No, difference between nominal and measured concentrations is < 20%.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: 48h-EC50 = 0.15 mg/L

Table 1: Immobility

Nominal concentration (mg/L)	Vessel	24 hours		48 hours
		Number of immobilized daphnids/Total daphnids	Immobility (%)	Number of immobilized daphnids/Total daphnids	Immobility (%)
Control	A	0 / 5	0	0 / 5	0
	B	0 / 5		0 / 5
	C	0 / 5		0 / 5
	D	0 / 5		0 / 5
0.854	A	0 / 5	0	0 / 5	0
	B	0 / 5		0 / 5
	C	0 / 5		0 / 5
	D	0 / 5		0 / 5
1.88	A	0 / 5	0	0 / 5	0
	B	0 / 5		0 / 5
	C	0 / 5		0 / 5
	D	0 / 5		0 / 5
4.13	A	0 / 5	0	1 / 5	15
	B	0 / 5		1 / 5
	C	0 / 5		1 / 5
	D	0 / 5		0 / 5
9.09	A	0 / 5	5	3 / 5	45
	B	0 / 5		2 / 5
	C	1 / 5		2 / 5
	D	0 / 5		2 / 5
20.0	A	5 / 5	95	5 / 5	100
	B	4 / 5		5 / 5
	C	5 / 5		5 / 5
	D	5 / 5		5 / 5

Table 2: Dissolved oxygen concentration of test solutions

Nominal concentration (mg/L)	At the start	24 hours		At the end
		Before the renewal	After the renewal
Control	7.9	7.8	7.8	7.0
0.854	8.0	7.8	7.9	7.4
1.88	7.9	7.8	7.9	7.3
4.13	7.9	7.8	8.0	7.4
9.09	7.9	7.9	8.1	7.5
20.0	8.0	8.0	8.3	7.8

Table 3: pH of test solutions

Nominal concentration (mg/L)	At the start	24 hours		At the end
		Before the renewal	After the renewal
Control	7.8	7.8	7.9	7.8
0.854	7.8	7.8	7.9	7.8
1.88	7.8	7.9	7.9	7.8
4.13	7.8	7.9	7.9	7.9
9.09	7.8	7.9	7.9	7.9
20.0	7.9	7.9	7.9	7.9

Table 4: Temperature in test solutions

Nominal concentration (mg/L)	At the start	24 hours		At the end
		Before the renewal	After the renewal
Control	19.9	20.0	19.9	20.0
0.854	19.9	20.0	19.9	20.0
1.88	19.9	20.0	19.9	20.0
4.13	20.0	20.0	19.9	19.9
9.09	20.0	20.0	19.9	19.9
20.0	20.0	20.0	19.9	19.9

Table 5: Measured concentration of the test item in test solutions

Nominal concentration (mg/L)	Measured concentration (mg/L) (Percentage of measured concentration versus nominal concentration %)
	At the start	24 hours			At the end	Geometric mean
		Before the renewal	After the renewal
Control	n.d.	n.d.		n.d.	n.d.
0.854	0.815 (95.4)	0.855 (100)	0.822 (96.3)		0.810 (94.9)	0.825 (96.7)
1.88	1.83 (97.2)	2.01 (107)	1.83 (97.5)		1.94 (103)	1.90 (101)
4.13	4.30 (104)	4.23 (103)	3.82 (92.4)		3.95 (95.7)	4.07 (98.6)
9.09	9.51 (105)	8.77 (96.5)	8.99 (98.9)		8.67 (95.4)	8.98 (98.8)
20.0	20.7 (104)	22.7 (113)	20.2 (101)		19.8 (99.2)	20.8 (104)

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (48h) of 7-Octen-1-al was determined as 8.24 mg/L based on nominal concentration.

Executive summary:

The toxicity of 7-Octen-1-al on aquatic invertebrates was determined according to OECD 202 and in compliance with GLP. Individuals of Daphnia magna were exposed to the test substance in concentrations of 0 (control), 0.854, 1.88, 4.13, 9.09 and 20.0 mg/L, equivalent to <LOQ, 0.825, 1.90, 4.07, 8.98 and 20.8 mg/L measured concentrations, for 48 hours. Concentrations were analytically verified by GC-FID and were < 20% of the nominal concentrations. Immobility on Daphnids after 48 hours exposure were observed in the 4.13, 9.09 and 20 mg/L test levels. The 48h-EC50 was determined as 8.24 mg/L based on nominal concentration.

Description of key information

EC50 (48h) = 8.24 mg/L based on nominal concentration

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

8.24 mg/L

Additional information

The toxicity of 7-Octen-1-al on aquatic invertebrates was determined according to OECD 202 and in compliance with GLP. Individuals of Daphnia magna were exposed to the test substance in concentrations of 0 (control), 0.854, 1.88, 4.13, 9.09 and 20.0 mg/L, equivalent to <LOQ, 0.825, 1.90, 4.07, 8.98 and 20.8 mg/L measured concentrations, for 48 hours. Concentrations were analytically verified by GC-FID and were < 20% of the nominal concentrations. Immobility on Daphnids after 48 hours exposure were observed in the 4.13, 9.09 and 20 mg/L test levels. The 48h-EC50 was determined as 8.24 mg/L based on nominal concentration.