Reaction mass of 2-methyldecan-1-al and undecanal

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

12 March 1991 to 15 March 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (non-GLP, no analytical verification of test item concentrations)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: German Industrial Standard DIN 38412, part 9

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Undecanal

EC Number:

203-972-6

EC Name:

Undecanal

Cas Number:

112-44-7

Molecular formula:

C11H22O

IUPAC Name:

undecanal

Details on test material:

- Name of test material (as cited in study report): undecanal
- Physical state: liquid
- Analytical purity: ca. 65% (not stated in study report, but derived from lot and batch number of other study report (Chapter 6.1.3: BASF, 1990)
- Lot/batch No.: product no. 07525, batch no. 5/89
- Expiration date of the lot/batch: no expiration date (unlimited if oxygen is excluded)
- Stability under test conditions: stable against temperature and hydrolysis, oxidises to form the corresponding acid

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: stock solution (51.2 mg/L test material)
- Controls: control with bidestillated water and control with acetone
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): stock solution: 150 mg/L (= 0.188 mL/L); according to study report: solvent concentration in test assays: 75 mg/L (= 0.094 mL/L) (based on initial vehicle concentration in stock solution, the maximum acetone concentration would be 0.047 mL/L)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green alga
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Collection of Algal Cultures (SAG), University of Göttingen, Germany)
- Age of inoculum (at test initiation): no data (exponential growth phase)
- Method of cultivation: 250 mL Erlenmeyer flasks, 100 mL sterile nutrient medium, pH 8.2±0.3 (according to DIN 38412/9)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

23±1 °C

pH:

test initiation (0 h): 8.5
test end (72 h): 8.1 to 9.7

Dissolved oxygen:

not determined

Nominal and measured concentrations:

nominal: 0 (control), 0 (solvent control), 0.80, 1.60, 3.20, 6.40, 12.80 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: test tubes with 10 mL medium
- Aeration: no
- Initial cells density: 10000 cells/mL (= fluorimeter value: 0.05±0.01)
- Control end cells density: fluorimeter value: 1.27
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

GROWTH MEDIUM
- Standard medium used: yes (according to DIN 38412/9)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: bidemineralized water

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous light
- Light intensity and quality: 8000 Lux, white light, 0.72E20 photons/m2s, 120 µE/m2s

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: fluorimeter (0, 24, 48, 72 h)
- Chlorophyll measurement: no
- Other: pH at 0 and 72 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.0
- Justification for using less concentrations than requested by guideline: not applicable
- Range finding study
- Test concentrations: no data
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.24 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

7.34 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.46 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: calculated from purity

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.37 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: calculated from purity

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.49 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 7

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.97 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks on result:

other: calculated from purity

Effect concentrations 8

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

2.07 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks on result:

other: calculated from purity

Details on results:

- Exponential growth in the control (for algal test): yes
- Any stimulation of growth found in any treatment: yes, at 0.80 mg/L
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: yes

Any other information on results incl. tables

Test concentration	pH		Biomass	Growth rate	Inhibition
(mg/L)	0 h	72 h			biomass (%)	growth rate (%)
0 (solvent control)	8.5	9.2	1.14	1.02
0.80	8.5	9.7	1.29	1.14	-13.68	-11.72
1.60	8.5	9.4	1.03	1.03	9.57	-1.60
3.20	8.5	8.7	0.43	0.83	61.94	18.54
6.40	8.5	8.4	0.17	0.57	85.04	44.11
12.80	8.5	8.1	-0.07	-0.46	106.27	145.45
0 (control)	8.5	9.2	1.09	1.07	4.40	-5.19

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Undecanal was acutely toxic to algae at elevated concentrations. (72-h ErC50 = 4.37 mg/L; Ökolimna, 1991). Classification for acute toxicity according to EU 286/2011 table 4.1.0 is therefore not required.

Executive summary:

Undecanal was tested for algal toxicity according to German Industrial Standard DIN 38412/9. The tested species was Desmodesmus subspicatus (reported as Scenedesmus subspicatus). The stock solution was prepared using acetone, the maximum concentration was below the limit of 100 µL according to OECD 201. No analytical monitoring was performed, therefore the effect concentrations are given as nominal values based on test material.

The 72 -h ErC50 (growth rate) was determined to be 7.34 mg/L (test material). Based on the purity of the test material the effect concentration was recalculated: 72 -h ErC50 = 4.37 mg/L active ingredient. A NOEC was not determined, instead the ErC10 was stated to be 2.24 mg/L (test material; recalculated based on 65% purity: 1 .46 mg/L act. ingr.). In the lowest tested concentration (0.80 mg/L) a growth stimulating effect was observed.

This result can be read across to n-/iso-undecanal. A detailed justification of read across is provided in the discussion field of the endpoint summary of this section. It should be noted that the experimental effect concentration calculated for the pure substance (72 -h ErC50 = 4.37 mg/L) is significantly higher than the LC50 value predicted for n-undecanal by ECOSAR (0.863 mg/L, cf. endpoint summary).