2,2'-oxydi(ethylamine)

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

QSAR prediction using the most recent version of ECOSAR (2009) - can be used as key information in a weight-of-evidence approach.

Qualifier:

according to guideline

Guideline:

other: ECOSAR v.1.00 (ECOWIN v.1.00)

Principles of method if other than guideline:

QSAR predictions were conducted using ECOSAR v.1.00 (2009) using the QSAR for aliphatic amines

Specific details on test material used for the study:

- 2,2'-oxydi(ethylamine)
- SMILES: NCCOCCN
- Molecular weight = 104.15 g/mol
- A log Kow of -1.89 was used (instead of direct estimation by KowWin)
- A water solubility was entered of 1E+006 mg/L

Test organisms (species):

other: green algae (not specified)

Details on test organisms:

green algae, not specified

Duration:

96 h

Dose descriptor:

other: chronic value (geometric mean of NOEC and LOEC)

Effect conc.:

24.505 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

21.985 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Validity of EC50 model:
1. Defined endpoint: 96-h EC50 for green algae.
2. Unambiguous algorithm: linear regression QSAR; log 96-h EC50 (mmol/L) = -0.3708 (log Kow) -1.3744
3. Applicability domain: This SAR may be used to estimate toxicity for aliphatic amines. LIMITATIONS: If the log Kow value is greater than 7, or if the compound is solid and the EC50 exceeds the water solubility by 10X, no effects at saturation are predicted.
4. Statistical characteristics: The EC50 is in millimoles per liter (mM/L); N = 49 + 10; and the Coefficient of Determination (R2) = 0.306. 

Validity of chronic value model:
1. Defined endpoint: chronic value for green algae (i.e. the geometric mean of NOEC and LOEC).
2. Unambiguous algorithm: linear regression QSAR; log ChV (mmol/L) = -0.4862 (log Kow) - 1.5487
3. Applicability domain: This SAR may be used to estimate toxicity for aliphatic amines with log Kow values less than or equal to 7.0 and molecular weights less than 1000. LIMITATIONS: If the log Kow value is greater than 7.0, or if the compound is solid and the ChV exceeds the water solubility by 10X, no effects at saturation are predicted.
4. Statistical characteristics: The ChV is in millimoles per liter (mM/L); N = 32 + 7; and the Coefficient of Determination (R2) = 0.5639

Adequacy of prediction: the substance falls within the applicability domains described above and therefore the predicted values can be considered reliable.

Validity criteria fulfilled:

not specified

Conclusions:

QSAR predictions were conducted using the latest version of US EPA's ECOSAR (v.1.00, 2009) using input values of -1.89 for log Kow and 1E+006 mg/L for water solubility in the QSAR for aliphatic amines. The model predicted a 96-h EC50 and a chronic value for green algae of 21.985 mg/L and 24.505 mg/L, respectively. Because the substance falls within the applicability domain of the models these predicted values can be considered reliable.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-11-15 - 2012-12-21

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Study performed according to internationally accepted test guidelines for toxicity to algae (OECD 201) and conform CLP requirements. The results of the study can be considered reliable but with restrictions. This because initial pH in the three highest test concentrations (circum-EC50) was quite high (9.2-10.2), which may have affected the results of the test.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): BAEE
- Physical state: liquid
- Analytical purity: 95.9 %
- Lot/batch No.: LL080179
- Expiration date of the lot/batch: not supplied
- Storage condition of test material: room temperature in the dark

Analytical monitoring:

yes

Details on sampling:

- Duplicate samples were taken at 0 and 72 h from the control and each test group for quantitative analysis of test substance concentrations (R1-R6
pooled).
- All samples were stored at approximately -20°C prior to analysis.

Vehicle:

no

Details on test solutions:

- 100 mg of test item was dissolved directly in culture medium and volume adjusted to 1 L to give a 100 mg/L stock solution.
- Other test concentrations were prepared by serial dilution using this stock solution.
- Stock and test solutions were inverted several times to ensure adequate mixing and homogeneity.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Strain: CCAP 278/4
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd, Scottisch Marine Institute, Oban, Argyll, Scotland
- Method of cultivation: master cultures were maintained in the lab by periodic replenishment of culture medium
- Age of inoculum (at test initiation): not reported, from preculture (usually 3-5 days prior to testing) grown until algal cell density was ca. 1E+04 to 1E+05 cells/mL (and cells are in log growth phase)
- Initial cell density in test: 5E+03 cells/mL (nominal)

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

Post exposure observation period:

none

Hardness:

ca. 15 mg/L (calculated)

Test temperature:

24 ± 1 °C

pH:

At initiation of test: 8.0 in control and 7.8-10.2 in treatments
After 72 h: 8.2 in control and 8.0-8.4 in treatments
The pH deviation in control cultures was < 1.5 pH units and was therefore within the limits required by the test guideline.

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

- Nominal concentrations: control, 1.0, 3.2, 10, 32, and 100 mg/L
- Measured concentrations ranged from 91-113% of nominal.

Details on test conditions:

TEST SYSTEM
- Test vessel: conical flasks
- Type (delete if not applicable): closed, plugged by polyurethane foam stoppers
- Kept under constant agitation by orbital shaker (100-150 rpm)
- Material, size, headspace, fill volume: glass, 250 mL, 100 mL fill volume
- Aeration: no
- Initial cell density: approximately 5E+03 cells/mL (nominal)
- Control end cells density: mean from six replicates: 5.09E+03 cells/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 3
- Incubated in INFORS Multitron® Version 2 incubator

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reversed osmosis purified deionised water
- Culture medium different from test medium: no
- Intervals of water quality measurement: pH was measured at test initiation and 72 h, temperature was recorded daily

OTHER TEST CONDITIONS
- Adjustment of pH of culture medium: yes, to 7.5 ± 0.1 with 0.1 N NaOH or HCl (not after addition of test substance)
- Photoperiod: continuous illumination
- Light intensity and quality: 7000 lux, warm white lighting (380-730 nm)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): cell density at 0, 24, 49 and 72 h
- Determination of cell concentrations: cell densities were measured using a Coulter® Multisizer Particle Counter

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Range finding study performed: yes
- Test concentrations in range finding study: 0.10, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: growth was not inhibited in the 0.10 and the 1.0 mg/L test treatments, whereas between 5 and 100 % inhibition was observed in the 10 and 100 mg/L conditions.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

39 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 33-47 mg/L

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Growth rate based:
- ErC10 (72h) = 18 mg/L
- ErC20 (72h) = 24 mg/L
- LOEC = 10 mg/L
Yield based:
- EbC10 (72h) = 5.9 mg/L
- EbC20 (72h) = 8.4 mg/L
- EbC50 (72h) = 15 mg/L (95% CI = 13-18 mg/L)
- NOEC = 3.2 mg/L
- LOEC = 10 mg/L
- No abnormalities wered detected in the control or the test cultures at 1.0, 3.2 and 10 mg/L.
- Enlarged cells and cell debris were observed in the 32 and 100 mg/L test cultures respectively.

Results with reference substance (positive control):

- ErC50(72h): 1.4 mg/L, 95 % C.I. 1.2-1.7 mg/L
- EyC50(72h): 0.59 mg/L, 95 % C.I. 0.53-0.65 mg/L
- NOEC based on growth rate: 0.25 mg/L
- LOEC based on growth rate: 0.50 mg/L
- The results were within normal ranges for this reference item

Reported statistics and error estimates:

- Significant differences (p < 0.05) between the control and the test concentrations were identified using one way ANOVA incorporating Bartlett's test for homogeneity of variance and Dunnett's multiple comparison procedure for comparing several treatments with a control (Dunnett, 1955).
- EC50 values and their confidence limits were calculated using the simplified method of evaluating dose-effect experiments of Litchfield and Wilcoxon (1949).

Validity criteria fulfilled:

yes

Conclusions:

In this study, the freshwater alga Pseudokirchneriella subcapitata was exposed to 0, 1.0, 3.2, 10, 32, and 100 mg/L of test substance for 72 hours. Based on growth rate, the 72-h EC50 was determined to be 39 mg/L and the NOEC was 3.2 mg/L. Analytical verification of test substance concentrations showed measured concentrations to be close to nominal. The pH of the test solutions was not adjusted after addition of test substance, causing initial pH levels of the 10, 32 and 100 mg/L test solutions to be quite high (pH 9.2, 9.8 and 10.2, respectively). At the end of testing pH had returned to normal (8.1-8.4 in this case). However, these high initial pH levels may have slowed down algal growth and may have affected the results of the test. Therefore, the results of the test can be considered reliable but with restrictions.

Description of key information

A full study was performed under GLP conditions and according to OECD 201 (Harlan, 2012).

Key value for chemical safety assessment

EC50 for freshwater algae:

39 mg/L

EC10 or NOEC for freshwater algae:

3.2 mg/L

Additional information

In a 72-hour static test with the green alga Pseudokirchnerella subcapitata according to EU Method C2 and OECD Guideline 201, the algae toxicity of the test substance was investigated (Harlan, 2012).

After 72 hours an ErC50 of 39 mg/L was estimated for the growth rate, related to the nominal concentration.