2-ethylhexyl 10-ethyl-4-[[2-[(2-ethylhexyl)oxy]-2-oxoethyl]thio]-7-oxo-8-oxa-3,5-dithia-4-phosphatetradecanoate 4-oxide

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:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: 87/302/EEC page 89-94 Algal Inhibition test

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

TEST MATERIAL (as stated in study report): TK 12184; trade name D 16-051

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsor / Batch No. 0870413, within specifications
- Expiration date of the lot/batch: 07/1996

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

Analytical monitoring:

yes

Details on sampling:

Sampling for analysis: Composite samples of each test concentration were drawn by mixing Identical volumes of the test Solutions taken from the approximate center of the test vessels. They were taken immediately before exposure and after 72 hours exposure and kept at - 18 deg C to - 22 deg C until analysis.

Vehicle:

no

Details on test solutions:

Stock solution: 50.3 mg test substance were mixed and made up to 500 ml with water. 100 ml of this blend were mixed and made up to 1000 ml with water (dilution 1:10). Calculated amounts of the stock solution to produce the desired test concentrations were given into the water and were homogeneously distributed.

Test organisms (species):

other: Scenedesmus subspicatus

Details on test organisms:

TEST ORGANISM
- Source (laboratory, culture collection): Collection of algae cultures, Pflanzenphysiologisches Institut, University, Nikolausberger Weg 18, D-3400 Göttingen, Germany

ACCLIMATION
- Acclimation period: 3 days under test conditions

Test type:

static

Water media type:

not specified

Limit test:

no

Remarks on exposure duration:

72 hours

Test temperature:

23 ± 1 deg C

Nominal and measured concentrations:

Nominal : 0.123, 0.37, 1.1, 3.3 and 10 mg test substance / L
Actual (end of exposure): 0.1, 0.1, 0.1, 1.1 and 5.3 mg test substance / L

Details on test conditions:

Each test concentration was tested in 3 replicates, the blank control in 6.

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

other: EbC50 (0-72 h)

Effect conc.:

3.1 mg/L

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Value based on actual end concentrations

Remarks:

95% confidence limit: 2.2 - 3.9 mg/L

Duration:

72 h

Dose descriptor:

other: NOEbC (0 - 72 h) (5% level)

Effect conc.:

0.1 mg/L

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Value based on actual end concentration

Reported statistics and error estimates:

The EbC-50 values were calculated according to the maximun likellhood method, logit model (Mc Cullagh, P., Neider, J.A., 1983: Generalized linear models, Chapman & Hall, London)

Validity criteria fulfilled:

yes

Conclusions:

In a guideline algal growth inhibition study of TK 12 184, the EbC50 (0 - 72 h) was 3.1 mg/L (95% confidence limits: 2.2 - 3.9 mg/L). The NOEbC was 0.1 mg/L.

Values were based on actual end of exposure concentrations.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Principles of method if other than guideline:

Results predicted by US EPA ECOSAR v1.11 model.

GLP compliance:

no

Details on results:

No effects are expected at saturated concentrations in water. The estimated logKow for this substance is greater than the class specific cut-offs for green algae toxicity, and the predicted effect level exceeds the water solubility of this substance by more than 10x.

Validity criteria fulfilled:

not applicable

Conclusions:

The US EPA ECOSAR v1.11 model predicts no effects at saturated concentrations in water for TGEPO (CAS No. 83547-95-9). The estimated logKow for this substance is greater than the class specific cut-offs for green algae toxicity, and the predicted effect level exceeds the estimated water solubility of this substance by more than 10x.

Description of key information

In an algal growth inhibition study of TK 12 184, the EbC50 (0 - 72 h) was 3.1 mg/L (95% confidence limits: 2.2 - 3.9 mg/L).  The NOEbC was 0.1 mg/L. Values were based on actual end of exposure concentrations.

Key value for chemical safety assessment

EC50 for freshwater algae:

3.1 mg/L

Additional information

The US EPA ECOSAR v1.11 model predicts no effects at saturated concentrations in water for TGEPO (CAS No. 83547-95-9).  The estimated logKow for this substance is greater than the class specific cut-offs for green algae toxicity, and the predicted effect level exceeds the estimated water solubility of this substance by more than 10x.