Alcohols, C12-13, branched and linear, ethoxylated, sulfates, sodium salts

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:

12 - 15 Jul 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

other: EU-Guideline 92/69 EWG

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: 86.81 SAG
- Source (laboratory, culture collection): originally obtained from Institut für Wasser-, Boden- und Lufthygiene, Berlin. In-house culture
- Age of inoculum (at test initiation): 3 days

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

24 °C +/- 2 °C

pH:

Test start: 7.9 - 8.1
Test end: 7.2 - 8.8

Nominal and measured concentrations:

nominal: 0.7, 1.5, 3, 6, 12 and 24 mg/L
mean measured: 0.93, 1.8, 3.2, 6.3, 13.8 and 24.5 mg/L (based on a-WAS)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Erlenmeyer flasks
- Aeration: yes
- Initial cells density: 20000 cells/mL
- Control end cells density: 730000 cells/mL
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 8


GROWTH MEDIUM
- Standard medium used: yes according to EU-Guideline 92/69/EWG


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Photoperiod: continuous illumination
- Light intensity and quality: approximately 8000 Lux (white)



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometer (wave length: 685 nm)

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

27 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: a-WAS concentration

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

27.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: endpoint re-calculated from the data given in the study: endpoint in a-WAS and purity of the test material

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.93 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: a-WAS concentration

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.95 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: endpoint re-calculated from the data given in the study: endpoint in a-WAS and purity of the test material

Details on results:

- Exponential growth in the control (for algal test): yes

Reported statistics and error estimates:

The EC-values were determined by probit transformation of percental growth inhibition values using regression analysis. Based on these values an additional probit analysis according to Cavalli-Sforza were conducted.

Concentration [mg/L]	Cell density (x 10^4cells/mL)
	Test duration
	0 h	24 h	48 h	72 h
Control	2	5	18	73
0.93	2	5	19	73
1.8	2	5	17	58
3.2	2	5	16	59
6.3	2	5	16	53
13.8	2	4	12	19
24.5	2	4	13	14

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to the Category Approach Justification provided in Section 13

Reason / purpose for cross-reference:

read-across source

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

27 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: a-WAS concentration

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source, key, 68891-38-3, 1993c

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

27.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: endpoint re-calculated from the data given in the study: endpoint in a-WAS and purity of the test material

Remarks:

Source, key, 68891-38-3, 1993c

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.93 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: a-WAS concentration

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source, key, 68891-38-3, 1993c

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.95 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Remarks on result:

other: endpoint re-calculated from the data given in the study: endpoint in a-WAS and purity of the test material

Remarks:

Source, key, 68891-38-3, 1993c

Description of key information

In the key-study an EC50-value for algae (growth rate) of 27.7 mg a.s./L and a NOEC of 0.95 mg a.s./L could be determined after 72 h. 
Nevertheless that endpoint is not used for PNEC-calculation as PNEC-values were calculated on the basis of a QSAR-model for chronic toxicity. 

Additional information

The assessment is based on the data currently available. New studies, based on the category review and the final decisions issued for some of the category substances, which are also relevant for this assessment, are currently being conducted. The hazard assessment with respect to aquatic toxicity will be updated once all ongoing studies have been finalised.

For AES (C12-13, 1-2.5EO) Na (CAS 161074-79-9) no acute test on algae is available. Thus, as a worst-case assumption, read-across is prepared to a study conducted with alcohol C12 -14 ethoxysulfates. In that tests Scenedesmus subspicatus were exposed to different concentrations of alcohol ethoxysulfates C12 -14 (2EO) (CAS 68891 -38 -3; content of active substance in test material: 69.7% a-WAS) in a static system according to the guidelines OECD 201 and EG Guideline 92/69 C.1. The GLP-study resulted in an EC50 (72 h)-value for growth rate of 27 mg/L as a-WAS (corresponding to 27.7 mg a.s./L) (Sasol, 1993c) and is determined as key study.