reaction mass of 2,2,4,6,6-pentamethylheptane-4-thiol, 2,3,4,6,6-pentamethylheptane-3-thiol , 2,4,4,6,6-pentamethylheptane-2-thiol, 2,3,4,6,6-pentamethylheptane-2-thiol

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: DIN-Norm 38412-L9

Principles of method if other than guideline:

DIN 38 412, Teil 9: Testverfahren mit Wasserorganismen (Gruppe L). Bestimmung der Wirkung von Wasserinhaltsstoffen auf Grünalgen (Scenedesmus-Zellvermehrungshemmtest) (German standard) Deutsches Institut für Normung e.V., Berlin (Weissdruck Mai 1989).
Comparable to OECD TG 201, adopted 1984

GLP compliance:

yes

Remarks:

The study was conducted under GLP (OECD) with exeption of the determination of the stability, homogeneity and concentration of the test material in the test medium.

Test material

Test material information

Constituent 1

Reference substance name:

2,2,4,6,6-pentamethylheptane-4-thiol

EC Number:

296-714-7

EC Name:

2,2,4,6,6-pentamethylheptane-4-thiol

Cas Number:

93002-38-1

Molecular formula:

C12H26S

IUPAC Name:

2,2,4,6,6-pentamethylheptane-4-thiol

Details on test material:

- Name of test material (as cited in study report): Tert. Dodecylmercaptan
- CAS No. as cited in study report: 25103-58-6 (tert. dodecanethiol), but the test material was material as defined in section 1 (CAS 93002-38-1). Therefore the new CAS number 93002-38 was assigned.
- Batch No.: 7131486
- Analytical purity: 79.4%

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

- Evidence of undissolved material: oily surface film, material precipitated to wall of the test vessels
- Preparation of test solutions with running magnetic stirrer (stock solution)

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Test temperature:

20.5-22.5 °C

Nominal and measured concentrations:

nominal: 100 mg/L, 32 mg/L, 10 mg/l, 3,2 mg/L, 1 mg/L, 0.32 mg/L, 0.1 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyerkolben (300 mL)
- Testvolume: 100 mL

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [electronic particle counter]
Thrombozytenzähler Sysmex F 300

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

81 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Validity criteria are fulfilled: 16 fold increase in cell number of the control throughout the test duration, exponential growth

Applicant's summary and conclusion

Executive summary:

Testing adverse effects of the test item towards algae, no significant effects were observed up to the limit of the water solubility (Bayer AG, 1990).