(R)-3,7-dimethyl-1,6-octadien-3-ol

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(R)-3,7-dimethyl-1,6-octadien-3-ol

EC Number:

204-811-2

EC Name:

(R)-3,7-dimethyl-1,6-octadien-3-ol

Cas Number:

126-91-0

Molecular formula:

C10H18O

IUPAC Name:

(3R)-3,7-dimethylocta-1,6-dien-3-ol

Test material form:

liquid

Test solutions

Vehicle:

not specified

Details on test solutions:

The primary stock solution used in the range-finding test was prepared by dissolving 0.0250 g of the test substance in 250 mL with OECD medium, resulting in a concentration of 100 mg.L-1. The stock solution of 1 mg.L-1 was prepared from dilution of the primary stock solution.
The primary stock solution used in the definitive test was prepared by dissolving 0.3200 g of the test substance in 1000 mL with OECD medium, resulting in a concentration of 320 mg.L-1. The stock solution of 100 mg.L-1 was prepared from dilution of the primary stock solution.

Test organisms

Test organisms (species):

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

Details on test organisms:

The unicellular green alga species Pseudokirchneriella subcapitata used is part of the Chloroficeae group, Chlorococcales order.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

22.3 to 22.4oC

Details on test conditions:

Temperature: 22.3 to 22.4oC
Light: 4716 lux (average)
Photoperiod: continuous light
Shaker velocity: 130 rpm (average)

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

other: EyC50

Effect conc.:

48.38 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Yield

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

191.82 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

The 72-hours EyC50 value of the reference substance potassium dichromate was 0.79 mg.L-1 (confidence limits at 95% = 0.72 to 0.85 mg.L-1), demonstrating that the toxic sensitivity of the algae was within the accepted range (ISO, 1989), which report toxicity ranged between 0.60 and 1.03 mg.L-1.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72-hours EyC50 value for alga Pseudokirchneriella subcapitata exposed to (R)-3,7-dimethyl-1,6-octadien-3-ol was 48.38 mg.L-1 and the 72-hours ErC50 value was 191.82 mg.L-1. The highest test substance concentration with no observed significant adverse effect (NOEC) on algal growth was 10 mg.L-1 and the lowest test substance concentration at which was observed significant reducing effect on growth (LOEC) was 32 mg.L-1.