Sandalwood, ext.

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2013 - January 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

This test determines the inhibition of cell division over 72-hours and is based on the OECD Test Guideline 201 (1984) and the protocol of Stauber et al. (Stauber, J.L., Tsai, J., Vaughan, G., Peterson, S.M. and Brockbank, C.I. (1994). Algae as indicators of toxicity of BEKM effluents. National Pulp Mills Research Program Technical Report Series No. 3, Canberra: CSIRO, pp. 1 - 82 AND Stauber, J.L. (1995) Toxicity testing using marine and freshwater unicellular algae. Australian Journal of Ecotoxicology 1:15-24).

GLP compliance:

yes

Remarks:

according to ISO 17025

Test organisms (species):

other: Isochrysis galbana

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22 °C

Details on test conditions:

Organism: Isochrysis galbana
Test Type: Static
Test Duration: 72 h
Temperature: 21 ±1 °C
Light Quality: Daylight Fluorescent Lighting
Light Intensity: 150 µmol photons/s * m²
Photoperiod: 12 hour light / 12 hour dark
Test Chamber Size: 120 mL
Test Solution Volume: 20 mL
Renewal of Test Solutions: None
Age of Test Organisms: 4 - 6 days
Initial Cell Density: 3 × 10E4 cells/mL
No. of Replicates: 3
Shaking Rate: Twice daily by hand
Dilution Water: 0.45 µm filtered seawater
Endpoint: Algal Growth Inhibition
Test Acceptability: Within cusum limits

Reference substance (positive control):

yes

Remarks:

copper

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

growth rate

Details on results:

negative control: cell number at 100 ±12% (mean of triplicate measurement)
0.5 mg/L sandalwood oil: cell number 100 ±10% (mean of triplicate measurement)
1 mg/L sandalwood oil: cell number 59 ±9% (mean of triplicate measurement)
5 mg/L sandalwood oil: cell number 12 ±5% (mean of triplicate measurement)
10 mg/L sandalwood oil: cell number 12 ±4% (mean of triplicate measurement)
100 mg/L sandalwood oil: cell number 9 ±4% (mean of triplicate measurement)

Concentrations reported as loading rate sandalwood oil due to the low water solubility (Water Accomodated Fraction) in seawater.

Results with reference substance (positive control):

The reference substance (positive control) copper showed an EC50 value of 33.2 µg/L, indicating the test system being sensitive.

Validity criteria fulfilled:

yes

Remarks:

Positive control showed results as expected

Conclusions:

The EC50 towards Isochrysis galbana (saltwater algae species) was found being 3.0 mg/L, whereas the NOEC was fond being 0.5 mg/L in this test.

Executive summary:

Sandalwod oil was tested for algae toxicity in a marine species (isochrysis galbana) for effects on cell number development. The low water solubility required testing unter water accomodated fraction (WAF) conditions showing a NOEC at 0.5 mg/L loading rate and an EC50 at 3.0 mg/L loading rate.

Description of key information

The EC50 towards Isochrysis galbana (saltwater algae species) was found being 3.0 mg/L, whereas the NOEC was fond being 0.5 mg/L in this test.

Key value for chemical safety assessment

EC50 for marine water algae:

3 mg/L

EC10 or NOEC for marine water algae:

0.5 mg/L