Butyl ricinoleate

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:

16 March 2018 to 19 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

2006

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

2009

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

The test substance is listed as Butyl Ricinoleate (CAS 151-13-3). The test substance was obtained from the Sponsor, Vertellus Holdings LLC and stored at ambient conditions.

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

The test was carried out using the unicellular green alga, Pseudokirchneriella subcapitata. Liquid cultures of Pseudokirchneriella subcapitata were obtained from the Culture Collection of Algae, University of Texas at Austin (UTEX). Master cultures were maintained in the laboratory by the periodic replenishment of culture medium. The master cultures were maintained in the laboratory under the same conditions as the definitive test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.7 °C to 24.1 °C

pH:

7.4 to 8.1

Nominal and measured concentrations:

Following a preliminary range-finding test, a definitive limit test was conducted with nominal concentrations of 0 (control), 0.30, 0.95, 3.1, 9.8, 31, and 100 mg TP/L using a water accommodated fraction (WAF).

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

67.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Test solution prepared as a Water Accomodated Fraction (WAF).

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

21.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Test solution prepared as a Water Accommodated Fraction (WAF).

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

11.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Test solution prepared as a Water Accommodated Fraction (WAF).

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Test solution prepared as a Water Accommodated Fraction (WAF).

Validity criteria fulfilled:

yes

Remarks:

Cell conc. of control increased by a factor of >16 after 72 h (protocol ≥ factor of 16); mean of coeff. of variation for growth rates control <35% (protocol ≤ 35%); coeffi. of var.of avg. sp. growth rate in replicate control cultures <7% (protocol ≤ 7%).

Conclusions:

The test substance caused a reduction of growth in the algal cultures (test units) exposed to a series of nominal test concentrations of the test item prepared with a water accommodated fraction (WAF) for 72 h; therefore, there were toxic or inhibitory effects. The 72-h EC50 (based on growth rate) was 67.8 mg TP/L (95% Confidence Limits 62.2 – 73.3 mg TP/L). The 72-h NOEC (based on growth rate) was 3.1 mg TP/L).

Description of key information

The key study was a static acute toxicity test on the effects of the substance on the freshwater unicellular green alga,Pseudokirchneriella subcapitata following OECD Guideline 201. The test substance caused a reduction of growth in the algal cultures (test units) exposed to a series of nominal test concentrations of the test item prepared with a water accommodated fraction (WAF) for 72 h; therefore, there were toxic or inhibitory effects.  The 72-h EC50, 72-h EC20, 72 -h EC10 and 72-h NOEC (based on growth rate) were reported as 67.8 mg total product (TP)/L, 21.9 mg TP/L, 11.3 mg TP/L and 3.1 mg TP/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:

67.8 mg/L

EC10 or NOEC for freshwater algae:

11.3 mg/L