Pregn-5-en-20-yne-21-carboxylic acid, 3,3-[1,2-ethanediylbis(oxy)]-17-hydroxy-, monolithium salt, (17.alpha.)-

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

Study period:

72h

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

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

1

Reference substance name:

Lithium 3[(8R,9S,10R,13S,14S,17S)-17-hydroxy-10-13-dimethyl-1,2,4,7,8,9,10,11,12,13,14,15,16,17-tetrahydrospiro[cylopenta[a]phenantrene-3,2´-[1,3]dioxolan]-17-yl]prop-2-ynoate

EC Number:

603-973-5

Cas Number:

136673-12-6

Molecular formula:

C24H31O5Li

IUPAC Name:

Lithium 3[(8R,9S,10R,13S,14S,17S)-17-hydroxy-10-13-dimethyl-1,2,4,7,8,9,10,11,12,13,14,15,16,17-tetrahydrospiro[cylopenta[a]phenantrene-3,2´-[1,3]dioxolan]-17-yl]prop-2-ynoate

Test material form:

solid: crystalline

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Details on test solutions:

The test organism was grown and hold in OECD medium which was used also for preparing test item solutions. The stock solution was prepared by measuring 150.05 mg of test item into 1 500 ml OECD growth medium. The suspension was ultrasonicated for 15 minutes. After it the suspension was filtered through a 0.2 μm WhatmanTM ME24 (Mixed cellulose ester) filter. The first 50 ml filtrate was disposed. The clear filtrate was the stock solution. The concentration of stock solution was 59.98 mg/L.

Test organisms

Test organisms (species):

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

Details on test organisms:

Test species: Pseudokirchneriella subcapitata (Korshikov) F.Hindák (formerly known as Selenastrum capricornutum and Raphidocelis subcapitata)
Source: Culture Collection of Algae and Protozoa, Scottish Marine
Institute (www.ccap.ac.uk)
Batch: CCAP 278/4
Date of arriving: 27 October 2017

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

The temperature inside the incubator at the test vessels was measured and registered continuously by Extech SD200 thermometer and datalogger. Throughout the test the temperature was nearly constant.

pH:

At the beginning of the test the pH values were measured in the remaining test solution of the concurrent test vessels at each dilution level.
At the end of the test the pH values were measured in each test vessel. The pH of test solutions was not adjusted at the beginning of the test.

Nominal and measured concentrations:

The toxic property of test item was investigated at six concentrations which were prepared by different dilutions of stock solution of test item. OECD medium was used for dilution of stock solution. In the test the following calculated concentrations were applied: 59.98; 41.99; 35.99; 23.99; 17.99 and 9.00 mg/L.

Details on test conditions:

Preparation and breeding of inoculum culture The inoculum culture (IN20/006) was prepared four days before starting the test and it was bred in incubator at 21 ± 2 °C. At the end of incubation the cell density of the inoculum culture was determined with a Bürker chamber. The cell concentration was 2 236 111 cell/ml

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

not determinable

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

not determinable

Details on results:

The yield is a response variable of the biomass increase during the test which is calculated as the difference of the biomass at the start and at the end of the test. The effective concentrations for yield are signed as EyCx. The EyCx values were determined including the 95 % confidence interval with Probit analysis using linear max. Likelihood regression. The EyC10, EyC20 and EyC50 were calculated for at both 24, 48 and 72 h period.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Acute toxic effect of Prak-Li was investigated in Freshwater Alga and Cyanobacteria, Growth Inhibition Test (according to OECD 201 guideline).
According to the test results Prak-Li has no toxic effect on alga growth rate even at its saturated concentration (53.83 mg/L). According to the Council Regulation (EC) 440/2008 Prak-Li is not hazardous to the aquatic environment [72 h EC50 (for algae or other aquatic plants) > saturated
concentration of Prak-Li (53.83 mg/L)]