Phenoxymethylpenicillin potassium

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:

9 September 2019 - 05 November 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2011

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Test Item name:Pen V Potassium
Lot No.: B519322
Appearance:white, solid powder
Expiry date: 30 April 2024
Storage:room temperature, protected from light

Analytical monitoring:

yes

Details on sampling:

For determination of the test item concentration six replicate samples (5 mL per replicate) were taken from the t est concentration on each day of the study and six replicate samples were taken (5 mL per replicate) from the control group at the start and at the end of the test. The analysis was performed by the analytical laboratory of TOXI-COOP ZRT. according to the results of the analytical method validation (Study number: 880-100-4606) using HPLCmethod with UV detection.

Vehicle:

no

Details on test solutions:

The test solution used in the test was prepared by mechanical dispersion without using any solubilizing agent. An amount of 0.0804 g test item was dissolved in 804 mL dilution water (OECD Medium) in order to obtain the nominal concentration of 100 mg/L. After the formulation procedure algal cells were immediately introduced into the test solution (start of the experiment).

Test organisms (species):

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

Details on test organisms:

Strain number: 61.81 SAG (identical strains: CCAP 278/4; UTEX 1648; ATCC 22662)
Origin: The algae were supplied by the SAG: Collection of Algal Cultures, D-37073 Göttingen, Germany
Breeding Conditions: The stock cultures are small algal cultures that are planted on agar regularly. These are transferred to fresh medium at least once every two months under standardized conditions according to the test guidelines.
Pre-culturing: The pre-culture is intended to give an amount of algae suitable for the inoculation of test cultures. The pre-culture was prepared with OECD Medium, incubated under the conditions of the test and used when still exponentially growing, normally after an incubation period of 2-4 days. (The pre-culture was incubated for four days at this test.) The algal cultures used in this study did not contain deformed or abnormal cells.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

According to the guideline.

Post exposure observation period:

No.

Hardness:

Not reported.

Test temperature:

Culture temperature was checked at the beginning of the study and every 24 hours thereafter in a flask filled with water, in the climatic chamber. In addition the ambient temperature was continuously measured (with a min/max thermometer) within the climate chamber. The temperature was between 22.7 and 22.9 °C measured in the flask and in the range of 21.8 – 23.7 °C measured within the climate chamber.

pH:

The pH was measured in each test group at the start (before test solutions had been distributed into the test vessels) and in each test vessel at the end of the test. The pH of the control medium was not increased by more than 1.5 units during the test. The range of the pH was 8.00 – 8.57 during the experiment. The pH of the test solutions was not adjusted during the study.

Dissolved oxygen:

Not reported.

Salinity:

No.

Conductivity:

Not reported.

Nominal and measured concentrations:

No toxic effect was observed during the preliminary test, therefore, one test concentration (100 mg/L nominal) and one control group were tested in a limit test.

Details on test conditions:

In order to select appropriate test concentrations for the definitive test, a non-GLP preliminary range-finding test was conducted to determine the approximate toxicity of the test item. Algal cells were exposed to one test concentration (100 mg/L) of the test item plus a control, for 72 hours. The test was performed with three replicates in the treatment group and three replicates in the control. For preparation of the test solution an amount of 0.0408 g test item was dispersed in 408 mL OECD Medium to obtain the 100 mg/L nominal concentration. The preliminary range-finding test was not performed in compliance with the GLP-Regulations and is excluded from the Statement of Compliance (Statement of the Study Director), but the raw data of this test will be archived under the study code of present study.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Analytical Results
Mean values and standard deviations were calculated for each treatment at each observation period using Microsoft Excel for Windows. A limit test was performed and no toxic effects were observed, therefore, statistical comparisons were not necessary. The NOEC and LOEC values of the test item related to growth rates and yield were determined directly from the raw data.

Biological Results:
All biological results are based on the nominal test concentration.

Average Specific Growth Rate
A limit test was performed and no toxic effects were observed, therefore, s tatistical analysis was not necessary. The LOEC and NOEC values were given directly from the raw data. Accordingly the 72-h NOEC based on growth rate was determined to be 100 mg/L nominal, while the 72-h LOEC based on growth rate was determined to be > 100 mg/ L nominal.

Yield:
A limit test was performed and no toxic effects were observed, therefore, s tatistical analysis was not necessary. The LOEC and NOEC values were given directly from the raw data. Accordingly the 72-h NOEC based on yield was determined to be 100 mg/L nominal, while the 72-h LOEC based on yield was determined to be > 100 mg/ L nominal.

Morphological Changes of Algal Cells:
No abnormal shape of algal cells was noticed in the control group and at the test itemconcentration (100 mg/L nominal) during the study.

Results with reference substance (positive control):

The date of the latest study performed in the laboratory of TOXI-COOP ZRT. (Study number: 392-201-4465) with the reference item Potassium dichromate was: 11 – 14 March 2019, Final Report issued: 02 April 2019.
The 72h ErC50: 0.83 mg/L, (95 % confidence limits: could not be calculated)
The 72h EyC50: 0.57 mg/L, (95 % confidence limits: 0.45 – 0.72 mg/L)

Validity criteria fulfilled:

yes

Conclusions:

The 72-h NOEC is 100 mg/L

Executive summary:

A 72-h algal growth inhibition test with Raphidocelis subcapitata, according to OECD and EC-guidelines was performed. The 72-h NOEC is 100 mg/L. The LOEC growth rate is > 100 mg/L.

All validity criteria were met.

Description of key information

A 72-h algal growth inhibition test with Raphidocelis subcapitata, according to OECD and EC-guidelines was performed. The 72-h LOEC is >100 mg/L (calculated: 242.8 mg/L). The NOEC growth rate is 100 mg/L.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

100 mg/L