Potassium (R)-(4-hydroxyphenyl)[(3-methoxy-1-methyl-3-oxoprop-1-enyl)amino]acetate

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:

end on September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study performed according to OECD guideline and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

yes

Remarks:

Temperature = 24.5°C (not considered to have an influence on the integrity of the study)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Potassium (R)-(4-hydroxyphenyl)[(3-methoxy-1-methyl-3-oxoprop-1-enyl)amino]acetate

EC Number:

273-992-8

EC Name:

Potassium (R)-(4-hydroxyphenyl)[(3-methoxy-1-methyl-3-oxoprop-1-enyl)amino]acetate

Cas Number:

69416-61-1

Molecular formula:

C13H15NO5.K

IUPAC Name:

potassium (4-hydroxyphenyl)[(3-methoxy-1-methyl-3-oxoprop-1-en-1-yl)amino]acetate

Details on test material:

- Name of test material (as cited in study report): D(-)-p-Hydroxyphenylglycine Dane Salt(K, Methyl)
- Substance type: monoconstituent substance
- Physical state: powder
- Stability under test conditions: stable (see analytical section)
- Storage condition of test material: at room temperature, protected from light

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 and 100mg/L
- Sampling method: data not available
- Sample storage conditions before analysis: data not available

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
The test item was applied as follows: stock solutions were made in ultrapure water. Aliquots of the stock solutions were made up with ultrapure water, „intermediate dilution“ and algal inoculum (or diluted „intermediate dilution“) to give 50 mL of final volume.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: Desmodesmus subspicatus CHODAT
- Source: Origin: Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universität Göttingen [SAG], Strain-No. 86.81
- Age of inoculum: two days prior to starting the test, a pre-culture was inoculated using the algal stock culture
- Method of cultivation: the algae are cultivated under aseptic conditions.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

none

Test conditions

Hardness:

data not available

Test temperature:

The mean temperature was 24.5°C, and the range was 24.1 to 24.8°C.

pH:

t0: 8.10 (control) and 8.54 (100 mg/L)
t48: 9.72 (control) and 9.29 (100 mg/L)
Remarque: the increase in pH of 1.62 units is slightly higher than the limit of 1.5 given by the OECD Test Guideline 201. This represents a deviation of the study plan which is not considered to have an influence on the integrity of the results.

Dissolved oxygen:

data not available

Salinity:

not applicable (freashwater)

Nominal and measured concentrations:

nominal: 100 mg/L
measured: 106.6 mg/L at t0 and 111.5 mg/L at t48

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL-glass-cylinders, heat sterilized
- Type: losed (the test solutions were covered with a lid made of plexiglass which had been previously sterilized by treatment with ethanol (~70%)
- Fill volume: 50 mL
- Aeration: in order to assure the input of CO2, the test solutions were stirred by means of a magnetic stirrer for the duration of 15 minutes per hour.
- Initial cells density: 2.64*10E3
- Control end cells density: 7.35*10E5
- No. of vessels per concentration (replicates): 7
- No. of vessels per control (replicates): 7

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
The mineral nutrient medium was prepared from three stock solutions (Mineral Nutrient Salts, Fe-Complex and Trace Elements) and NaHCO3.
The medium was prepared in deionised water and autoclaved or sterilized by ultrafiltration.

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: constant light
- Light intensity and quality: illumination rate of >=120 µE/m2s ([~8000 Lux]

EFFECT PARAMETERS MEASURED :
The increase in biomass was determined using a spectrophotometer after 24, 48, and 72 h. As a measure for the biomass the absorbance of the test solutions measured at 578 nm was used.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: only one concentration
- Justification for using less concentrations than requested by guideline: limit test
- Range finding study
- Test concentrations: 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: as there was no toxicity at the highest concentration tested within the screening-test, the main test was performed as a limit test using 100 mg/L as the sole concentration.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

same for yield

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

same for yield

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

same for yield

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities: not indicated
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

not determined

Reported statistics and error estimates:

The inhibition values for yield and the growth rates of the algae as well as the statistical calculations were done according to the Guideline using the commercial computer program ToxRatPro Version 2.10.

Any other information on results incl. tables

Table 1 : Cell numbers (Main test)

time	T0	T25h	T48h	T72h
Control	2.64*10^3	3.12*10^4	1.56*10^5	7.35*10^5
100 mg/L	2.64*10^3	1.90*10^4	1.11*10^5	7.12*10^5

 

Table 2: Inhibition Values (Main Test)

NominalConcen­tra­tion of the Test Item [mg/L]	Growth Rates (day^-1)	Inhibition of the Growth Rate after 72h [%]	Yield after 72h^1)	Inhibition of the Yield after 72h [%]
Control (0)	1.877	-	7.33*10^5	-
100	1.866	0.6	7.10*10^5	3.2

¹⁾Yield = Cell number at time t_72h– cell number at time t₀

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The test is considered valid as all conditions for validity were met (pH slightly higher but not considered as significant)

Conclusions:

72h NOErC and 72 ECr50 > 100 mg/L

Executive summary:

The chronic toxic effect of D(-)-p-Hydroxyphenylglycine Dane Salt (K, Methyl) was investigated by determination of the inhibition of the growth rate of the algae and the yield during the exposure period of 72 h (OECD 201, GLP). The test item was tested up to 100 mg test item/L (final concentration). As a conclusion of the analytical part of this study, recoveries of the concentrations determined after 72h were > 80% of those determined at t0, and therefore the effective concentrations are based on the nominal concentrations determined. As there was no toxicity at the highest concentration tested within the screening-test, the main test was performed as a limit test using 100 mg/L as the sole concentration.

 

From the results of the main test, toxic effects were determined with the following values:

 

On the Basis of the Nominal Concentrations tested [mg/L]
Yield (0 - 72 h) EC10     >100 EC20      >100 EC50      >100 LOEC     >100 NOEC   = 100		Growth rate (0 - 72 h) EC10     >100 EC20      >100 EC50      >100 LOEC     >100 NOEC   = 100

 

The test is considered valid as all conditions for validity were met. The increase in pH of 1.62 units in the controls is slightly higher than the limits given by the OECD test guideline 201 but are nor considered to have an influence on the integrity of the results.