Phenol, 2-methoxy-5-nitro-, 1-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

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-methoxy-5-nitrophenyl acetate

Cas Number:

53606-41-0

Molecular formula:

C9H9NO5

IUPAC Name:

2-methoxy-5-nitrophenyl acetate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Test solutions

Vehicle:

yes

Details on test solutions:

The water with conductivity smaller than 5 μS·cm-1 was used for the preparation of solutions. All chemicals used were of analytical-grade.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

The green freshwater algae Desmodesmus subspicatus Brinkmann 1953/SAG 86.81 obtained from the collection of autotrophic organisms of The Botanic Institute of the Czech Academy of Science, Třeboň on date 3.6.2014.
The sensitivity of test species is periodically monitored by testing with the reference substance, potassium dichromate. The strain culture was preinoculated from the stock solution and cultivated in flasks with the test medium on indirect daylight at laboratory temperature. Algae inoculum for the test was sampled from exponentially growing inoculum culture. The strain culture was always set to pre-culturing of cells for 3-4 days before the start of the test. Inoculum culture was kept 3-4 days under conditions at which the test was performed. After this period the culture was in the state of the exponential growth and had the cell density suitable for the performance of the test. The cell density of the pre-culture was measured just before the start of the test and the needed inoculum volume was calculated

Study design

Test type:

not specified

Water media type:

not specified

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22.5°C

pH:

7.6

Details on test conditions:

Temperature: 21 - 24 °C controlled at ± 2 °C
Lighting: under continuous white light, 4 440 lux to 8 880 lux
Exposition time: 72 hours
Volume of tested mixture: 50 mL
Initial concentration of algae culture: 5 000 cells in a 1 mL
Without aeration.
Agitation of algae culture by shaking.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.53 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Remarks on result:

other: 1.04-2.38

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.27 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Results with reference substance (positive control):

The results of the verification test with K2Cr2O7, carried out in period from 30.3. to 2.4. 2015, are the following:
72 hour – ErC50 = 0.79 mg·L-1 (95% confidence limit: 0.70 – 0.89 mg·L-1)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

The test substance, 2-methoxy-5-nitrophenyl acetate, was tested for growth inhibition on algae Desmodesmus subspicatus. The test was performed according to method C.3. - Freshwater Algae and Cyanobacteria, Growth Inhibition Test, Commission Regulation (EC) No. 761/2009, Annex IV. The preliminary test was performed in range of test substance nominal concentrations 1 – 100 mg·L-1. The analytical results showed, that the test substance 2-methoxy-5-nitrophenyl acetate was not stable in the test medium at conditions of the test in concentration range 1 – 100 mg·L-1 . Based on the toxicity of the test substance found in preliminary test, the full test was performed in appropriate concentration range. The full test was performed in range of test substance nominal concentrations 5 – 62 mg·L-1. Samples for analytical determination were taken at the beginning, after 24 hours, 48 hours and at the end of the test. The analytical results showed that the test substance 2-methoxy-5-nitrophenyl acetate was not stable in test medium at conditions of the test. With respect to this observation the geometric mean concentrations were used for results presentation and evaluation. Test results: 72 hour – ErC50 = 1.53 mg·L-1 (geometric mean concentration) (95% confidence limit: 1.04 – 2.38 mg·L-1) 72 hour – EyC50 = 0.16 mg·L-1 (geometric mean concentration) (95% confidence limit: 0.02 – 0.38 mg·L-1) 72 hour – NOECr = 0.27 mg·L-1 (geometric mean concentration) 72 hour – NOECy < 0.18 mg.L-1