2,5-xylenol

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Publication; test procedure comparable to guideline

Data source

Reference

Reference Type:

publication

Title:

Toxicity of 58 substituted anilines and phenols to algae Pseudokirchneriella subcapitata and bacteria Vibrio fischeri: Comparison with published data and QSARs

Author:

Aruoja, V.

Year:

2011

Bibliographic source:

Chemosphere 84 (2011) 1310–1320

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,5-xylenol

EC Number:

202-461-5

EC Name:

2,5-xylenol

Cas Number:

95-87-4

Molecular formula:

C8H10O

IUPAC Name:

2,5-dimethylphenol

Test material form:

not specified

Details on test material:

- Name of test material: 2,5-dimethylphenol (2,5-DMP)
- Molecular weight:122.2
- Analytical purity: > 99 %
- Hydrophobicity (log Kow): 2.33

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

no

Details on test solutions:

All test sulutions were prepared in algal test medium.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: P. subcapitata
- Source: commercial test system Algal Toxkit F (MicroBioTests Inc., Nazareth, Belgium)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

24 ± 1 °C

pH:

8.0 ± 0.5

Details on test conditions:

TEST SYSTEM
- Test vessel: 20-mL glass scintillation vials
- Initial cells density: 10000 cells /mL after inoculation
- No. of vessels per concentration: 2
- No. of vessels per control: 8


GROWTH MEDIUM
- Standard medium used: yes



OTHER TEST CONDITIONS
- Sterile test conditions: no
- Adjustment of pH: yes
- Light intensity and quality: vials were illuminated from below with Philips TL-D 38W aquarelle fluorescent tubes


EFFECT PARAMETERS MEASURED :
- Determination of cell concentrations: optical density at 682 nm directly from the incubation vials (spectrophotometer)


TEST CONCENTRATIONS
- Test concentrations: 6 or 7 concentrations, depending on previously available toxicity data from literature or preliminary experiments

Reference substance (positive control):

yes

Remarks:

Aniline

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

32.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

The determined EC50 values of the test item in P. subcapitata 72-h growth inhibition was 32.5 mg/L.

Results with reference substance (positive control):

The determined EC50 values of P. subcapitata 72-h growth inhibition was 54.2 mg/L.