3,4-xylenol

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: No informations on GLP and Guideline followed, but sufficiently documented in the publication.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1988

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

3,4-xylenol

EC Number:

202-439-5

EC Name:

3,4-xylenol

Cas Number:

95-65-8

Molecular formula:

C8H10O

IUPAC Name:

3,4-dimethylphenol

Details on test material:

- Name of test material (as cited in study report): 3,4-Xylenol
- Analytical purity: > 95 %
- Other: Commercial Source, not repurified before test

Test solutions

Vehicle:

yes

Details on test solutions:

AFNOR (1974) reconstituted hard water for toxicity tests (pH, 7.8-8.2; hardness, 200mg 1-1 expressed as CaCO3).
Acetone was used as dispersent-solvent (<0.1 ml/l)

Test organisms

Test organisms (species):

other: Daphnia magna Straus 1820

Details on test organisms:

Daphnids (Daphnia magna Straus 1820) from the IRCHA Laboratory and have been cultured parthenogenetically in
the Pasteur Institute Laboratory since 1975. Daphnids were cultured in 10-1 tanks, with aerated hardwater (7.5 + 0.4mg 1-1 as Ca; 5.2 + 0.3mg 1 1 as Mg;pH = 7). The breeding room was maintained at a regulated temperature of 22 + I°C under a photoperiod of 16 h daylight/8 h darkness. The Daphnids were fed with a diet of Chlorella vulgaris (1.0 x 106 cells/daphnid/h).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test conditions

Hardness:

(7.5 + 0.4mg 1-1 as Ca; 5.2 + 0.3mg 1 1 as Mg

Test temperature:

22 + I°C

pH:

pH = 7

Dissolved oxygen:

>= 25% saturation (2.27 ml-1 02 at 20°C)

Details on test conditions:

Observations of test populations were carried out after 24h exposure. Daphnids which were unable to swim within 15 s after stimulation by gentle agitation of the water were considered to be immobilized, even if they could still move their antennae. Dissolved oxygen, pH, and temperature were measured at the end of the toxicity tests. Percentages of immobilization (between 10 and 90% on the basis of total number of Daphnia per concentration) were recorded and plotted as a function of concentration on log-probit paper. The points obtained were fitted to a straight line from which the IC50 was read as the abscissa of the point corresponding to 50% immobilization. The results were considered valid if dissolved oxygen measured at the end of the test was at least equal to 25% saturation (2.27 ml- 1 02 at 20°C), if the percentage of immobilization observed for the controls was zero (ISO, 1980), and if the IC50 of the reference compound (potassium dichromate) ranged between 0.9 and
1.5mg 1-1 after 24h exposure. Each chemical was assayed in duplicate with a minimum of three replicates on the following days. The 24-h IC50 and 95%.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Duration:

24 h

Dose descriptor:

IC50

Effect conc.:

0.153 mmol/L

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 0.136-0.163

Applicant's summary and conclusion

Validity criteria fulfilled:

yes