N-butyl phenyl ether

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The toxicity test was based on the OECD Guideline Daphnia Acute Immobilization Test, equivalent to the EEC test protocol Acute Toxicity to Daphnia. No specific details on dose levels were provided.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

The concentrations of the test solutions was determined at the beginning and and at the end of the experiment.

Details on test solutions:

Dilution water was prepared by mixing Milli-Q and tap water in a basically 1:1 ratio, which was adjusted to attain a hardness of 150 mg/L (CaCO3); total hardness 130 mg/L (expressed as CaCO3), pH 8.2 +/- 0.5, conductivity 400 +/- 25 uS/cm. Stock solutions were prepared by adding the chemical to the dilution water under mechanical stirring. Test solutions were obtained by diluting the stock solutions.

Five concentration levels and a control were tested. No specific details provided on concentration levels.

Test organisms (species):

Daphnia magna

Details on test organisms:

Experimental animals were daphnids less than 24 h old from an in-house laboratory culture maintained in the same water as the dilution water and fed yeast and Selenastrum capricornutum.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

hardness of 150 mg/L (CaCO3)

Test temperature:

temperature was 20 +/- 1 degree C

pH:

pH 8.2 +/- 0.5

Dissolved oxygen:

No data.

Salinity:

Not applicable.

Nominal and measured concentrations:

No specific details provided on concentration levels.

Details on test conditions:

Ten animals, subdivided in two replicates, were used for each of the concentrations tested (a minimum of five) and the control. The tests were performed in closed bottles (150 mL) filled to the top in order to avoid loss of chemical due to volatilization. The temperature was 20 +/-1 degree C and the photoperiod was 16 h light, 8 h dark.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

2.1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Remarks on result:

other: CL: 1.7-2.6

Reported statistics and error estimates:

The 24h-EC(50) value was estimated by the Litchfield and Wilcoxon method.

Validity criteria fulfilled:

yes

Conclusions:

The 24 hr EC50 for the Daphnia magna was determined to be 2.1 mg/l with a confidence limit of 1.7-2.6.

Executive summary:

Daphnia magna were exposed to Butyl Phenyl Ether at five concentrations. A control group was also included in the study. The 24 hr EC50 for the Daphnia magna was determined to be 2.1 mg/l with a confidence limit of 1.7-2.6.

Description of key information

The acute toxicity of Butyl Phenyl Ether was experimentally determined in two species of invertebrates, Daphnia magna and Ceriodaphnia dubia.

The 24-hr LC50 for Butyl Phenyl Ether with C. dubia was 3.2 mg/L, and the 24-hr LC50 for Butyl Phenyl Ether with D. magna was 2.1 mg/L. A daphnia acute toxicity QSAR was conducted and the estimated 48-hr LC50 for Daphnia sp. was 3.3 mg/L. Since the experimental LC50 value with D. magna was the lowest value, this value was used as the key value for the assessment of acute invertebrate toxicity.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.1 mg/L

Additional information

The acute toxicity of Butyl Phenyl Ether was experimentally determined in two species of invertebrates, Daphnia magna and Ceriodaphnia dubia. The 24-hr LC50 for Butyl Phenyl Ether with C. dubia was 3.2 mg/L, and the 24-hr LC50 for Butyl Phenyl Ether with D. magna was 2.1 mg/L. A daphnia acute toxicity QSAR was conducted and the estimated 48-hr LC50 for Daphnia sp. was 3.3 mg/L. Since the experimental LC50 value with D. magna was the lowest value, this value was used as the key value for the assessment of acute invertebrate toxicity.