2,4-xylenol

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

Gas chromatography (GC

Details on test solutions:

Test solution volume: 100 dishes L/container

Test organisms (species):

Daphnia magna

Details on test organisms:

Numbers of test organism: 20 daphnia / test plot (5 daphnia / container)

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test temperature:

20 ± 1℃

Nominal and measured concentrations:

1.0, 1.78, 3.16, 5.60, 10 mg/L
The results of a Gas chromatography (GC) analysis of the test solution, resulted in the ratio of the measured value at the start of exposure to the nominal value, to be within ± 20%. Therefore, the test results were based on nominal concentrations.

Details on test conditions:

Illumination: Room light, 16 hours bright (8001ux or less) / 8 hours dark
Number of test vessels: 4 containers / test plot

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4.21 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming inhibition

Remarks on result:

other: 95% CI: 3.72-4.761mg/L

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming inhibition

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.78 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming inhibition

Details on results:

1) Concentration of test substance in test solution: As a result of the analysis of the test solution, the ratio of the measured values ​​to the set values ​​was ± 20% or more. 
The set value was used to calculate the result
2) Results after 24 h exposure:
Half swimming inhibition concentration (EiC50): 9.25
Maximum inactive concentration (NOECi): 3.16
100% inhibition minimum concentration: more than 10.0

95% confidence interval (mg/L): 7.96～11.5

3) Results after 48 hours of exposure:
Half swimming inhibition concentration (EiC50): 4.21
Maximum inactive concentration (NOECi): 1.78
100% inhibition minimum concentration: more than 10.0

95% confidence interval (mg/L): 3.72～4.76

Validity criteria fulfilled:

not specified

Conclusions:

Under the study conditions, the 48 h NOEC, EC50 and EC100 values were determined to be 1.78, 4.2 and 10 mg/L respectively.

Executive summary:

A study was conducted to determine the acute toxicity of test substance to Daphnia magna according to OECD Guideline 202, in compliance with GLP. 20 daphnia per group were exposed to the test substance at nominal concentrations of 0, 1.0, 1.78, 3.16, 5.60, 10 mg/L, under static conditions. The results of a Gas chromatography (GC) analysis of the test solution, resulted in the ratio of the measured value at the start of exposure to the nominal value, to be within ± 20%. Therefore, the test results were based on nominal concentrations. Under the study conditions, the 48 h NOEC, EC50 and EC100 values were determined to be 1.78, 4.2 and 10 mg/L respectively (MOEJ, 2001).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

not specified

Details on test solutions:

Test solution volume: 100 mL

Test organisms (species):

Daphnia magna

Details on test organisms:

Number of organisms: 20 daphnia / 1 concentration group (5 daphnia per test vessel, 20 daphnia per concentration group)
Number of test vessls: 4 containers per concentration group

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Test temperature:

20 ± 1° C

Nominal and measured concentrations:

0.53, 0.95, 1.71, 3.09, 5.56 and 10.0 mg/L

Details on test conditions:

Lighting: Room light, 16 hours bright / 8 hours dark

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.66 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming inhibition

Remarks on result:

other: 95% CI: 2.12-3.4 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

5.56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming inhibition

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: swimming inhibition

Details on results:

1) Results after 24-hour exposure:  
24-hour and half-swimming inhibition concentration (EiC50) = 6.24 mg / L (95% confidence interval: 4.84 mg / L to 8.85 mg / L) 
2) Results after 48 hours of exposure:   
48 hours and a half swimming inhibition concentration (EiC50) = 2.66 mg / L (95% confidence interval: 2.12 mg / L to 3.40 mg/L))   
Maximum inactive concentration (NOECi) = 0.53 mg / L    
100% inhibition minimum concentration: 5.56 mg / L   
(The above concentration is a value based on all)

Conclusions:

Under the study conditions, the 48 h NOEC, EC50 and EC100 were determined to be 0.53, 2.66 and 5.56 mg/L respectively.

Executive summary:

A study was conducted to determine the acute toxicity of test substance to Daphnia magna according to OECD Guideline 202, in compliance with GLP. 20 daphnia per group were exposed to the test substance at nominal concentrations of 0, 0.53, 0.95, 1.71, 3.09, 5.56 and 10.0 mg/L under static conditions. Under the study conditions, the 48 h NOEC, EC50 and EC100 were determined to be 0.53, 2.66 and 5.56 mg/L respectively (MOEJ, 2000).

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.12 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Details on results:

The available data for 2,4-dimethylphenol indicate that acute toxicity to freshwater aquatic life occurs at concentrations as low as 2.12 mg/L

Conclusions:

Under the study conditions, the 48 h EC50 was determined to be 2.12 mg/L.

Executive summary:

A study was conducted to determine the acute toxicity of test substance to Daphnia magna. Under the study conditions, the 48 h EC50 was determined to be 2.12 mg/L (US EPA, 1980).

Description of key information

Based on the results from the available studies, the lower 48 h EC50 value of 2.66 mg/L (nominal) from the guideline compliant study has been considered further for hazard/risk assessment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

2.66 mg/L

Additional information

Study 1: A study was conducted to determine the acute toxicity of test substance to Daphnia magna according to OECD Guideline 202, in compliance with GLP. 20 daphnia per group were exposed to the test substance at nominal concentrations of 0, 1.0, 1.78, 3.16, 5.60, 10 mg/L in static test conditions.The results of a Gas chromatography (GC) analysis of the test solution, resulted in the ratio of the measured value at the start of exposure to the nominal value, to be within ± 20%. Therefore, the test results were based on nominal concentrations.Under the study conditions, the 48 h NOEC, EC50 and EC100 values were determined to be 1.78, 4.2 and 10 mg/L (nominal) respectively (MOEJ, 2001).

Study 2: A study was conducted to determine the acute toxicity of test substance to Daphnia magna according to OECD Guideline 202, in compliance with GLP. 20 daphnia per group were exposed to the test substance at nominal concentrations of 0, 0.53, 0.95, 1.71, 3.09, 5.56 and 10.0 mg/L in static test conditions. Analysis of the test solutions were not specified. Under the study conditions, the 48 h NOEC, EC50 and EC100 were determined to be 0.53, 2.66 and 5.56 mg/L (nominal) respectively (MOEJ, 2000).

Another limited detailed acute study in Daphnia magna conducted under static test conditions was reported in the US EPA (1980) report on the test substance. This study reported a 48 h EC50 value of 2.12 mg/L (US EPA, 1980).

Based on the results from the available studies, the lower 48 h EC50 value of 2.66 mg/L (nominal) from the guideline compliant study has been considered further for hazard/risk assessment.