6-tert-butyl-2,4-xylenol

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:

Not specified

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: "Testing Method Concerning New Chemical Substances, etc.,”

Deviations:

no

Principles of method if other than guideline:

This study was performed in accordance with "Testing Method Concerning New Chemical Substances, etc.,” the Joint Notice of Director of Pharmaceutical and Food Safety Bureau, the Ministry of Health, Labour and Welfare, Director of Manufacturing Industries Bureau, the Ministry of Economy, Trade and Industry, and Director of Environmental Policy Bureau, the Ministry of the Environment (November 21, 2003, Yakushoku-hatsu No. 1121002, Heisei 15-11-13 Seikyoku No. 2, Kanpoki-hatsu No. 031121002, final revision partly on November 20, 2006).

GLP compliance:

yes

Specific details on test material used for the study:

No further details specified in the report.

Analytical monitoring:

yes

Details on sampling:

Test concentration (nominal): control, 1.0, 1.5, 2.2, 3.2, 5.6, 10 mg/L
common ratio; 1.8 (irregular ratio of 1.5 was applied for 1.0-3.2 mg/L.)

Vehicle:

not specified

Details on test solutions:

Not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

Test organism:water flea (Daphnia magna)
Number of test organism: 20 animals/test area (5 animals/vessel)
Lighting: room light, 16 hours light/8 hours dark
Feeding: no feeding

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No post exposure observation period specified.

Hardness:

Not specified.

Test temperature:

20±1°C

pH:

Not specified

Dissolved oxygen:

Not specified

Salinity:

Not applicable.

Nominal and measured concentrations:

Nominal concentrations

Details on test conditions:

Exposure method: static water
Exposure period: 48 hours
Volume of test solution: 100 mL/vessel
Replicates: 4 vessels/test area
pH: pH adjustment of the test solution was not performed.

Reference substance (positive control):

not specified

Key result

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

2.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limit: 2.5-3.4 mg/L

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No further results detailed in the report.

Results with reference substance (positive control):

Reference substance not utilised in the study.

Reported statistics and error estimates:

Test substance concentration in the test solution
The variance of test substance concentration was considered to be measurement error in the analysis. Therefore, the arithmetic mean was calculated using measured value at the start and end of exposure to calculate each effect concentration.

Validity criteria fulfilled:

yes

Conclusions:

Result after 24 hours
50% effective inhibitory concentration (EC50): > 10 mg/L. The highest concentration causing 0% immobility: 2.1 mg/L. The lowest concentration producing 100 % immobility: > 10 mg/L

Result after 48 hours
50% effective inhibitory concentration (EC50): 2.9 mg/L (95% confidence limit: 2.5-3.4 mg/L). The highest concentration causing 0% immobility: 1.5 mg/L. The lowest concentration producing 100 % immobility: 10 mg/L

Executive summary:

This study was performed in accordance with "Testing Method Concerning New Chemical Substances, etc.,” the Joint Notice of Director of Pharmaceutical and Food Safety Bureau, the Ministry of Health, Labour and Welfare, Director of Manufacturing Industries Bureau, the Ministry of Economy, Trade and Industry, and Director of Environmental Policy Bureau, the Ministry of the Environment (November 21, 2003, Yakushoku-hatsu No. 1121002, Heisei 15-11-13 Seikyoku No. 2, Kanpoki-hatsu No. 031121002, final revision partly on November 20, 2006).

Result after 24 hours

50% effective inhibitory concentration (EC50): > 10 mg/L. The highest concentration causing 0% immobility: 2.1 mg/L. The lowest concentration producing 100 % immobility: > 10 mg/L

 

Result after 48 hours

50% effective inhibitory concentration (EC50): 2.9 mg/L (95% confidence limit: 2.5-3.4 mg/L). The highest concentration causing 0% immobility: 1.5 mg/L. The lowest concentration producing 100 % immobility: 10 mg/L

 

On the basis of the results noted in the study, classification under the Dangerous Substance Directive (67/548/EEC) and the CLP Regulation (EC No 1272/2008 is as follows:

N; R51/53 Dangerous for the environment; Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment.

Chronic aquatic toxicity, Category 2; H411: Toxic to aquatic life with long lasting effects.

Description of key information

Key value determined using Japanese test guidelines.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

LC50

Effect concentration:

2.9 mg/L

Additional information

Result after 24 hours

50% effective inhibitory concentration (EC50): > 10 mg/L. The highest concentration causing 0% immobility: 2.1 mg/L. The lowest concentration producing 100 % immobility: > 10 mg/L

 

Result after 48 hours

50% effective inhibitory concentration (EC50): 2.9 mg/L (95% confidence limit: 2.5-3.4 mg/L). The highest concentration causing 0% immobility: 1.5 mg/L. The lowest concentration producing 100 % immobility: 10 mg/L

 

On the basis of the results noted in the study, classification under the CLP Regulation (EC No 1272/2008 is as follows:

 

Chronic aquatic toxicity, Category 2; H411: Toxic to aquatic life with long lasting effects.