2-tert-butylphenol

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-01-21 - 2008-03-31

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study was conducted according to acceptable guidelines and was GLP compliant. However, information on controls is missing

Qualifier:

according to guideline

Guideline:

other: Bioaccumulation test of a chemical substance in fish or shellfish" provided in “the Notice on the Test Method Concerning New Chemical Substances

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 (Bioconcentration: Flow-through Fish Test)

GLP compliance:

yes

Vehicle:

yes

Details on preparation of test solutions, spiked fish food or sediment:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances) - Chemical name of vehicle (organic solvent, emulsifier or dispersant): Dimethyl sulfoxide

Test organisms (species):

Cyprinus carpio

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Test temperature:

1st concentration 24.0 - 24.2 degreeC, 2nd concentration 24.0 - 24.2 degreeC, control 24.0 - 24.1 degreeC

pH:

1st concentration 8.0, 8.1, 2nd concentration 8.0, 8.1, control 8.1, 8.1

Dissolved oxygen:

1st concentration 7.7 - 8.2 mg/L, 2nd concentration 7.6 - 8.1 mg/L, control 7.8 - 8.2 mg/L

Nominal and measured concentrations:

(nominal) 1st Concentration area 20 ug/L, 2nd Concentration area 2 ug/L

Details on estimation of bioconcentration:

Range-finding / Preliminary study - Test concentrations: 96hr LC50: 3.54 mg/L (Oryzias latipes)

Lipid content:

4.15 %

Time point:

start of exposure

Lipid content:

3.77 %

Time point:

end of exposure

Type:

BCF

Value:

62 dimensionless

Time of plateau:

15 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:20 ug/L

Type:

BCF

Value:

78 dimensionless

Time of plateau:

15 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:2 ug/L

Details on results:

Measured concentration of the test substance in test water (ug/L)
2 -day 8 -day 10 -day 15 -day 21 -day 28 -day Average (sd)
1st concentration 20.8 20.3 20.7 20.3 20.5 20.8 20.6 (0.22)
2nd concentration 2.07 2.05 2.07 2.10 2.06 2.05 2.07 (0.017)

Result of measurement of BCFs

	8 -day	10 -day	15 -day	21 -day	28 -day
1st concentration (average)	85, 73 (79)	40, 53 (46)	48, 59 (53)	73, 56 (65)	74, 61 (68)
2nd concebtration (average)	78, 79 (78)	80, 78 (79)	75, 88 (82)	63, 74 (68)	79, 89 (84)

Validity criteria fulfilled:

not specified

Conclusions:

A bioaccumulation test using the common carp, Cyprinus carpio, following OECD 305 guidelines determined the BCF to be 78.

Executive summary:

A reliable BCF study (Klimisch 1) was conducted according to OECD 305 methods and was GLP compliant. The common carp, Cyprinus carpio, were exposed to o-tert-butylphenol where the uptake, tissue distribution and elimination of the test substance in freshwater exposure was investigated. Fish were exposed to measured concentrations of the test substance at 20 ug/L and 2 ug/L in a flow-through system for 28 days. The time of plateau was 15 days and the BCF was based on steady state. The measured BCF for the 20 ug/L exposure was 62 and the BCF for the 2 ug/L exposure was 78.   

Description of key information

CERI Japan (2008) provided a measured BCF value of 78 for the common carp.

Key value for chemical safety assessment

BCF (aquatic species):

78 dimensionless

Additional information

Reliable measured and modeled BCF data for o-tert-butylphenol are available and included in the dossier. Additionally, reliable measured and modeled BCF data for the structural analogue, o-sec-butylphenol is available and included in this dossier.

Chemical Evaluation and Research Institute Japan (2008) conducted a reliable BCF study (Klimisch 2) according to OECD 305 methods and was GLP compliant. The common carp, Cyprinus carpio, were exposed to o-tert-butylphenol where the uptake, tissue distribution and elimination of the test substance in freshwater exposure was investigated. Fish were exposed to measured concentrations of the test substance at 20 ug/L and 2 ug/L in a flow-through system for 28 days. The time of plateau was 15 days and the BCF was based on steady state. The measured BCF for the 20 ug/L exposure was 62 and the BCF for the 2 ug/L exposure was 78.

The European Union System for the Evaluation of Substances (EUSES) model was used to estimate bioconcentration for o-tert-butylphenol by Sasol (2013). Using the measured log K_ow of 3.3, a BCF for fish was estimated at 127 L/kg wwt.

Chemical Inspection and Testing Institute (2000) conducted a reliable (Klimisch 2) BCF study following OECD 305 methods. Two-year old common carp, Cyprinus carpio, were exposed to measured concentrations of 0.001 and 0.10 mg/L of the structural analogue, o-sec-butylphenol, in a flow-through system for 28 days. Study results indicated that the BCF for fish was 16 for the 0.10 mg/L concentration and 27 for the 0.001 mg/L concentration.

Japan (2012) provided modeled BCF results for o-sec-butylphenol. Using an octanol-water partition coefficient (log Kow) of 3.49, a bio-concentration factor of 101.5 was calculated with USEPA BCFBAF, version 3.00.

Reliable measured BCF data for o-tert-butylphenol and for the analogue o-sec-butylphenol are available and included in this dossier. Chemical Evaluation and Research Institute Japan (2008) provide a measured BCF value of 78 for the common carp exposed to o-tert-butylphenol. Consequently, this value will be taken for the aquatic bioaccumulation in aquatic organisms endpoint.