Phenol, mono- + distyrenated (MSP+DSP)

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study, basic data given; test was performed by an laboratory with an high reputation for delivery of robust data.

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 C (Bioaccumulation: Test for the Degree of Bioconcentration in Fish)

Version / remarks:

Test method used corresponds to OECD TG 305 C from May 12, 1981

Principles of method if other than guideline:

The test was performed by a laboratory with a high reputation for delivery of robust data.
This test was conducted in accordance with the test method "Bioaccumulation test of chemical substance in fish and shellfish" stipulated in the Order Prescribing the Items of the Test Relating to the New Chemical Substance (1974, Order of the Prime Minister, the Minister of Health and Welfare, the Minister of International Trade and Industry No.1). It corresponds to OECD TG 305 C of May 12, 1981)

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): 4-(1-methyl-1-phenylethyl)phenol [synonym: 2-phenyl-2-(4-hydroxyphenyl)propane]
- Purity of test material: 99.9 % (GC)
- no further information on test material

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: 2 fish every two weeks
- Sampling intervals/frequency for test medium samples: twice a week
- Sample storage conditions before analysis: no data
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods): no data

Vehicle:

yes

Remarks:

2-Methoxyethanol

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): 2-methoxyethanol
- Concentration of vehicle in test medium: high and low water concentration ca. 25 ppm (v/v)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no data

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: carp
- Source: Sugishima Fish Farm, Kumamoto, Japan
- Length at study initiation: about 10 cm
- Weight at study initiation: about 30 g
- Lipid content: 3.5 g (start); 4.1 (end)
- Weight at termination: no data
- Method of breeding: flow through system at 25 ± 2°C
- Health status: only visibly healthy fish were used; after reception, fish were externaly desinfected (static conditions,
50 mg/L Terramycin (Taito Pfizer) and 7g/L sodium chloride for 24 h).
- Feeding during test:
- Food type: pelleted feed for carp (Japan Haigo Shiryo K.K.)
- Amount: 2% of total body weight
- Frequency: twice a day, half of total amount each

ACCLIMATION
- Acclimation period: at least one month
- Acclimation conditions (same as test or not): yes
- Type and amount of food: pelleted feed for carp (Japan Haigo Shiryo K.K.), 2% of total body weight
- Feeding frequency: twice a day, half of total amount each
- Health during acclimation (any mortality observed): no data, abnormal fish were removed

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

60 d

Hardness:

--

Test temperature:

25 ± 2°C

Dissolved oxygen:

6 - 8 mg/L

Details on test conditions:

TEST SYSTEM (see also CITI 1992)
- Test vessel:
- Type (delete if not applicable): no data
- Material, size, headspace, fill volume: glas tank , volume 100 L
- Aeration: aeration of dilution water
- Type of flow-through (e.g. peristaltic or proportional diluter): no data
- Renewal rate of test solution (frequency/flow rate): 2.9 to 11.5 per day / flow rate 200 to 800 mL/min
- No. of organisms per vessel: 15 - 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control / vehicle control (replicates): no data
- Biomass loading rate: 4.5 - 6 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: underground water pumped at the site of Kurume Research Laboratories
- dilution water was confirmed to meet the quality criteria fisheries
- Intervals of water quality measurement: once every six month; temperature, pH and dissolved oxygen continuously.
- Intervals of test medium replacement: flow through system, see above

RANGE-FINDING / PRELIMINARY STUDY
- Results used to determine the conditions for the definitive study: test concentrations were decided on basis of an acute toxicity test (Oryzias latipes; 48h-LC50 5.4 mg/L)

Nominal and measured concentrations:

High exposure level (level 1): 10 µg/L
low exposure level (level 2): 1 µg/L

Reference substance (positive control):

no

Details on estimation of bioconcentration:

Calculation of bioconcentration factor = concentration of test substance in fish / concentration of test substance in water

Lipid content:

3.5 %

Time point:

start of exposure

Lipid content:

4.1 %

Time point:

end of exposure

Key result

Conc. / dose:

10 µg/L

Temp.:

25 °C

Type:

BCF

Value:

168 L/kg

Basis:

whole body w.w.

Time of plateau:

14 d

Calculation basis:

steady state

Remarks on result:

other: average of measurements during steady state (three measurements from day 28 to day 60 with two fish per measurement)

Remarks:

high exposure level

Conc. / dose:

10 µg/L

Temp.:

25 °C

Type:

BCF

Value:

139 - 187 L/kg

Basis:

whole body w.w.

Time of plateau:

14 d

Calculation basis:

steady state

Remarks on result:

other: maximum and minimum BCF value of measurements from day 28 to day 60 (three measurements with two fish each)

Conc. / dose:

1 µg/L

Temp.:

25 °C

Type:

BCF

Value:

69 - 190 L/kg

Basis:

whole body w.w.

Remarks on result:

other: maximum and minimum BCF value of measurements from day 7 to day 60 (five measurements)

Elimination:

not specified

Details on kinetic parameters:

--

Metabolites:

--

Results with reference substance (positive control):

--

Details on results:

--

Reported statistics:

--

Bioaccumulation test results

 

		7 d	14 d	28 d	42 d	60 d
1st concentration area	Test substance concentration (mg/L)	0.00953	0.00960	0.00971	0.00970	0.00978
	Bioconcentration factor (L/kg)	154	123	181	171	173
		133	172	158	139	187
2nd concentration area	Test substance concentration (mg/L)	0.000987	0.001038	0.001016	0.0010000	0.000996
	Bioconcentration factor (L/kg)	69	99	75	85	104
		104	87	102	190	136

 

Validity criteria fulfilled:

not specified

Conclusions:

Taking into account the derived values for the Bioconcentration Factors (during steady state mean 165, min/max 123/187 for the 1st concentration area (10 µg/L) and min/max 69/190 for the 2nd concentration area (1 µg/L)), it can be concluded that p-cumylphenol exhibits a low bioconcentration potential.

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Secondary source (reference 1) is a reliable expert evaluation of data on styrenated phenol. Original report is an OECD guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure) -III: Dietary Exposure Bioaccumulation Fish Test

Version / remarks:

study was based on a draft of the guideline before adoption on 02 Oct. 2012

Deviations:

not specified

Principles of method if other than guideline:

Similar to OECD TG 305 with some deviations: test substance was applied spiked in food, uptake phase is only 10 days, only one test substance concentration was applied.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): mixture of distyrenated phenol and tristyrenated phenol
- Percentage of components:
- Distyrenated phenol: 40 % w/w
- Tristyreanted phenol: 60 % w/w

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: day 0, 1, 5, and 10 of uptake phase
day 1, 2, 4, 7, 14, 28, and 42 of depuration phase
- Sampling intervals/frequency for test medium samples: samples of the water phase and test and control diets were also analysed at the beginning of the test and at various times during the uptake phase

Vehicle:

no

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

PREPARATION OF SPIKED FOOD
- Method: distyrenated phenol (57.6 mg) and tristyrenated phenol (86.4 mg) were added to 10 mL of solvent (methyl tertiary butyl ether - MTBE) and 7.2 mL of fish oil, shaken for 10 seconds and then added to 144 g of standard fish food (floating and/or sinking pelletised diet) in 750 μL portions. The food was mixed by hand after addition of each portion. Once all of the MTBE/fish oil solution had been added, the spiked food was mixed on a bottle roller for 10 minutes and then shaken (20 rpm) for a further hour. The MTBE was allowed to evaporate under a gentle flow of nitrogen for 24 hours and the spiked food was again shaken for a final 30 minutes. Control food and positive control food was prepared in the same way without addition of the test substance (control food) or with the addition of hexachlorobenzene in place of the test substance. The prepared food was stored under a nitrogen atmosphere at -18 °C until required.
- Concentration of test substance in food: 1000mg/kg food, mixture of distyrenated phenol (40%) and tristyrenated phenol (60%)
- Controls: negative controls, positive controls - hexachlorobenzene (250 mg/kg food)

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: no data
- Age at study initiation (mean and range, SD): three month
- Length at study initiation (lenght definition, mean, range and SD):
- Weight at study initiation (mean and range, SD): 1.57 g (mean, Brooke et al. 2009, p. 41)
- Weight at termination (mean and range, SD): 2.36 g (mean after 10 d of uptake: Brooke et al. 2009, p. 44)
- Feeding during test: yes
- Food type: standard fish food (floating and/or sinking pelletised diet)
- Amount: three per cent of body weight per day
- Frequency: two feedings daily

Route of exposure:

feed

Justification for method:

dietary exposure method used for following reason: very poor vater solubility of test substances

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

10 d

Total depuration duration:

42 d

Hardness:

55 -57 mg/L as CaCO3

Test temperature:

15°C

pH:

7.06 - 7.70

Dissolved oxygen:

> 60% of saturation

Details on test conditions:

TEST SYSTEM
- Test vessel: no data
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: 140 L of water (test group), 110 L of water (control groups)
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate): 3 renewals per day
- No. of organisms per vessel: 125
- No. of vessels per concentration (replicates): 1
- No. of vessels per control / vehicle control (replicates): 1
- Biomass loading rate: 0.57 g fish/L/d

Nominal and measured concentrations:

Nominal concentration of test substance in food: 1000 mg/kg food (distyrenated phenol 40 % / 400 mg/kg, tristyrenated phenol 60 % /600 mg/kg)
Measured concentrations in food: distyrenated phenol: 342 ± 50 mg/kg food (mean ± s.d.)
tristyrenated phenol: 509 ± 110 mg/kg food (mean ± s.d.)

Reference substance (positive control):

yes

Remarks:

hexachlorobenzene (250 mg/kg food)

Lipid content:

5.8 %

Key result

Conc. / dose:

342 other: µg distyrenated phenol/g food

Temp.:

15 °C

pH:

7.5

Type:

BMF

Remarks on result:

not determinable

Remarks:

test substance distyrenated phenol: a BMF could not be determined, as the test substance could not be detected any more in test fish after day 5 of the uptake phase. Therefore, it was not possible to estimate the depuration rate and a BMF

Key result

Conc. / dose:

509 other: µg tristyrenated phenol/g food

Temp.:

15 °C

pH:

7.5

Type:

BMF

Value:

0.355

Calculation basis:

kinetic, corrected for growth

Remarks on result:

other: test substance tristyrenated phenol: the BMF is growth-corrected and lipid-normalised; the growth-corrected BMF as reported in the study is 0.110

Key result

Remarks on result:

not determinable

Remarks:

already at the end of uptake phase and during depuration, concentrations of distyrenated phenol in fish remained below limit of quantification

Key result

Elimination:

yes

Parameter:

DT50

Depuration time (DT):

18.4 d

Remarks on result:

other: test substance is tristyrenated phenol; depuration half-life is based on the growth corrected depuration rate

Details on kinetic parameters:

- Uptake rate constant (k1): uptake rate constants are not determined in a dietary bioaccumulation study in fish
- Depuration (loss) rate constant (k2): test substance distyrenated phenol: could not be determined due to concentrations in fish below LOD
: test substance tristyrenated phenol: 0.038 1/day (growth corrected)

Details on results:

- Mortality of test organisms: no mortality in the test group
- Other biological observations: no significant non-lethal effects
- Organ specific bioaccumulation: at day 10 of the uptake phase, in gut no test substance could be detected (di- as well as tristyrenated phenol)
- Bound residues forming a plateau:
- Mortality and/or behavioural abnormalities of control:no mortality in control group, 1 fish of 125 died in the positive control group (hexachlorobenzene) on day 42 of the depuration phase; no significant non-lethal effects were evident in any of the groups.

Levels of test substance measured in fish following exposure via the diet

 

		Uptake phase			Depuration phase
Day	Substance	1	5	10	1	2	4	7	14	28	42
Concentration [mg/kg fish]	Distyrenated phenol	5.89	3.95	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.
	Tristyrenated phenol	7.39	17.4	21.6	17.1	14.0	8.04	13.9	6.71	3.75	1.61

 

n. d.: not detectable - less than limit of quantification

 

For distyrenated phenol, a rapid decrease of the concentrations in fish was detected leading to undetectable levels by day 10 of the uptake phase and throughout the depuration phase. A steady state could not be observed. This unusual pattern could be explained by a rapid increase of depuration (increased metabolism/clearance) after initial intake of the substance evidenced by the fish body concentrations found on day 1 and 5 of the uptake phase. But by days 5 to 10, elimination exceeds uptake by far resulting in non-detectable concentrations of the substance in fish. Based on this data, a BCF could not be determined. But it can be concluded that the bioaccumulation potential of distyrenated phenol is low.

 

The uptake and depuration pattern for tristyrenated phenol shows increasing concentrations with time over the entire exposure period followed by decreasing concentrations during the depuration period. This pattern of accumulation and depuration is in line with that normally expected in accumulation studies.

Validity criteria fulfilled:

yes

Conclusions:

In a bioconcentration study, a mixture of distyrenated and tristyrenated phenol (40/60% w/w) was used to determine bioaccumulation of test substances in fish (rainbow trout). Test substances were applied in feed (1000 mg/kg food). Already during uptake phase (day 1 to 10), a decrease in distyrenated phenyl body concentrations was observed. At the end of uptake phase and during depuration, concentrations of distyrenated phenol in fish remained below limit of quantification. Test results do not allow determination of a bioconcentration factor. But it can be concluded that the bioaccumulation potential of distyrenated phenol in fish is low.
Uptake and depuration of tristyrenated phenol followed the expected pattern (continuous increase and decrease of test substance in fish during uptake and depuration phase, respectively). A BMF of 0.355 (growth corrected and lipid normalised) could be calculated resulting in estimates of BCF between 6.695 and 10.395 L/kg. Data clearly indicate that the substance is very bioaccumulating (vB).

Description of key information

In a study according to OECD TG 305 using the supporting substance cumylphenol, BCF between 69 and 190 were determined. The highest value is taken to characterise the bioaccumulation potential of phenol, mono- & distyrenated.

Key value for chemical safety assessment

BCF (aquatic species):

190 L/kg ww

Additional information

Two experimental studies were identified providing data to assess the bioaccumulation potential of phenol, mono- & distyrenated (LS 500). In one study, the supporting substance cumylphenol (4-(1-methyl-1-phenylethyl)phenol) was tested according to OECD TG 305. The BCF values determined were in the range between 65 and 190 L/kg. In a second study, a mixture of distyrenated and tristyrenated phenol (40 and 60% w/w, respectively) was applied in a feeding study (uptake phase 10 days, depuration phase 42 days). A BMF/BCF for distyrenated phenol could not be established, as the test substance concentration in fish decreased below limit of detection already during the second half of the uptake phase (after day 5). For tristyrenated phenol, a growth corrected, lipid normalised BMF of 0.355 was determined. Applying different calculation methods, BCF values between 6,695 and 10,395 were estimated. Results of both studies indicate that the bioaccumulation potential of ca. 93 % of phenol, mono- & distyrenated is low, but that a minor component (ca. 2 %) has a high bioconcentration potential (BCF > 5000). In an averall consideration, the highest BCF value measured for the supporting substance 4-cumylphenol is used to characterise the aquatic bioconcentration potential of > 90 % phenol, mono- & distyrenated.