4-methylstyrene

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

Study period:

1981 - 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: US EPA guideline published in the Federal Register 43 (132):29696-29741 and Federal Register 44 (53):16284-16292. ASTM Committee E-35.21 v6 1977 and 1979

Deviations:

not specified

Principles of method if other than guideline:

This guideline requires testing in a static soil/water system where the test substance is applied to the soil. Exposure lasts for 30 d, after which a depuration phase commences. Concentrations in the fish are monitored throughout both the accumulation and depuration phases of the experiment. In this study, the rate of transfer from the treated soil to the water was monitored.

GLP compliance:

yes

Remarks:

EPA 1978 - Regulations for Good Laboratory Practice in Non clinical Animal Studies 21 CFR Part 58.

Radiolabelling:

yes

Details on sampling:

- Sampling intervals/frequency for test organisms:
- Sampling intervals/frequency for test medium samples:
soil
1. post preparation 1 (3 subsamples).
2. 30 day posted treatment ageing period sample on days 0, 1, 15 & 30
3. 8 day equlibration period following the addition of water sampled on days 1, 3 & 8.
4. uptake phase sampled on days 1, 3, 7, 10, 14, 22 & 30.

water.
1. 8 day equlibration period following the addition of water sampled on days 1, 3 & 8.
2. uptake phase sampled on days 1, 3, 7, 10, 14, 22 & 30.

fish
sample size six fish that were disected into, fillet (muscle, skin & skeleton) and viscera (fins, head & internal organs). At each interval a further four fish were used for whole fish analysis.
1. uptake phase sampled on days 1, 3, 7, 10, 14, 22 & 30.
2. depuration phase sampled on days 1, 3, 7, 10 & 15.

- Sample storage conditions before analysis: deep frozen.

Vehicle:

no

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

PREPARATION OF SPIKED SEDIMENT

- Pooling or mixing of different substrates: sandy loam soil
- Method of mixing: cement mixer.
- Equilibration time: eight days following addition of water - 30 days equalibration period before water and reduced.
- Equilibration conditions:
- Controls:
- Chemical name of vehicle (organic solvent, emulsifier or dispersant):
- Concentration of vehicle in test medium (stock solution and final test solution):
- Evaporation of vehicle before use: Yes

Test organisms (species):

Ictalurus punctatus

Details on test organisms:

TEST ORGANISM
- Common name: Channel catfish
- Source: Northrup Hatchery, Colombia USA
- Length at study initiation (lenght definition, mean, range and SD): mean 6.5 g length 73 mm
- Method of breeding: captive
- Health status: okay (acceptable/satifactory)
- Description of housing/holding area: Aquarium

ACCLIMATION
- Acclimation period: fourteen days
- Acclimation conditions (same as test or not): Yes

Route of exposure:

sediment

Test type:

static

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

30 d

Total depuration duration:

15 d

Hardness:

225 ppm CaCO3

Test temperature:

19.0 +/-2.0C

pH:

Control 7.7 - 8.3
Treated 7.8 - 8.4

Dissolved oxygen:

Conbtrol 7.4 - 8.9 mg/l
Treated 6.6 - 9.1 mg/l

TOC:

Not applicable to water. the soil contained 0.1 % organic matter.
Ammonia conc Control and treated <0.1 - 0.45 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open / closed: open with continuous aeration

- Type of flow-through (e.g. peristaltic or proportional diluter): depuration phase only.
- Renewal rate of test solution (frequency/flow rate):
- No. of organisms per vessel:a minimum of 150
- No. of vessels per concentration (replicates):as per guidelines

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:local well water
- Particulate matter: none

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: sixteen hours light
- Light intensity: not recorded

RANGE-FINDING / PRELIMINARY STUDY - not conducted.

Nominal and measured concentrations:

nominal concentration target 2.0 mg/kg. measured concentration at the start of the study in the soil was 0.36 mg/kg. Losses are attributed to volatisation during the soil preparation process. Concentrations were considered adequate by the study supervisor for the study to proceed as adequate concentrations were present in the water phase.

Reference substance (positive control):

no

Details on estimation of bioconcentration:

not recorded. QSAR Kow 3.44

Key result

Type:

BCF

Value:

4.9 dimensionless

Basis:

whole body w.w.

Time of plateau:

22 d

Calculation basis:

other: Calculated for each sampling interval - not steady state as levels were too low for the analytical method

Remarks on result:

other: No bioconcentration occurred

Remarks:

Concentration in environment / dose: 0.16 mg/kg in aged soil

Details on kinetic parameters:

- Uptake rate constant (k1): not calculated
- Depuration (loss) rate constant (k2): Too low to measure

Details on results:

- Mortality of test organisms: None reported
- Behavioural abnormalities: None reported
- Observations on body length and weight:None reported
- Other biological observations:None reported
- Organ specific bioaccumulation:
Fillet - 9.2
Viscera - 4.0
- Mortality and/or behavioural abnormalities of control: None reported
- Loss of test substance during test period:
Initial dose - 2.0 mg/kg soil,
After mixing into test soil - 0.36 mg (18% of applied dose - loss through volatilisation).
After aging (30 days) - 0.16 mg/kg (total loss pre introduction of water 53% of initial dose).
Loss during uptake phase - 0.02 mg/kg.

Reported statistics:

None reported

		14C-PMS Concentrations
Day		Water μg/L	Soil mg/kg	Fillet				Whole fish				Viscera
				mg/kg		BCF		mg/kg		BCF		mg/kg		BCF
Ageing	0	-	0.34
	1	-	0.28
	15	-	0.18
	30	-	0.16
Equilibration	1	0.34	0.16
	3	0.12	0.15	*	*		*		*		*		*
	8	0.55	0.16	*	*		*		*		*		*
Uptake	1	0.73	0.23	0.0067	9.2		*		*		*		*
	3	0.88	0.24	*	*		*		*		*		*
	7	0.90	0.14	*	*		0.0015		1.7		*		*
	10	0.79	0.15	*	*		*		*		0.0025		3.2
	14	0.95	0.14	*	*		0.0024		2.5		0.0023		2.4
	22	1.5	0.19	0.0024	1.6		0.0073		4.9		0.006		4.0
	30	1.3	0.14	*	*		*		*		0.0058		4.5
Depuration	1	*	-	0.00035			0.0007				0.0061
	3	*	-	0.001			0.0035				0.0052
	7	*	-	*			0.0019				*
	10	*	-	*			*				*
	14	*	-	0.0061			0.0051				0.0058

Key - Not applicable at this point in the study, * below the limit of detection.

All values for concentrations in tissues are deemed “qualified values” as they are below the LOQ.

Validity criteria fulfilled:

not applicable

Conclusions:

Under the study conditions, based on the semi-qualitative values, maximum tissue concentrations were estimated to be 0.0073 mg/kg for whole fish, 0.0067 mg/kg for fillet and 0.006 mg/kg for viscera. Dividing these concentrations by the analysed concentrations in water yielded bioconcentration factors of 4.9, 9.2 and 4.0, respectively. As all concentrations recorded in the uptake phase were “qualitative” (below the level of qualification for the analytical methods used), no calculation of depuration rates was possible

Executive summary:

A study was conducted to determine the bioconcentration potential of the test substance in channel catfish (Ictalurus punctatus) in a static system according to the US EPA guideline for pesticide registration (1978). The design consisted in four continuous phases, namely 30 d of ageing, 8 d of equilibration, 30 d of uptake and 14 d of depuration. The exposure phase test system consisted in stainless steel tanks (70 x 101 x 304 cm) containing both water and sandy loam soil. The depuration tanks were 100 L glass aquatic containing 75 L of well water. The soil was spiked with 14C-labelled test substance at an intended application rate of 2 mg/kg. However, due to volatility, 82% loss occurred during application and mixing. The mean treated soil 14C-residues on Day 0 of ageing and Day 30 of bioconcentration were 0.34 and 0.14 mg/kg (14-C test substance equivalents), respectively. The mean concentrations in the water phase ranged from 0.34 µg/L on Day 1 of equilibration to 1.3 µg/L at the end of the uptake phase. Under the study conditions, based on the semi-qualitative values, maximum tissue concentrations were estimated to be 0.0073 mg/kg for whole fish, 0.0067 mg/kg for fillet and 0.006 mg/kg for viscera. Dividing these concentrations by the analysed concentrations in water yielded bioconcentration factors of 4.9, 9.2 and 4.0, respectively. As all concentrations recorded in the uptake phase were “qualitative” (below the level of qualification for the analytical methods used), no calculation of depuration rates was possible (Johnson, 1982).

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1981 - 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: EPA steady state guideline applicable at the time the study was conducted

Deviations:

not specified

Principles of method if other than guideline:

The guideline required testing in a dynamic flow through the system where fish were exposed to the test substance for a period of 30 d. Analysis of whole fish and selected portions of the fish were conducted at intervals to determine when the concentration plateau is reached. After exposure, a 14 d depuration period follows during which analysis is conducted to determine how quickly the accumulated test substance is lost. Based on these results, a two-compartment mathematical model is used to calculate the uptake rate constant and the depuration rate constant together with a steady state bioaccumulation factor.

GLP compliance:

yes

Remarks:

EPA 1978 - Regulations for Good Laboratory Practice in Non clinical Animal Studies 21 CFR Part 58.

Radiolabelling:

yes

Details on sampling:

- Sampling intervals/frequency for test organisms:
fish
- samples on uptake days 1, 3, 7, 10, 14, 22 and 30. sampled on depuration days 1, 3, 7, 10 and 14.
- number of fish per sample: minimum of the six maximum of 10. (analysed conducted on whole fish, fillets and viscera). in addition samples were taken for metabolites analysis
- metabolite analysis conducted on the uptake days 3, 22 and 30 + days 3 and 14 of the depuration phase of the study
- Sampling intervals/frequency for test medium samples: dates the same as those above for fish samples
- Sample storage conditions before analysis: frozen
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods):
- fish that were disected into, fillet (muscle, skin & skeleton) and viscera (fins, head & internal organs). At each interval a further four fish were used for whole fish analysis. All analysis by scintillation counts.
- Water no preparation scintillation counting and HPLC (used for both water samples and determination of concentrations in stock solutions).

Vehicle:

no

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

The test system used consisted of two 100 L aquaria for treated water and 2 for untreated control water. Aerated well water was delivered at a rate of 350 mls/min. Dosing to the treated aquaria was achieved using a proportional dilutor set to deliver a nominal concentration of 0.25 mg/L. All four aquaria were maintained in a water bath at 22°C.

Radiolabelled solutions were prepared initially by dissolving radiolabelled material in acetone to give a specific activity of 0.395 mCi/m. From this active ingredient working stock solutions were made up my dilution with 12C-labeled test substance to give working solutions of 740 DPM/ug. concentration of final stock solutions were analysed using HPLC - UV against an analytical standard of the test substance.

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill sunfish
- Source: Kurtz Fish Hatchery, Pennsylvania.
- Length at study initiation: 6.1g x 61 mm
- Health status: satisfactory
- Description of housing/holding area: larger aquaria (holding tanks) 16 h daylight, daily observations,
- Feeding during test
- Food type: commercial fish food.
- Amount: 3 % of body weight
- Frequency: daily


ACCLIMATION
- Acclimation period:fourteen days
- Acclimation conditions: same as test
- Type and amount of food: commercial fish food, 3 % of body weight
- Feeding frequency: daily
- Health during acclimation (any mortality observed): none

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

30 d

Total depuration duration:

14 d

Hardness:

225 ppm

Test temperature:

22C

pH:

8.2

Dissolved oxygen:

9.3 ppm

TOC:

total ammonia <0.1ppm

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 L aqaria
- Type: open / closed not specified but thought to be open.
- Material fill volume: 100 L
- Aeration: supplied with aerated well water
- Type of flow-through: proportional dilutor
- Renewal rate of test solution (frequency/flow rate): 350 mls/min
- No. of organisms per vessel: 50
- No. of vessels per concentration (replicates): 2
- No. of vessels per control / vehicle control (replicates): 2
- Photoperiod:16 h light

Nominal and measured concentrations:

nominal concentration - 0.25 mg/L.
measured concentrations during the uptake phase of the study ranged from 0.24 to 0.27 mg/L

Reference substance (positive control):

not required

Details on estimation of bioconcentration:

BASIS INFORMATION
- Measured/calculated logPow: QSAR Kow 3.44

Key result

Type:

BCF

Value:

ca. 96 - <= 180 dimensionless

Basis:

whole body w.w.

Time of plateau:

3 d

Calculation basis:

steady state

Remarks on result:

other: Concentration in environment / dose:0.25mg/L

Key result

Type:

BCF

Value:

> 25 - < 92 dimensionless

Basis:

edible fraction

Time of plateau:

3 d

Calculation basis:

steady state

Remarks on result:

other: Concentration in environment / dose: 0.25 mg/L

Key result

Type:

BCF

Value:

>= 100 - <= 320 dimensionless

Basis:

non-edible fraction

Time of plateau:

3 d

Calculation basis:

steady state

Remarks on result:

other: Concentration in environment / dose: 0.25 mg/L

Key result

Elimination:

yes

Parameter:

other: 94% clearance in whole fish

Depuration time (DT):

14 d

Key result

Elimination:

yes

Parameter:

other: 95% clearance from edible portions

Depuration time (DT):

14 d

Key result

Elimination:

yes

Parameter:

other: 94% clearance from non-edible portions

Depuration time (DT):

14 d

Details on kinetic parameters:

- Uptake rate constant (k1): 350 ppm in fish/ppm in water/day
- Depuration (loss) rate constant (k2): 3.2 days
- Steady state BCF - 110

Metabolites:

No metabolite identification was undertaken.

Results with reference substance (positive control):

Not included in the report

Details on results:

- Mortality of test organisms: None
- Behavioural abnormalities: None recorded

Reported statistics:

2 phase kinetic model using regression analysis.

The mean tissue residues after 30 days exposure were 30ug/g, 13ug/g and 43ug/g for whole fish, fillet and viscera respectively. The analysed concentrations are shown in the table below.

Day	Water Conc mg/L	Fish fillet		Whole fish		Viscera
		μg/g	BCF	μg/g	BCF	μg/g	BCF
Uptake
0	0.26
1	0.25	22	85	26	100	79	300
3	0.24	6.2	25	39	160	25	100
7	0.25	23	92	40	160	66	260
10	0.26	20	80	25	100	79	320
14	0.24	11	44	24	96	33	210
22	0.27	16	64	45	180	56	220
30	0.26	13	52	30	120	43	170
Depuration			% Depuration		% Depuration		% Depuration
1	0.0067	4.0	69	14	53	20	53
3		2.2	83	7.2	76	7.2	83
7		1.0	92	2.8	91	4.5	90
10		0.9	93	1.5	95	3.2	93
14		0.68	95	1.7	94	2.6	94

Depuration - Initial concentration 30μg/g for whole fish, 13 μg/g for fillet and 43 μg/g for viscera.

Based on these concentrations the calculated BCF for whole fish, fillet and viscera were 120, 52 and 170 respectively.

Validity criteria fulfilled:

not applicable

Conclusions:

Under the study conditions, based on measured concentrations, the calculated BCF for whole fish, edible portion (fillet) and viscera were 120, 52 and 170, respectively.

Executive summary:

A study was conducted to determine the bioconcentration potential of the test substance in bluegill sunfish (Lepomis macrochirus) in a 44 d dynamic flow-through system study according to EPA steady state guidelines (1979). The study consisted in an uptake phase of 30 d, followed by a depuration phase of 14 d. The fish were maintained in large aquaria supplied with 14C-labelled test substance via a dynamic flow-through system to maintain a nominal concentration in water of 0.25 mg/L. The fish were analysed as whole fish, edible portion (fillet) and viscera. A plateau was reached in the uptake phase of the study within 7 d, equivalent to 30 µg/g for whole fish, 13 μg/g for fillet and 7 d for viscera. Under the study conditions, based on measured concentrations, the calculated BCF for whole fish, edible portion (fillet) and viscera were 120, 52 and 170, respectively (Johnson, 1982).

Reference 3

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

The substance falls within the applicability domain of the selected (Q)SAR method.

Qualifier:

according to guideline

Guideline:

other: EPI SUITE v 4.11

GLP compliance:

no

Key result

Value:

86.74 L/kg

Basis:

whole body w.w.

Conclusions:

Under the study conditions, the test substance BCF was determined to be 86.74 L/kg w.w.

Executive summary:

A study was conducted to determine the BCF of the test substance using EPI SUITE v 4.11 modelling. The log BCF was estimated from a regression-based method (BCFBAF v 3.01) and was derived at 1.938. Under the study conditions, the test substance BCF was determined to be 86.74 L/kg w.w. (US EPA, 2017).

Reference 4

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

The substance falls within the applicability domain of the selected (Q)SAR method.

Qualifier:

according to guideline

Guideline:

other: T.E.S.T. v 4.2

Key result

Value:

119.91 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: mean of two isomers

Conclusions:

Under the study conditions, the test substance BCF was determined to be 119.91.

Executive summary:

A study was conducted to determine the BCF of the test substance using T.E.S.T. v 4.2 modelling. The derived value was the mean from four systemic methods. The similarity coefficient indicated good reliability. Under the study conditions, the test substance BCF was determined to be 119.91 (US EPA, 2017).

Description of key information

Two studies were conducted to investigate the bioaccumulation of the test substance in fish using either treated soil (sediment) or water (flow-through study). The results from the simulated sediment study showed that a very large proportion of the test substance was lost through volatilisation during the ageing process, with the result that concentrations in water were extremely low. In the flow-through study, the test substance showed no tendency to bioaccumulate in fish. Plateau concentrations were achieved in approximately the first 3 d of the 33 d exposure period and > 90% of the test substance was lost within the first week of the 14 d depuration phase.

Key value for chemical safety assessment

BCF (aquatic species):

120 dimensionless

Additional information

BCF study, channel catfish

A study was conducted to determine the bioconcentration potential of the test substance in channel catfish (Ictalurus punctatus) in a static system according to the US EPA guideline for pesticide registration (1978). The design consisted in four continuous phases, namely 30 d of ageing, 8 d of equilibration, 30 d of uptake and 14 d of depuration. The exposure phase test system consisted in stainless steel tanks (70 x 101 x 304 cm) containing both water and sandy loam soil. The depuration tanks were 100 L glass aquatic containing 75 L of well water. The soil was spiked with 14C-labelled test substance at an intended application rate of 2 mg/kg. However, due to volatility, 82% loss occurred during application and mixing. The mean treated soil 14C-residues on Day 0 of ageing and Day 30 of bioconcentration were 0.34 and 0.14 mg/kg (14-C test substance equivalents), respectively. The mean concentrations in the water phase ranged from 0.34 µg/L on Day 1 of equilibration to 1.3 µg/L at the end of the uptake phase. Under the study conditions, based on the semi-qualitative values, maximum tissue concentrations were estimated to be 0.0073 mg/kg for whole fish, 0.0067 mg/kg for fillet and 0.006 mg/kg for viscera. Dividing these concentrations by the analysed concentrations in water yielded bioconcentration factors of 4.9, 9.2 and 4.0, respectively. As all concentrations recorded in the uptake phase were “qualitative” (below the level of qualification for the analytical methods used), no calculation of depuration rates was possible (Johnson, 1982).

BCF study, bluegill sunfish

A study was conducted to determine the bioconcentration potential of the test substance in bluegill sunfish (Lepomis macrochirus) in a 44 d dynamic flow-through system study according to EPA steady state guidelines (1979). The study consisted in an uptake phase of 30 d, followed by a depuration phase of 14 d. The fish were maintained in large aquaria supplied with 14C-labelled test substance via a dynamic flow-through system to maintain a nominal concentration in water of 0.25 mg/L. The fish were analysed as whole fish, edible portion (fillet) and viscera. A plateau was reached in the uptake phase of the study within 7 d, equivalent to 30 µg/g for whole fish, 13 μg/g for fillet and 7 d for viscera. Under the study conditions, based on measured concentrations, the calculated BCF for whole fish, edible portion (fillet) and viscera were 120, 52 and 170, respectively (Johnson, 1982).

BCF, EPI SUITE modelling

A study was conducted to determine the BCF of the test substance using EPI SUITE v 4.11 modelling. The log BCF was estimated from a regression-based method (BCFBAF v 3.01) and was derived at 1.938. Under the study conditions, the test substance BCF was determined to be 86.74 L/kg w.w. (US EPA, 2017).

BCF, T.E.S.T. modelling

A study was conducted to determine the BCF of the test substance using T.E.S.T. v 4.2 modelling. The derived value was the mean from four systemic methods. The similarity coefficient indicated good reliability. Under the study conditions, the test substance BCF was determined to be 119.91 (US EPA, 2017).