Registration Dossier

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
bioaccumulation: aquatic / sediment
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Remarks:
Internationally accepted method, EPI-Suite, EPA (USA)
Principles of method if other than guideline:
Calculation by EPI-Suite, EPA (USA) / BCFWIN v2.17
GLP compliance:
no
Type:
BCF
Value:
598.4
Remarks on result:
other: log Kow used: 5.10 (expkow database)
Validity criteria fulfilled:
not applicable
Conclusions:
The estimated BCF is 598.4 (EPI-Suite, BCFWIN v2.17).
Executive summary:

The estimated BCF is 598.4 (EPI-Suite, BCFWIN v2.17).

Endpoint:
bioaccumulation: aquatic / sediment
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Test design not equivalent to current standard methods. This study exhibits methodological deficiencies concerning number of exposed test organism and analytical test procedure.
Principles of method if other than guideline:
Experiment A: 14C-phenyl-BHT (5.0 ppm relative to dry weight of soil) was mixed thoroughly with Katano soil (500 g) and placed at the bottom of a glass aquarium. To this was added the standard mineral solution (10 l) and was circulated between the two compartments by a water pump with constant air supply at 25 ± 2 ºC. After 4 days of addition of water, carps were added to the smaller compartment and the whole system was operated for 1, 2 and 4 weeks.

Experiment B: The same soil (500 g) was spread on the bottom of the aquarium and to this was added water (10 l) and then 2 carps. After 1 day, 14C-phenyl-BHT (2.0 ppm to the said water) as an aqueous emulsion (100 ml) with 10 fold amounts of Tween-80 to BHT was added. The whole system was then operated for 1, 2 and 4 weeks and water, fish and soil were sampled.

Experiment C: Two kg of soil treated with 14C-phenyl-BHT (2.0 ppm relative to dry weight of soil) were placed in the larger compartment of the aquarium and flooded with water (30 l). Four days after flooding, two carps were added to the smaller compartment and two snails, Daphnids and algae solution were added to the larger compartment. The ecosystem was then operated in a greenhouse for 1, 2 and 4 weeks.
GLP compliance:
no
Radiolabelling:
yes
Details on sampling:
The contents of BHT and its degradation products in water were measured at the specified intervals during operation and the carps and the soil were analysed at 1, 2 and 4 weeks in each of the three studies.
Details on preparation of test solutions, spiked fish food or sediment:
Soil: Katano sandy loam; sand 80%, silt 12% and clay 8%, organic matter content 1.8%, pH 5.8.
Details on test organisms:
Fish: Cyprinus carpio (15-25 g) from the Nango Fisheries Center, Shiga Pref. and acclimatised dechlorinated tap water for two weeks at 25 ºC prior to use.
Snails: Cypangopaludina japonica (15-25 g) from Katada Fisheries Union, Shiga Pref. were acclimatised on Katano soil flooded with dechlorinated water.
Daphnids: Daphnia pulex from Nihon Dobutsu Co. were acclimatised in flooded water on Katano soil.
Algae: fillamentous green algae and Chlorella, appearing and grown in the culture solution for the growth of Chlorella were used.
Details on test conditions:
Experiment A: 14C-phenyl-BHT (5.0 ppm relative to dry weight of soil) was mixed thoroughly with Katano soil (500 g) and placed at the bottom of a glass aquarium. To this was added the standard mineral solution (10 l) and was circulated between the two compartments by a water pump with constant air supply at 25 ± 2 ºC. After 4 days of addition of water, carps were added to the smaller compartment and the whole system was operated for 1, 2 and 4 weeks.

Experiment B: The same soil (500 g) was spread on the bottom of the aquarium and to this was added water (10 l) and then 2 carps. After 1 day, 14C-phenyl-BHT (2.0 ppm to the said water) as an aqueous emulsion (100 ml) with 10 fold amounts of Tween-80 to BHT was added. The whole system was then operated for 1, 2 and 4 weeks and water, fish and soil were sampled.

Experiment C: Two kg of soil treated with 14C-phenyl-BHT (2.0 ppm relative to dry weight of soil) were placed in the larger compartment of the aquarium and flooded with water (30 l). Four days after flooding, two carps were added to the smaller compartment and two snails, Daphnids and algae solution were added to the larger compartment. The ecosystem was then operated in a greenhouse for 1, 2 and 4 weeks.
Key result
Temp.:
ca. 25 °C
Type:
BCF
Value:
>= 2 - <= 17 other: Bioaccumulation defined as concentration in fish at day 28/average concentration in water during 0-28 days
Basis:
whole body w.w.
Calculation basis:
other: day 28
Remarks on result:
other: No data on pH.
Remarks:
The concentration of radioactive compounds (BHT and metabolites) in fish showed maximum values in 7 and 14 days and then went down gradually
Details on results:
Experiment A: It was found that more than 60% of the applied 14C remained in soil, 20-30% being released into water and only 1-2% was translocated in fish. The concentrations of the radioactive compounds in fish showed maximum values in 7 or 14 days and then went down gradually. The bioaccumulation ratios of the total 14C, BHT, BHT-OH and BHT-OOH were at the maximum 29, 25, 26 and 4, respectively. It was noticed that all these ratios went down as the time progressed. This means the compounds in fish were excreted or metabolised fairly rapidly.

Experiment B: About 30% of the applied 14C remained in water, 5-14% was adsorbed by soil and 3-10% was translocated in fish. The recovery of the total 14C was only 40-50% suggesting that more than 50% of BHT was evaporated into atmosphere. The radioactive compounds in fish increased during a week and then decreased. The bioaccumulation ratios of BHT-OH, BHT-COOH and BHT-CHO at 7th day were extremely high: 350, 110 and 150 against that of BHT: 20. This means that carps exposed to a high concentration of BHT at the beginning of the operation incorporated BHT and then metabolised it before excretion.

Experiment C: 66-74% of the applied 14C remained in soil, 9-16% was dissolved into water and only 0.3-0.5% was translocated in organisms. The accumulated amounts of BHT and the metabolites increased for the first 7-14 days of exposure, and then decreased except BHT-COOH in fish, which reached a plateau. The bioaccumulation ratios of BHT and the metabolites in the organisms increased for the first 7-14 days and then decreased exemplifying the low accumulation potentials of these compounds.
Validity criteria fulfilled:
not applicable
Conclusions:
BHT was easily degraded in aquatic environments into numerous polar intermediates and none of them were accumulated in aquatic organisms as compared with other environmental contaminants which were observed to accumulate.
Executive summary:

Experiment A: 14C-phenyl-BHT (5.0 ppm relative to dry weight of soil) was mixed thoroughly with Katano soil (500 g) and placed at the bottom of a glass aquarium. To this was added the standard mineral solution (10 l) and was circulated between the two compartments by a water pump with constant air supply at 25 ± 2 ºC. After 4 days of addition of water, carps were added to the smaller compartment and the whole system was operated for 1, 2 and 4 weeks.

Experiment B: The same soil (500 g) was spread on the bottom of the aquarium and to this was added water (10 l) and then 2 carps. After 1 day, 14C-phenyl-BHT (2.0 ppm to the said water) as an aqueous emulsion (100 ml) with 10 fold amounts of Tween-80 to BHT was added. The whole system was then operated for 1, 2 and 4 weeks and water, fish and soil were sampled.

Experiment C: Two kg of soil treated with 14C-phenyl-BHT (2.0 ppm relative to dry weight of soil) were placed in the larger compartment of the aquarium and flooded with water (30 l). Four days after flooding, two carps were added to the smaller compartment and two snails, Daphnids and algae solution were added to the larger compartment. The ecosystem was then operated in a greenhouse for 1, 2 and 4 weeks.

BHT was easily degraded in aquatic environments into numerous polar intermediates and none of them were accumulated in aquatic organisms as compared with other environmental contaminants which were observed to accumulate.

The BCF values determined for BHT and its metabolites after a 28 -day exposure period ranged from 2 -17 in fish. However, this study exhibits methodological deficiencies concerning number of exposed test organism and analytical test procedure.

Endpoint:
bioaccumulation in aquatic species: fish
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Remarks:
The bioaccumulation of BHT in fish was determined in a test according to OECD guideline 305C. However, no explanation of the high variation of results is given and no details on analytical monitoring are provided although it is stated that the test water is analyses twice a week. The report is not available. The information is taken into account for the weight of evidence analysis.
Qualifier:
according to
Guideline:
OECD Guideline 305 C (Bioaccumulation: Test for the Degree of Bioconcentration in Fish)
Deviations:
not specified
GLP compliance:
not specified
Radiolabelling:
not specified
Vehicle:
not specified
Test organisms (species):
Cyprinus carpio
Test type:
flow-through
Water / sediment media type:
natural water: freshwater
Total exposure / uptake duration:
56 d
Test temperature:
25 ºC
Nominal and measured concentrations:
Nominal concentration: 0.05 mg/L
Reference substance (positive control):
not specified
Key result
Conc. / dose:
0.05 mg/L
Type:
BCF
Value:
>= 230 - <= 2 500 dimensionless
Remarks on result:
other: No data on temperature or pH
Validity criteria fulfilled:
not specified
Conclusions:
The bioaccumulation of BHT in fish (Cyprinus carpio) was determined in a test according to OECD guideline 305 C using a concentration of BHT of 0.05 mg/l. Bioconcentration factors (BCF) in the range of 230 - 2500 after 56 days were reported. No explanation of the high variation of results is given and only a general test procedure without mentioning analytical details is reported.
Executive summary:

The bioaccumulation of BHT in fish (Cyprinus carpio) was determined in a test according to OECD guideline 305 C using a concentration of BHT of 0.05 mg/l. Bioconcentration factors (BCF) in the range of 230 - 2500 after 56 days were reported. No explanation of the high variation of results is given and only a general test procedure without mentioning analytical details is reported.

Description of key information

MITI study: The bioaccumulation of BHT in fish (Cyprinus carpio) was determined in a test according to OECD guideline 305 C using a concentration of BHT of 0.05 mg/l. Bioconcentration factors (BCF) in the range of 230 - 2500 after 56 days were reported. No explanation of the high variation of results is given and only a general test procedure without mentioning analytical details is reported.

Based on the estimated results using EPI-Suite, the BCF is 598.4.

Experimental results from a scientific article: The BCF values determined after a 28 -day exposure period were 2 -17 for fish. However, this study exhibits methodological deficiencies concerning number of exposed test organism and analytical test procedure.

BHT was easily degraded in aquatic environments into numerous polar intermediates and none of them were accumulated in aquatic organisms as compared with other environmental contaminants which were observed to accumulate.

Key value for chemical safety assessment

BCF (aquatic species):
598.4 L/kg ww

Additional information

Weight of evidence: Experimental results from a MITI study and estimated results using EPI-Suite.