3a,4,7,7a-tetrahydro-4,7-methanoindene

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:

Final report, July 1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status not known, near guideline study, information from review article, limitations in design and/or reporting but otherwise acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

slightly lower test temperature, design

Principles of method if other than guideline:

slightly lower test temperature design

GLP compliance:

no

Specific details on test material used for the study:

Dicyclopentadiene (DCPD): clear liquid received from Aldrich Chemical company, Milwaukee, Wisconsin. The DCPD was tested on a 95% active ingredient basis.
The DCPD used in the 14 C-accumulation study was received as clear liquids contained in sealed screw—cap vials from Litton Bionetics , Inc.
Correspondence which accompanied these vials identified their contents as: 14C-DCPC, 100 µCi (50 µL).

Radiolabelling:

yes

Details on sampling:

Water and bluegill were sampled from the units after 1, 2, 4, 7, 10 and 14 days of exposure. During the depuration period, fish were sampled 1, 3 and 7 days after transfer. Water was not sampled during this period. Duplicate 5 mL water samples were taken directly from both units on all sample days during the exposure period. Each sample was pipetted from the test unit into a glass vial containing 15 mL of counting solution.

At each sampling interval 3 fish were removed from each unit, eviscerated, and the distribution of 14C-residues in the edible potion invetigated radiometric analysis. Each portion (0.75-1.50 g) of the muscle tissue from each fish sampled was air dried for approximately 24 hrs in a combusion cone at 21°C. Each dired sample was combusted in a Packard Model 306 Tri-Carb Sample Oxidizer.
The resulting 14CO2 was trapped as a carbonate ina mixture of Carbosorb (1M hyamine hydroxide in methanol) and scintillator cocktain (4 g, 98% PPO + 2% bis-MSB/liter toluene) in counting vial. Prior to analyses of a set of tissue samples, the oxidizer unit was cleaned by consecutively burning two pressed paper discs to elininate any residual 14 C-activity.

Vehicle:

yes

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

The contents of the vial containing 14C-DCPD and an additional 236 mg of unlabelled DCPD were quantitatively transferred to a 1-liter volumetric flask and diluted to volume with distilled water. To determine the specific activity three 1 mL aliquots of the superstock solution were transferred to glass vials containing 15 mL of counting solution. These vials were placed in the liquid scintillation spectrometer and the mean specific activity was measured to be 6.46 ± 0.55 dpm/µg, equivalent to 69% of the theoretical concentration. Stock solutions were prepared from the superstock solutions and were mixed in acetone. The mechanical dilution apparatus was used to establish and maintain desired chemical concentration.

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

Fish in all units fed a dry pelleted ration ad libitum each day. Mean and standard deviation (N=30) wet weight of 1.75 + 0.65 g and standard length of 36.1 + 5.5 mm obtained from commercial fish farmer in Connecticut and were held in these conditions for 30 days prior to initiation of study.

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

14 d

Total depuration duration:

7 d

Hardness:

35 mg/L as CaCo3

Test temperature:

18 + 1.0 °C

pH:

7.1

Dissolved oxygen:

greater than (>) 60% of saturation

TOC:

data not reported

Salinity:

N/A

Conductivity:

N/A

Details on test conditions:

Studies were conducted using a modification of a proportional dilution apparatus which provided for the automatic, intermittent introduction of the test material and dilutent water into the test chamber. Three 30 liter experimental units were utilised in the system. 50 bluegill wre placed into each of the three experimental units. Flow rate of 5 L/hr. Bluegill in one unit were exposed to 150 mg/L of 14C-DIMP, those in the second unit were exposed to 1.00 mg/L 14C-DCPD, and the thrid unit served as control.

Nominal and measured concentrations:

Mean measured 14C-residue concentration water - Day 0 = 0.77, day 1=1.44, day 2 = 0.70, day 4= 0.91, day 7 = 0.87, day 10=1.08, day 14= 1.11 mg/L.
The mean measured concentration of 14C-DCPD in the water through 14 days of exposure was 0.98 mg/L ± 0.25 mg/L

Reference substance (positive control):

no

Details on estimation of bioconcentration:

Radiometric analysis indicate that the mean measured concentration of 14C-residue was 50.73 ± 6.43 mg/kg and was calculated for the period of apparent equilibrium (days 2-4).

Key result

Type:

BCF

Value:

ca. 53 dimensionless

Basis:

edible fraction

Time of plateau:

2 d

Remarks on result:

other: Conc.in environment / dose:0.98mg/l

Key result

Elimination:

yes

Parameter:

DT50

Depuration time (DT):

7 d

Details on kinetic parameters:

After 24 hours in clean water residues in the edible portions had reduced to below the limit of detection, <5 mg/kg.

Metabolites:

data not reported

Results with reference substance (positive control):

N/A

Details on results:

Bluegill exposed to 1.0 mg/L 14C-DCPD durign bioconcentration study appeared normal, fed readily and generally showed no signs of stress due to chemical toxicity. Mean measured concentratio of 14 C-DCPD in the water through 14 days of exposure was 0.98 ± 0.25 mg/L. Estimated BCF for bluegill exposed to 14C-DCPD is 53 (dimensionless). Report states "it appears that the potential of DCPD to bioconcentrate is slight"

Reported statistics:

BCF reported to be 53 (dimensionless) no other statistic was reported.

N/A

Validity criteria fulfilled:

not applicable

Remarks:

This is non-standard study

Conclusions:

A BCF of 53 (dimensionless) was reported in Bluegill for DCPD. This value would not indicate that this substance would meet the criteria for Bioaccumulative in the PBT assessment, nor indicate the potential for chronic effects in the environment in the classification and labelling assessment of this substance.

Executive summary:

Bentley 1976 ran a bioaccumulation study considered similar to OECD 305 except for some minor deviations (e.g. slightly lower test temperature) and reported a BCF of 53 (dimensionless) in Bluegill for DCPD.

This study method is equivalent to a standard guideline, and although it is accepted that there are some limitations in the study design, this study is still considered adequate for the assessment of this endpoint.

Description of key information

A BCF of 53 (dimensionless) was reported in Bluegill for DCPD.

Key value for chemical safety assessment

BCF (aquatic species):

53 dimensionless

Additional information

The value indicates that this substance would not meet the criteria for Bioaccumulative in the PBT assessment, nor indicate the potential for chronic effects in the environment in the classification and labelling assessment of this substance.

Bentley (1976) follows a study method equivalent to a standard guideline and, although it is accepted that there are some limitations in the study design, this study is still considered adequate for the assessment of this endpoint. OECD SIDS for Dicyclopentadiene identified a MITI (1997) study which showed a BCF range of 58.9 - 384 for Carp. This study was unavailable for review but considered adequate for assessment as a supporting study.