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

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

adult fish: sub(lethal) effects

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP, similiar to standard guideline, published, minor restrictions in design and/or reporting but otherwise adequate for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

Deviations:

yes

Remarks:

Length of fish, temperature, water hardness, design

Principles of method if other than guideline:

Macroinvertebrate and fish toxicity tests followed the recommended bioassay procedures as described in the “Methods for Acute Toxicity Tests with Fish, Macro invertebrates, and Amphibians” (US EPA 1975).
Test guidelines are similar to the OECD guideline 204 with some deviations ( length of the fish, temperature, water hardness and 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.

Analytical monitoring:

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. Duplicate 5mL 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 15mL 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.

Vehicle:

yes

Remarks:

acetone was used as a solvent/carrier

Details on test solutions:

The contents of the vial containing 14C-DCPD and an additional 236 mg of unlabelled DCPD were quantitatively transferred to a 1L volumetric flask and diluted to volume with distilled water. To determine the specific activity three 1mL 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:

Obtained from a commercial fish hatchery in Conneticut and had a mean and standard deviation (N=30) wet weight of 1.75 ± 0.65 g and standard length of 36.1 ± 5.5 mm. Fish in all units were fed a dry pelleted ration ad libitum each day. Fish remaining in the test units after 14 days were transferred to clean flowing water for 7 days.
The test animal were acclimatized to the test conditions for a minimum of 30 days.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Post exposure observation period:

7 day depuration period

Hardness:

35 mg/L as CaCO3

Test temperature:

18 ± 1.0 °C

pH:

7.1

Dissolved oxygen:

greater than (>) 60% of saturation

Salinity:

N/A

Conductivity:

N/A

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

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/h. 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.

Reference substance (positive control):

no

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

0.98 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 0.98±0.25

Details on results:

bluegill exposed to 1.00 mg/L 14C-DCPD during bioconcentration study appeared normal, fed readily and generally showed no signs of stress due to chemical toxicity. This study was performed in order to assess bioaccumulation potential. However, the author states that no adverse effects were seen at 0.98 ± 0.25 mg/L.

Results with reference substance (positive control):

N/A

Reported statistics and error estimates:

see table above

N/A

Validity criteria fulfilled:

not applicable

Remarks:

This is a non standard study

Conclusions:

No effect concentration of 0.98 ± 0.25 mg/L was reported in the study. As this was the highest tested concentration in the bioaccumulation study, a NOEC could not be confirmed.

Executive summary:

Although this study is not GLP and does not fully comply with standard guidelines, it is considered to be adequate for the assessment of this endpoint. A NOEC of 0.98 ± 0.25 mg/L was reported in the study. As this was the highest tested concentration in the bioaccumulation study, a NOEC could not be confirmed.

Description of key information

An experimental NOEC of 0.98 ± 0.25 mg/L and a QSAR estimated NOEC of 0.767 mg/L were reported. The estimated NOELR value from TLM QSAR is 1.286 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Effect concentration:

0.98 mg/L

Additional information

Bentley et al. (1976) report the results of a long term toxicity study with dicyclopentadiene. At the highest test concentration in the bioaccumulation study, no mortality or change in behaviour was observed and so this value has been taken as a NOEC for the long-term toxicity to fish. Although this study is not GLP and does not fully comply with standard guidelines, it is considered to be adequate for the assessment of this endpoint.

The ECOSAR model predicted a 30 day ChV of 1.084 mg/L, which corresponds to a NOEC of 0.767 mg/L

The Target Lipid model derived an estimated NOELR for this substance of 1.286 mg/L.

The use of a QSAR model is considered appropriate as part of the weight of evidence for this endpoint.