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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29/07/2016 - 02/05/2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Principles of method if other than guideline:

N/A

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Test item (as specified in the report): Dicyclopentadiene
Batch number: 1518148 (LIMS Sample manager report date 2016-02-17)
Cas number: 77-73-6
Active substance / content: Dicyclopentadiene / 92.66%
pH: Not applicable
Appearance: Colourless liquid
Water solubility <= 0.01%
Specific gravity 0.9856

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure intervals (0 and 24 hours), sampling was carried out after preparation of the concentration levels from the stock before addition of daphnids. At the end of the exposure intervals (24 and 48 hours), samples of the old media were taken directly from the test vessels containing daphnids. All samples were analyzed on the same day at the latest 6 hours after sampling. The samples were stored in the autosampler at room temperature until analysis.
Due to 100% mortality after 24 hours at the two highest test concentrations (50 and 100% saturated solutions), the 100% saturated solution was analysed at the beginning of the second exposure period (24 hours) to compare to the saturated solution at the start of the first exposure period (0 hours) but was excluded from evaluation.

Vehicle:

no

Details on test solutions:

Solution preparation: Duplicate fresh saturated solutions of the test item (nominal concentration of 10 mg/L) were prepared one day prior to the test start and the 24 hour exposure interval (i.e. at -24 and 0 hours). The test item was added to dilution water and stirred continuously for 24 hours at 1100 rpm at room temperature, before being left to settle for 30 minutes. The saturated solution was removed via a tap at the bottom of the vessel and checked for undissolved test material with a Tyndall beam. The saturated solution was used as the highest test concentration and as the stock solution for preparing other test concentrations by dilution with Elendt M4 medium.
Undissolved test item: No Tyndall effect observed. Tested concentration levels were visually clear throughout the exposure period.
Dilution water: Elendt M4 medium.

Test organisms (species):

Daphnia magna

Details on test organisms:

STRAUS Clone 5
Origin: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany
Breeder: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
Culture medium: Same as test medium, no acclimation
Age: Less than 24 hours at start of study

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

N/A

Post exposure observation period:

None

Hardness:

Control: 174-177 mg CaCO3/L

Test temperature:

Control: 20.3 - 20.5 °C

pH:

Start of exposure intervals: 7.38 - 8.02
End of exposure intervals: 7.72 - 8.17

Dissolved oxygen:

Start of exposure intervals: 7.76 - 9.16
End of exposure intervals: 6.97 - 8.75

Salinity:

Not applicable

Conductivity:

Control: 472-492 µS/cm

Nominal and measured concentrations:

Spacing factor: 5 test item concentrations in a geometric series with a separation factor of 2, prepared by dilution of the saturated solution with dilution water
Nominal concentrations: 6.25, 12.5, 25, 50 and 100 % saturated solution
Geometric mean concentrations: 0.3, 0.57, 1.11, 2.39, 5.09 mg/L
Control: Dilution water without test item

Details on test conditions:

TEST SYSTEM
Test vessel: Sealed glass flasks (4.5 i.d. x 9.5 cm) with polypropylene screw caps, containing approximately 130 mL test medium.
Type: Closed test vessel with no headspace due to high vapour pressure of the test item.
Renewal rate of test solution: 24 hours
No. of organisms per vessel: 5
No. of vessels per concentration (replicates): 4
No. of vessels per control (replicates): 4
Intervals of water quality measurement: Dissolved oxygen and pH were measured in an additional replicate per concentration without daphids at the start of the exposure periods (0 and 24 hours). At the end of the exposure periods (24 and 48 hours), water quality parameters were measured in all replicates containing daphnids per concentration.

OTHER TEST CONDITIONS
Photoperiod: 16 hours light to 8 hours dark
Light intensity: Diffuse light (maximum intensity 1500 Lux)
Feeding: Daphnids were not fed during the study

EFFECT PARAMETERS MEASURED: Immobilisation was determined in all groups after 24 and 48 hours. No other observations were made.

RANGE-FINDING STUDY
Range finding study: Yes, 1, 10 and 100% saturated solution of nominal concentration 10 mg/L
Test conditions: Same as definitive study.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.823 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

As the measured concentrations were in the range of 51% to 66% at 24 hours (the end of the first renewal period) and 84% to 91% at the end of the test (the end of the second renewal period), the geometric mean measured concentrations were determined.

Results with reference substance (positive control):

24 hour EC50: 1.26 mg/L (95% confidence limits 1.04 to 1.45 mg/L)
Results are in the validity range of 0.6 - 2.1 mg/L

Reported statistics and error estimates:

24 and 48 hour EC50 values were estimated by sigmoidal dose-response regression. The repsective 95% confidence limits were estimated from the standard error and the t-distribution.

Table 6:   Measured Concentrations and Percent of the Initially Measured Concentrations of the Test Item during the Definitive Test

Sampling date	0 hours	24 hours		24 hours	48 hours		Geometric mean measured conc. of the test item [mg/L]
Sampling time in the exposure interval	Start	End		Start	End
Dilution level of the saturated solution [%]	Meas. conc. [mg/L]		%	Meas. conc. [mg/L]		%
100*	6.29	4.12	66	6.92^1)	-  ^2)		5.09
50	3.08	1.86	60	-  ^2)	-  ^2)		2.39
25	1.41	0.72	51	1.27	1.16	91	1.11
12.5	0.7	0.426	61	0.649	0.545	84	0.57
6.25	0.346	0.19	55	0.369	0.333	90	0.3
Control	< LOQ	< LOQ		< LOQ	< LOQ

Meas. conc.      Measured concentration of the test item, dilution factor taken into account

%                     Percent of the initially meas. conc. of the test item at start of the corresponding exposure interval

LOQ                Limit of quantification of the analytical method (50.0 µg test item /L)

*                      Saturated solution

¹⁾                      Measured concentration not taken into account for geometric mean due to 100% mortality after 24 hours

²⁾                      Not analyzed due to 100% mortality after 24 hours

 

Validity criteria fulfilled:

yes

Remarks:

Control daphnids showed no immobilisation or signs of disease or stress. The dissolved O2 concentration at the end of the exposure was = 6.97 mg/L (required: = 3 mg/L) in all test vessels.

Conclusions:

Based on the geometric mean measured concentrations, the 48 hour EC50 is 0.823 mg/L.

Executive summary:

The acute toxicity of DCPD to Daphnia magna was determined in a GLP-compliant study following OECD guideline 202. Based on geometric mean measured concentrations, the 48 hour EC₅₀ was 0.823 mg/L, with 95% confidence limits of 0.740 to 0.909 mg/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09/02/1995 – 11/02/1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Compliant, guideine study, available as unpublished report, acceptable with restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

N/A

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

DCPD 92%, clear colourless liquid. Test material prepared as solvent stock solution.
400 mg of test material dissolved in 10 mL dimethylformamide containing 1% (v/v) Tween 80.
200 µl of this stock solution dispersed in reconstituted water and volume adjusted to 2 litres to give test concentration of 4.0 mg/L.
Authors state "determination of the concentration and stability of the test material in the test solutions were not a requirement of the study plan".

Analytical monitoring:

yes

Details on sampling:

Water temperature recorded dialy, pH an oxygen concentration recorded at 0 and 48 h.

Vehicle:

yes

Remarks:

400 mg of test material were dissolved in 10 ml dimethylformamide containing 1% (v/v) Tween 80

Details on test solutions:

Test material was freshly prepared as a solvent stock solution. 400 mg of test material was dissolved in 10 ml dimethylformamide containing 1% (v/v) Tween 80. 200 µL of this stock solution was dispersed in reconstituted water and the volume adjusted to 2 litres to give a test concentration of 4.0 mg/L from which dilutions were made to give the test series.
Range finding study test concentrations: 0 mg/L (solvent control), 0 mg/L (untreated control) 0.040 mg/L, 0.40 mg/L, 4.0 mg/L.
Main study test concentrations: 0.040 mg/L, 0.071mg/L, 0.13 mg/L, 0.22 mg/L, 0.40 mg/L, 0.71 mg/L, 1.3 mg/L, 2.2 mg/L, 4.0 mg/L untreated control solvent control (100 µL/L 1% (V/V) Tween 80 in dimethylformamide. Duplicate test vessels each containing 10 daphnids.

Test organisms (species):

Daphnia magna

Details on test organisms:

maintained as lab culture originating from a strain supplied by Institut National de Recherche Chimique Appliquee France. First instar Daphnia used for testing

Test type:

static

Water media type:

other: Husbandry: for the purpose of the study reconstituted water was used.

Remarks:

The following stock solutions were prepared. CaCl2.2H2O – 11.76 g/L MgSO4.7H2O – 4.93 g/L NaHCO3 – 2.59 g/L KCL – 0.23 g/L 25 mL of each stock solutions were added to each litre (final volume) of deionised water (conductivity <5 µS cm^-1).

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

N/A

Post exposure observation period:

N/A

Hardness:

Theoretical hardness 270 mg/L as CaCO3

Test temperature:

21 °C

pH:

7.7 (adjusted if necessary with NaOH or HCl)

Dissolved oxygen:

reconsititued water aerated until dissolved oxygen concentration was approx air-saturation value

Salinity:

not reported

Conductivity:

N/A

Nominal and measured concentrations:

nominal concentations

Details on test conditions:

Range finding study then main study 20 daphnids (2 replicates of 10) exposed to aqueous solution of test material. Number of immobilised Daphnia recorded after 24 and 48 hrs

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.62 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits of 0.53 - 0.72 mg/L

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.22 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Authors stated that the No observed effect concentration was 0.22 mg/L.

Details on results:

With a vapour pressure of 1.3 volatilisation of the substance at 21 °C is not considered to be substantial. Nominal concentrations are therefore adequate.

Results with reference substance (positive control):

N/A

Reported statistics and error estimates:

95% confidence limits

N/A

Validity criteria fulfilled:

yes

Conclusions:

48h median effective concentration (EC50) of DCPD 92% to Daphnia Magna calculated to be 0.62 mg/L with 95% confidence limits of 0.52 - 0.72 mg/L. The no observed effect concentration was 0.22 mg/L

Executive summary:

The study identified a 48 hour median effect concentration (EC₅₀) of DCPD to Daphnia magna. This was calculated to be 0.62 mg/L with 95% confidence limits of 0.52-0.72 mg/L. The test material was prepared as a solvent stock solution, though the concentration and stability of the test material was not determined. The test included both untreated and solvent controls. As the volatilisation of the substance is not expected to be critical, based on the low vapour pressure, the reporting of the results as nominal concentrations was considered to be adequate.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

up to 2020

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 Target Lipid Model (TLM) is a framework that relates toxicity to the physicochemical properties of a nonpolar organic constituent. It is a well documented and peer reviewed model that is widely used across the petrochemicals industry. This substance fits within the criteria of the model and there are no reservations about the validity of the model runs. It is expected that this data is reliable with restrictions.

Qualifier:

no guideline required

Principles of method if other than guideline:

The endpoint calculated is the LL50, EL50, and NOELR -
The narcosis target lipid model was developed to predict the toxicity of chemicals to aquatic organisms that act via narcosis. It is based on the hypothesis that target lipid is the site of toxic action within the organism, that octanol is the appropriate surrogate, and that target lipid has the same physical–chemical properties in all organisms.
The approach describes:
• The theory and how to predict the acute toxicity to these organisms;
• Development of an Acute to Chronic ratio [ACR] for only hydrocarbons and for 29 data points.

GLP compliance:

no

Remarks:

QSAR

Specific details on test material used for the study:

A logkow of 2.78 was used as input for the prediction

Analytical monitoring:

not required

Remarks:

QSAR

Details on sampling:

N/A

Vehicle:

no

Remarks:

QSAR

Details on test solutions:

N/A

Test organisms (species):

Daphnia magna

Details on test organisms:

N/A

Test type:

other: QSAR

Water media type:

other: QSAR

Limit test:

no

Remarks on exposure duration:

N/A

Post exposure observation period:

N/A

Hardness:

N/A

Test temperature:

N/A

pH:

N/A

Dissolved oxygen:

N/A

Salinity:

N/A

Conductivity:

N/A

Nominal and measured concentrations:

N/A

Details on test conditions:

N/A

Reference substance (positive control):

no

Remarks:

QSAR

Key result

Duration:

48 h

Dose descriptor:

LL50

Effect conc.:

12.556 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Result from QSAR

Details on results:

N/A

Results with reference substance (positive control):

N/A

Reported statistics and error estimates:

N/A

N/A

Validity criteria fulfilled:

not applicable

Remarks:

QSAR

Conclusions:

The estimated LL50 for this substance is 12.556 mg/L.

Executive summary:

The short-term aquatic toxicity to this substance was estimated using the Target Lipid Model based on methodologies described by McGrath et al. (2004, 2015). The estimated LL₅₀ for this substance is 12.556 mg/L.

The prediction is considered to fall within the model domain.

Description of key information

The 48 hour EC₅₀ for toxicity to aquatic invertebrates is 0.823 mg/L. The estimated LL₅₀ value from TLM QSAR is 12.556 mg/L.

The lowest value was used for the chemical safety assessment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Remarks:

48 hour EC50

Effect concentration:

0.823 mg/L

Additional information

The acute toxicity of DCPD to Daphnia magna was determined in a GLP-compliant study following OECD guideline 202. Based on geometric mean measured concentrations, the 48 hour EC₅₀ was 0.823 mg/L, with 95% confidence limits of 0.740 to 0.909 mg/L. The test material was prepared as a saturated solution (nominal 10 mg/L) and diluted to give test concentrations of 6.25, 12.5, 25, 50 and 100% saturated solution (corresponding geometric mean measured concentrations were 0.3, 0.57, 1.11, 2.39 and 5.09 mg/L). The study followed a semi-static design, with renewal at 24 hours, and was conducted in a sealed vessel with no headspace.

In the Safepharm Laboratories (1995) study it identified a 48 hour median effect concentration (EC₅₀) of DCPD to Daphnia magna. This was calculated to be 0.62 mg/L with 95% confidence limits of 0.52-0.72 mg/L. The test material was prepared as a solvent stock solution, though the concentration and stability of the test material was not determined.

The MITI study reviewed in the OECD SIDS showed an EC₅₀ of 8 mg/L. The study, which follows OECD 202, with a solubiliser control, was unavailable for review so could not be assessed for reliability. However, as it has been through the regulatory review process, it has been included here as a supporting study. Passino-Reader (1997) is a near guideline study which provides an EC₅₀ of 4.2 mg/L for Daphnia pulex. The study follows ASTM (1980) E728-80 with a solvent control and, though there are restrictions in design and/or reporting, the study is considered adequate as a supporting study. A QSAR result has also been included as a supporting study, which used the ECOSAR program to derive a 48 hour LC₅₀ of 6.4 mg/L.

The short-term aquatic toxicity to this substance was estimated using the Target Lipid Model based on methodologies described by Mcgrath et al. (2004). The estimated LL₅₀ for this substance is 12.556 mg/L.

As a new proprietary study conducted under GLP and to guideline is available for the acute toxicity of DCPD to aquatic invertebrates, this value has been used as the key study for this endpoint. Although a lower result is available, this is taken from a study with no analytical confirmation of the test concentrations and therefore the new proprietary study is considered more robust. The use of the lower result would not change the classification applied or the exposure assessment.