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

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Remarks:

growth inhibition

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21/07/1992 – 19/08/1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Compliant, Guideline Study, Available as unpublished report, Acceptable with Restrictions

Qualifier:

according to guideline

Guideline:

other: Standard Test Method 172-07

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Test material
Identification: Dicyclopentadiene-E 92%
Description: Colourless liquid

Analytical monitoring:

not specified

Details on sampling:

Three test cultures of 80% WAF and ten control cultures. Cultures determiend uising a Pye Unicam PU6800 UV/VISA spectrophotometer. Spectrophotometer was blanked against distilled water for the control cultures and the corresponding uninoculated dilution for the test cultures

Vehicle:

not specified

Details on test solutions:

Dose Range-finding study was performed using two dilution series of the Water accommodation Fraction (WAF) to determine concentrations suitable for the main study. The concentrations tested were as follows:
Initial concentration = 80% WAF
1 in 2 = 40% WAF
1 in 4 = 20% WAF
1 in 8 = 10% WAF
1 in 16 = 5% WAF
1 in 32 = 2.5% WAF
1 in 64 = 1.25% WAF
1 in 128 = 0.63% WAF
1 in 256 = 0.32% WAF
1 in 512 = 0.16% WAF
1 in 1024 = 0.08% WAF
1 in 2048 = 0.04% WAF
The dilutions were prepared using 300 ml Erlenmeyer flasks sealed with non-absorbent cotton wool such that the dilutions contained 1 part by volume of the WAF in 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048 parts by volume of distilled water.
The following procedure was employed: to the first flask in each dilution series 160 mL of the initial solution was added. 80 mL of distilled water was added to each of the remaining flasks.

Main study: four dilution series of the WAF were prepared from an initial WAF of 80% determined from the range-finding study.

Test organisms (species):

other: Pseudomonas putida

Details on inoculum:

The cultures of the test organism used in this study were freshly prepared by inoculating 100 mL of “Nutrient solution for pre-cultures” from a seven day old stock culture. After incubation at 25 °C ± 2 °C for 18 ± 2 hours, the cultures were diluted with sterile sodium chloride solution until the extinction value corresponded with that of the standard formazine solution with a Haze number of TE/F=100

Test type:

not specified

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

18 h

Post exposure observation period:

not reported

Hardness:

not reported

Test temperature:

ca. 25 degrees C

pH:

not reported

Dissolved oxygen:

not reported

Salinity:

not reported

Conductivity:

N/A

Nominal and measured concentrations:

Dilution WAF (%)
initial concentration 80
1 in 2 40
1 in 4 20
1 in 8 10
1 in 16 5
1 in 32 2.5
1 in 64 1.25
1 in 128 0.63
1 in 256 0.32
1 in 512 0.16
1 in 1024 0.08
1 in 2048 0.04

Details on test conditions:

A dose range finding study was performed. For the main study, 4 dilution series of the WAF were prepared from an initial WAF of 80% determined from the range finding study.
To each flask of three of the four test material dilutions, and to ten control flasks, 5 mL of stock solution I, 5 mL of stock solution II, and 10 mL of the prepared bacterial suspension were added. This gave three test cultures of 80% WAF and ten control cultures.
To the fourth test material dilution, 5 mL of stock solution I, 5 mL of stock solution II and 10 mL of sodium chloride solution were added. This acted as the uninoculated dilution.
After incubation at 25 °C ± 2 °C for 18 ± 2 hours, the extinction at 436 nm of each of these test and control cultures was determined using a Pye Unicam Pu6800 UV/VIS spectrophotometer.
The following mean extinctions were determined form the spectrophotometric data:
a) control cultures
b) three test cultures at 80% WAF and by calculation
c) control cultures reduced by 10%.

Reference substance (positive control):

not specified

Key result

Dose descriptor:

other: Minimum inhibitory concentration

Effect conc.:

2 other: ppm expressed as Total Organic Carbon

Nominal / measured:

meas. (not specified)

Conc. based on:

other: Total Organic Carbon

Basis for effect:

growth inhibition

Remarks on result:

other: mean concentration of the test material which began to inhibit growth of the test organism was 17% WAF - corresponding to about 2ppm expressed as Total Organic Carbon

Details on results:

Mean concentration of the test material which began to inhibit growth of the test organism was 17% WAF corresponding to about 2 ppm expressed as Total Organic Carbon

Results with reference substance (positive control):

not reported

Reported statistics and error estimates:

not reported

Mean concentration of the test material which began to inhibit growth of the test organism was 17% WAF. This corresponding to about 2ppm expressed as Total Organic Carbon

Validity criteria fulfilled:

not specified

Conclusions:

The mean concentration of the test material which began to inhibit growth of the test organism was 17% WAF. This corresponds to about 2 ppm expressed as Total Organic Carbon.

Executive summary:

This is a GLP compliant study which followed a standard method and is considered adequate for assessment. The mean concentration of the test material which began to inhibit growth of the test organism was 17% WAF. This corresponds to about 2 ppm expressed as Total Organic Carbon.

Reference 2

Endpoint:

toxicity to microorganisms, other

Remarks:

QSAR

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 limited 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):

activated sludge

Details on inoculum:

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:

72 h

Dose descriptor:

other: El50

Effect conc.:

102.533 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

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 72-h EL50 value for activated sludge is 102.533 mg/L.

Executive summary:

The aquatic toxicity of this substance was estimated using the Target Lipid Model based on methodologies described by Mcgrath et al. (2004, 2015). The estimated 72-h EL50 value for activated sludge is 102.533 mg/L.

The prediction is considered to fall within the model domain

Description of key information

The mean concentration of the test material which began to inhibit growth of the test organism was 17% WAF. This corresponds to about 2 ppm expressed as Total Organic Carbon, which in turn corresponds to 2.2 mg DCPD/L. The estimated EL₅₀ value from TLM QSAR towards activated sludge is 102.533 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

102.533 mg/L

EC10 or NOEC for microorganisms:

2.2 mg/L

Additional information

One study was available for review for toxicity to microorganisms. This is a WAF, GLP compliant study which followed a standard method and is considered adequate for assessment

The aquatic toxicity of this substance was estimated using the Target Lipid Model based on methodologies described by Mcgrath et al. (2004).The estimated 72-h EL₅₀ value for activated sludge is 102.533 mg/L.