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

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: The information reported here has been taken from the SIDS for 77-73-6 as we were unable to obtain this study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material: not applicable

Analytical monitoring:

yes

Details on sampling:

not reported

Vehicle:

yes

Details on test solutions:

5 nominal concentrations (10,18, 32.4, 58.3 and 105 mg/L). Minimal amount of Tqween 80 - acetone (1:1) or DMSO HCO- 40 (9:1) is used as solubilizer

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

ATCC 22662

Test type:

static

Water media type:

not specified

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

not reported

Hardness:

not reported

Test temperature:

not reported

pH:

not reported

Dissolved oxygen:

not reported

Salinity:

not reported

Nominal and measured concentrations:

5 nominal concentrations 10,18, 32.4, 58.3 and 105 mg/L

Details on test conditions:

not reported

Reference substance (positive control):

not specified

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

27 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

not specified

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

not specified

Details on results:

not reported

Results with reference substance (positive control):

not reported

Reported statistics and error estimates:

not reported

Validity criteria fulfilled:

not specified

Remarks:

insufficient data to confirm validity

Conclusions:

The 72 hour EC50 (growth rate) was 27mg/L and a NOEC of 18 mg/L was reported

Executive summary:

As we were unable to obtain a copy of this report we have been unable to assess its reliability. The data reported here has been taken from the SIDS for dicylcopentadiene and can be used as part of a weight of evidence approach to assess the acute toxicity to aquatic invertebrates. The 72 hour EC50 (growth rate) was 27mg/L and a NOEC of 18 mg/L was reported.

Description of key information

The 96 hr EC₅₀ range for the toxicity to aquatic algae, obtained from a single reliable experimental study, was 22 - >100 mg/L. The estimated EL₅₀ and NOELR from TLM QSAR towards P. subcapitata are 6.948 mg/L and 1.331 mg /L, respectively. However, there is a MITI (1997) study for which we do not have all the study design details which reports an EC₅₀ and NOEC of 27 mg/L and 18 mg/L, respectively. These values are in much more agreement with those published by Bentley (1976) and should be given more weight than the QSAR derived values. Therefore, the MITI values will be used in chemical safety assessment.

Key value for chemical safety assessment

EC50 for freshwater algae:

27 mg/L

EC10 or NOEC for freshwater algae:

18 mg/L

Additional information

Bentley et al (1976) tested the toxicity of dicyclopentadiene to three species of algae. The range of EC₅₀ values reported within the paper was between 22 - >100 mg/L. The study followed a method similar to standard guidelines but did not include analytical confirmation of the exposure concentrations.

The OECD SIDS identified an Environmental Agency Japan test which showed the 72 hour EC₅₀ to be 27 mg/L and the NOEC to be 18 mg/L. This study was unavailable for review but is included here as part of a weight of evidence approach together with the Bentley studies.

A QSAR result has also been included as part of the weight of evidence, which used the ECOSAR program to derive a 96 hour EC₅₀ of 5.1 mg/L and a ChV of 2.4 mg/L, which corresponds to a NOEC value of 1.7 mg/L (calculated by ChV ÷v2 as ChV is geometric mean of NOEC and LOEC).

The aquatic toxicity of this substance was estimated using the Target Lipid Model based on methodologies described by Mcgrath et al. (2004). The estimated EL₅₀ for this substance is 6.948 mg/L and the NOELR is 1.331 mg/L.