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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference Type:
study report

Materials and methods

Test guideline
according to guideline
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
trans-4-Methylcyclohexyl isocyanate
EC Number:
Cas Number:
Molecular formula:
C8 H13 N O
trans-4-Methylcyclohexyl isocyanate

Sampling and analysis

Analytical monitoring:
not specified

Test organisms

Test organisms (species):
Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:
not specified
Water media type:
not specified
Total exposure duration:
72 h

Test conditions

Not specified
Test temperature:
Not specified
Not specified
Dissolved oxygen:
Not specified
Nominal and measured concentrations:
A concentration of 100 mg/L test item in water was used in a preliminary solubility work.
Details on test conditions:
Not specified
Reference substance (positive control):
not specified

Results and discussion

Effect concentrations
Key result
Remarks on result:
not determinable because of methodological limitations
Details on results:
A preliminary solubility/water reactivity work was done before performing the study.
The test substance was not soluble at 100 mg/L. The 100 mg/L medium was sonicated for 30 minutes but the media was not in solution. Thus, the media was stirred for 24h. However, the media was observed as a homogenous hazy dispersion of very small particulate/oily globules.
Moreover, no reaction was observed when the test substance was added to water.
The study with Pseudokirchneriella subcapitata was decided not to be conducted due to these analytical difficulties.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
At the request of the client, the study was stopped after water reactiveness/solubility work. The reasons for the cancellation of the study are:
- the compound was very likely to break down into metabolites such as amine; the amine can potentially react further with the isocyanate into a urea compound
- due to the nature of the compound, it was considered likely that difficulties would be encountered with the analytical method
The toxicity of the test item on Pseudokirchneriella subcapitata couldn't thus be determined.