Cyclohexyl isocyanate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data from peer-reviewed handbook or collection of data

Data source

Reference

Reference Type:

review article or handbook

Title:

Unnamed

Year:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexylamine

EC Number:

203-629-0

EC Name:

Cyclohexylamine

Cas Number:

108-91-8

Molecular formula:

C6H13N

IUPAC Name:

cyclohexanamine

Details on test material:

purity is not specified

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

concentration were determined in the freshly prepared test solution and after 72 h of exposure

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22 °C +/- 1 °C

pH:

at test begin: between 7.5 and 9.3
after 72 h of exposure: between 8.1 and 9.0

Nominal and measured concentrations:

nominal concentrations: 3.2 mg/L, 5.7 mg/L, 10.3 mg/L, 18.5 mg/L, 33.3 mg/L, 60.0 mg/L
measured concentrations: 3.5 mg/L, 5.7 mg/L, 10.9 mg/L, 20.1 mg/L, 37.7 mg/L, 65.4 mg/L,

Details on test conditions:

- OECD test media

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

10.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

29.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % CL 27.4 to 31.4

Details on results:

- measured concentrations did not fall below 80 % of nominal ones justifying the use of nominal concetrations for the test evaluation
- exponential growth in the control group througout the whole test duration
- The cell concentration in the control cultures increased well by a factor of at least 16 within three days

Applicant's summary and conclusion

Executive summary:

Concerning the toxicity to algae, the fresh water algae Pseudokirchnerella subcapitata was exposed to cyclohexylamine for 72 hours. The experiment was conducted according to OECD Guideline 201 yielding a 72 -h NOEC of 10.3 mg/L and a 72-h EC50 of 29.3 mg/L having inhibition of growth as endpoint (MITI, 1997).