Benzoic acid, compound with cyclohexylamine (1:1)

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:

key study

Study period:

9 December 2002 to 12 December 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Reliable experimental study following ISO/DIS 10253 and GLP standards.

Qualifier:

according to guideline

Guideline:

ISO 10253 (Water quality - Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum)

Version / remarks:

Not Specified

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

The test substance is cyclohexylamine benzoate. The test substance was obtained from the study Sponsor on 5th September 2002 and stored in the original container at 15 ± 2°C.

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Skeletonema costatum

Details on test organisms:

The test organism, Skeletonema costatum CCAP1077/5, was obtained from Culture Collection of Algae and Protozoa,Dunstaffnage.

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

18 °C at 0 h and 19.5 to 20.5 °C during the test

pH:

7.00 to 8.31

Dissolved oxygen:

90.5% - 99.8 % Air Saturation Values

Nominal and measured concentrations:

An experimental study was conducted with nominal test concentrations of 10.0, 17.8, 31.6, 56.2, and 100 mg/L.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol was used as the positive reference control substance.

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

17.84 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

12.26 -25.40 mg/L 95% Fiducial Limits

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

37.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

25.99 -188.04 mg/L Fiducial Limits

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

17.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

Raw results with reference substance 3,5-dichlorophenol were reported, but the EC50 was not calculated.

Validity criteria fulfilled:

not specified

Conclusions:

The test substance caused a reduction of growth in the algal cultures (test units) exposed to a series of nominal test concentrations of the test item; therefore, there were toxic or inhibitory effects. The 72-h EC50 (based on growth rate) was calculated to be 17.84 mg/L. The 72-h NOEC (based on growth rate) was calculated to be 10 mg/L).

Description of key information

The key study was a static acute toxicity test on the effects of the substance on the marine alga, Skeletonema costatum, following guideline ISO/DIS 10253. The test substance caused a reduction of growth in the algal cultures (test units) exposed to a series of nominal test concentrations of the test item. The 72-h EC₅₀ (based on growth rate) was calculated to be 17.84 mg/L. The 72-h NOEC and 72-h LOEC (each based on growth rate) were reported as 10.0 mg/L and 17.8 mg/L, respectively.

Key value for chemical safety assessment

EC50 for marine water algae:

17.84 mg/L

EC10 or NOEC for marine water algae:

10 mg/L