complex reaction mass of Chinese gum rosin post reacted with acrylic acid

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: GLP, Guideline study however the test material was observed to be unstable to light conditions in the culture media and a decline in test concentration in the test solutions was observed over the test period.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

Sponsors identification: ARAKAWA KE-604
Description: pale yellow blocks
Batch No.: R61132
Purity: no data

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 mg of the test substance was dissovled in dimethylformamide and the volume adjusted to 10ml to give a 100mg/10ml solvent stock solution. An aliquot (20µl) of this stock solution was dispersed in algal suspension (200 ml) to give a test concentration of 1.0 mg/l.
- Controls: negative and solvent
- Chemical name of vehicle: dimethylformamide
- Concentration of vehicle in test medium: 1.0 mg/l.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: Scenedesmus subspicatus strain CCAP 276/20.
- Source (laboratory, culture collection): Culture Centre tor Algae and Protozoa (CCAP), Institute of Freshwater Ecology, Ferry House, Ambieside, Cumbria.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

24 ± 1 °C

pH:

8.5 - 8.6

Nominal and measured concentrations:

Analysis of the test preparations (filtered and unfiltered) at 0 hours showed the measured test concentrations to be near nominal. Analysis of the test preparations at 72 hours showed a marked decline in measured test concentrations to 18% in the unfiltered the filtered samples and to 21% to 23% in the filtered samples.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, fill volume: 250 ml glass conical flasks loosely covered with aluminium foil to reduce evaporation. Each vessel contained 100 ml of solution
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): none
- Initial cells density: 10000 algal cells per ml.
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): 3


GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
The culture medium was prepared using reverse osmosis purified deionised water (EIga Optima 15+) and the pH adjusted to 7.5 ± 0.1 with 0.1N NaOH or HCI. The prepared media was sterilised by 0.22 pm membrane filtration and stored in darkness.


OTHER TEST CONDITIONS
- Light intensity and quality: continuous illumination (intensity approximately 7000 lux) and constantly shaken at 100 rpm for 72 hours.


TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: Based on the result of the range-finding study a “limit test“ was conducted for the definitive study at a test concentration of 1.0 mg/l to confirm that at the highest attainable test concentration of 1.0 mg/l, no effect on algal growth was observed.
- Range finding study
- Test concentrations: 1.0 mg/l
- Results used to determine the conditions for the definitive study: 1.0 mg/l.

Reference substance (positive control):

yes

Remarks:

100µl/l dimethylformamide

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.49 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.49 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Any other information on results incl. tables

Chemcial Analysis:

Analysis of the test concentrations (filtered and unfiltered) at 0h showed the measured test concentrations to be near nominal. Analysis of the test concentrations at 72 h showed a marked decline in the measured test concentrations to 18 % in the unfiltered samples and to 21 - 23 % in the filtered samples. The decline in the measure test concentrations over the study period, in line with the pre-study stability analysis, is considered to be due to the photocatalysed reaction of the test material with the salts/ complexing agents in the test media.

In order to give a worst case analysis of the data, it was considered justifiable to base the results on the time weighted mean of the measured test concentrations of the filtered test samples.

Nominal concentration(mg/l)	Time-weighted mean measured test concentration (mg/l)	Expressed as a % of the nominal concentration
1.0	0.493	49

The following results are based on the time weighted mean measured test concentration of the filtered test samples.

EbC50 (72h): >0.49mg/l

ErC50 (72h): >0.49mg/l

NOEC = 0.49 mg/l