Registration Dossier

Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991-03-14 to 1991-04-26 (experimental phase)
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study with acceptable restrictions, analytical recovery of test substance concentration not sufficient, test medium was turbid with precipitations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 203 (Fish, Acute Toxicity Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): E-326 Catalyst
- Substance type/physical state: grey-green powder
- Lot/batch No.: 326-104

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Duplicate levels were analysed at the start and end of the test; one sample from each pair was analysed immediately and the other was filtered (0.2 micron pore size) before analysis.

Test solutions

Vehicle:
no
Details on test solutions:
Test media were prepared individually by adding the total required weights of test material to a series of volumetric flasks containing dilution water (approximately 0.8 litre). Each flask was sonicated for ten minutes before being further diluting to a final volume of twenty litres in the test vessels. Test media were then aerated for approximately one hour before the test was started.

Test organisms

Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
TEST ORGANISM
- Common name: Rainbow trout
- Source: The batch of rainbow trout used for the definitive test was supplied by Hauxton Fishery Services Limited, Blackborough, Devon. They were reared at West Acre Trout Farm, Kings Lynn, Norfolk, from Danish eggs which hatched January 1991.
- Length at study initiation (length definition, mean, range and SD): 5.2 cm
- Weight at study initiation (mean and range, SD): 1.8 g
- Feeding during test: no


ACCLIMATION
Monitoring water quality during the 14-day holding period immediately preceding the definitive test showed the following (flow through):
- temperatures ranged from 12.0 to 14.7°C
- pH values ranged from 7.5 to 8.2
- dissolved oxygen concentrations (DO) ranged from 84 to 99% air saturation value (ASV)
- water hardness ranged from 240 to 250 mg/l as CaC03.

Each day during the holding period, the fish were fed with proprietary trout pellets (BP Nutrition Ltd., Mainstream Trout Fry 02), an amount equivalent to approximately between 1 and 2% of the total wet-weight of the fish in the holding tank.

Mortality during the seven day period before the definitive test was less than 2.5 %.
The fish were last fed 25 hours before the start of the definitive test.

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
96 h

Test conditions

Hardness:
226-280 mg/L CaCO3
Test temperature:
14.1-14.9 °C
pH:
6.28-8.0
Dissolved oxygen:
83 - 101 %
Nominal and measured concentrations:
0, 100, 180, 320, 560, 1000 mg/L nominal
Details on test conditions:
TEST SYSTEM
- Type: open
- Material, size, headspace, fill volume: all-glass aquaria, with a total capacity of 25 litres; the depth of the test dilutions (20 l) was approximately 20.5 cm
- Aeration: yes
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The test organisms were maintained and the study conducted in treated tap water. Treatment involved blending tap water, previously filtered through activated carbon to remove chlorine with tap water, which had been softened and treated by reverse 'osmosis, to achieve hardness in the range 200 - 250 mgl/l as CaC03. This water was delivered to an intermediate tank where it was equilibrated to the test temperature and gently aerated before being supplied to the holding and test areas.

OTHER TEST CONDITIONS
- Adjustment of pH: not during test
- Photoperiod: 16:8 L:D
- Light intensity: no data, dawn and dusk was simulated

EFFECT PARAMETERS MEASURED:
Mortality and behaviour daily

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 1, 10, 100, 1000 mg/L
Reference substance (positive control):
not specified

Results and discussion

Effect concentrations
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
51.8 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mortality

Any other information on results incl. tables

E-326 Catalyst affected the pH of the test media which became more acidic with increasing concentration. At all concentrations test media were green, non-homogeneous dispersions with undissolved test material visible in suspension and on the bases of the test vessels; during the test, undissolved test material settled out of suspension.

 

Concentrations in both filtered and unfiltered samples were lower than nominal values (between 13 and 39% of nominal values), but showed a generally dose-related trend and were maintained over the test period.

 

The highest concentration at which no mortalities occurred and lowest at which there was 100% mortality after 96 hours were 51.2 and 128 mg/l respectively, based on measured concentrations in unfiltered samples, and 33.2 and 93.5 mg/l based on measured levels in filtered samples. Mortalities were progressive during the test.

 

At each exposure level except for the highest (nominally 1000 mg/l), some fish exhibited lethargic behaviour, including one at the lowest level which was affected at the end of the test. A no-observed-effect concentration (NOEC) was not therefore obtained but is presumed to be less than 31.4 mg/l based on measured levels in unfiltered test media and less than 20 mg/l based on levels in filtered media.

 

Table. Approximate median lethal concentrations (LC50s), calculated at intervals during the test using mean measured concentrations in unfiltered and filtered test media:

 

Time (h)

LC50 (mg/l) un-filtered

LC50 (mg/l) filtered

24

>185

>154

48

120

90

72

83.5

72

96

66.3

51.8

 

Quoted values are approximate as data did not permit statistfcally valid calculations.

 

Although measured concentrations were lower than intended, it is considered that the maximum attainable exposure levels were achieved and maintained during the test.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes