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Ecotoxicological information

Short-term toxicity to fish

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Administrative data

Endpoint:
short-term toxicity to fish
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25 July 2011 to 30 July 2011
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report date:
2011

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: OSPAR Commission 2006 Part B. Protocol for a fish acute toxicity test Study number 1531a-22 was commissioned by Nalco Limited to determine the aquatic (96h limit test
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Test material form:
other: Solid

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
Samples not taken

Test solutions

Vehicle:
no
Details on test solutions:
Natural local seawater is pumped to holding tanks from Scapa Flow, Orkney. The treatment process was: sand filtered to remove particulate, filtered to 1μm, heated to 16 ºC, UV treated, degassed and held at a quantity of 3000 to 5000 litres. The water is constantly pumped through the system and trickle replenished as the water is used.


In order to determine an appropriate test preparation method, an assessment was made of its behaviour in seawater. A 1000 mg.l-1 stock was prepared in filtered seawater, and the resulting mixture was stirred for one hour. If the material was observed to be soluble then its behaviour was assessed. If it was poorly soluble after one hour stirring then it was stirred for approximately a further 19 hrs, and then left to settle for one hour and its behaviour assessed, and prepared according to SOP 403. Readily soluble materials were added directly via treated seawater to the appropriate tank in the required quantity.

The test substance was characterised as poorly soluble and therefore prepared as Water Accommodated Fraction (WAF). Solutions of 2 litres were prepared, stirred for 20 hours and then one litre siphoned into the test vessels.

Test organisms

Test organisms (species):
Cyprinodon variegatus
Details on test organisms:
The test organisms were reared and maintained at Opus Plus Ltd. The length of fish was 1.5-2.5 cm and at test termination control fish were measured to confirm the length range. Sheepshead minnow were held under flow-through conditions in 50 litre capacity glass tanks, containing 1 μm filtered ultra-violet treated seawater and supplied with gentle aeration. Water quality measurements and mortality observations were conducted daily and fed food in flake form ad libitum at least twice daily. Fish were randomly selected for testing.

Study design

Test type:
semi-static
Water media type:
saltwater
Limit test:
yes
Total exposure duration:
96 h

Test conditions

Test temperature:
Temperature was measured at each concentration prior to and following each renewal of media.
The temperature range during the test was 18.5 - 20.7ºC
pH:
pH was measured at each concentration prior to and following each renewal of media.
the pH range over 96h was 7.94 - 8.04
Dissolved oxygen:
Dissolved oxygen was measured at each concentration prior to and following each renewal of media.
Dissolved oxygen was 93 - 98% during the test
Salinity:
Salinity was measured at each concentration prior to and following each renewal of media.
Salinity was 36 - 38% during the test
Nominal and measured concentrations:
Nominal test concentration 65.06 mg/l
Details on test conditions:
The tests were conducted in a temperature controlled room to maintain 20±2 ºC in the test medium. The tests were conducted in 15 litre capacity glass tanks containing 3 litres of test media. The preparations were mixed in situ to ensure thorough dissolution before introduction of the test organisms. Gentle aeration was supplied to all tanks.

Limit tests were conducted under semi-static conditions (with replacement of media after 48h) over 96h with ten fish exposed to the single concentration along with one control.

Results and discussion

Effect concentrations
Duration:
96 h
Dose descriptor:
LC50
Effect conc.:
> 65.06 other: mg/L WAF
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality (fish)
Details on results:
The test substance exhibited no effect at 65.06mg.l-1 after 96h (Water Accommodated Fraction (WAF)) to the marine fish Cyprinodon variegatus in the water phase.
Reported statistics and error estimates:
Mortalities were determined in each vessel every 24h period. The number of dead organisms were expressed as a proportion of the total number exposed.

No statistical methods were employed in the limit test.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test substance exhibited no effect at 65.06mg.l-1 after 96h (Water Accommodated Fraction (WAF)) to the marine fish Cyprinodon variegatus in the water phase.
Executive summary:

Acute toxicity (96 h LC50semi-static test) of the test substance to Cyprinodon variegatus has been assessed in accordance with OSPAR Commission 2006 Part B. Protocol for a fish acute toxicity test

The 96h limit test was conducted in accordance with the study plan and met all relevant validity criteria and there were no interferences in this test. The test substance exhibited no effect at 65.06mg.l-1 after 96h (Water Accommodated Fraction (WAF)) to the marine fish Cyprinodon variegatus in the water phase.