Diamminediisocyanatozinc

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

in accordance with the Commission of European Communities directive 84/449/EEC

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Belleau Bridge Farm (Mr. A. Harrop), Alford, Lincolnshire
- A stock of 500 Rainbow trout approximately 9 weeks old and an average length of 4 cm were used, collected on the 27 th November 1985
- Ten fish at each concentration.

FEEDING DURING TEST
- The fish were not fed 24 hr prior to testing and during the whole test.

ACCLIMATION
- The stock was divided equally into two 250 l holdinh tanks containing aerated charcoal filtered water at a temperature of 12 +- 2 °C and with a flow-throughrate of 1 l/min.
- The fish were exposed to a photoperiod of 16 h light and 8 h darkness each day and were fed once daily to repletion with BP mainstream salmon diet No. 03.
- The fish were acclimatised under these conditions for 14 days.
- Feeding frequency during acclimation: The fish were not fed 24 hr prior to testing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

at start of study: 326.0 mg/L CaCO3
at the end of study: 340.0 mg/L CaCO3

Test temperature:

13°C + 2°C

pH:

overall pH: 7.4 (ranging from a mean of pH 7.3 at a concentration of 1.25 mg/L test item to pH 7.5 at 20.0 mg/L test item)
Control vessels: pH 7.2

Dissolved oxygen:

Oxygen concentrations fell from a mean of 98.6% saturation in freshly prepared solutions to a mean of 89.4% saturation in 24 hour old solutions.

Conductivity:

at start of study: 643 µS/cm
at the end of study: 644 µS/cm

Nominal and measured concentrations:

Nominal: 0, 1.25, 2.5, 5.0, 10.0, 20.0 mg/L
Measured (after correction): 1.29, 2.28, 4.89, 9.52, 18.93 mg/L

Details on test conditions:

TEST SYSTEM
- Aeration: The test solutions were aerated during the incubation period (96 hr) in order to verify an oxygen content of >60% of the saturation value during the study
- Type of flow-through: semi-static
- at the start of the experimental period, ten rainbow trout were added at random to each vessel (including an untreated control)
- Biomass loading rate: 1.5 grams per litre

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : behaviour, mortality (daily)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light, 8 h darkness
- Light intensity: 2000 lux

TEST CONCENTRATIONS
- Test concentrations: 20 , 10, 5, 2.5 and 1.25 mg test material per litre

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

4.67 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

2.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No mortalities occurred over the 96 h period in the control water or at the two lowest concentrations of the test item. A 100% mortality of fish occurred at 10 mg test item/L after 48 h exposure. The 'no observed effect' concentration was 2.5 mg/L of the test item.

Results with reference substance (positive control):

n/a

Sublethal observations / clinical signs:

After 24 h exposure, 3/10 fish at 2.5 mg/L of the test item, 5/9 at 5.0 mg/L and 5/5 at 10 mg/L had all darkened skin colour compared with the controls, 2/5 fish at 10 mg/L showed abnormal swimming behaviour. By 48 h, all fish at 2.5 mg/L had returned to normal colouration.

A precipitate, increasing in density with increased test item concentration was present in the test vessels at concentrations of 2.5 mg/L and above.

Validity criteria fulfilled:

yes

Conclusions:

The study was performed according to EU method C.1 with no relevant deviations, the results were so obtained via a scientifically reasonable method. Hence, there is no doubt that the obtained results are not reliable: Under the conditions used for the test, a moderate toxic effects of the test item towards fish were observed at 20 mg/L. However, it is highly probable that the intact molecule itself is not the cause of the observed fish mortalities. As previously mentioned in this report, the test item is rapidly hydrolysed on contact with water to form ammonia.
Based on these results, the test item does not need to be classified as acute or chronic toxic to the aquatic environment.

Executive summary:

In a 96-h acute toxicity study, Rainbow trout, (Salmo Gairdneri) were exposed to the test item at nominal concentrations of 0, 1.25, 2.5, 5.0, 10.0, 20.0 mg/L under semi-static conditions.

The 96-h LC₅₀ was 4.67 mg a.i./L. 

This toxicity study is classified as acceptable and satisfies the guideline requirement for EU method C.1 short term to rainbow trout toxicity study.

Based on these results, the test item does not need to be classified as acute or chronic toxic to the aquatic environment.

 

Results Synopsis

 

Test organism of 4 cm length

Test Type (Semi-Static)

LC50:  4.67 mg a.i./L                        95% C.I.:  3.72 to 5.85 mg a.i./L

NOEC: 2.5 mg a.i./L                       

                      

 

Description of key information

Acute toxicity to fish: LC50 (96h) = 4.67 mg/L for Onchorynchus mykiss (EU C1, GLP, semi-static).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

4.67 mg/L

Additional information

Based on the results, the test item does not need to be classified as acute or chronic toxic to the aquatic environment.