Cyclohexane, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethyl-, homopolymer, acetone oxime-blocked

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-06-13 to 2001-08-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- after 0 and 48 hours
- separate vessels without test item were made up in the same way as the vessels with test organisms
- the stock solution was analysed as well

Vehicle:

no

Details on test solutions:

The stock solution (1 g/L) was equilibrated in synthetic freshwater and stirred for about 18 hours and was subsequently filtered.

Test organisms (species):

Daphnia magna

Details on test organisms:

- Strain: Daphnia magna Straus, clone 5
- Source/supplier: bred in-house
- Breeding method: in 1 l beakers with M4 medium (Elendt, 1990), water renewal each 2-3 days, isolation of offspring for further breeding ca. every 4 weeks
- Age: < 24 hours
- Feeding: Scenedesmus subspicatus, daily as much as consumed
- Pretreatment: Filtration of adults 24 h prior to testing

Selection of test organisms:
Females are separated from the offspring 24 hours before the start of the test. The juveniles produced over night is used for teh test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 +/- 1 °C

pH:

7.8-8.0

Dissolved oxygen:

7.7-8.2 mg/L

Nominal and measured concentrations:

nominal: 0.63 mg/L
measured: 0.64 mg/L (after 48 h)

Details on test conditions:

TEST SYSTEM
- Renewal of test solution: no
- Exposure vessel type: round-bottom test tubes with 10 ml
- Number of replicates, individuals per replicate:  4 replicates with 5 individuals each
- Adjustment of pH: no
- Photoperiod: dark
- Feeding during test: no

TEST PARAMETER: immobilisation

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.63 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The measured test concentration after 48 h did not deviate by more than 20% from the freshly prepared test solution. Therefore, it can be concluded that the test item was stable over the whole exposure period. Thus the effect concentrations were derived from the nominal concentration.

Results with reference substance (positive control):

The reference substance was tested every 3 months:
1 mg/L: <= 50% effect
2 mg/L: >= 50% effect

RESULTS: EXPOSED, CONTROL
- Effect data (Immobilisation): no. of immobile daphnia
  control:     0 (24 h) /   0 (48 h)
   0.63 mg/l:  0 (24 h) /   0 (48 h)

Validity criteria fulfilled:

yes

Conclusions:

No effects were observed up to the water solubility limit (0.63 mg/L) indicating that the test substance does not pose a significant hazard to aquatic invertebrates.

Executive summary:

The acute toxicity of the test substance to Daphnia magna was studied under static conditions according to OECD TGD 202 and EU method C2. Daphnids were exposed to the test item at one concentration (highest soluble concentration) for 48 h. No effects were observed up to the water solubility limit (0.63 mg/L) indicating that the test substance does not pose a significant hazard to aquatic invertebrates.

The study was assessed as "reliable without restrictions".

Description of key information

The acute toxicity of the test substance to Daphnia magna was studied under static conditions according to OECD TGD 202 and EU method C2. Daphnids were exposed to the test item at one concentration (highest soluble concentration) for 48 h. No effects were observed up to the water solubility limit (0.63 mg/L) indicating that the test substance does not pose a significant hazard to aquatic invertebrates

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

630 µg/L

Additional information

The substance showed no effect on daphnids up to maximum water solubility.