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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD guideline study conducted under GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
As noted in the hydrolysis section, oximesilanes quicky hydrolyze to the corresponding oxime and reactive silanols which spontaneously cross link to form high molecular weight silicone polymers. The relevant hydrolysis product is MPKO, the substance that was tested.

Data on selected oximes and oxime silanes are summarized in the attached Table. Although data for each endpoint is not available for all products, the available data show similarities between oxime silanes and their hydrolysis products (oxime). These materials show low toxicity to fish, and daphnia. For algal studies, the toxicity shows a structure activity relationship. The smaller oximes are more toxic to alga, the larger oximes and associated oxime silanes are less toxic. The similarities in response between the oximes and oxime silanes provide additional support of the silicone containing moieties do not contribute to the aquatic toxicity of these materials. Due to the rapid hydrolysis, it is appropriate to use the oxime as surrogate data for t he oxime silane.


Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: continuous laboratory cultures held at the laboratory
- Age at study initiation (mean and range, SD): < 24 hours
- Feeding during test - No

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
none

Test conditions

Test temperature:
20 +/- 1°C, and a photoperiod of 16 hours light: 8 hours dark, with 20 minute dusk and dawn transition periods
pH:
7.87 to 7.97
Dissolved oxygen:
9.2 mg/l for both control and test article vessels
Nominal and measured concentrations:
Measured concentrations within 95% of nomimal (98% average). Results reported as nominal values
Details on test conditions:
TEST SYSTEM
- Test vessel:Glass beakers of 250 ml nominal capacity
- Material, size, headspace, fill volume: 200ml
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4




TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: no
- Intervals of water quality measurement: time 0 and 48 hours


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod:16 hours light:8 hours dark, with 20 minute dusk and dawn transition periods

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : at 24 and 48 hours, daphnia were observed by eye for 15 seconds to determine movement and overt signs of toxicity

TEST CONCENTRATIONS
- limit test - 100 mg/l

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Details on results:
- Behavioural abnormalities: none
- Other adverse effects control: 1 of 20 were immobile at 48hrs
- Abnormal responses: none observed
Reported statistics and error estimates:
None needed - no immobilization was observed

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
immobilization of controls and dissolved oxygen within appropriate range
Conclusions:
MPKO is not toxic to daphnia. No immobilization was observed in daphnia exposed to 100 mg/l MPKO. OS1600 ia not expected to be toxic to daphnia.