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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
toxicity to soil microorganisms
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Type of information:
experimental study planned (based on read-across)
Study period:
After approval by ECHA
Justification for type of information:
The soil hazard category 3 (ECHA 2017, guidance part R7(c) Table R.7.11—2) has been derived for the substance based on the expected persistence of the silanol hydrolysis product, methylsilanetriol. In accordance with the screening assessment for soil hazard category 3 substances, a PNECsoil has been calculated from the aquatic data on the basis of the equilibrium partitioning method. The PNEC calculated by Equilibrium Partitioning has been derived for the purpose of chemical safety assessment and the risk characterisation ratios are below 1. In addition, a confirmatory long-term soil toxicity test should be conducted. A chronic earthworm reproduction test with methylsilanetriol is proposed to fulfil the testing requirements for soil hazard category 3.
Qualifier:
according to guideline
Guideline:
OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2009-09-03 to 2009-09-03
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
yes
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
53 µl of the test substance, Milli-RO water, synthetic sewage feed (16 ml) and activated sludge (200 ml) were mixed and made up to 500 ml with Milli-RO water in a 1 litre bottle.
Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
Preparation of inoculum for exposure: The sludge was coarsely sieved to remove large particles. The sludge was then washed by centrifuging at 1000 g for 10 minutes. The supernatant was decanted and replaced with ISO-medium. The washing step was performed three times. The pH was 7.7 on the day of testing. The batch of sludge was used one day after collection; therefore 50 ml of synthetic sewage feed was added per litre of activated sludge at the end of the collection day. The sludge was kept aerated at test temperature until use.

- Initial biomass concentration: 3.8 g/L
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
3 h
Post exposure observation period:
Oxygen consumption was measured and recorded for approximately 10 minutes.
Test temperature:
19.9-20.3°C
pH:
8.2 to 8.3
Nominal and measured concentrations:
100 mg/l (loading rate). Performance of a limit concentration at 100 mg/l is acceptable, because 100 mg/l exceeds the expected concentration in a Sewage Treatment Plant.
Details on test conditions:
Test vessel:
- Material, size, headspace, fill volume: glass, 300ml oxygen bottles, 1L test bottles

- Aeration: continuous

- No. of vessels per concentration (replicates): two

- No. of vessels per control (replicates): two

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: tap water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges (Milli-Q)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
After the 3-hour contact time, a well mixed sample of the contents of the reaction mixture was poured into a 300 ml oxygen bottle, and the flask was sealed with an oxygen electrode connected to a recorder, forcing the air out of the vessel. WTW inolab Oxi 730 supplied with a WTW CellOx 325 oxygen electrode, electrolyte type ELY/G

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 100 mg/L only, tested in duplicate

- Justification for using less concentrations than requested by guideline: No significant inhibition of respiration rate of the sludge was recorded for the test substance at a loading rate of 100 mg/L in both replicates and therefore no further testing was required.
Reference substance (positive control):
yes
Remarks:
(3,5-Dichlorophenol)
Key result
Duration:
3 h
Dose descriptor:
EC10
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
The two controls had a difference in respiration rate of 6%, which is less than the 15% limit required by the guideline for a valid study.
Results with reference substance (positive control):
A positive control test with 3, 5-dichlorophenol yielded an EC50 of 8.7 mg/L, which is within the accepted range of 5 to 30 mg/l required by the guideline for a valid study.

Table 1: Results of the activated sludge respiration inhibition test

Test sample

Loading rate (mg/l)

Oxygen conc. at start (mg O2/l)

Oxygen consumption (mg O2/l/h)

% Inhibition

respiration rate

pH

 

 

Initial control

0

7.3

34

-

8.3

Final control

0

6.5

32

-

8.2

Trimethoxy(methyl)silane replicate (1)

100

7.1

33

0

8.3

Trimethoxy(methyl)silane replicate (2)

100

7.1

31

6

8.3

 

 

3,5-Dichlorophenol

5

-

-

38

-

12

-

-

59

-

30

-

-

72

-

 

 

Validity criteria fulfilled:
yes
Conclusions:
An activated sludge respiration inhibition 3 hr EC10 value of >100 mg/L (loading rate) was determined in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.

Data source

Materials and methods

Test material

Constituent 1
Chemical structure
Reference substance name:
Trimethoxy(methyl)silane
EC Number:
214-685-0
EC Name:
Trimethoxy(methyl)silane
Cas Number:
1185-55-3
Molecular formula:
C4H12O3Si
IUPAC Name:
trimethoxy(methyl)silane

Results and discussion

Applicant's summary and conclusion