Registration Dossier
Registration Dossier
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EC number: 205-492-2 | CAS number: 141-63-9
Toxicity to microorganisms
Administrative data
Link to relevant study record(s)
Description of key information
Toxicity to microorganisms: 3 hour EC50 >100 mg/l (ASRI), read-across from a structurally-related substance.
Key value for chemical safety assessment
Additional information
There are no reliable microorganism toxicity data available for L5.
A category approach is applied to this endpoint and is detailed in the Siloxane Category report (PFA, 2017). The hypothesis for read-across is that siloxane substances exhibit no evidence of significant toxicity to sewage treatment plant microorganisms. This is consistent with a non-polar narcosis mode of action. Therefore, good quality data for the structurally-related substance, decamethyltetrasiloxane, L4, (CAS 141-62-8), have been read across to L5.
L5 and L4 are members of the Reconsile Siloxanes Category within which, in general, the substances exhibit no evidence of significant toxicity to microorganisms.
The table below presents microorganism toxicity data available for substances within the Siloxanes Category.
Additional information is given in a supporting report (PFA, 2017) attached in Section 13 of the IUCLID dossier.
Table: Microorganism toxicity data for substances within the Siloxane Category
CAS |
Name |
Result: E(I)C50(mg/l) |
Result: NOEC (or EC10/ EC20) (mg/l) |
Guideline Number |
Test method |
Duration (h) |
Reliability |
540-97-6 |
Dodecamethylcyclohexasiloxane |
>100 |
|
OECD 209 |
ASRI |
3 |
1 |
541-05-9 |
Hexamethylcyclotrisiloxane |
>100 |
>100 |
OECD 209 |
ASRI |
3 |
1 |
541-02-6 |
Decamethylcyclopentasiloxane |
>2000 |
|
C11 |
ASRI |
3 |
1 |
107-46-0 |
Hexamethyldisiloxane |
>>100 |
≥100 |
OECD 209 |
ASRI |
3 |
1 |
141-62-8 |
Decamethyltetrasiloxane |
>100 |
|
OECD 209 |
ASRI |
3 |
1 |
352230-22-9 |
Siloxanes and Silicones, di-Ph, Ph (trimethylsilyl)oxy |
>1000 |
≥1000 |
OECD 209 |
ASRI |
3 |
1 |
2627-95-4 |
1,1,3,3-tetramethyl-1,3-divinyldisiloxane |
>1000 |
≥1000 |
OECD 209 |
ASRI |
3 |
1 |
2554-06-5 |
2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane |
>1000 |
≥1000 |
OECD 209 |
ASRI |
3 |
1 |
N/A (EC 939-487-8) |
Phenyl silsesquioxanes |
>1000 |
≥1000 |
OECD 209 |
ASRI |
3 |
1 |
99363-37-8 |
dimethyl, methyl(3-aminopropyl) siloxane, trimethylsiloxy-terminated |
> water soluble fraction |
≥ water soluble fraction |
OECD 209 |
ASRI |
3 |
1 |
71750-79-3 |
dimethyl, (aminoethylaminopropyl)methyl siloxane, trimethylsiloxy-terminated |
> water soluble fraction |
≥ water soluble fraction |
OECD 209 |
ASRI |
3 |
1 |
In the study with L4, an activated sludge respiration inhibition 3 hour EC50 value of >100 mg/l was reported.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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