Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no hazard identified

Marine water

Hazard assessment conclusion:
no hazard identified

STP

Hazard assessment conclusion:
no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:
no hazard identified

Sediment (marine water)

Hazard assessment conclusion:
no hazard identified

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Conclusion on classification

Trimethoxy(propyl)silane (CAS No. 1067-25-0) hydrolyses rapidly in contact with water (DT50 = 2.6 h, QSAR) to form the silanol hydrolysis product propylsilanetriol and the alcohol hydrolysis product methanol (CAS No. 67-56-1).


The ECHA guidance R.16 states that “for substances where hydrolytic DT50 is less than 12 h, environmental effects are likely to be attributed to the hydrolysis product rather than to the parent itself” (ECHA, 2016). The TGD (EC2003) and ECHA guidance R.16 (ECHA 2010) also suggest that in case the hydrolysis half-life is less than 12 h, the breakdown products, rather than the parent


substance, should be evaluated for aquatic toxicity.  


Thus, the environmental hazard and risk assessment in this dossier is based on the hydrolysis products propylsilanetriol and methanol rather than the parent substance. The alcohol hydrolysis product, methanol, is not considered contributory to the environmental hazard profile of the parent substance based on the available body of evidence (OECD SIDS, 2004).


 


Abiotic degradation – hydrolysis


DT50 = 2.6 h (pH 7, 20 °C, QSAR)


 


Biodegradation in water, sediment and soil


Not readily biodegradable (EU Method C.4-A)


 


Bioaccumulation


Log Kow (parent) = 1.7 (20 °C, QSAR)


Log Kow (silanol hydrolysis product) = -1.4 (20 °C, QSAR)


 


Acute aquatic toxicity


Fish


LC50 (96 h) > 746 mg/L (arithmetic mean measured, EU method C1, B. rerio, RL 1)


Aquatic invertebrates


EC50 (48 h) > 816 mg/L (nominal, EU method C2, D. magna, RL 1)


Algae


ErC50 (72 h) value of > 913 mg/L (nominal, EU method C3, S. subspicatus, RL1)


 


Chronic aquatic toxicity


Fish


Not available


Aquatic invertebrates


Not available


Algae


NOErC (72 h) of ≥ 913 mg/L (nominal, EU method C3, S. subspicatus, RL1)


 


Classification according to CLP


Trimethoxy(propyl)silane hydrolyses rapidly in contact with water (DT50 = 2.6 h) to form propylsilanetriol and methanol (CAS No. 67-56-1). The silanol hydrolysis product is not readily biodegradable and has a low potential for bioaccumulation based on its low log Kow (-1.4). Acute aquatic toxicity data are available for all three trophic levels and chronic aquatic toxicity data are available for aquatic algae only. No effects on aquatic organisms were recorded up to the highest concentrations tested. Therefore, the parent substance trimethoxy(propyl)silane (CAS No. 1067-25-0) is not classified and labeled according to the consolidated version of Regulation (EC) No. 1272/2008 including all further amendments (ATPs).


 


Reference


OECD SIDS, 2004. Methanol - SIDS Initial Assessment Report For SIAM 19, Berlin, Germany: UNEP Publications.