Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 252-161-3
CAS number: 34708-08-2
Approach to the
Terrestrial Chemical Safety Assessment
The registered substance,
triethoxy(3-thiocyanatopropyl)silane (CAS 34708-08-2, EC 252-161-3),
will hydrolyse moderately rapidly (half-life 23 hours at pH 7 at 25°C)
in contact with water and atmospheric moisture to
(3-thiocyanatopropyl)silanetriol and ethanol. REACH guidance (ECHA 2016,
R.16) states that “for substances where hydrolytic DT50
is less than 12 hours, environmental effects are likely to be attributed
to the hydrolysis product rather than to the parent itself”. ECHA
Guidance Chapter R.7b (ECHA, 2017) states that where degradation rates
fall between >1 hour and <72 hours, testing of parent and/or degradation
product(s) should be considered on a case-by-case basis. Therefore, in
accordance with REACH guidance, the terrestrial chemical safety
assessment for triethoxy(3-thiocyanatopropyl)silane is based on both the
registration substance and its silanol product,
(3-thiocyanatopropyl)silanetriol. The non-silanol hydrolysis product,
ethanol, is not expected to contribute to toxicity to terrestrial
is classed as hazard category 3 for the terrestrial environment (Table
R.7.11-2 of ECHA guidance R7.c, 2017) based on potential for high
persistence (DT50 > 180 days), lack of ready biodegradability
and low toxicity to aquatic organisms (EC/LC50 not <1 mg/l).
In this situation, a
screening approach is applied: a confirmatory long-term terrestrial test
is conducted, in addition to the equilibrium partitioning approach with
an extra factor of ten in order to determine whether further full tests
There are ongoing long-term
aquatic studies conducted according to OECD TG 211 and 210 for aquatic
invertebrates and fish, respectively. There are also ongoing long-term
terrestrial toxicity studies conducted according to OECD TG 216 and 222
for soil microorganisms and soil macrorganisms except arthropods,
respectively. An OECD TG 208 terrestrial plant toxicity study is also
required by ECHA final decision number TPE-D-2119966910-31-01/F.
However, the studies are being carried out in a tiered manner with the
OECD 210, 211, 216 and 222 studies being conducted first.
Once the results from these
studies become available, the PNECsoil will be updated, a new
environmental exposure assessment will be conducted and the need for
further terrestrial testing with terrestrial plants will be evaluated
based on the updated agricultural soil RCRs and observations of toxicity
in the OECD 222 study.
Until the results from these
studies become available, the PNECsoil and risk characterisation ratio
have been derived based on the equilibrium partitioning method, details
of which can be found in IUCLID Section 6 and Chapters 9 and 10 of the
Chemical Safety Report, respectively.
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.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again