Bis(triethoxysilylpropyl)amine

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to the attached justification for grouping of substances provided in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Type:

BCF

Value:

< 0.44 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Remarks on result:

other: Conc.in environment / dose:520 μg/L

Type:

BCF

Value:

< 4.2 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Remarks on result:

other: Conc.in environment / dose:52 μg/L

Details on results:

- Behavioural abnormalities: none observed
- Other biological observations: lipid content of the test fish before test initiation: 3.23%, lipid content of the test fish after test completion: 3.05% (within the ± 25% range)
- Steady state: as the test item in all test fish at last three successive analyses were not higher than LOQ, BCFss was not calculated. However, because all BCFs were less than 100, it was evaluated that a steady-state was reached on the 28th day.

pH variation during the test period was 0,6 (Level 1) to 0.8 (Control), which was higher than the value stipulated in the test method (±0.5).

Concentrations of the test item were maintained > 88% of nominal concentrations and the variations were within ± 20% of the average measured concentrations.

Table 1: Measured concentrations of test item in test water in μg/L.

Level	3 days	10 days	18 days	21 days	25 days	28 days	Average (Standard deviation)
1	455	485	481	518	520	528	498 (28.4)
2	51.6	50.5	51.7	49.2	52.3	53.2	51.4 (1.41)

Validity criteria fulfilled:

yes

Conclusions:

Bioconcentration factors were found to be BCF (28 d, 520 μg/L) < 0.44 and BCF (28 d, 52 μg/L) < 4.2 for Cyprinus carpio.

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Jan - 22 Feb 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Method for Testing the Degree of Accumulation of Chemical Substances in Fish Body, s tipulated in the Testing Methods for New Chemical Substances, Ministry of the Environment, Japan

GLP compliance:

yes

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: analysis of test fish were performed 5 times during the exposure period. Test fish of control was analyzed before the experimental start and after the
experimental completion.
- Sampling intervals/frequency for test medium samples: test water of Level 1 and 2 were analyzed once before the first analysis of test fish and at the same time as analysis of test fish.
- Details on sampling and analysis of test organisms: 4 fish per treatment level were taken out at each sampling time and divided into 2 groups (2 fish per group) and analyzed individually. Test fish collection at final 3 successive analyses was carried out at intervals of more than 48 h, and the final analysis was performed at 28th d. Weight and body length of the fish was measured. Fish were chopped into pieces and refined. 4 – 5 g were mixed with 15 mL 5 mmol/L IPCC-MS7 in methanol and homogenize d for 1 min. Mixture was washed in 5 mL 5 mmol/L IPCC-MS7 in methanol and centrifuged at 7000 x g for 5 min. Supernatant was filtered and filled up to 50 mL with 5 mmol/L IPCC-MS7 in methanol. 1 mL was taken out and mixed with 5 mL of a 1/1 (v/v) mixture of 10 mmol/L IPCC-MS7 in methanol and ultra pure water. Filtrate was measured with LC-MS.
- Details on sampling and analysis of test media samples: 1 mL sample of test level 1 and 5 mL from test level 2 were collected. The sample of the test level 1 was filled up to 10 mL with water and 5 mL of this dilution was diluted 1:2 with 10 mmol/L IPCC-MS7 in methanol for LC-MS analysis.

Vehicle:

no

Details on preparation of test solutions, spiked fish food or sediment:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 104 mg/L stock solution was prepared by dissolving (stirring) the appropriate amount of the test item in ion exchanged water

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Common carp
- Source: CERI Kurume
- Age at study initiation (mean and range, SD): yearling fish
- Length at study initiation: 7.1 -7.7 cm
- Weight used for BCF calculation: 10 g
- Lipid content of fish: determined for control fish before and after the experiment with gravimetric analysis after chloroform-methanol extraction
- Feeding during test: yes, fish were starved for 24 h before sampling
- Food type: feed for fry of carp (proteins content > 43.0 %, lipid content > 3.0 %, Nippon Formula Feed Mfg. Co., Ltd.)
- Amount: 3 % of total body weight was fed
- Frequency: daily dose of food was split into two feedings

ACCLIMATION
- Acclimation period: 50 d
- External desinfection of fish: was carried out in an aqueous solution containing OTC for fisheries (oxytetracycline hydrochloride, Kyoritsu Seiyaku Corporation) and sodium chloride (The Salt Industry Center of Japan)
- Acclimation conditions (same as test or not): fish were acclimatized in a flow through system at 25 °C

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

28 d

Hardness:

15 mg/L (meas.)

Test temperature:

Level 1: 23.7-24.5 °C
Level 2: 24.0-25.0 °C
Control: 23.5-24.5 °C

pH:

Level 1: 7.4 - 8.0
Level 2: 7.3 - 8.0
Control: 7.2 - 8.0

Dissolved oxygen:

Level 1: 7.3-8.1 mg/L
Level 2: 7.2-8.1 mg/L
Control: 7.2-8.1 mg/L

TOC:

0.8 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 70 L glass tank
- Aeration: yes
- Flow rate: 2 mL/min for stock solution, 400 mL/min for dilution water and control (579 L/d)
- No. of organisms per vessel: 24 at levels 1 and 2, 10 in the control
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: analyzed groundwater from the premises of CERI Kurume
- Suspended solid: <1 mg/L
- TOC: 0.8 mg/L
- Pesticides: <0.004 mg/L
- Chlorine: < 0.02 mg/L
- Intervals of water quality measurement: flow rate, water temperature were measured daily, dissolved oxygen was verified once per week and pH was recorded twice in the experimental period
- Intervals of observations: observation of test fish: twice a day
- Intervals of test medium replacement: flow - through system

OTHER TEST CONDITIONS
- Photoperiod: 14 h light /10 h dark
- Light intensity: artificial light of white fluorescent lamp

Nominal and measured concentrations:

High exposure level (Level 1): 520 μg/L (nominal)
Low exposure level (Level 2): 52 μg/L (nominal)

Reference substance (positive control):

no

Type:

BCF

Value:

< 0.44 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Remarks on result:

other: Conc.in environment / dose:520 μg/L

Type:

BCF

Value:

< 4.2 dimensionless

Basis:

whole body w.w.

Time of plateau:

28 d

Remarks on result:

other: Conc.in environment / dose:52 μg/L

Details on results:

- Behavioural abnormalities: none observed
- Other biological observations: lipid content of the test fish before test initiation: 3.23%, lipid content of the test fish after test completion: 3.05% (within the ± 25% range)
- Steady state: as the test item in all test fish at last three successive analyses were not higher than LOQ, BCFss was not calculated. However, because all BCFs were less than 100, it was evaluated that a steady-state was reached on the 28th day.

pH variation during the test period was 0,6 (Level 1) to 0.8 (Control), which was higher than the value stipulated in the test method (±0.5).

Concentrations of the test item were maintained > 88% of nominal concentrations and the variations were within ± 20% of the average measured concentrations.

Table 1: Measured concentrations of test item in test water in μg/L.

Level	3 days	10 days	18 days	21 days	25 days	28 days	Average (Standard deviation)
1	455	485	481	518	520	528	498 (28.4)
2	51.6	50.5	51.7	49.2	52.3	53.2	51.4 (1.41)

Validity criteria fulfilled:

yes

Conclusions:

Bioconcentration factors were found to be BCF (28 d, 520 μg/L) < 0.44 and BCF (28 d, 52 μg/L) < 4.2 for Cyprinus carpio.

Description of key information

BCF < 0.44 (whole body w.w. for 520 µg/L, OECD 305, RA CAS No. 82985-35-1)

BCF < 4.2 (whole body w.w. for 52 µg/L, OECD 305, RA CAS No. 82985-35-1)

Key value for chemical safety assessment

BCF (aquatic species):

4.2 dimensionless

Additional information

The registered compound 3-(triethoxysilyl)-N-[3-(triethoxysilyl)propyl]-1-propanamine (CAS No. 13497-18-2) hydrolyses rapidly (DT50 = 11.9 h at 20 °C and pH 7) to form the silanol hydrolysis product 3-(trihydroxysilyl)-N-[3-(hydroxysilyl)propyl]-1-propanamine and the alcohol hydrolysis product ethanol. Bioaccumulation of the alcohol hydrolysis product ethanol in aquatic organisms is not expected (OECD SIDS, 2004) and thus can be disregarded for the assessment of the bioaccumulation potential. Taking into consideration the rapid hydrolysis of the parent compound and the exposure time of a standard aquatic bioaccumulation study in fish (7 - 28 days), the assessment of bioaccumulation potential should be based on the silanol hydrolysis product.

 

No experimental study is available for the bioaccumulation potential of the registered substance or its silanol hydrolysis product in aquatic species. Therefore, adequate and reliable data was read-across from the structural analogue substance 3-(trimethoxysilyl)-N-[3-(trimethoxysilyl)propyl]-1-propanamine (CAS No. 82985-35-1). The source substance is expected to hydrolyse rapidly under environmental conditions (DT50 = 6.9 h at pH 7 and 20 – 25 °C, QSAR) to form the same silanol hydrolysis product as the target compound,

3-(trihydroxysilyl)-N-[3-(hydroxysilyl)propyl]-1-propanamine, and methanol instead of ethanol as for the target compound. Bioaccumulation of the alcohol hydrolysis product methanol in aquatic organisms is not expected (OECD SIDS, 2004) and thus can be disregarded for the assessment of the bioaccumulation potential.

 

In the available study with the source substance, the bioaccumulation potential was assessed according to the "Method for Testing the Degree of Accumulation of Chemical Substances in Fish Body" as stipulated by the Ministry of Environment, Japan.

In the flow-through test, Cyprinus carpio was exposed to two nominal exposure levels (52 and 520 µg/L) for 28 d. The test item was analytically measured via LC-MS. Hydrolysis of the test item was confirmed by LC-MS. Therefore the bioconcentration test was performed following the silanol hydrolysis product 3-(trihydroxysilyl)-N-[3-(hydroxysilyl)propyl]-1-propanamine as test item. The test item was recovered by > 88% in the test medium at the start and at the end of the experiment. BCF values of <0.44 and <4.2 whole body w.w. were determined for the 520 µg/L and the 52 µg/L concentrations respectively showing that no concern regarding bioaccumulation arises by the substance.

 

Since the target and source are expected to hydrolyse within a similar time frame and have an identical silanol hydrolysis product, the bioaccumulation of the target substance and its silanol hydrolysis product is predicted from the experimental result for the source substance. Based on the experimental findings, it is concluded that bioaccumulation is not of concern for either substance, which is also supported by the low, predicted log Kow value of the silanol hydrolysis product (-4.0, QSAR).

 

Reference:

OECD (2004): SIDS Initial Assessment Report for SIAM 19, Berlin, Germany, 19-22 October 2004, Ethanol, CAS 64-17-5.

OECD (2004): SIDS Initial Assessment Report for SIAM 19, Berlin, Germany, 19-22 October 2004, Methanol, CAS 67-56-1.