1,1,1"((methylsilanetriyl)tris)(oxy))tris(2-methylpropan-2-amine)

Endpoint summary

Description of key information

Readily biodegradability:

The target test item was investigated for it’s readily biodegradability test by following OECD 301D guideline. The test item was exposed to activated sludge (supernatant) from the aeration tank ofa domestic waste water treatment plant for 28 days. The activated sludge was collected from SMS municipal sewage treatment plant (130 MLD STP) in a thoroughly cleansed container. The sampling depth was 1-2 feet from the aeration tank. The temperature of the activated sludge was measured (38±1º C) at the site of collection. Oxygen concentration of the activated sludge sample was 2.9 mg/L. The sample was transported to the test facility within 3 hours from collection and kept it aerobic during transport. Inoculum was pre-conditioned for 1-2 days to the experimental conditions. The supernatant solution of the activated sludge was used in the study. 125 mL BOD vessels were used in the study. The test system includes an inoculum blank control group, a procedure control group, and a test item group a toxicity control group, each maintained in replicates. The biodegradation was determined by following the BOD, oxygen consumption of the test item in the incubation BOD vessels during exposure. Sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. All test vessels were incubated at BOD incubator at a constant temperature of 20±1° C. Sampling of 0th h test vessels from each test group concentration were collected for analysis at zerotime (immediately after set-up). Samples were removed at regular intervals i.e., 7th, 14th, 21st, 28th, 35th and 42nd day which were measured for D.O and pH. The theoretical oxygen demand (ThOD) was calculated based on the chemical identifier. The procedure control Sodium benzoate was sufficiently degraded to 65.87% after 14 days, and to 74.85% after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the procedure control sodium benzoate, 32.28% biodegradation was noted within 14 days and 48.58% biodegradation was determined after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory to the activated sludge microorganisms. Under the test conditions the percentage biodegradation of test item reached 45.45.5% after 28 days of incubation based on BOD consumption. As the final biodegradation is less than 70% in this test and all validity criteria were met, test item can be considered to be inherently biodegradablein nature.

Biodegradation in water and sediment:

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 6.72% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 60 days (1440 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is persisten in water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of test chemical in sediment is estimated to be 541.66 days (13000 hrs). Based on this half-life value, it indicates that test chemical is persistent in sediment.

Biodegradation in soil:

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 78.7% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 120 days (2880 hrs). Based on this half-life value of test chemical, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Additional information

Readily biodegradability:

Based on the calculation method, the test chemical is expected to not readily biodegradable in water.

The target test item was investigated for it’s readily biodegradability test by following OECD 301D guideline. The test item was exposed to activated sludge (supernatant) from the aeration tank ofa domestic waste water treatment plant for 28 days. The activated sludge was collected from SMS municipal sewage treatment plant (130 MLD STP) in a thoroughly cleansed container. The sampling depth was 1-2 feet from the aeration tank. The temperature of the activated sludge was measured (38±1º C) at the site of collection. Oxygen concentration of the activated sludge sample was 2.9 mg/L. The sample was transported to the test facility within 3 hours from collection and kept it aerobic during transport. Inoculum was pre-conditioned for 1-2 days to the experimental conditions. The supernatant solution of the activated sludge was used in the study. 125 mL BOD vessels were used in the study. The test system includes an inoculum blank control group, a procedure control group, and a test item group a toxicity control group, each maintained in replicates. The biodegradation was determined by following the BOD, oxygen consumption of the test item in the incubation BOD vessels during exposure. Sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. All test vessels were incubated at BOD incubator at a constant temperature of 20±1° C. Sampling of 0th h test vessels from each test group concentration were collected for analysis at zerotime (immediately after set-up). Samples were removed at regular intervals i.e., 7th, 14th, 21st, 28th, 35th and 42nd day which were measured for D.O and pH. The theoretical oxygen demand (ThOD) was calculated based on the chemical identifier. The procedure control Sodium benzoate was sufficiently degraded to 65.87% after 14 days, and to 74.85% after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the procedure control sodium benzoate, 32.28% biodegradation was noted within 14 days and 48.58% biodegradation was determined after 28 days of incubation. Thus, the test item can be assumed to be not inhibitory to the activated sludge microorganisms. Under the test conditions the percentage biodegradation of test item reached 45.45.5% after 28 days of incubation based on BOD consumption. As the final biodegradation is less than 70% in this test and all validity criteria were met, test item can be considered to be inherently biodegradablein nature.

The ready biodegradability of the test material was investigated in a Closed Bottle Test conducted in accordance with OECD TG 301D and EU method C.4 under GLP conditions. For this purpose the test item was exposed to activated sludge from the aeration tank of a domestic waste water treatment plant in completely full and closed bottles in the dark at controlled temperature (22 ± 2 °C) for 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure.

The test item was investigated at the concentration of 3.0 mg/L. The test item concentration was chosen based on the theoretical oxygen demand of the test item (ThOD_NH4 calculated according to equation given in the guidelines, assuming that no nitrification occurs) of 1.93 mg O₂/mg. In parallel (under the same conditions as the test item), positive reference item, sodium benzoate at the concentration of 3.0 mg/L (as procedure control), inoculum control and toxicity control were investigated. All validity criteria of the study were met.

Under the applied test conditions, no ready biodegradation of this test item was noticed. The percentage biodegradation of the test item reached a mean of 7.9 % after 28 days based on its theoretical oxygen demand (ThOD_NH4). (The highest biodegradation value of 8.9 % was obtained on the 21st day of the test.)

The concurrently conducted analytical determination of possible nitrite and nitrate development showed slight changes in nitrite concentrations in both parallels of the end (28-day) toxicity control samples; however, the measured dissolved oxygen concentrations did not correspond to the consumed oxygen of ammonium oxidation processes; the relationship between oxygen uptake resulting from a possible ammonium oxidation and oxygen uptake of applied microbial population was equivocal; therefore any correction of the measured dissolved oxygen concentrations was considered as not possible. Most likely technical effects (turbidity and/or discoloration) influenced the nitrite concentration determinations. The biodegradability value of the test item was calculated based on its ThOD_NH4; any correction, based on the measured nitrite nitrate content was not performed.

The reference item, sodium benzoate, was sufficiently degraded to a mean of 75.3 % after 14 days, and to a mean of 77.5 % after 28 days of incubation, based on ThOD_NH4. (The biodegradation reached its plateau on about the 7th day and from this day onwards the observed slight changes were considered as being within the biological variability range of the applied test system). In the toxicity control containing both, the test item and the reference item, a mean of 37.2 % biodegradation was noted within 14 days and 39.9 % after 28 days of incubation (from about the 5th -7th days of the test onwards the obtained slight changes in the biodegradability values were considered as being within the biological variability range of the applied test system).

The test item is considered to be not readily biodegradable, since the pass level for ready biodegradability is removal of 60 % theoretical oxygen demand (ThOD_NH4) in a 10-day window.

The percentage biodegradation of the reference item confirms the suitability of the used activated sludge inoculum. According to the test guidelines the test item can be assumed as not inhibitory at the applied concentration level on the activated sludge microorganisms because the degradation in the toxicity control group was higher than 25 % within 14 days.

Biodegradation in water and sediment:

Estimation Programs Interface prediction model was run to predict the half-life in water and sediment for the test chemical. If released in to the environment, 6.72% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of test chemical in water is estimated to be 60 days (1440 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is persisten in water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of test chemical in sediment is estimated to be 541.66 days (13000 hrs). Based on this half-life value, it indicates that test chemical is persistent in sediment.

Biodegradation in soil:

The half-life period of test chemical in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database. If released into the environment, 78.7% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of test chemical in soil is estimated to be 120 days (2880 hrs). Based on this half-life value of test chemical, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.