Aluminium tristearate

Endpoint summary

Description of key information

Biodegradation in water

Biodegradability of aluminum trioctadecanoate (CAS no. 637 -12 -7) is predicted using QSAR toolbox version 3.3 with logKow as the primary descriptor (2017). Test substance undergoes 76.75% degradation by CO2 evolution parameter in 28 days. Thus, based on percentage degradation, the test chemical aluminum trioctadecanoate was estimated to be readily biodegradable in water.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound aluminum trioctadecanoate (CAS No. 637 -12 -7). If released in to the environment, 12.8% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of aluminum trioctadecanoate in water is estimated to be 60 days (1440 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of aluminum trioctadecanoate in sediment is estimated to be 541.66 days (13000 hrs). However, as the percentage release of test chemical aluminum trioctadecanoatei into the sediment is less than 1% (i.e, reported as 0.00000000418%), indicating that the chemical aluminum trioctadecanoate is not persistent in sediment.

Biodegradation in soil

The half-life period of aluminum trioctadecanoate (CAS No. 637 -12 -7) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 87.1% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of aluminum trioctadecanoate in soil is estimated to be 120 days (2880 hrs). Based on this half-life value of aluminum trioctadecanoate, 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.

Bioaccumulation: aquatic / sediment:

From BCFBAF (v3.00) model of EPI suite, the estimated bio concentration factor (BCF) for Aluminum trioctadecanoate is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000.Thus it is concluded that chemical Aluminum trioctadecanoate is not expected to be bioaccumulative in fish and the food chain.

Adsorption / desorption:

The Soil Adsorption Coefficient i.e Koc value of Aluminum trioctadecanoate was estimated using EPI suite  KOCWIN Program (v2.00) as Koc 10000000000 L/kg (log Koc = 10) by means of MCI method at 25 deg.C. This Koc value indicates that the substance Aluminum trioctadecanoate has a very strong sorption to soil and sediment and therefore have negligible migration potential to groundwater.

Additional information

Biodegradation in water

1 predicted data for the target compound aluminum trioctadecanoate (CAS no. 637-12-7) and the total 4 weight of evidence studies (2 from peer reviewed journal and 2 from authoritative database) for its closest read across substance with logKow as the primary descriptor were reviewed for the biodegradation end point which are summarized as below:

 

In a predicted data done by SSS (2017) using QSAR toolbox version 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical aluminum trioctadecanoate (CAS no. 637 -12 -7) was estimated.Test substance undergoes 76.75% degradation by CO2 evolution parameter in 28 days. Thus, based on percentage degradation, the test chemical aluminum trioctadecanoate was estimated to be readily biodegradable in water.

 

In a weight of evidence study from peer reviewed journal (Chemosphere, 1987) for read across substancecalcium stearate(CAS no. 1592-23-0),biodegradability of calcium stearate was assessed by OECD 301B guideline also known as Sturm test. Installations and equipment used in the test were as described in the OECD Guideline 301B. The size of the carbosys was reduced from 5 l to 3l and the volume of the solution from 2 to 1.5 l. A magnetic stirrer with a PTFE – coated rod of 6 cm length rotating at approximately 60 rpm was used for agitation. A constant temperature of 23°C was maintained by immersion of carbosys in a water bath. Sludge for the preparation of the inoculum was taken from a sewage treatment plant receiving predominantly domestic waste. The inoculum and the mineral solutions were prepared according to the OECD 301 guidelines.

In the method with direct dispersion of the test chemical, calcium stearate (20mg/l) was added as a powder or as a suspension in water prepared by ultrasonic dispersion, to the carbosys containing the inoculum. No additional treatment was given to the mixture containing the inoculum. In the method with solid carriers the samples were prepared by melting calcium stearate on glass filter papers. The glass filter papers were cut into small pieces before putting them into carbosys. The test chemical was biodegraded under all test conditions, fulfilling the strict criteria of ready biodegradability [60% within 10 days] except in one case where it was applied on a glass filter in a non-agitated container. The solubility of 2mg/l water was apparently sufficient to ensure the continuous availability of the test chemical to the bacteria. The decreased rate of biodegradation of the sample melted on the glass filter can be explained by a reduction in the availability of calcium stearate as a consequence of the melting operation [glazing of the surface] and the absence of agitation. The percentage degradation of test substance was determined to be 91% degradation by CO2 evolution parameterin 24 days in absence of agitation and glass filter paper was not used as a carried, whereas 99% degradation was observed by CO2 evolution parameter in 24 days in absence of agitation and 55 and 88% degradation was observed by CO2 evolution parameter in 24 days when glass filter papers was used as a carrier. In addition to this, test substance also undergoe degradation upto 72% and 84% in 20 days by CO2 evolution parameter using glass filter papers and ultrasound as a carrier and in presence of agitation. Thus, based percentage degradation, Calcium stearate was considered to be readily biodegradable in water.

 

Another supporting weight of evidence study of biodegradation for read across substancecalcium stearate(CAS no. 1592-23-0)was assessed by OECD 301C guideline also known as MITI test(Chemosphere, 1987). The test was carried out at 22±3°C in a HACH manometric respirometer according to OECD 301 C guidelines. The mineral solution was prepared according to the guidelines. Sludges for the preparation of the inoculum were obtained from domestic sewage treatment works, washed twice by centrifugation and resuspension in the test medium. These sludges were dispersed in the test medium to give a final activated sludge concentration of 30mg/l. Prior to the start of the test the bottles were incubated for 1 week at the test temperature to reduce the endogenous rate of the inoculum. The test chemical was added to the bottles to give a final concentration of 100mg/l Nonyphenol was used as an emulsifier. Blank tests were set up with the emulsifiers at the concentration used to correct the oxygen uptake. The test chemical is readily biodegradable under all test conditions, fulfilling the strict criterion of biodegradation [60% degradation in 10 days]. The percentage degradation of test substance was determined to be 91% degradation by BOD and ThOD parameterin 32 days. Thus, based on percentage degradation, Calcium stearate was considered to be readily biodegradable in nature.

 

In an additional study for the same read across substance calcium stearate(CAS no. 1592-23-0), biodegradation experiment was conducted for 28 days for evaluating the percentage biodegradability of test substance Calcium stearate (GSBL database, 2016). The study was performed according OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test).The percentage degradation of test substance was determined to be 95% degradation by ThOD or COD parameter in 28 days. Thus, based on percentage degradation, Calcium stearate was considered to be readily biodegradable in nature.

 

For read across substance Lead distearate (CAS no. 1072 -35 -1), biodegradation study was conducted for 14 days for evaluating the percentage biodegradability of substance Lead distearate (J-CHECK, 2016). Concentration of inoculum i.e, activated sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. When the test substance was esterified and a GC analysis was performed, the results contained Lead distearate and substances with fewer number of carbons, namely, Lead dipalmitate and Lead myristate. Degree of degradation of each substance was found to be Lead dipalmitate: 59.5%, Lead myristate: 67.7%. The percentage degradation of read across substance was determined to be 32.9 and 49.1% by BOD and GC parameter in 14 days. Thus, based on percentage degradation, Lead distearate is considered to be readily biodegradable in nature.

 

On the basis of above results for target chemicalaluminum trioctadecanoate (from OECD QSAR toolbox version 3.3) and for its read across substance (from peer reviewed journal and authoritative database J-CHECK and GSBL, 2016), it can be concluded that the test substance aluminum trioctadecanoate can be expected to be readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound aluminum trioctadecanoate (CAS No. 637 -12 -7). If released in to the environment, 12.8% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of aluminum trioctadecanoate in water is estimated to be 60 days (1440 hrs). The half-life (60 days estimated by EPI suite) indicates that the chemical is persistent in water and the exposure risk to aquatic animals is moderate to high whereas the half-life period of aluminum trioctadecanoate in sediment is estimated to be 541.66 days (13000 hrs). However, as the percentage release of test chemical aluminum trioctadecanoatei into the sediment is less than 1% (i.e, reported as 0.00000000418%), indicating that the chemical aluminum trioctadecanoate is not persistent in sediment.

Biodegradation in soil

The half-life period of aluminum trioctadecanoate (CAS No. 637 -12 -7) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 87.1% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of aluminum trioctadecanoate in soil is estimated to be 120 days (2880 hrs). Based on this half-life value of aluminum trioctadecanoate, 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.

On the basis of available information, the test substance aluminum trioctadecanoate can be considered to be readily biodegradable in nature.

Bioaccumulation: aquatic / sediment:

Three studies including predicted data from validated model and experimental results from authorative data source for bioaccumulation (BCF) endpoint of test substance Aluminum trioctadecanoate (Cas no. 637-12-7) with relevant read across which is structurally similar to target were summarized as follows:

First study from BCFBAF (v3.00) model of EPI suite indicate the estimated bio concentration factor (BCF) for Aluminum trioctadecanoate is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000. Thus it is concluded that chemical Aluminum trioctadecanoate is not expected to be bioaccumulative in fish and the food chain.

Above target prediction supported by experimental result of read across chemical Dibutyltin dilaurate (Cas no. 77-58-7) which suggest Bioaccumulation test was conducted for 8 weeks for determination the bioconcentration factor (BCF) and lipid content of substance Dibutyltin dilaurate (Cas no. 77-58-7) on test organism Cyprinus carpio. The recovery ratio is given- Test water: 85.9 %, Fish: 73.5 %, And Nominal concentrations used in the study as - 1st Concentration area: 2.5 microg/L,2nd Concentration area: 0.25 microg/L and Range finding study was carried out on Rice fish (Oryzias latipes) and the 48 hr LC50 value was found to be >= 0.5 mg/L. By analytical methods, the limit of detection was found to be- Test water: 1st concentration area: 0.34 ng/mL, 2nd concentration area: 0.034 ng/mL,Fish : 2.6 ng/g. Whereas the lipid content at the start and end of exposure was found to be 4%. Thus according to static Fish Test the BCF value for test substance Dibutyltin dilaurate (Cas no. 77-58-7) was observed to be 2.2<= 40 L/kg at dose concentration 2.5 microg/L and 13 <= 110 L/kg at dose concentration 0.25 microg/L on test organism Cyprinus carpio during 8 weeks period. These values indicate that the substance is not bioaccumulative in fish and food chain.(J-CHECK database;2017)

And last study from another data source for same read across i.e Dibutyltin dilaurate (Cas no. 77-58-7) indicate the observed BCF for dibutyltin dilaurate in round crucian carp (Carassius carassius grandoculis) muscle, vertebra, liver, and kidney tissue were 31, 54, 813, and 138, respectively these BCF values suggests bioconcentration in aquatic organisms is low.(HSDB database;2017)

Thus all above available values for bioaccumulation (BCF) is in the range of 2.2 to 813 (L/kg or dimensionless) which gives the final conclusion as target substance Aluminum trioctadecanoate (Cas no. 637-12-7) is non Bioaccumulative in aquatic environment.

Adsorption / desorption:

Two studies including predicted data from validated model and experimental results from authorative data source for adsorption (KOC) endpoint of test substance Aluminum trioctadecanoate (Cas no. 637-12-7) with relevant read across which is structurally similar to target were summarized as follows:

First study from EPI suite KOCWIN Program (v2.00) model indicate the estimated the Soil Adsorption Coefficient i.e Koc value of Aluminum trioctadecanoate was estimated as Koc 10000000000 L/kg (log Koc = 10) by means of MCI method at 25 deg.C. This Koc value indicates that the substance Aluminum trioctadecanoate has a very strong sorption to soil and sediment and therefore have negligible migration potential to groundwater.

Above target prediction supported by experimental result of read across chemical Dibutyltin dilaurate (Cas no. 77-58-7) which suggest the chemical Dibutyltin dilaurate is expected to hydrolyze in water forming the cation, dibutyltin and Cations generally adsorb to organic carbon and clay; therefore, dibutyltin may be expected to have limited mobility in soil (i.e immobile in soil) whereas in sediment compartment distribution constants obtained for adsorption of dibutyltin to sediment of 700-26,000 l/kg which also indicate the substance is immobile in sediment also.

Thus both available result for adsorption (KOC) gives the common conclusion as target substance Aluminum trioctadecanoate (Cas no. 637-12-7) is expected to immobile in soil and sediment compartment.