Bentonite, acid-leached

Additional toxicological data

Administrative data

Endpoint:

additional toxicological information

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Testing was conducted between 28 June 2010 and 21 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed in accordance with GLP and is well documented

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Principles of method if other than guideline:

The solubility of bentonite acid leached in simulated gastric fluid was determined. The determination was carried out using a procedure based on ASTM D5517-07, Standard Test Method for Determining Extractability of Metals from Art Materials.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Bentonite, acid-leached

EC Number:

274-324-8

EC Name:

Bentonite, acid-leached

Cas Number:

70131-50-9

Molecular formula:

unspecified for this UVCB substance

IUPAC Name:

Bentonite, acid-leached

Details on test material:

Sponsor's identification: Bentonite acid-leached
Description : off white solid
CAS No : 70131-50-9
Batch number : not supplied
Label : EX 2119 Sud-Chemie AG 2269081A
Date received : 21 January 2010
Expiry date : 31 December 2010
Storage conditions: room temperature, in the dark

Results and discussion

Any other information on results incl. tables

On completion of the equilibration period at 37°C, all samples were observed to remain saturated with excess, undissolved test item. The sample solution pH’s are shown in the following table:

Sample  Number	Initial Solution pH after 1 Minutes Swirling	Solution pH after Final Equilibration
1	0.9	1.2
2	0.9	1.1
3	1.0	1.2

The mean concentration (mg/l) of each element in the sample solutions is shown in the following table:

Sample  Number	Mean Concentration (mg/l)at 37.0 ± 0.5°C
	Sodium	Magnesium	Aluminium	Silicon	Potassium	Calcium
1	4.69	16.3	32.7	7.63	18.2	96.8
2	4.46	15.2	33.0	7.95	38.5	99.4
3	4.75	17.2	33.9	8.00	30.2	104
Mean/Overall  Result	4.63	16.2	33.2	7.86	≤38.5	100

Calculation of sample concentrations was performed using the⁴⁴calcium isotope/mass data. The isotope/mass⁴³calcium was monitored as a confirmatory mass only as a precaution against interference at the first choice of analytical mass and gave essentially identical sample concentrations on calculation.

The different dilution factors of the sample solutions were prepared and analysed to ensure that the sample solution instrument responses (concentrations) fell into the valid calibration range of the standard solutions. Sodium, magnesium and silicon concentrations were calculated from the most concentrated sample solutions (A and B), aluminium and potassium concentrations were calculated from the next most concentrated sample solutions (G and H) and finally calcium concentrations were calculated from the x 50 dilution factor samples (C and D).

Consistent triplicate results were obtained for all elements monitored with the exception of potassium. In the case of potassium, a high degree of variability was observed and therefore an overall limit value of the maximum observed concentration has been reported as the definitive result. This was concluded not to impact significantly on the validity of the study as of the elements monitored, aluminium was considered the primary concern with respect to potential toxicity.