Barium sulfate

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Remarks:

leaching in soil columns

Type of information:

experimental study

Remarks:

according to OECD guideline 312

Adequacy of study:

weight of evidence

Study period:

October 14, 2014 to October 21, 2014

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 312

Version / remarks:

2004

Deviations:

yes

Remarks:

1. Amendment: Correction of CaCl2 concentration of artificial rainfall 2. Amendment: Change of extraction method for the leachate 3. Amendment: Increase of artificial rainfall The specified amendments did not influence the results of the test.

GLP compliance:

yes (incl. QA statement)

Type of study / information:

Leaching in soil columns

Test material

Test material information

Constituent 1

Reference substance name:

Barium sulfate

EC Number:

231-784-4

EC Name:

Barium sulfate

Cas Number:

7727-43-7

Molecular formula:

BaO4S

IUPAC Name:

barium sulfate

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Chemical name: nano-Barium sulfate
Chemical formula: BaSO4
Available form: powder
Colour: white
Odour: odourless
Molecular weight: 233.39 g/mol

Results and discussion

Any other information on results incl. tables

The results indicate that Ba is mostly found in the upper soil layer (0 – 2 cm) with mean concentrations ranging from 257 mg Ba/kg (RefeSol 02-A) to 131mg Ba/kg (RefeSol 04-A). Very small amounts of Ba moved to the sublayers. Ba concentrations of all leachates (including controls) decreased with time and were nearly similar after 8 days with means ranging from 51 to 58 µg/L for controls and from 53 to 62 µg/L for the treated soils.

 

Table: Barium concentration of treated soil sublayers, background concentration of controls and background-corrected Barium concentration (measured soil conc. - background conc)

soil -layer	Ba conc. of sublayers(mg/kg)	Ba BG of control (mg/kg)	Ba conc. of sublayers - BG corrected (g/kg)	Ba conc. of sublayers - BG corrected Mean (mg/kg)	SD (mg/kg)
01-A-1, 0-2 cm	148.09	16.36	131.73	131.04	0.99
01-A-2, 0-2 cm	146.70	16.36	130.34	.	.
01-A-1, 2-4 cm	48.26	16.36	31.90	39.75	11.10
01-A-2, 2-4 cm	63.96	16.36	47.60	.	.
01-A-1, 4-6 cm	17.30	16.36	0.94	19.27	25.92
01-A-2, 4-6 cm	53.96	16.36	37.60	.	.
01-A-1, 6-8 cm	18.30	16.36	1.94	21.09	27.08
01-A-2, 6-8 cm	56.60	16.36	40.24	.	.
01-A-2, 8-10 cm	15.12	16.36	-1.24	-0.44	1.13
01-A-2, 8-10 cm	16.72	16.36	0.36	.	.
1-A-1, 10-30 cm	17.97	16.36	1.61	1.94	0.47
1-A-2, 10-30 cm	18.63	16.36	2.27	.	.
02-A-1, 0-2 cm	345.35	16.36	280.98	256.90	34.04
02-A-2, 0-2 cm	297.20	64.37	232.83	.	.
02-A-1, 2-4 cm	64.47	64.37	0.10	-2.20	3.25
02-A-2, 2-4 cm	59.88	64.37	-4.49	.	.
02-A-1, 4-6 cm	59.23	64.37	-5.14	-3.47	2.36
02-A-2, 4-6 cm	62.57	64.37	-1.80	.	.
02-A-1, 6-8 cm	61.66	64.37	-2.71	-4.64	2.74
02-A-2, 6-8 cm	57.79	64.37	-6.58	.	.
02-A-1, 8-10 cm	59.12	64.37	-5.25	-5.96	1.01
02-A-2, 8-10 cm	57.70	64.37	-6.67	.	.
02-A-1, 10-30 cm	60.49	64.37	-3.88	-4.89	1.44
02-A-1, 10-30 cm	58.46	64.37	-5.91	.	.
04-A-1, 0-2 cm	104.77	11.56	93.21	189.30	135.88
04-A-2, 0-2 cm	295.05	11.56	285.38	.	.
04-A-1, 2-4 cm	12.80	11.56	1.24	1.64	0.56
04-A-2, 2-4 cm	13.59	11.56	2.03	.	.
04-A-1, 4-6 cm	13.46	11.56	1.90	0.70	1.70
04-A-2, 4-6 cm	11.05	11.56	-0.51	.	.
04-A-1, 6-8 cm	13.42	11.56	1.86	0.79	1.51
04-A-2, 6-8 cm	11.28	11.56	-0.28	.	.
04-A-1, 8-10 cm	13.61	11.56	2.05	0.85	1.69
04-A-2, 8-10 cm	11.21	11.56	-0.35	.	.
04-A-2, 8-10 cm	14.92	11.56	3.36	1.54	2.57
04-A-2, 10-30 cm	11.28	11.56	-0.28	.	.

BG=Background

 

Ba concentrations of aqueous samples from soil columns treated with BaSO4. Dilution factor of 1.5 was applied due to digestion.

Sample	Measured Ba conc. [µg/L]	Mean measured Ba conc. [µg/L]	SD measured Ba conc. [µg/L]
14.10.14 01-A/ 1	228.3	.	.
14.10.14 01-A/ 2	224.9	226.6	2.4
14.10.14 02-A/ 1	130.9	.	.
14.10.14 02-A/ 2	125.9	128.4	3.6
14.10.14 04-A/ 1	157.5	.	.
14.10.14 04-A/ 2	150.5	154.0	5.0
.	.	.	.
15.10.14 02-A/ 2	103.7	.	.
15.10.14 02-A/ 2	89.9	96.8	9.8
15.10.14 02-A/ 1	67.4	.	.
15.10.14 02-A/ 2	57.4	62.4	7.1
15.10.14 04-A/ 1	131.0	.	.
15.10.14 04-A/ 2	77.3	104.1	37.9
.	.	.	.
16.10.14 01-A/ 1	74.4	.	.
16.10.14 01-A/ 2	72.2	73.3	1.5
16.10.14 02-A/ 1	55.3	.	.
16.10.14 02-A/ 2	46.6	50.9	6.2
16.10.14 04-A/ 1	91.0	.	.
16.10.14 04-A/ 2	78.0	84.5	9.2
.	.	.	.
17.10.14 01-A/ 1	65.4	.	.
17.10.14 01-A/ 2	67.1	66.3	1.2
17.10.14 02-A/ 1	55.1	.	.
17.10.14 02-A/ 2	43.5	49.3	8.2
17.10.14 04-A/ 1	83.6	.	.
17.10.14 04-A/ 2	71.5	77.5	8.6
.	.	.	.
18.10.14 01-A/ 1	61.6	.	.
18.10.14 01-A/ 2	60.3	61.0	0.9
18.10.14 02A/ 1	56.5	.	.
18.10.14 02-A/ 2	46.8	51.7	6.8
18.10.14 04-A/ 1	82.9	.	.
18.10.14 04-A/ 2	64.0	73.5	13.4
.	.	.	.
19.10.14 01-A/ 1	59.9	.	.
19.10.14 01-A/ 2	57.6	58.8	.
19.10.14 02-A/ 1	62.0	.	.
19.10.14 02-A/ 2	49.5	55.7	.
19.10.14 04-A/ 1	81.2	.	.
19.10.14 04-A/ 1	57.4	69.3	.
.	.	.	.
20.10.14 01-A/ 1	57.8	.	.
20.10.14 01-A/ 2	54.9	56.4	2.0
20.10.14 02-A/ 1	61.6	.	.
20.10.14 02-A/ 2	53.6	57.6	5.7
20.10.14 04-A/ 1	79.3
20.10.14 04-A/ 2	53.1	66.2	18.5
.	.	.	.
21.10.14 01-A/ 1	54.7	.	.
21.10.14 01-A/ 2	52.0	53.3	1.9
21.10.14 02-A/ 1	61.0	.	.
21.10.14 02-A/ 2	51.6	56.3	6.6
21.10.14 04-A/ 1	75.5	.	.
21.10.14 04-A/ 2	49.7	62.6	18.2

 

 

Applicant's summary and conclusion

Conclusions:

In an 8-day soil leaching study according to OECD 312, the nano-sized BaSO4 (NM-220) was applied to columns of three different soil, varying in texture, cation exchange capacity, and organic carbon content, i.e., a loamy sand with a lower CEC, a silt loam, and another loamy sand with a higher CEC. BaSO4 solutions were applied onto the top of the columns simulating rainfall. Ba concentrations of the leachates were analysed daily. After the study, the Ba concentrations of individual soil sublayers were analysed.
Barium concentrations of control leachates differ for the three soils at test start but are similar after 8 days. Furthermore, barium concentrations of controls are higher than for leachates of the corresponding treated columns at test start, but are similar after 8 days. In fact, barium concentrations of all leachates were similar after 8 days. Thus, the addition of barium sulfate in nano form does not result in higher barium concentrations of the leachates of 3 different soils. Based on the analysis of respective soil sublayers, barium sulfate remained in the top layer (0-2 cm) except in the loamy sand with the lower CEC, in which barium moved to sublayers (2-8 cm).