Activated Carbon - High Density Skeleton

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10/03/2010 - 10/03/2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study according to international guideline (EC ECB/TM/Feb. 1996) under GLP. No deviations from guideline reported.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: •EUROPEAN COMMISSION, Directorate General XII-JRC, Science Research and Development-Joint Research Centre. “Particle Size Distribution, Fibre Length and Diameter Distribution” Guidance Document, ECB/TM/February 1996.

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes (incl. QA statement)

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Key result

Percentile:

D50

Mean:

20.9 µm

Remarks on result:

other: range between 0.3 and 200 um (migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.)

Percentile:

other: D5

Mean:

< 3 µm

St. dev.:

0.353

Percentile:

D10

Mean:

< 4.8 µm

St. dev.:

0.605

Percentile:

D50

Mean:

< 20.9 µm

St. dev.:

0.634

Percentile:

D90

Mean:

< 43.1 µm

St. dev.:

1.884

For detailed results (distribution of different passages) see attached file results.doc.

Steam Activated Carbon is a black powder. Under the microscope (with a magnification of 100), small-sized particles were observed.

 

A solubility test showed, that the test item is both: sparingly soluble and well dispersible in water. The particle size distribution of Steam Activated Carbon was performed with two samples of the stock dispersion each measured in duplicate.

The results obtained during the measurements showed no relevant difference. Therefore the study is considered to be valid and no further testing is necessary.

Conclusions:

The mass median diameter (MMD) of steam activated carbon is 20.9 µm, the particle size distribution ranges from 0.5 to 250.0 µm.

Executive summary:

The particle size distribution of steam activated carbon was determined according to "EC ECB/TM/Feb. 1996" using the laser diffraction method. The mass median diameter (MMD) of steam activated carbon was found to be 20.9 µm, the particle size distribution was found to range from approximately 0.5 to 250.0 µm.

Reference 2

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP study according to international Guidelines

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: EN 15051, Workplace atmospheres – Measurement of the dustiness of bulk materials – Requirements and reference test methods. Method B "continuous drop"

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: DIN 33897-2 "continuous drop"

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

no

Type of method:

continuous drop method

Type of distribution:

mass based distribution

Key result

Percentile:

other: respirable concentration

Mean:

0.14

St. dev.:

1.58

Remarks on result:

other: The geometric mean of the respirable concentration equals 0.14 mg/m3 and the reliability that the respirable concentration is below 0.61 mg/m3 is 95 %.

No.:

#1

Size:

13 807 - 88 272 other: mg/kg

Remarks on result:

other: Sample 11029: Respirable - Inhalable dust fractions

No.:

#2

Size:

1 524 - 43 301 other: mg/kg

Remarks on result:

other: Sample 11032: Respirable - Inhalable dust fractions

No.:

#3

Size:

2 033 - 47 621 other: mg/kg

Remarks on result:

other: Sample 11037: Respirable - Inhalable dust fractions

No.:

#4

Size:

2 995 - 47 038 other: mg/kg

Remarks on result:

other: Sample 11038: Respirable - Inhalable dust fractions

No.:

#5

Size:

2 862 - 41 499 other: mg/kg

Remarks on result:

other: Sample 11040: Respirable - Inhalable dust fractions

No.:

#6

Size:

2 128 - 41 393 other: mg/kg

Remarks on result:

other: Sample 11045: Respirable - Inhalable dust fraction

No.:

#7

Size:

2 317 - 46 190 other: mg/kg

Remarks on result:

other: Sample 11046: Respirable - Inhalable dust fractions

No.:

#8

Size:

3 074 - 39 379 other: mg/kg

Remarks on result:

other: Sample 11048: Respirable - Inhalable dust fractions

Results

Based on the test results of a 90-day inhalation toxicity study with Activated Carbon (AC-HDS) a DNEL_{Inhalation, long term local, worker}of 0.61 mg/m3 has been derived for the respirable fraction (see chapter 7).

The dustiness was determined in 8 representative samples of activated carbon. The results of these measurements and the calculated respirable / inhalable fractions are presented in Table 1.

The geometric mean of the respirable/inhalable ratio is 6.16 * 10-2, and the geometric standard deviation is 1.58 (see Table 2). It was concluded that the test results form an adequately uniform dataset. Evaluation of PSD data (see attachment) from each of the activated carbon samples demonstrated that sample 11029 could not be regarded as an outlier and was therefore included in the dataset. The calculations show that when using an inhalable DNEL of 2.3 mg/m3, the geometric mean of the respirable fraction equals 0.14 mg/m3 and the reliability that the respirable fraction is below 0.61 mg/m3 is 95 %.

Table1Results of respirable and inhalable dust fraction and the calculated respirable / inhalable fraction

Sample number	Respirable dust fraction (mg/kg)	Inhalable dust fraction (mg/kg)	Respirable / inhalable ratio of Activated Carbon
11029	13807	88272	0.156
11032	1524	43301	0.035
11037	2033	47621	0.043
11038	2995	47038	0.064
11040	2862	41499	0.069
11045	2128	41393	0.051
11046	2317	46190	0.050
11048	3074	39379	0.078

 

Table2Determination of the Inhalable DNEL based on the respirable/inhalable ratio of activated carbon

Sample number	Respirable / inhalable ratio of Activated Carbon	Respirable concentration (mg/m3) if Inhalable concentration = 2.3 mg/m3
11029	0.156	0.36
11032	0.035	0.08
11037	0.043	0.10
11038	0.064	0.15
11040	0.069	0.16
11045	0.051	0.12
11046	0.050	0.12
11048	0.078	0.18
GM	6.16E^-02	0.14
GSD	1.58	1.58
Reliability, respirable fraction < 0.61mg/m^3		95.1%

Conclusions:

When using a representative set of 8 different samples of activated carbon, the statistical calculations show that when using an inhalable DNEL of 2.3 mg/m3, the geometric mean of the respirable fraction equals 0.14 mg/m3 and the reliability that the respirable fraction is below 0.61 mg/m3 is 95 %.

Executive summary:

Based on the test results of a 90-day inhalation toxicity study with Activated Carbon (AC-HDS) a DNEL_{Inhalation, long term local, worker}of 0.61 mg/m3 has been derived for the respirable fraction (see chapter 7).

The dustiness was determined in 8 representative samples of activated carbon and the respirable / inhalable fractions were calculated.

The geometric mean of the respirable/inhalable ratio was 6.16 * 10-2, and the geometric standard deviation was 1.58. It was concluded that the test results form an adequately uniform dataset. The calculations show that when using an inhalable DNEL of 2.3 mg/m3, the geometric mean of the respirable fraction equals 0.14 mg/m3 and the reliability that the respirable fraction is below 0.61 mg/m3 is 95 %.

Description of key information

mass median diametre 20,9 micrometre µm

Additional information

PSD

In a key study, the particle size distribution of Activated Carbon - High Density Skeleton was determined according to "EC ECB/TM/Feb. 1996" using the laser diffraction method. The mass median diameter (MMD) of steam activated carbon was found to be 20.9µm, the particle size distribution was found to range from approximately 0.5 to 250.0µm.

Detailed results:

Percentile	Mean	St. dev.
other: D5	< 3 µm	0.353
D10	< 4.8 µm	0.605
D50	< 20.9 µm	0.634
D90	< 43.1 µm	1.884

Dustiness

Based on the test results of a 90-day inhalation toxicity study with Activated Carbon (AC-HDS) a DNEL_{Inhalation, long term local, worker}of 0.61 mg/m3 has been derived for the respirable fraction (see chapter 7).

The dustiness was determined in 8 representative samples of activated carbon and the respirable / inhalable fractions were calculated.

The geometric mean of the respirable/inhalable ratio was 6.16 * 10-2, and the geometric standard deviation was 1.58. It was concluded that the test results form an adequately uniform dataset. The calculations show that when using an inhalable DNEL of 2.3 mg/m3, the geometric mean of the respirable fraction equals 0.14 mg/m3 and the reliability that the respirable fraction is below 0.61 mg/m3 is 95 %.