Registration Dossier

Administrative data

Endpoint:
nanomaterial dustiness
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The method is recommended in the respective ECHA guidance and was regarded as suitable to determine the distribution of particles of respirable or inhalable size. However, only limited documentation of the data evaluation was provided in the full study report.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EN 15051 (Workplace atmospheres - Measurement of the dustiness of bulk materials - Requirements and reference test methods)
Version / remarks:
2006
Deviations:
not specified
GLP compliance:
no
Type of method:
rotating cylinder
Details on methods and data evaluation:
The dustiness of the sample powder will be carried out using the rotating drum method specified in the new European standard of the dustiness of bulk samples (EN15051). This device uses two porous size-selective foam stages and a filter to provide information about the dustiness of the powders in terms of the inhalable, thoracic and respirable fractions of the dust dispersed. Three replicate tests of the powder will be carried out to obtain an estimate of the precision of the measurements. The standard also requires simple moisture content measurements to be made for each material, as dustiness has been found to be a function of moisture content. Analysis is carried out at 50+5% relative humidity. For each measurement 35 ml will be tested.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: nanoform

Results and discussion

Any other information on results incl. tables

Table1. Mean and SD of the dustiness results (in terms of the inhalable, thoracic and respirable fractions of dust dispersed) and moisture content of the PROSPEcT sample powders.

Sample Name

Supplier

Batch number

Inhalable fraction

(mg kg−1)

Thoracic fraction
(mg kg−1)

Respirable fraction
(mg kg−1)

Moisture content (%)

Mean

SD

Mean

SD

Mean

SD

Mean

SD

NM110

BASF,

ZC250#78

2905

371

599

239

27

3

0.5

0.10

NM111

BASF,

ZB250#64

5880

610

1340

241

138

105

0.3

0.00

NM112

Micronisers,

ZA250#30

1095

222

317

37

42

8

1.2

0.20

NM113

Sigma,

ZrA250#33

166

26

34

10

10

2

0.4

0.10

 

Table2. The calculated coefficient of variation (COV) values of the results inTable1. The coefficient of variation is the ratio of the standard deviation to the mean. It is a measure of variability in relation to the mean and is used to compare the relative dispersion in one type of data with the relative dispersion in another type of data. The data to be compared may be in the same units, in different units, with the same mean, or with different means.* 

Sample Name

Inhalable fraction

(mg kg−1)

Thoracic fraction
(mg kg−1)

Respirable fraction
(mg kg−1)

Moisture content (%)

COV (%)

COV (%)

COV (%)

COV (%)

NM110

12.8

39.9

12.7

21

NM111

10.4

18.0

76.2

0

NM112

20.3

11.5

19.9

18

NM113

15.8

29.5

17.6

34

 

Applicant's summary and conclusion

Executive summary:

NPL, 2010 investigated the dustiness of the nanomaterials. The dustiness of the sample powder was carried out using the rotating drum method specified in the new European standard of the dustiness of bulk samples (EN15051). Three replicate tests of the powder were carried out to obtain an estimate of the precision of the measurements. The standard also requires simple moisture content measurements to be made for each material, as dustiness has been found to be a function of moisture content. Analysis was carried out at 50 + 5 % relative humidity. For each measurement 35 mL was tested. Test results of the dustiness studies showed a significant difference in the inhalable dustiness levels. The respirable dustiness index, however, was quite comparable and possibly influenced by larger variation than the inhalable dust fraction. The inhalable dustiness index is classified to be at the high end of “low” dustiness (NM‑110) to just “moderate” (NM‑111). This compares approximately to the levels of nanoparticle powders of goethite, organoclay and talc compared to dustiness data on other test nanomaterials. For Respirable dust both samples are in the lower “moderate” dustiness range (range: 50 to 250 mg/kg).